Tag Archives: Salt

Salt and CancerWhen I was in the middle of my academic career during the mid to late 1990’s (I retired from Colorado State University in December 2013,) I had the great pleasure of corresponding with Birger Jansson, Ph.D. at the University of Texas, M.D. Anderson Cancer Center in Houston, Texas. Dr. Jansson was a Professor in the Department of Biomathematics at the M.D. Anderson Cancer Center and worked as a biomathematician for the National Large Bowel Cancer Project (NLBCP) between 1973 and 1983 when President Nixon launched his war against cancer in the early 1970s. Birger was known internationally for his brilliant mathematical modeling of all types of cancer, but today he is perhaps best known for his epidemiological and review publications demonstrating how a high salt (sodium) diet promotes all types of cancer, whereas a high potassium diet impedes cancer (1-8).

My correspondence with Dr. Jansson came about from my interest in the reported low incidence of all types of cancers in hunter-gatherers (9-17) who were essentially salt free populations. From animal and tissue experiments, I had long suspected that salt added to diet acted as a promoter of various cancers whereas a high potassium intake retarded cancer development. My correspondence with Birger further confirmed the evidence I had compiled.

Almost exactly 20 years ago in May of 1997 (see attached PDF file), Birger sent me his unpublished and unedited book entitled, Sodium: “NO!” Potassium: “Yes!” Sodium increases and potassium decreases cancer risks. This book represented Birger’s scientific work, from 1981 to 1997, documenting the relationship between dietary sodium and potassium (1-8). The data from his book includes hundreds of scientific references from 1) epidemiological studies, 2) animal studies, 3) tissue studies, and a limited number of 4) randomized controlled human trials with various disease endpoints and markers.

Unfortunately, my correspondence with Birger ceased shortly after he sent me his unpublished and unedited book manuscript on May 10, 1997. I only recently discovered that Birger died (May 23, 1998) about a year to the date after our last correspondence at age 77 as a Professor Emeritus at the University of Texas, M.D. Anderson Cancer Center.

I am in a unique position, in that I probably have one of the few copies of Dr. Jansson’s unpublished book in existence. The book runs about 350 pages in length and is comprised of 10 chapters. My copy clearly was produced as a Xeroxed copy of Birger’s hand typed manuscript (one sided, double spaced pages) and spiral bound with plastic. From my correspondence with Birger (May 10, 1997), you can see that he was contemplating publication of his book in the popular literature, but unfortunately it never happened with his untimely death in 1998.

I have always felt a debt to this great scientist, and after consultation with my colleague Anthony Sebastian (M.D.) at the University of California, San Francisco, we concluded that Birger would have been happy to see that his unpublished book was finally made known to the scientific and world communities.

In this blog I have included a single chapter (Chapter II of Birger’s book), entitled “Human Diet Before Modern Times” that I thought would be of interest to the “Paleo Community” and to worldwide scientists as well. Enjoy!

 

References

1. Jansson B. Potassium, sodium, and cancer: a review. J Environ Pathol Toxicol Oncol. 1996;15(2-4):65-73

2. Jansson B. Dietary, total body, and intracellular potassium-to-sodium ratios and their influence on cancer. Cancer Detect Prev. 1990;14(5):563-5

3. Jansson B. Intracellular electrolytes and their role in cancer etiology. In Thompson JR, Brown BW, eds. Cancer modeling. New York: Marcel Dekker 1987:1-59.

4. Jansson B. Geographic cancer risk and intracellular potassium/sodium ratios. Cancer Detect Prev. 1986;9(3-4):171-94

5. Jansson B, Jankovic J. Low cancer rates among patients with Parkinson’s disease. Ann Neurol. 1985 May;17(5):505-9

6. Newmark HL, Wargovich MJ, Bruce VR, Boynton AL, Kleine LP, Whitfield JF. Jansson B, Cameron IL. Ions and neoplastic development. In: Mastromarino AJ, Brattain MG, eds. Large bowel cancer. Clinical and basic science research. Cancer Research Monographs, Vol 3, New York: Praeger Publisher 1985:102-129.

7. Jansson B. Geographic mappings of colorectal cancer rates: a retrospect of studies, 1974-1984. Cancer Detect Prev. 1985;8(3):341-8

8. Jansson B. Seneca County, New York: an area with low cancer mortality rates. Cancer. 1981 Dec 1;48(11):2542-6

9. Bulkley JL. Cancer among primitive tribes. Cancer 1927; 4:289-295.

10. Henson, WW. Cancer in Kafirs: suggested cause. Guy’s Hospital Gazette, March 26, 1904, 131-133

11. Hearsey H. The rarity of cancer among the aborigines of British Central Africa. Brit Med J, Dec 1, 1906, 1562-63.

12. Hildes JA, Schaefer O. The changing picture of neoplastic disease in the western and central Canadian Arctic (1950-1980). Can Med Assoc J 1984; 130:25-32.

13. Rabinowitch IM. Clinical and other observations on Canadian Eskimos in the Eastern Arctic. Can Med Assoc J 1936; 34:487-501.

14. Renner W. The spread of cancer among the descendants of the liberated Africans or Creoles of Sierre Leone. Brit Med J, Sept 3, 1910, 587-589.

15. Riveros M. First observation of cancer among the Pampidos (Chulupi) Indians of the Paraguayan Chaco. Int Surg 1970; 53:51-55.

16. Stefansson V. Cancer: Disease of Civilization? Hill and Wang, NY, 1960.

17. Urquhart JA. The most northerly practice in Canada. Can Med Assoc J. 1935;33:193-196.

New Studies on Salt: Adverse Influence Upon Immunity, Inflammation and Autoimmunity | The Paleo Diet

INTRODUCTION

The Paleo community clearly is not in complete agreement on all dietary issues. One of the more touchy topics is added dietary salt.  A number of popular (non-scientific/non-peer review) bloggers advocate the use of refined salt or various forms of sea salt added to recipes and meals.1 Highly salted meats such as bacon are wildly popular in the Paleosphere.2 Other concentrated, salty foods such as cheese, olives, canned sardines, tuna, anchovies, caviar, salted nuts, manufactured jerky, canned tomato paste, and other salted, processed foods frequently find their way into so-called Paleo diets. You will be hard pressed to find a Paleo diet cookbook anywhere that is completely free of added, salt – that is, except for one The Real Paleo Diet Cookbook (Houghton, Mifflin, Harcourt, New York, 2015).

I have written extensively on the health problems associated with added dietary salt – be it refined salt or sea salt. In the past two years startling, animal and human studies demonstrate that salt added to our diets doesn’t merely increase the risk for stroke, hypertension and heart disease,3, 4, 5, 6 but it also adversely affects immune function, promotes chronic inflammation and represents a previously unrecognized dietary factor in the pathogenesis of autoimmune diseases.7, 8, 9, 10, 11, 12

SODIUM CONSUMPTION: THE EVOLUTIONARY/ANTHROPOLOGICAL EVIDENCE

The USDA daily recommended intake of sodium is 2300 mg. However, it must be remembered that dietary sodium and dietary salt are not equivalent. 1 gram (1000 mg) of salt (NaCl) = 390 mg of sodium.  Hence 2300 mg of sodium would equal 5.9 grams of salt (NaCl).

In perhaps the most comprehensive study of hunter gatherers and non-westernized people worldwide, Denton demonstrated that their average dietary salt intake ranged from 0.6 grams to 2.9 grams of salt (NaCl) per day or 234 to 1131 mg of daily sodium.13 These numbers are derived from population wide urinary sodium excretion rates and are considerably lower than the USDA recommended value of 2300 mg sodium per day, and much lower than the wildly speculative values (3000 to 7000 mg sodium per day or 7.7 to 17.9 grams of daily salt) suggested by a non-scientific/non-peer review Paleo blogger.1

SODIUM CONSUMPTION: EVIDENCE FROM CONTEMPORARY, NON-PROCESSED FOODS

Consider Figure 1 below which demonstrates the sodium content of four contemporary Paleo foods: meat/seafoods (n=8), fruit (n=20) and vegetables (n=18). Note that meat/seafood averages 694 mg of sodium per 1000 kcal, vegetables 764 mg sodium per 1000 kcal and fruit 54 mg of sodium per 1000 kcal.

New Studies on Salt: Adverse Influence Upon Immunity, Inflammation and Autoimmunity | The Paleo Diet

Figure 1.  The Sodium Content of Contemporary Paleo Foods to Processed Foods.

Accordingly, contemporary Paleo diets averaging 55% to 66% of daily calories (range 2200 to 3000 kcal) from animal foods and the balance from plant foods would contain sodium intakes ranging from 1600 to 2200 mg.  These calculations show that unless processed foods containing added salt are consumed, it would be difficult to obtain the USDA 2300 mg recommendation for  daily sodium, and almost impossible to obtain a popular bloggers’ advice (3000 to 7000 mg sodium).1

If fruits were primarily consumed in lieu of vegetables for contemporary Paleo diets, the range of daily sodium intake would be lower still (900 to 1200 mg) which falls within the values of historically studied fully, non-westernized populations.13 With contemporary Paleo foods (fresh fruits, vegetables, meats, seafood, eggs, nuts etc.) and no added salt, you will be obtaining not only sufficient sodium intakes, but also therapeutically lower sodium intakes that are consistent with values that conditioned our species’ genome over millions of years of evolutionary wisdom.

