Tag Archives: olive oil

Introduction

The olive tree (Olea europaea) is native to the Mediterranean basin and is cultivated in many other parts of the world.  The fruit of the olive tree is a drupe (a stone fruit) in which a hard inner seed is surrounded by a fleshy outer portion.  The olive has a low sugar content (2.6 – 6%) compared with other drupes (apricots, peaches, plum etc., which may contain 12% or more sugar).  Olives maintain a high oil content (12 – 30%) depending on the time of year and variety of olive harvested (1).  The olive fruit generally cannot be consumed directly from the tree because it contains a strong bitter component, oleuropein, which can be removed or lessened in concentrations by a series of processing techniques that vary considerably from region to region, but almost always involve treating the olives in brine or salt water.  Depending on local methods and customs, the fruit is first generally treated in sodium or potassium hydroxide (lye).  The olives are put into brine solutions and then rinsed in water.

Table olives are classified by the International Olive Council (IOC) into three groups according to the degree of ripeness achieved before harvesting (1):  

  1. Green olives are picked when they have obtained full size, but before the ripening cycle has begun; they are usually shades of green to yellow.
  2. Semi-ripe or turning-color olives are picked at the beginning of the ripening cycle, when the color has begun to change from green to multicolor shades of red to brown. Only the skin is colorful, as the flesh of the fruit lacks pigmentation at this stage, unlike that of ripe olives.
  3. Black olives or ripe olives are picked at full maturity when fully ripe. They are found in assorted shades of purple to brown to black. 

Green Olives

Green olives are processed in two principal ways: with fermentation (Spanish or Sevillian Type) and without fermentation (Picholine or American Type) (1).  

Spanish or Sevillian Type
The olives are treated in diluted lye solutions (sodium hydroxide or potassium hydroxide) to eliminate the oleuropein and transform sugars into form organic acids that aid in subsequent fermentation, and to also increase the permeability of the fruit. The lye concentrations vary from 2% to 3.5%, depending on the ripeness of the olives, the temperature, the variety, and the quality of the water. The olives remain in this solution until the lye has penetrated two thirds of the way through the flesh. The lye is then replaced by water, which removes any remaining residue, and the process is repeated, eliminating the oleuropein but keeping sufficient sugars which are necessary for subsequent fermentation.

Fermentation is carried out in inert containers in which the olives are covered with brine. The brine causes the release of the fruit cell juices, forming a culture medium suitable for fermentation. Brine concentrations are 9 – 10% to begin with, but rapidly drop to 5% because of the olive’s content of interchangeable water.

At first the contaminating Gram-negative bacteria multiply, but after a week and a half they disappear.  At a pH of 6 and upwards, lactobacilli develop until the Gram-negative bacteria disappear, and the brine attains a pH of 4.5. The lactobacilli produce lactic acid from the olive’s glucose, and when the fermentable sugars are spent, fermentation stops.

When properly fermented, olives keep for lengthy periods. The original brine is replaced and the olives are packed in barrels, tin or glass containers. Sometimes they are pitted or stuffed with anchovies, pimento, nuts and other food items. The most commonly consumed Spanish varieties are Manzanillo, Gordal and Moroccan Picholine (1).

Picholine Type
Olives belonging to the Picholine variety from Languedoc and Lucques in southern France are prepared in this manner, as are other varieties from Morocco and Algeria (1).  The bitter tasting oleuropein of the olives is removed by treating them in a 3 – 3.5 % lye solution (sodium or potassium hydroxide) until the lye has penetrated three-quarters of the way through the flesh. They are rinsed several times over the next day or two, and then placed into a 5 to 6% brine solution for two days. A second 7% brine solution is prepared, and acidity is corrected with citric acid (pH 4.5). After 8-10 days they are ready to be eaten and retain their intense green color. Before shipment, the olives are washed repeatedly, sorted, and packed in suitable containers in 5 to 6 % brine solutions (1).

 

Semi-Ripe Olives

Semi-ripe olives are harvested when their color is starting to change. They are picked before full maturity, when the flesh is quite firm and oil formation has not concluded.  Olives suitable for processing as green olives are selected as they enter the factory, then placed into brine at concentrations between 2.5 and 10 percent depending upon fruit size (1).