Lowered, or no consumption of added, manufactured dietary salt will lessen your risk for hypertension, stroke and cardiovascular disease,3, 4, 5, 6 certain cancers,14, 15, 16 and now autoimmune and immune diseases, as well as multiple diseases involving chronic low level, systemic inflammation.7, 8, 9, 10, 11, 12

DIETARY SODIUM: ADVERSE EFFECTS UPON INFLAMMATION, IMMUNOLOGICAL FUNCTION AND AUTOIMMUNITY

I have now laid out the necessary foundation for the focus of this article. So, let’s get back into the topic at hand.

Unexpectedly, experimental studies in the past two years have provided powerful, new evidence that high salt diets cannot solely be related to hypertension, stroke , cardiovascular disease3, 4, 5, 6 and cancer,14, 15, 16 but also to diseases involving dysfunction of the immune system, chronic systemic inflammation and autoimmunity.7, 8, 9, 10, 11, 12

Let’s not forget that cardiovascular disease, cancer and autoimmune diseases cannot proceed without chronic, low level inflammation, or that the typical U.S diet is a high salt diet.17 Would it be surprising that the typical western diet which includes 70 % or more of its calories as salt laden processed foods17 and 10 to 12 grams of sodium per day5, 7, 17 might have any adverse effects upon the immune system and diseases of chronic inflammation?

The evolutionary discordance template18, 19 would predict that any recently introduced dietary elements found in concentrations many standard deviations above or below those which conditioned the human genome over 2 million years of evolutionary experience, might adversely impact contemporary health and well being. Indeed is the case for immunity, inflammation and autoimmunity.

ANALYSIS OF RECENT STUDIES

In April of 2013, before my recent retirement from CSU, I awoke to a flurry of emails from scientific colleagues around the world as well as from a few of my graduate students regarding two astounding papers that had just been published in the prestigious scientific journal, Nature.8, 9  These papers represented the first experimental evidence indicating that high salt diets fundamentally altered the immune system of experimental animals in a manner that promoted autoimmune disease.

Over the past decade, numerous studies (human, animal and tissue) have implicated a specific component of the immune system (Th17 or T Helper Cell 17) in a wide variety of autoimmune diseases.20, 21, 22, 23 The two papers on salt and autoimmunity published in Nature8, 9 were crucial, because for the first time empirical evidence demonstrated that high dietary intakes of salt were capable of up-regulating (increasing) Th17 cells in experimental animals and promoting autoimmunity.

OK – no big deal – these were just animal studies and until human studies were conducted, the link between dietary salt and the immune system, chronic low level inflammation and autoimmunity was tenuous.  The currency of science to demonstrate causality between diet and disease requires not just animal studies, but also tissue studies, epidemiological studies and most importantly experimental randomized controlled human trials.

Science typically moves slowly, but occasionally good ideas are rapidly pounced upon by scientists and researchers, thereby resulting in major leaps of knowledge.  Such was the case with salt and autoimmunity. Concurrent with the two animal studies on dietary salt and immune function,8, 9 came the first human study published by Zhou and colleagues, also in April of 2013.11 Their study showed that after a 7 day (short term) high salt diet (> 15  NaCl/day) compared to a lower salt (< 5 g NaCl/day), markers (CD14++ and CD16+) of pro-inflammatory immune responses increased.  CD14++ and CD16+ are molecules expressed on certain immune system cells called monocytes/macrophages. Normally, these cells produce pro-inflammatory cytokines (hormones) when bacterial infection occurs24, 25 or with autoimmune diseases.26, 27  Surprisingly, even a short term (7 day) high salt diet11 caused the human immune system to become inflamed, just as if it were being attacked by foreign pathogens24, 25 or during autoimmunity.26, 27

In the most powerful human study to date, Yi and colleagues have convincingly demonstrated that a high salt diet (12 g per day) promoted a pro-inflammatory immune response whereas a lower salt intake (6 g per day) reduced these effects and caused beneficial immune system changes. The sophistication and high scientific validity of this experiment occurred because it was conducted under metabolic ward conditions over a long (205 day) duration for a simulated spaceflight program (Mars520 Mission).7

With metabolic ward conditions, each and every meal or snack are exclusively provided to test subjects.  Consequently all nutrients (including sodium) are under strict control. During the experiment in an enclosed environment, daily salt intake was solely modified from 12 g/day to 9 g/day to 6 g/day for 50 + 10 days and then reversed back to 12 g/day for 30 days. During the high salt (12 g/day) stages of the experiment, the pro-inflammatory cytokines (localized hormones) IL-6 and IL-23 increased whereas the anti-inflammatory cytokine, IL-10 decreased. Further the high salt diet caused an expansion of white blood cells (monocytes) that occur during chronic inflammation, autoimmune diseases and cancer. On the low salt (6 g/day) diet, these deleterious immune system changes were reversed. Interestingly, during the high salt phase of this experiment, IL-17 was higher than during the low salt phase (P= 0.08). As I have mentioned earlier, numerous studies (human, animal and tissue) have implicated this specific component (Th-17) of the immune system in a wide variety of autoimmune diseases.20, 21, 22, 23

So, there you have it.  The most powerful and scientifically valid study in humans has indisputably demonstrated that a high salt diet promotes chronic inflammation and adversely affects the immune system.  Note that the high salt (12 g/day) phase of this experiment actually represents the normal (10-12 g/day) salt intake in the U.S.5, 7, 17 and that cardiovascular disease, cancer and autoimmune diseases cannot proceed without chronic inflammation.  It is not only irresponsible for certain Paleo bloggers1 to promote high salt diets, but potentially life threatening.

 

REFERENCES

[1] Kresser K. Shaking Up The Salt Myth: Healthy Salt Recommendations. May 4, 2012.

[2] Huntley T.  The Path to Culinary Bliss: Home Cured Bacon.

[3] Strazzullo P, D’Elia L, Kandala NB, Cappuccio FP. Salt intake, stroke, and cardiovascular disease: meta-analysis of prospective studies. BMJ. 2009 Nov 24;339:b4567. doi: 10.1136/bmj.b4567.

[4] Aaron KJ, Sanders PW. Role of dietary salt and potassium intake in cardiovascular health and disease: a review of the evidence.  Mayo Clin Proc. 2013 Sep;88(9):987-95.

[5] He FJ, MacGregor GA. A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. J Hum Hypertens. 2009 Jun;23(6):363-84.

[6] Ando K, Kawarazaki H, Miura K, Matsuura H, Watanabe Y, Yoshita K, Kawamura M, Kusaka M, Kai H, Tsuchihashi T, Kawano Y. [Scientific statement] Report of the Salt Reduction Committee of the Japanese Society of Hypertension(1) Role of salt in hypertension and cardiovascular diseases. Hypertens Res. 2013 Dec;36(12):1009-19.

[7] Yi B, Titze J, Rykova M, Feuerecker M, Vassilieva G, Nichiporuk I, Schelling G, Morukov B, Choukèr A. Effects of dietary salt levels on monocytic cells and immune responses in healthy human subjects: a longitudinal study. Transl Res. 2015 Jul;166(1):103-10.

[8] Kleinewietfeld M, Manzel A, Titze J, Kvakan H, Yosef N, Linker RA, Muller DN, Hafler DA.  Sodium chloride drives autoimmune disease by the induction of pathogenic TH17 cells. Nature. 2013 Apr 25;496(7446):518-22.

[9] Wu C, Yosef N, Thalhamer T, Zhu C, Xiao S, Kishi Y, Regev A, Kuchroo VK. Induction of pathogenic TH17 cells by inducible salt-sensing kinase SGK1. Nature. 2013 Apr 25;496(7446):513-7.

[10] O’Shea JJ, Jones RG. Autoimmunity: Rubbing salt in the wound. Nature. 2013 Apr 25;496(7446):437-9.

[11] Zhou X1, Zhang L, Ji WJ, Yuan F, Guo ZZ, Pang B, Luo T, Liu X, Zhang WC, Jiang TM, Zhang Z, Li YM. Variation in dietary salt intake induces coordinated dynamics of monocyte subsets and monocyte-platelet aggregates in humans: implications in end organ inflammation.  PLoS One. 2013 Apr 4;8(4):e60332. doi: 10.1371/journal.pone.0060332. Print 2013.

[12] van der Meer JW1, Netea MG. A salty taste to autoimmunity. N Engl J Med. 2013 Jun 27;368(26):2520-1.

[13] Denton D.  Salt intake and high blood pressure in man. Primitive peoples, unacculturated societies: with comparisons.  In: The Hunger for Salt, An Anthropological, Physiological and Medical Analysis. Springer-Verlag, New York, 1984, pp. 556-584).

[14] D’Elia L, Rossi G, Ippolito R, Cappuccio FP, Strazzullo P. Habitual salt intake and risk of gastric cancer: a meta-analysis of prospective studies. Clin Nutr. 2012 Aug;31(4):489-98.

[15] Ge S, Feng X, Shen L, Wei Z, Zhu Q, Sun J. Association between Habitual Dietary Salt Intake and Risk of Gastric Cancer: A Systematic Review of Observational Studies.  Gastroenterol Res Pract. 2012;2012:808120. doi: 10.1155/2012/808120. Epub 2012 Oct 22.

[16] Hu J, La Vecchia C, Morrison H, Negri E, Mery L; Canadian Cancer Registries Epidemiology Research Group. Salt, processed meat and the risk of cancer. Eur J Cancer Prev. 2011 Mar;20(2):132-9.

[17] Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr. 2005 Feb;81(2):341-54.

[18] Konner M, Eaton SB. Paleolithic nutrition: twenty-five years later. Nutr Clin Pract. 2010 Dec;25(6):594-602.

[19] Frassetto L1, Morris RC Jr, Sellmeyer DE, Todd K, Sebastian A. Diet, evolution and aging–the pathophysiologic effects of the post-agricultural inversion of the potassium-to-sodium and base-to-chloride ratios in the human diet.  Eur J Nutr. 2001 Oct;40(5):200-13.

[20] Burkett PR, Meyer Zu Horste G, Kuchroo VK. Pouring fuel on the fire: Th17 cells, the environment, and autoimmunity. J Clin Invest. 2015 Jun 1;125(6):2211-9.

[21] Ryu H, Chung Y. Regulation of IL-17 in atherosclerosis and related autoimmunity. Cytokine. 2015 Apr 15. pii: S1043-4666(15)00126-X. doi: 10.1016/j.cyto.2015.03.009. [Epub ahead of print]

[22] Li D, Guo B, Wu H, Tan L, Chang C, Lu Q. Interleukin-17 in systemic lupus erythematosus: A comprehensive review.  Autoimmunity. 2015 Apr 20:1-9. [Epub ahead of print]

[23] Patel DD , Lee DM, Kolbinger F, Antoni C. Effect of IL-17A blockade with secukinumab in autoimmune diseases. Ann Rheum Dis. 2013 Apr;72 Suppl 2:ii116-23. doi: 10.1136/annrheumdis-2012-202371. Epub 2012 Dec 19.

[24] Rietschel ET, Schletter J, Weidemann B, El-Samalouti V, Mattern T, Zähringer U, Seydel U, Brade H, Flad HD, Kusumoto S, Gupta D, Dziarski R, Ulmer AJ. Lipopolysaccharide and peptidoglycan: CD14-dependent bacterial inducers of inflammation. Microb Drug Resist. 1998 Spring;4(1):37-44.

[25] Scherberich JE1, Nockher WA. CD14++ monocytes, CD14+/CD16+ subset and soluble CD14 as biological markers of inflammatory systemic diseases and monitoring immunosuppressive therapy. Clin Chem Lab Med. 1999 Mar;37(3):209-13.

[26] Chuluundorj D, Harding SA, Abernethy D, La Flamme AC. Expansion and preferential activation of the CD14(+)CD16(+) monocyte subset during multiple sclerosis.  Immunol Cell Biol. 2014 Jul;92(6):509-17.

[27] Kawanaka N1, Yamamura M, Aita T, Morita Y, Okamoto A, Kawashima M, Iwahashi M, Ueno A, Ohmoto Y, Makino H. CD14+,CD16+ blood monocytes and joint inflammation in rheumatoid arthritis. Arthritis Rheum. 2002 Oct;46(10):2578-86.

Easy With That Salt Shaker: The Effect of Dietary Salt On Sleep | The Paleo Diet

INTRODUCTION

Got sleep? Fact is many of us have a problem sleeping. You probably fall into one category, either being unable to sleep, or not getting enough sleep. In actuality, “counting sheep” and staring at the clock may be the favorite pastimes of many adults. Poor sleep quality, and associated sleep disorders like insomnia remain at the foremost of global health issues. For many, a common solution to tiredness entails having a daily fix of caffeine. Yet, the negative effects of caffeine on the heart, as well as the importance of sleep in regulating chemical imbalances within the brain, cannot be overstated.1

Sleep disorders have long-term consequences. They increase the risk of chronic diseases such as cardiovascular conditions and diabetes, resulting in a dismal quality of life. In addition, this leads to a big hole in your wallet and great financial burden to the economy.2 Given the increasing prevalence of reduced sleep quality and its costs, finding hidden factors that affect sleep is required to improve public health. Many are aware of risk factors like alcohol and sugar consumption, but a possible risk factor that normally goes unmentioned may lie in the individual’s dietary salt intake.3

While devoted Paleo followers are conscious of reducing dietary salt, after reading Dr. Loren Cordain’s books, it is important to understand the scientific basis behind this premise. Let’s put together results from past research to connect the dots.

DIETARY SALT AND THE BIG WHAMMY CORTISOL

Research studies have shown possible evidence between high dietary salt consumption and increased levels of the stress hormone cortisol.4 Furthermore, there appeared to be indication of metabolic syndrome. This group of conditions are characterized by risk factors including truncal obesity (where fat deposits around the waist line), low HDL cholesterol levels (which helps eliminate bad cholesterol from the body), hypertension and insulin resistance (which leads to hyperglycemia-high blood sugar)5.

This sounds like a lot, but let us put this in perspective. An individual diagnosed with metabolic syndrome doubles the risk of cardiovascular (heart) disease, while also quintupling the risk of diabetes. This should have set some alarms going off.

What exactly is cortisol, and how does it affect the body physiologically and psychologically? That answer will help you really understand where this is headed. Cortisol is a glucocorticoid hormone made in the adrenal cortex, near your kidneys.6 Aldosterone, which regulates sodium, is also made in the same area. Known as the key stress hormone in the body, the highest levels of cortisol are seen in the early part of the morning. A term coined as the “awakening response.” That feeling when you wake up excited and ready to start the day, yes thanks should go to cortisol. Cortisol helps your body in maintaining homeostasis. It keeps everything “A-okay” during and after exposure to stress.7 Regulation of cortisol takes place via the hypothalamic–pituitary–adrenal (HPA axis).

Cortisol acts on many parts of the body. In your immune system, cortisol exhibits weakening effects, while inhibiting the inflammatory process. It leaves you prone to developing infections.8 Cortisol encourages gluconeogenesis, basically it increases glucose/sugar production within the body.9 Makes sense right? In a stressful situation, your body needs energy.

In the brain, the memory zone, known as the hippocampus, has numerous cortisol receptors. Excess cortisol during stress has been shown to affect the hippocampus, through atrophy or wasting, resulting in severe memory loss.10 Evidence shows that cortisol affects the limbic system in the brain, which is responsible for mood and emotion.11

Cortisol prepares the body for a fight or flight response to stress, which explains the link between cortisol and insomnia. High levels of cortisol have been linked with a dysfunctional HPA axis, which helps regulate the sleep-wake circadian cycle. This affects sleep quality, and decreases slow-wave sleep aka deep sleep, and sleep time.12 Well the problem is that we need deep sleep. This is where human growth hormone is released, and where the body undergoes healing and repairs.13

Some evidence has shown the likelihood that cortisol also inhibits the production and release of melatonin, the sleep hormone, from the pineal gland.14 Adequate melatonin hormone is needed to induce good sleep. Melatonin and cortisol work inversely, think of it like a see-saw. Melatonin levels are naturally higher at night, but high cortisol levels at night leave melatonin unable to regulate this process.15

TIME TO CONNECT THE DOTS

Enough said. You may be thinking cortisol is pretty bad, but what does that have to do with dietary salt and sleep again. Well, it is a simple linear relationship. Dietary salt leads to increased cortisol levels, and these excess levels affect sleep. This means you can deduce dietary salt may affect sleep. Sounds simple right? Well in science, a hypothesis can be proposed, but a study must be carried out to provide answers.

A research study using a sample size of 20 individuals validated this hypothesis.16 In the study, significantly affected sleep quality, decreased deep sleep, resulting in frequent awakenings, alongside increased thirst. Given the small sample size of this study, further work is needed. Another study also confirmed the hypothesis that salt affects sleep.17

Yet another study shows that dietary salt increased the severity of the sleep disorder known as obstructive sleep apnea.18 With this condition, your airway narrows, decreasing oxygen availability, and leaving you with the inability to breathe for periods at a time.19

So now you have some science to back up your knowledge, when asked the real reason behind your decreased salt intake. Also remember that increased salt intake will make you wake up frequently to use the bathroom. As the body tries to get rid of the sodium, water goes out with it, leaving you thirsty and feeling dehydrated. As you place the almost empty salt shaker next to the empty wine glass, remember there is indeed a science behind this supposed madness.