The olives are placed in large concrete tanks containing a 2 percent lye solution. When the olives are prepared for the market, they are placed in low-concentration lye and then washed in water that is injected with compressed air. Further treatments in dilute lye, each followed by aeration in water, facilitate penetration of the lye through the flesh to the pit. Next, the olives are washed to eliminate lye residue and lower the pH close to neutral. Solutions of 0.1 percent ferrous gluconate or lactate are often applied to California dark olives to enhance fruit darkening by oxidation.  After placement in brine for a few days, the olives are ready for canning. Heat processing in the form of temperature and pressure-controlled sterilization is fundamental to ensure the olives keep properly (1).

 

Ripe Olives

Ripe olives are harvested when the fruit is close to full ripeness, once it has attained the maximal color and oil content corresponding to the particular variety. The are many types of ripe olive processing techniques depending on local tastes.  Two of these are outlined below.

Black Olives in Brine
These olives are typical of eastern Mediterranean countries.  In Greece they are produced from the Conservolea variety, and in Turkey they are made from the Gemlik variety. The fruit is picked by hand when the fruit is black ripe, but before the olives over ripen. They have to be transported as quickly as possible to the processing plant where they are sorted, washed and immersed into tanks and vats containing an 8-10 % brine solution. At the start of fermentation, the tanks are tightly sealed to prevent the olives from being exposed to air. The brine stimulates the microbial activity for fermentation and also reduces the bitterness of the oleuropein. As the fermentation process takes over, if the brine solution drops below 6 %, it is increased back to 8-10% while homogenizing the brine solution with a pump.   

When the bitterness of the oleuropein has been sufficiently weakened, the fruit is sold. The olives’ color may fade during brining, but is later corrected by aerating the olives and by treating them with 0.1 percent ferrous gluconate or lactate to increase oxidation to make them a deeper black. Lastly, the olives are selected and packed into barrels, cans or jars which are filled with 8 percent brine. Theses olives are popular because of their slightly bitter taste and aroma.

They may also be packed in vinegar (25 percent of the brine volume); be heat processed and a little oil are then added to form a surface layer. The Kalamata olive variety from Greece is prepared in this way.

Black Olives in Dry Salt
Black olives in dry salt are also of Greek origin, and they are prepared using overripe olives of the Megaritiki variety. They are washed and placed in baskets with alternating layers of dry salt equivalent to 15 percent of the weight of the olives. The end product is not bitter, but salty, and it looks like a raisin.

 

Why Olives Are Not Paleo, But Olive Oil Is

From the information the International Olive Council has provided above (1), you can easily see that extensive processing is required to remove the bitter compound (oleuropein) from raw, fresh olives.  To make fresh olives edible requires massive additions of salt at nearly every stage of processing.   

Table 1 shows the high sodium (Na+) and low potassium (K+) content of processed olives.  A 500 kcal serving of green olives would supply you with 5,365 mg of Na+, whereas the same serving of jumbo black olives would give you 4,537 mg of Na+, and a 500 kcal serving of black olives would provide 3,196 mg of Na+.  The recommended daily intake of Na+ is 2300 mg for adult men and women (3-6).  Accordingly, even modest consumption of olives gives you way too much Na+ and not enough K+.

Table 1. Na+ and K+ content of olives (drupes) and olive oil (2)

Olives

Na+ mg/

1000 kcal

K+ mg/

1000 kcal

K+/Na+  

(mg/mg)

Green Olives

10731

290

0.027

Jumbo Black olives

9074

111

0.012

Black Olives

6391

70

0.011

Olive Oil

2.26

1.13

0.500

 

Now contrast the Na+ concentrations in a comparable 1000 kcal serving of olive oil to that found in whole olives.   A 1000 kcal serving of olive oil only contains 2.26 mg of Na+, or 4,748 times less Na+ than found in a 1000 kcal serving of green olives.

As I mentioned earlier, olives are member of the stone fruit (drupe) family.  Table 2 compares the Na+ and K+ concentrations of fresh drupes to processed olives.  Note that fresh drupes contain very low concentrations of Na+, comparable to olive oil, but additionally they  contain high concentrations of the health promoting ion K+.  A high K+/Na+ ratio is a universal characteristic of both wild and domesticated plant foods (7), and K+ is typically 5-10 times higher than Na+ in hunter gatherer diets (7-11).

Table 2. Na+ and K+ content of other drupes (stone fruit), including apricots, peaches, plums and nectarines (2)

  Drupes (stone fruits)

Na+ (mg)/

1000 kcal

K+ (mg)/

1000 kcal

K+/Na+ (mg/mg)

Apricot

21

5396

259.00

Nectarine

2

4568

2849.20

Peach

2

4872

2850.00

Plum

1

3413

2591.50

 

It is obvious that all olives contain much more Na+ than K+ (on average 18.5 times more Na+ than K+) compared to unadulterated, non-salted olive oil.  Clearly, the K+/Na+ ratios in processed olives lie far beyond the evolutionary normative values which conditioned our species’ genome (8-16).  Accordingly, it is not surprising that randomized controlled trials of salt consumption in humans as well as epidemiological studies (17-24) support the notion that added salt (be it sea salt or refined salt) from olives or any other processed food promotes cardiovascular disease, cancer, autoimmunity, chronic inflammation, immune system dysfunction, and ill health (17-51).

References

1.”About Olives”. International Olive Council. Retrieved September 5, 2017.  http://www.internationaloliveoil.org/estaticos/view/77-about-olives
2.Axxya systems. Nutritionist Pro. http://www.nutritionistpro.com/
3.Centers for Disease Control and Prevention (CDC). Vital signs: food categories contributing the most to sodium consumption – United States, 2007-2008. MMWR Morb Mortal Wkly Rep. 2012 Feb 10;61(5):92-8.
4.McDonough AA, Veiras LC, Guevara CA, Ralph DL. Cardiovascular benefits associated with higher dietary K+ vs. lower dietary Na+: evidence from population and mechanistic studies. Am J Physiol Endocrinol Metab. 2017 Apr 1;312(4): E348-E356.
5.Mozaffarian D, Fahimi S, Singh GM, Micha R, Khatibzadeh S, Engell RE, Lim S, Danaei G, Ezzati M, Powles J, et al.  Global burden of diseases nutrition and chronic diseases expert group.
Global sodium consumption and death from cardiovascular causes. N Engl J Med. 2014 Aug 14;371(7):624-34
6.He FJ, Li J, Macgregor GA. Effect of longer-term modest salt reduction on blood pressure. Cochrane Database Syst Rev. 2013 Apr 30;(4):CD004937
7.http://thepaleodiet.com/further-evidence-against-a-high-sodium-paleo-diet/
8.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;81:341-54
9.Jansson B. Human diet before modern times.   In: Sodium: “No!” Potassium: “Yes!”. Sodium increases and potassium decreases cancer risk.  Unpublished book manuscript, 1997, Chapter 2 pp. 1-20.
10.Frassetto L, 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.
11.Sebastian A, Frassetto LA, Sellmeyer DE, Morris RC Jr. The evolution-informed optimal dietary potassium intake of human beings greatly exceeds current and recommended intakes. Semin Nephrol. 2006 Nov;26(6):447-53
12.Gleibermann L. Blood pressure and dietary salt in human populations. Ecol Food Nutr 1973;2:143-56
13.Dahl L. Possible role of salt intake in the development of hypertension. In: Cottier P. Bock KD eds. Essential hypertension: an international symposiu. Berlin: Springer-Verlag. 1960:53-65.
14.Froment A. Milon H, Gravier C. Relationship of sodium intake and arterial hypertension. Contribution of geographical epidemiology. Rev Epidemiol Sante Publique 1979;27:437-54.
15.Shaper AG. Communities without hypertension. In: Shaper AG, Hutt MSR, Fejfar Z eds. Cardiovascular disease in the tropics. London: British Medical Association. 1974:77-83.
16.Denton D. The hunger for salt: an anthropological, physiological and medical analysis. Chapter 27, Salt intake and high blood pressure in man. Primitive peoples, unacculturated societies: with some comparisons. Berlin: SpringVerlag, 1982, 556-578.