Best wishes,

Obianuju Helen Okoye, M.D, M.B.A, M.S.-Epi

 

REFERENCES

[1] Harvard Medical School Division of Sleep Medicine. (2007, December 18). Under The Brain’s Control. Retrieved May 19, 2015, from http://healthysleep.med.harvard.edu/healthy/science/how/neurophysiology

[2]<Grandner, M., Jackson, N., Gerstner, J., & Knutson, K. (2014). Sleep Symptoms Associated with Intake of Specific Dietary Nutrients. J Sleep Res, 23(1), 22–34. Retrieved June 22, 2015, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866235/

[3] Ibid.

[4] Baudrand, R., Campino, C., Carvajal, C. A., Olivieri, O., Guidi, G., Faccini, G., . . . Cerda, J. (2014). High sodium intake is associated with increased glucocorticoid production, insulin resistance and metabolic syndrome. Clin Endocrinol, 677–684. doi:10.1111/cen.12225

[5] National Health, Lung and Blood Institute. (2011, November 3). What Is Metabolic Syndrome? Retrieved June 23, 2015, from Metabolic Syndrome: http://www.nhlbi.nih.gov/health/health-topics/topics/ms

[6]  Johns Hopkins Medicine. (2015). The Adrenal Glands. Retrieved June 23, 2015, from Health Library: http://www.hopkinsmedicine.org/healthlibrary/conditions/endocrinology/adrenal_glands_85,P00399/

[7] Randall, M. (2011, February 3). The Physiology of Stress: Cortisol and the Hypothalamic-Pituitary-Adrenal Axis. Dartmouth Undergraduate Journal of Science. Retrieved June 24, 2015

[8] Ibid.

[9] Ibid.

[10] Ibid.

[11] Kandhalu, P. (2013, November 4). Berkley Scientific Journal, 18(1), 13-16. Retrieved June 22, 2015, from http://bsj.berkeley.edu/wp-content/uploads/2013/11/04-FeaturesEffects-of-Cortisol_Preethi-KandhaluKim.pdf

[12] Kandhalu, P. (2013, November 4). Berkley Scientific Journal, 18(1), 13-16. Retrieved June 22, 2015, from http://bsj.berkeley.edu/wp-content/uploads/2013/11/04-FeaturesEffects-of-Cortisol_Preethi-KandhaluKim.pdf

[13] National Sleep Foundation. (2006). Sleep-Wake Cycle: Its Physiology and Impact on Health. Washington DC. Retrieved May 15, 2015, from http://sleepfoundation.org/sites/default/files/SleepWakeCycle.pdf

[14] Nikaidoa, Y., Aluru, N., McGuire, A., Park, Y., Vijayan, M., & Takemura, A. (2010, Jan). Effect of cortisol on melatonin production by the pineal organ of tilapia, Oreochromis mossambicus. Comp Biochem Physiol A Mol Integr Physiol, 155(1), 84-90. doi:10.1016/j.cbpa.2009.10.006

[15] Roden, M., Koller, M., Pirich, K., Vierhapper, H., & Waldhauser, F. (1993). The circadian melatonin and cortisol secretion pattern in permanent night shift workers. Am J Physiol, 265(1), R261-7. Retrieved June 24, 2015, from http://ajpregu.physiology.org/content/265/1/R261

[16] Baudrand, R., Campino, C., Carvajal, C. A., Olivieri, O., Guidi, G., Faccini, G., . . . Cerda, J. (2014). High sodium intake is associated with increased glucocorticoid production, insulin resistance and metabolic syndrome. Clin Endocrinol, 677–684. doi:10.1111/cen.12225

[17] Grandner, M., Jackson, N., Gerstner, J., & Knutson, K. (2014). Sleep Symptoms Associated with Intake of Specific Dietary Nutrients. J Sleep Res, 23(1), 22–34. Retrieved June 22, 2015, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3866235/

[18] Pimenta, E., Stowasser, M., Gordon, R., Harding, S., Batlouni, M., Zhang, B., . . . Calhoun, D. (2013). Increased dietary sodium is related to severity of obstructive sleep apnea in patients with resistant hypertension and hyperaldosteronism. Chest, 143(4), 978-83. Retrieved June 21, 2015, from 10.1378/chest.12-0802

[19] Pimenta, E., Stowasser, M., Gordon, R., Harding, S., Batlouni, M., Zhang, B., . . . Calhoun, D. (2013). Increased dietary sodium is related to severity of obstructive sleep apnea in patients with resistant hypertension and hyperaldosteronism. Chest, 143(4), 978-83. Retrieved June 21, 2015, from 10.1378/chest.12-0802

 

Add Salt and Stop Gaining Weight? | The Paleo Diet

“In a study that seems to defy conventional dietary wisdom, scientists have found that adding high salt to a high-fat diet actually prevents weight gain in mice.”1

So, after all this time, is adding salt to the diet not really as consequential as we thought?  Can we just douse our food with it, eat whatever foods we fancy and then magically stay lean and fit? Let’s investigate.

The researchers hypothesized that fat and salt, both tasty and easy to overeat, would collectively increase food consumption and promote weight gain. They tested the hypothesis by feeding groups of mice different diets: normal or high-fat chow with varying levels of salt. To their surprise, the mice on the high-fat diet with the lowest salt gained the most weight.

But how can this be? Don’t we need to eat a diet lower in fat and salt, per USDA recommendations,2 in order to be as healthy as possible?

“Our findings, in conjunction with other studies, are showing that there is a wide range of dietary efficiency, or absorption of calories, in the populations, and that may contribute to resistance or sensitivity to weight gain”, says Michael Lutter, MD, PhD, co-senior study author and UI assistant professor of psychiatry.

Well, that certainly makes sense. Humans certainly are not all cut from the same cloth. We have to factor in genetic variability, and nature versus nurture, in terms of what we we’re fed growing up and whether our upbringing favored activity and exercise.

Furthermore, we need to consider what we are eating in the grand scheme of things. How does this affect our macronutrient ratios and consequently what is our body using for its fuel source? For example, if we eat a ‘healthy’ diet with many servings of natural fruit during the day, we provide our body with a constant, steady stream of carbohydrates. This prevents the body from tapping into stored fat which requires the body to put forth significantly more effort. If, however, we begin the process of becoming fat adapted, we force the body to do the latter and turn to fat as its primary fuel source.3

Many of us who are already in sync with the recommendations of a real Paleo diet are comfortable with the recommendation to eat a diet higher in fat. But, the mention of adding salt really throws us a curve ball! After all, added salt is linked to a host of negative side effects including high blood pressure, osteoporosis and kidney stones, stomach cancer, stroke, Menierre’s Syndrome, insomnia, motion sickness, asthma and exercise induced asthma.4

A brief glance at our colleagues, friends and family’s food habits, provide all the proof we need that the typical American is following a diet far too high in sodium. It’s a fair bet most could do with, at the very least, weaning off the salt, by cutting back on the salt shaker and simultaneously omitting processed foodstuffs. But, this begs the question, how should athletes balance their Paleo diets and replace electrolytes through sweat?

Rehydrating with pure water without also replenishing salts can be potentially fatal and lead to hyponatremia, a condition that can occur when the level of sodium in your blood is abnormally low. Drinking too much water during endurance sports causes the sodium in your body to become diluted. When this happens, your body’s water levels rise, and your cells begin to swell. This swelling can cause many health problems, from mild to life threatening.5 Other side effects may include lightheadedness, fatigue, headaches and constipation.

Moreover, on a low carb diet where the body becomes reliant on fat as its fuel, more salt is used in the process when insulin levels go down and the body starts shedding excess sodium and water along with it. On a high carb diet, insulin signals the cells to store fat and the kidneys to hold on to sodium, which is why people often get rid of excess bloat within a few days of low-carb eating.6

But again, if sodium is a crucial electrolyte in the body, how do we replace it? Presuming you’re following a healthy, high in fat, but void of refined, processed carbs and with adequate wild proteins and local veggies Paleo diet, adding a few pinches of salt to a recovery drink is permitted7 and may, in some instances, be a part of preventing weight gain. The general takeaway is not to simply add salt and watch the pounds melt away. Rather, train your body to become fat adapted in conjunction with following a real Paleo approach.

These findings “may lead to the developments of new anti-obesity treatments” and “may support continued and nuanced discussions of public policies regarding dietary nutrient recommendations.”

Let’s hope the new treatments go beyond a new pill or surgery, and the recommendations are evidenced by science versus the current guidelines deterring us as a society to truly follow a path to optimal health!

 

REFERENCES

[1] ScienceDaily. ScienceDaily, n.d. Web. 15 June 2015.

[2] “Dietary Guidelines.” Dietary Guidelines. N.p., n.d. Web. 15 June 2015.

[3] Volek, Jeff, Stephen D. Phinney, Eric Kossoff, Jacqueline A. Eberstein, and Jimmy Moore. The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable. Lexington, KY: Beyond Obesity, 2011. Print.

[4] “Sea Salt: Between the Devil and the Deep Blue Sea.” The Paleo Diet. N.p., 20 Apr. 2014. Web. 15 June 2015.

[5] “Hyponatremia.” – Mayo Clinic. N.p., n.d. Web. 15 June 2015.

[6] “Insulin’s Impact on Renal Sodium Transport and Blood Pressure in Health, Obesity, and Diabetes.” Insulin’s Impact on Renal Sodium Transport and Blood Pressure in Health, Obesity, and Diabetes. N.p., n.d. Web. 15 June 2015.

[7] Cordain, Loren, and Joe Friel. “Stages III, IV, V: Eating After Exercise.” The Paleo Diet for Athletes: The Ancient Nutritional Formula for Peak Athletic Performance. New York: Rodale, 2012. 56-57. Print.

Fish Roe and Caviar: Paleo? Yes and No | The Paleo Diet

INTRODUCTION

Unless you frequently eat at sushi bars or enjoy caviar with your champagne, most Americans have rarely if ever tasted fish roe (eggs). Worldwide, roe is not only consumed from just about any and all species of fish or aquatic animals that can be harvested or caught, but is considered a delicacy in most cultures and societies outside of the U.S.4, 33, 43 Table 1 below shows some of the more commonly consumed fish roe and aquatic animal eggs.

The Japanese are fond of almost all roe, particularly caviars such as salmon (Ikura), pollock (Tarako), flying fish (Tobiko),  herring (Kazunoko), mullet (Karasumi) and smelt (Masago).4, 33, 44 The Italian version of processed mullet roe is known as “Bottarga.”4, 25, 26, 28

Fish Roe and Caviar: Paleo? Yes and No

ROE VS. CAVIAR

I hate to split hairs, but a distinction must be made between roe and caviar. The commonly edible eggs of fish and other aquatic animals (sea urchins, squid, shrimp, lobster, scallops etc.) represent the mature ovaries of the females of these species. Roe, unlike chicken eggs, do not present themselves as a single distinct egg, but rather the eggs occur attached to one another in connective tissue called “skeins.”4 Roe skeins can be consumed in their raw (“green”) unadulterated state or processed in a manner that separates individual eggs from one another.

When salt is added to separated fish eggs (a procedure called “brining”) it yields a food product called “caviar” which may also be subject to other “curing” processes and added chemicals.4 In the U.S. only sturgeon caviar can be labeled as “caviar.”4 Other salted fish roe such as salmon must be labeled with the fish from which it was made. So, salted cured salmon roe becomes “salmon caviar.”4

Sturgeon caviar is one of the most expensive foods in the world with a one ounce (30 gram) tin costing between $50 and $75. High end Osetra sturgeon caviar runs about $12,000 a kilo or about $378 for an ounce. Surprisingly, much less expensive caviar from salmon, herring, squid and other species is nutritionally superior to sturgeon caviar, particularly in regard to omega 3 fatty acids.20, 34, 39, 40

SALT AND CAVIAR

Any and all caviars are by definition manufactured using salt.4 Accordingly, these processed foods would have been unavailable for consumption to our pre-agricultural ancestors. However there is little doubt that fresh, “green” unadulterated fish roe would have been relished.

Below in Table 2, you can see that fresh, non-processed fish roe represents a very low dietary source of sodium, whereas caviar is a concentrated source of sodium because of its processing with salt (NaCl).

Fish Roe and Caviar: Paleo? Yes and No | The Paleo Diet

The USDA recommended limit for daily sodium intake is 2,300 mg. Caviar eggs whether from sturgeon, salmon, herring or other species typically is packaged in 1 oz. (30 g) or 50 g (1.76 oz.) tins, but can be purchased in higher bulk quantities. Accordingly, a single 1 oz. (30 g) tin of caviar (on low end estimates) delivers a whopping 450 mg of sodium, whereas on high end values, it is more devastating still at 1162 mg of sodium.

From table 2 above, you can see that if you are going to eat roe, a better strategy (sodium wise) would be to consume fresh or frozen fish eggs without added salt.

In the U.S. fresh roe (“green”) and frozen roe is considerably more difficult to obtain than salted caviar, but not impossible. Go online and you can see a substantial number of retailers offering unprocessed fresh or frozen roe without salt. So the bottom line with salted caviar is to eat it infrequently or as a treat – better yet eat non-salted roe if you can find it.

TASTE TEST OF THREE NON-STURGEON CAVIARS

As long as I am writing about the scientific merits or lack thereof caviar and fish roe, I thought that it might be useful for me to give you my taste test impressions of three caviars (whitefish, capelin, lumpfish) which I purchased from our local World Market store. Below are my taste impressions of these three items.

1. I started off my culinary caviar adventures with Pacific Plaza Imports “Golden Whitefish Caviar.”47

I bought a 50 g tin of this roe for $6.99 and carefully read the label which indicated the following items and their respective order: wild pasteurized whitefish roe, natural caramel coloring, truffle oil, water, tragacanth gum (as a stabilizer), salt, sodium benzoate (as a preservative).

Whew! That’s quite a list of non-Paleo ingredients. The label tells us that this whitefish caviar is harvested from a species known as Coregonus clupeaformis. By contrasting the slightly lower sodium content of this roe to capelin and lumpfish (Table 2) from the same company, I was expecting that my taste test would be somewhat positive or at least better than the capelin and lumpfish taste tests. Yuck! What a disappointment.

I gingerly picked out a clump of black whitefish caviar from the 50 g tin with a small hors d’oeuvres fork. Immediately, upon hitting my mouth, this tiny amount of roe sickened me with its overpowering salty taste to the point that I wanted to spit it out. It didn’t taste like any food I have ever eaten, but rather more like putting pure salt crystals on my tongue, but perhaps worse.

The fish oil seemed to cause the processed roe salt to permeate my tongue in a greater manner than salt itself.  This food was so excessively salty that I have little desire to ever again eat caviar. But waitFor this review, I had to sample capelin and lumpfish caviar which both contain considerably more salt than whitefish.

2. Lumpfish and Capelin Caviar.

I pop open the lids from the tins of both lumpfish and capelin caviar and prepare to dive into them with my hors d’oeuvres fork. After a brief taste (only a few caviar eggs of each), I simply cannot tolerate the overpowering salty queasiness this food brings on.

THERAPEUTIC HEALTH BENEFITS OF FRESH FISH ROE

Fish roes are one of the most concentrated food sources of long chain omega 3 fatty acids EPA (20:5n3) and DHA (22:6n3).3-5, 13, 14, 19,  20, 26, 28, 34, 38-40 In numerous animal experiments roe consumption has been shown to improve various markers of health and well being and to reduce morbidity and mortality.11, 21, 22, 33, 44, 46 Only a handful of human studies has evaluated roe consumption in regard to this food’s potential therapeutic health effects.3, 4 So, if you can find unsalted roe, it represents one of the best dietary sources of  healthful long chain omega 3 fatty acids.

The long chain omega 3 fatty acids found in roe are different from these beneficial fatty acids that you my get if you take fish oil or fish oil capsules. The omega 3 fatty acids (DHA and EPA) in fish roe are contained in phospholipids (structural fat) whereas EPA and DHA in fish oil are contained in the triglyceride (storage fat) fraction.48 A number of studies suggest that ingestion of EPA and DHA bound to phospholipids are more readily absorbed and better utilized than EPA and DHA bound to triglycerides.3, 48 – 52 Accordingly, some scientists propose that the omega 3 fatty acids (EPA and DHA) found in fish eggs39, 48 and krill oil48, 50, 52 are more effective in enriching our bloodstream with these healthy nutrients. Unfortunately, few human experimental trials3, 50 have shown this proposed effect, and the best evidence to date indicates the “jury may still be out” on this concept because of experimental and methodological issues.8, 27

Nevertheless, whether you consume fresh roe, krill oil, fish, fish oil, or fish oil capsules you will be doing your body a favor by ingesting long chain omega 3 fatty acids which reduce the risk of cardiovascular disease, cancer and other pro-inflammatory illnesses.

FISH ROE LECTINS AND ALLERGY

When most people in the Paleo diet community see the word, “lectin” it typically conjures up images of plant foods such as whole grains and legumes which contain lectins such as wheat germ agglutinin (WGA in wheat) and phytohemagglutinin (PHA in beans).

In experimental animals, both of these lectins have been shown to bypass the gut barrier and promote adverse physiological effects.53, 54 To date, these lectins have been scarcely studied in human tissue (in vitro) experiments  and almost never examined in living humans (in vivo studies).55

Rarely do Paleo dieters recognize that certain animal foods may also contain various antinutrients, including lectins. Starting in the late 1970s, fish roe from most species was discovered to be a significant source of certain lectins.56-59 As more recent work has confirmed, most fish roe lectins belong to a category of lectins called rhambose-binding lectins (RBLs).12, 16, 23, 32, 36, 37, 41, 42

The biological function of RBLs in fish eggs seems to primarily involve activation of innate immunity, host pathogen interaction and inflammatory reactions  in various fish tissues.32, 41, 42  Multiple RBLs (CSL1, 2 and 3) from chum salmon roe induced production of the pro-inflammatory cytokines (IL-1 β1, IL-2β2,  TNFα1 and IL-8) in fish macrophages.42 To date no experimental mammal, or human studies have determined if RBLs from fish roe interact with our immune systems to produce inflammation or undesired health effects.

However, substantial literature exists showing that fish roe consumption represents a common food allergen in humans, particularly children.7, 15, 24, 18, 29, 30, 31, 35 The primary allergen in fish roe is known as “ ß`- component”18, 29 and may cause severe anaphylactic reactions.

CONCLUSIONS

In the U.S., caviar is rarely eaten by the average consumer, whereas it is a common food item in Japan and other countries worldwide. Because caviar represents a concentrated salt source, it should be rarely consumed or avoided by regular Paleo dieters. If you can find it, fresh or frozen fish roe of any species represents one of the most concentrated dietary sources of the healthful, long chain, omega 3 fatty acids, EPA and DHA. Eat it if you can. However, if you experience an allergenic reaction – hives, itching skin, running nose, difficulty breathing, rashes, etc. – know that fish roe is a common dietary allergen, and the immunological flip side of allergy frequently involves autoimmunity.

 

REFERENCES

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[2]Al‐Holy , M. A., & Rasco, B. A. (2006). Characterization of salmon (Oncorhynchus keta) and sturgeon (Acipenser transmontanus) caviar proteins. Journal of food biochemistry, 30(4), 422-428.

[3]Bjørndal, B., Strand, E., Gjerde, J., Bohov, P., Svardal, A., Diehl, B. W., … & Berge, R. K. (2014). Phospholipids from herring roe improve plasma lipids and glucose tolerance in healthy, young adults. Lipids in health and disease, 13(1), 82.

[4]Bledsoe GE, Bledsoe CD, Rasco B. Caviars and fish roe products. Crit Rev Food Sci Nutr. 2003;43(3):317-56.

[5]Caprino F, Moretti VM, Bellagamba F, Turchini GM, Busetto ML, Giani I, Paleari MA, Pazzaglia M. Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus). Anal Chim Acta. 2008 Jun 9;617(1-2):139-47.

[6]Chalamaiah M, Hemalatha R, Jyothirmayi T, Diwan PV, Bhaskarachary K, Vajreswari A, Ramesh Kumar R, Dinesh Kumar B. Chemical composition and immunomodulatory effects of enzymatic protein hydrolysates from common carp (Cyprinus carpio) egg. Nutrition. 2015 Feb;31(2):388-98.

[7]Fujita, S., Shimizu, Y., Kishimura, H., Watanabe, K., Hara, A., & Saeki, H. (2012). In vitro digestion of major allergen in salmon roe and its peptide portion with proteolytic resistance. Food Chemistry, 130(3), 644-650.

[8]Ghasemifard S, Turchini GM, Sinclair AJ. Omega-3 long chain fatty acid “bioavailability”: a review of evidence and methodological considerations. Prog Lipid Res. 2014 Oct;56:92-108.

[9]Higuchi T, Shirai N, Suzuki H. Effects of dietary herring roe lipids on plasma lipid, glucose, insulin, and adiponectin concentrations in mice.J Agric Food Chem. 2006 May 17;54(10):3750-5.

[10]Higuchi T, Shirai N, Suzuki H. Effects of herring roe on plasma lipid, glucose, insulin and adiponectin levels, and hepatic lipid contents in mice. J Nutr Sci Vitaminol (Tokyo). 2008 Jun;54(3):230-6

[11]Higuchi T, Shirai N, Suzuki H. Effects of dietary herring roe lipids on plasma lipid, glucose, insulin, and adiponectin concentrations in mice. J Agric Food Chem. 2006 May 17;54(10):3750-5

[12]Hosono M, Kawauchi H, Nitta K, Takayanagi Y, Shiokawa H, Mineki R, Murayama K. Purification and characterization of Silurus asotus (catfish) roe lectin. Biol Pharm Bull. 1993 Jan;16(1):1-5.

[13]Intarasirisawat, R., Benjakul, S., & Visessanguan, W. (2011). Chemical compositions of the roes from skipjack, tongol and bonito. Food Chemistry, 124(4), 1328-1334.

[14]Kaitaranta JK, Linko RR. Fatty acids in the roe lipids of common food fishes. Comp Biochem Physiol B. 1984;79(3):331-4

[15]Kondo, Y., Kakami, M., Koyama, H., Yasuda, T., Nakajima, Y., Kawamura, M., … & Urisu, A. (2005). IgE cross-reactivity between fish roe (salmon, herring and pollock) and chicken egg in patients anaphylactic to salmon roe. Allergology International, 54(2), 317-323.

[16]Lam YW, Ng TB. Purification and characterization of a rhamnose-binding lectin with immunoenhancing activity from grass carp (Ctenopharyngodon idellus) ovaries.Protein Expr Purif. 2002 Dec;26(3):378-85.

[17]Ng TB, Lam YW, Woo NY. The immunostimulatory activity and stability of grass carp (Ctenopharyngodon idellus) roe lectin. Vet Immunol Immunopathol. 2003 Aug 15;94(3-4):105-12.

[18]Liu, Y. Y., Cao, M. J., Zhang, M. L., Hu, J. W., Zhang, Y. X., Zhang, L. J., & Liu, G. M. (2014). Purification, characterization and immunoreactivity of β′-component, a major allergen from the roe of large yellow croaker (Pseudosciaena crocea). Food and Chemical Toxicology, 72, 111-121.

[19]Méndez, E., Fernández, M., Pazo, G., & Grompone, M. A. (1992). Hake roe lipids: composition and changes following cooking. Food chemistry, 45(3), 179-181.

[20]Mol S, Turan S. Comparison of proximate, fatty acid and amino acid compositions of various types of fish roes. Int J Food Properties . Volume 11, Issue 3, 2008, 669-677.

[21]Moriya H, Hosokawa M, Miyashita K. Combination effect of herring roe lipids and proteins on plasma lipids and abdominal fat weight of mouse. J Food Sci. 2007 Jun;72(5):C231-4.

[22]Moriya, H., Kuniminato, T., Hosokawa, M., Fukunaga, K., Nishiyama, T. , Miyashita, K. (2007), Oxidative stability of salmon and herring roe lipids and their dietary effect on plasma cholesterol levels of rats. Fisheries Science, 73: 668–674.

[23]Ogawa T, Watanabe M, Naganuma T, Muramoto K. Diversified carbohydrate-binding lectins from marine resources. J Amino Acids. 2011;2011:838914. doi: 10.4061/2011/838914.

[24]Perez-Gordo M, Sanchez-Garcia S, Cases B, Pastor C, Vivanco F, Cuesta-Herranz J. Identification of vitellogenin as an allergen in Beluga caviar allergy. Allergy. 2008 Apr;63(4):479-80.

[25]Rosa A, Scano P, Atzeri A, Deiana M, Falchi AM. Potential anti-tumor effects of Mugil cephalus processed roe extracts on colon cancer cells. Food Chem Toxicol. 2013 Oct;60:471-8.

[26]Rosa, A., Scano, P., Melis, M. P., Deiana, M., Atzeri, A., & Dessi, M. A. (2009). Oxidative stability of lipid components of mullet (Mugil cephalus) roe and its product “bottarga”. Food chemistry, 115(3), 891-896.

[27]Salem N Jr, Kuratko CN. A reexamination of krill oil bioavailability studies. Lipids Health Dis. 2014 Aug 26;13:137.

[28]Scano P, Rosa A, Cesare Marincola F, Locci E, Melis MP, Dessì MA, Lai A. 13C NMR, GC and HPLC characterization of lipid components of the salted and dried mullet (Mugil cephalus) roe “bottarga”. Chem Phys Lipids. 2008 Feb;151(2):69-76

[29]Shimizu, Y., Oda, H., Seiki, K., & Saeki, H. (2015). Development of an enzyme-linked immunosorbent assay system for detecting β′-component (Onk k 5), a major IgE-binding protein in salmon roe. Food chemistry, 181, 310-317.

[30]Shimizu Y1, Kishimura H, Kanno G, Nakamura A, Adachi R, Akiyama H, Watanabe K, Hara A, Ebisawa M, Saeki H. Molecular and immunological characterization of β’-component (Onc k 5), a major IgE-binding protein in chum salmon roe. Int Immunol. 2014 Mar;26(3):139-47.

[31]Shimizu Y, Nakamura A, Kishimura H, Hara A, Watanabe K, Saeki H. Major allergen and its IgE cross-reactivity among salmonid fish roe allergy. J Agric Food Chem. 2009 Mar 25;57(6):2314-9.

[32]Shirai T, Watanabe Y, Lee MS, Ogawa T, Muramoto K. Structure of rhamnose-binding lectin CSL3: unique pseudo-tetrameric architecture of a pattern recognition protein. J Mol Biol. 2009 Aug 14;391(2):390-403.

[33]Shirai N, Higuchi T, Suzuki H. Effect of lipids extracted from a salted herring roe food product on maze-behavior in mice. J Nutr Sci Vitaminol (Tokyo). 2006 Dec;52(6):451-6

[34]Shirai, N., Higuchi, T., & Suzuki, H. (2006). Analysis of lipid classes and the fatty acid composition of the salted fish roe food products, Ikura, Tarako, Tobiko and Kazunoko. Food Chemistry, 94(1), 61-67.

[35]Tanaka K, Kondo Y, Inuo C, Nakajima Y, Tsuge I, Doi S, Yanagihara S, Yoshikawa T, Urisu A. Allergen analysis of sea urchin roe using sera from five patients. Int Arch Allergy Immunol. 2014;164(3):222-7

[36]Tateno H, Ogawa T, Muramoto K, Kamiya H, Saneyoshi M. Distribution and molecular evolution of rhamnose-binding lectins in Salmonidae: isolation and characterization of two lectins from white-spotted Charr (Salvelinus leucomaenis) eggs. Biosci Biotechnol Biochem. 2002 Jun;66(6):1356-65

[37]Terada T, Watanabe Y, Tateno H, Naganuma T, Ogawa T, Muramoto K, Kamiya H. Structural characterization of a rhamnose-binding glycoprotein (lectin) from Spanish mackerel (Scomberomorous niphonius) eggs. Biochim Biophys Acta. 2007 Apr;1770(4):617-29.

[38]Tocher DR, Sargent JR. Analyses of lipids and fatty acids in ripe roes of some Northwest European marine fish. Lipids. 1984 Jul;19(7):492-9.

[39]Wang, Q., Xue, C., Li, Z., & Xu, J. (2008). Analysis of DHA-rich phospholipids from egg of squid Sthenoteuthis oualaniensis. Journal of food composition and analysis, 21(4), 356-359.

[40]Wang, Q., Xue, Ch, Li, Z. J., & Xu, J. (2008). Phosphatidylcholine levels and their fatty acid compositions in squid egg: a comparison study with pollack roe and sturgeon caviar. Journal of Food Lipids, 15(2), 222-230.

[41]Watanabe Y, Shiina N, Shinozaki F, Yokoyama H, Kominami J, Nakamura-Tsuruta S, Hirabayashi J, Sugahara K, Kamiya H, Matsubara H, Ogawa T, Muramoto K. Isolation and characterization of l-rhamnose-binding lectin, which binds to microsporidian Glugea plecoglossi, from ayu (Plecoglossus altivelis) eggs.  Dev Comp Immunol. 2008;32(5):487-99.

[42]Watanabe Y, Tateno H, Nakamura-Tsuruta S, Kominami J, Hirabayashi J, Nakamura O, Watanabe T, Kamiya H, Naganuma T, Ogawa T, Naudé RJ, Muramoto K. The function of rhamnose-binding lectin in innate immunity by restricted binding to Gb3. Dev Comp Immunol. 2009 Feb;33(2):187-97.

[43]http://en.wikipedia.org/wiki/Roe

[44]Shirai N, Higuchi T, Suzuki, H. A comparative study of lipids extracted from herring roe products and fish oil on plasma glucose and adipocytokine levels in ICR aged mice. Food Science and Technology Research, Vol. 14 (2008) No. 1, 25-31

[45]Nutritionist Pro Software, Version 4.7.0. Axxya Systems LLC. Redmond WA. http://www.nutritionistpro.com/

[46]Bjørndal B, Burri L, Wergedahl H, Svardal A, Bohov P, Berge RK. Dietary supplementation of herring roe and milt enhances hepatic fatty acid catabolism in female mice transgenic for hTNFα. Eur J Nutr. 2012 Sep;51(6):741-53

[47]Pacific Plaza Imports Caviar label information. 1) Golden Whitefish Caviar, 2) Black Lumpfish Roe, 3) Black Capelin Roe. www.plazadecaviar.com

[48]Burri L, Hoem N, Banni S, Berge K. Marine omega-3 phospholipids: metabolism and biological activities. Int J Mol Sci. 2012 Nov 21;13(11):15401-19.

[49]Murru E, Banni S, Carta G. Nutritional properties of dietary omega-3-enriched phospholipids. Biomed Res Int. 2013;2013:965417. doi: 10.1155/2013/965417

[50]Ramprasath VR, Eyal I, Zchut S, Jones PJ. Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil. Lipids Health Dis. 2013 Dec 5;12:178. doi: 10.1186/1476-511X-12-178.

[51]Rossmeisl M, Jilkova ZM, Kuda O, et al. Metabolic effects of n-3 PUFA as phospholipids are superior to triglycerides in mice fed a high-fat diet: possible role of endocannabinoids. PLoS One. 2012;7(6):e38834.

[52]Schuchardt JP, Schneider I, Meyer H, Neubronner J, von Schacky C, Hahn A. Incorporation of EPA and DHA into plasma phospholipids in response to different omega-3 fatty acid formulations–a comparative bioavailability study of fish oil vs. krill oil.  Lipids Health Dis. 2011 Aug 22;10:145. doi: 10.1186/1476-511X-10-145.

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[57]Krajhanzl A, Horejsí V, Kocourek J. Studies on lectins. XLII. Isolation, partial characterization and comparison of lectins from the roe of five fish species. Biochim Biophys Acta. 1978 Feb 15;532(2):215-24.

[58]Nosek J, Krajhanzl A, Kocourek J. Studies on lectins. LVII. Immunofluorescence localization of lectins present in fish ovaries. Histochemistry. 1983;79(1):131-9.

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Celtic Sea Salt | The Paleo Diet

Did you look into keltisch seasalt? (sic). I’ve read that it’s full of minerals and has the same balance between minerals and elements as our blood.

Willemieke Bakker on Sea Salt: Between the Devil and the Deep Blue Sea

Dr. Cordain’s Response:

“Celtic” sea salt, most commonly known as Sel gris or gray salt in French is harvested from seawater in the estuaries near the town of Guérande in France. As the tide comes in, seawater is first allowed to settle in clay silt ponds where the combined effects of wind and sun form a dense brine. The brine is then channeled to shallow salt pans dug in the native clay where it crystallizes via solar evaporation to form salt. The clay from the silt as well as from the salt pans impart Sel gris with its characteristic gray color. Sel gris is a coarse salt that is typically harvested with a moisture content of 15%, whereas most sea salts and commercially manufactured salt maintain moisture contents of less than 1%.

I know of no comprehensive, modern analysis of Sel gris, so it is difficult to determine if the harvesting of sea salt from the estuaries near Guérande affects the salt concentrations normally found in seawater. From a chemical perspective, there is no reason to expect that the relative concentrations of the dissolved elements normally found in sea water would be altered, unless the processing of Sel gris adds or subtracts elements. The salts in seawater are stable chemical compounds whose relative percentages are invariant.1, 2 The absolute weights of each of seawater’s dissolved salts will vary depending only upon the amount of moisture that is retained in Sel gris at harvest. Because Sel gris is typically harvested with a 15% moisture content, then the absolute weight of the dissolved salts will be about 85% of their equivalent amount in dry sea salt (<1 % moisture).

In the single account3 I am aware of, the following concentrations of dissolved salts were reported for Sel gris (100 grams):

  1. Sodium 34 grams
  2. Calcium 287 mg
  3. Potassium 109 mg
  4. Magnesium 34 mg
  5. Iron 11 mg,
  6. Manganese 1 mg
  7. Zinc 0.35 mg

Let’s take a look at these values and contrast them to normal dry (no moisture) sea salt or normal sea salt containing 15% moisture which is similar to Sel gris’ moisture content in the table below.

table1

We should first address a few important points:

  1. Does the data reported for Sel gris appear to be accurate?
  2. Is it possible that the addition of clay to sea salt increases its concentration of some minerals?
  3. Is it possible that evaporation of sea salt in clay pans could reduce the relative concentration of normal sea salts?
  4. Is Sel gris healthful and should it be a part of contemporary Paleo Diets?

To answer these questions we first must take a quick look at the minerals normally found in clays.4 Geologists have classified clay minerals into four groups:

  1. Kaolinite
  2. Illite
  3. Smectite
  4. Vermiculite

All clays are rich in iron (Fe) and magnesium (Mg).4 The principal cations in illites are potassium (K), calcium (Ca) and Mg; in smectites they are Ca, sodium (Na), Mg, Fe, Manganese (Mn) and zinc (Zn); in vermiculites the principle cation is Mg, but these compounds also contains significant quantities of Fe and Na. Accordingly, sea salts contaminated with residual clays during harvest might be expected to contain additional amounts of Na, Ca, Mg, Fe, Mn, Zn and/or K.

Indeed, if the reported Sel gris data is accurate, then the spreadsheet above confirms that Sel gris contains nearly 31% more salt (both sodium and chloride) than normal salt derived from sea water – definitely not a good thing health wise! Although some clays contain significant amounts of magnesium and potassium, the data above actually demonstrate Sel gris to maintain lower concentrations of both of these elements than normal sea salt. Regular sea salt represents a physiologically insignificant source of Ca and Fe, whereas the reported values for the reported Sel gris data are considerable higher. Whether these data are accurate or represent measurement errors is unknown. Although consumption of 100 grams of Sel gris delivers moderate quantities of Ca (287 mg) and Fe (11 mg), it does so at a terrible nutritional cost in terms of salt ingestion.   100 grams of Sel gris using reported data translates to 34 grams or 3400 mg of sodium. The United States Centers for Disease Control (CDC) recommends that we limit our sodium consumption to no more than 2300 mg per day.5

On paper, it may appear that Sel gris may be slightly more nutrient dense for a selected few mineral than normal sea salt, but the bottom line is that Sel gris, sea salt and common table salt all have undesirably high concentrations of NaCl (salt) which promote hypertension, osteoporosis, kidney stones, Menierre’s Syndrome (ear ringing), insomnia, motion sickness, asthma, and a variety of cancers.

Salt be it in the form of Sel gris, sea salt or plain commercial salt is definitely not Paleo.

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

References

1. Castro P, Huber M. Marine Biology, McGraw-Hill, 9th Ed., New York, NY, 2012.

2. Baseggio G. 1974. The composition of seawater and its concentrates. Proc. 4th Int. Symp. Salt Vol. 2, pp. 351-358. Northern Ohio Geological Society, Inc., Cleveland, OH.

3. Bitterman, M. Salted: A Manifesto On The World’s Most Essential Mineral With Recipes. Ten Speed Press, New York, 2010.

4. http://earth.usc.edu/~dfarris/Mineralogy/17_ClayMinerals.pdf

5. Centers for Disease Control and Prevention (CDC). Vital signs: food categories contributing the most to sodium consumption – United States, 2007 – 2008, February 7, 2012.

Sea Salt | The Paleo Diet

One of the most gratifying rewards of having written The Paleo Diet in 2002 and having been involved in the Paleo movement from its very beginnings is that I receive numerous queries about various nutritional aspects of this lifelong way of eating. Clearly, I nor anyone else, have an inside track to all dietary questions that may arise about contemporary Paleo diets. However, I am happy to share with you the information I have compiled over more than 25 years of my research into this fascinating topic.

As the Paleo Diet gains traction and notoriety worldwide, it seems that part of the original idea has become partially diluted as more and more people discover and write about this lifetime nutritional program. I am flattered by the huge number of Paleo books and cookbooks released to market and available for purchase on Amazon, Barnes & Noble, and other outlets. These books and authors are a testament to the worldwide success and effectiveness of The Paleo Diet.

Unfortunaely, as I browse Paleo cookbooks and magazine recipes, I see that many authors have decided to add sea salt to their recipes, presumably in lieu of regular salt. Before I get into the scientific details let me make it clear from the beginning that neither sea salt nor conventional manufactured salt should be considered “Paleo,” as both were rarely or never consumed by our hunter gatherer ancestors, and both maintain nutritional qualities that adversely affect our health when consumed regularly.1

Sea salt contains high concentrations of sodium chloride (NaCl), just like manufactured salt. Sea salt is nothing more than evaporated sea water and can be mined from naturally occurring beds of rock salt or manufactured by solar evaporation of sea water. The salinity (concentration of all dissolved salts) in sea water is usually 35 parts per thousand (35 0/00), but varies somewhat in various oceans.

Salinity of Seawater | The Paleo Diet

The salinity of sea water near the mouth of a large fresh water river, like The Amazon, is lower, but the percentages of all salts in all sea water remains constant.2, 3
 

Salt Dissolved | The Paleo Diet

Dissolved Salts | The Paleo Diet

You can see from the Table 1 and Figure 2 that sea salt contains high concentrations of salt (NaCl) amounting to 85.62% of all the dissolved salts. Now let’s contrast sea salt to commercially manufactured table salt. Table Salt is refined sea salt, rock salt or lake salt in which almost all impurities are removed leaving pure NaCl. Most table salt is produced using vacuum pan refining and is typically 99.8 to 99.95 pure NaCl.4 Under US law, 2% of salt by weight can include the following additives:

1. Anti-caking agents (typically calcium silicate) are added to table salt.
2. Frequently iodine (a mineral that prevents goiter) is added to table salt in the form of potassium iodide (0.006% to 0.01%).
3. Along with stabilizers (sodium bicarbonate, sodium thiosulfate or dextrose) to prevent degradation of the iodine.

There is absolutely no doubt that the average American consumes excessive amounts of salt which in turn may adversely affect health and well being.1

Total Salt | The Paleo Diet

Sources of Salt | The Paleo Diet

From Table 2 and Figure 3, you can see that far and away, processed foods are the highest contributor (77%) of salt to the American diet. Because processed foods generally are not part of the contemporary Paleo Diet, you will not have to worry about salt – that is unless you add sea salt to your Paleo menu and Paleo recipes. And if you do so, you can see that the salt (NaCl) concentration of sea salt (85.62%) is not much better than manufactured salt (99.8%).

In Table 3, I have presented the top 10 food sources of salt in the U.S. Diet.5 Note that almost all of these high salt foods are not part of The Paleo Diet. If you decide to prepare your Paleo meals or recipes with sea salt, you will be changing a once healthful, low-salt Paleo diet with to high salt diet. The choice is yours, but know that sea salt is not healthier than conventional salt and in fact, may be worse.

Top 10 Salt Sources | The Paleo Diet

On paper, it appears that sea salt is more nutrient dense than table salt and may be nutritionally superior? Unfortunately both salts have undesirably high concentrations of salt (NaCl) as I have pointed out. Animal studies show sea salt to increase hypertension (high blood pressure) compared to table salt.6, 7

Many people including physicians and nutritionists assume that salt’s (NaCl) detrimental health effects occur only from the sodium ion (Na) contained within salt. Yet human experimental studies show the chloride anion is also responsible.8, 9 Chloride (Cl) yields a net acid load to kidney producing a slight metabolic acidosis that promotes high blood pressure, osteoporosis and kidney stones. These diseases along with stomach cancer and stroke are also associated with high salt consumption. Other less well recognized chronic illnesses known to be caused by a high salt diet include: Menierre’s Syndrome (Ear ringing), insomnia, motion sickness, asthma and exercise induced asthma.

Finally, an obscure fact in medical literature is dietary salt loading in even healthy subjects has been shown via MRI to:

  • Increase intracellular Sodium (Na)
  • Reduce intracellular Potassium (K)
  • Increase intracellular Calcium (Ca)
  • Decrease intracellular Magnesium (Mg) and reduce intracellular ph (increases acidity)10

All of these intracellular ionic changes are known to be associated with or promoters of a variety of cancers.11-13

Salt is definitely not Paleo, and neither is sea salt.

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

 

References

1. Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr. 2005 Feb;81(2):341-54
2. Castro P, Huber M. Marine Biology, McGraw-Hill, 9th Ed., New York, NY, 2012.
3. Baseggio G. 1974. The composition of seawater and its concentrates. Proc. 4th Int. Symp. Salt Vol. 2, pp. 351-358. Northern Ohio Geological Society, Inc., Cleveland, OH.
4. Kurlansky M. Salt, A World History. Penguin Books, NY, NY, 2002.
5. Centers for Disease Control and Prevention (CDC). Vital signs: food categories contributing the most to sodium consumption – United States, 2007 – 2008, February 7, 2012.
6. Dahl LK, Heine M. The enhanced hypertensogenic effect of sea salt over sodium chloride. Am J Cardiol. 1961 Nov;8:726-31
7. Dahl LK, Heine M. Effects of chronic excess salt feeding. Enhanced hypertensogenic effect of sea salt over sodium chloride. J Exp Med. 1961;113:1067-76
8. Kurtz I et al. Effect of diet on plasma acid-base composition in normal humans. Kidney Int 1983;24:670-80
9. Boegehold MA, Kotchen TA. Importance of dietary chloride for salt sensitivity of blood pressure. Hypertension. 1991 Jan;17(1 Suppl):I158-61.
10. Resnick et al. Intracellular ionic consequences of dietary salt loading in essential hypertension. J Clin Invest 1994;94:1269-76
11. Jansson B. Geographic cancer risk and intracellular potassium/sodium ratios. Cancer Detection and Prevention 1986; 9:171-94
12. Lee AH, Tannock IF. Heterogeneity of intracellular pH and of mechanisms that regulate intracellular pH in populations of cultured cells. Cancer Res. 1998 May 1;58(9):1901-8.
13. Mijatovic T et al. Cardiotonic steroids on the road to anti-cancer therapy. Biochim Biophys Acta. 2007 Sep;1776(1):32-57.

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