17.O’Donnell M1, Mente A, Rangarajan S et al. Urinary sodium and potassium excretion, mortality, and cardiovascular events. N Engl J Med. 2014 Aug 14;371(7):612-23.
18.Oberleithner H, Callies C, Kusche-Vihrog K, Schillers H, Shahin V, Riethmüller C, Macgregor GA, de Wardener HE. Potassium softens vascular endothelium and increases nitric oxide release. Proc Natl Acad Sci U S A. 2009 Feb 24;106(8):2829-34
19.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.
20.McDonough AA, Veiras LC, Guevara CA, Ralph DL. Cardiovascular benefits associated with higher dietary K<sup>+</sup> vs. lower dietary Na<sup>+</sup>: evidence from population and mechanistic studies. Am J Physiol Endocrinol Metab. 2017 Apr 1;312(4):E348-E356.
21.McDonough AA, Youn JH. Potassium Homeostasis: The Knowns, the Unknowns, and the Health Benefits. Physiology (Bethesda). 2017 Mar;32(2):100-111
22.Du S, Batis C, Wang H, Zhang B, Zhang J, Popkin BM. Understanding the patterns and trends of sodium intake, potassium intake, and sodium to potassium ratio and their effect on hypertension in China. Am J Clin Nutr. 2014 Feb;99(2):334-43.
23.Drewnowski A, Maillot M, Rehm C. Reducing the sodium-potassium ratio in the US diet: a challenge for public health. Am J Clin Nutr. 2012 Aug;96(2):439-44.
24.Fang Y, Mu JJ, He LC, Wang SC, Liu ZQ. Salt loading on plasma asymmetrical dimethylarginine and the protective role of potassium supplement in normotensive salt-sensitive asians. Hypertension. 2006 Oct;48(4):724-9
25.Jantsch J, Schatz V, Friedrich D et al. Cutaneous Na+ storage strengthens the antimicrobial barrier function of the skin and boosts macrophage-driven host defense. Cell Metab. 2015 Mar 3;21(3):493-501.
26.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
27.Hucke S, Eschborn M, Liebmann M, Herold M, Freise N, Engbers A, Ehling P, Meuth SG, Roth J, Kuhlmann T, Wiendl H, Klotz L. Sodium chloride promotes pro-inflammatory macrophage polarization thereby aggravating CNS autoimmunity. J Autoimmun. 2016 Feb;67:90-101.
28.Zostawa J, Adamczyk J, Sowa P, Adamczyk-Sowa M. The influence of sodium on pathophysiology of multiple sclerosis. Neurol Sci. 2017 Mar;38(3):389-398.
29.Dmitrieva NI, Burg MB. Elevated sodium and dehydration stimulate inflammatory signaling in endothelial cells and promote atherosclerosis. PLoS One. 2015 Jun 4;10(6): e0128870. doi: 10.1371/journal.pone.0128870.
30.Schatz V, Neubert P, Schröder A, Binger K, Gebhard M, Müller DN, Luft FC, Titze J, Jantsch J. Elementary immunology: Na+ as a regulator of immunity. Pediatr Nephrol. 2017 Feb;32(2):201-210.
31.Hernandez AL, Kitz A, Wu C, Lowther DE, Rodriguez DM, Vudattu N, Deng S, Herold KC, Kuchroo VK, Kleinewietfeld M, Hafler DA. Sodium chloride inhibits the suppressive function of FOXP3+ regulatory T cells. J Clin Invest. 2015 Nov 2;125(11):4212-22.
32.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.
33.Zhou X, 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.
34.Zhou X, Yuan F, Ji WJ, Guo ZZ, Zhang L, Lu RY, Liu X, Liu HM, Zhang WC, Jiang TM, Zhang Z, Li YM. High-salt intake induced visceral adipose tissue hypoxia and its association with circulating monocyte subsets in humans. Obesity (Silver Spring). 2014 Jun;22(6):1470-6.
35.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.
36.Kostyk AG, Dahl KM, Wynes MW, Whittaker LA, Weiss DJ, Loi R, Riches DW. Regulation of chemokine expression by NaCl occurs independently of cystic fibrosis transmembrane conductance regulator in macrophages. Am J Pathol. 2006 Jul;169(1):12-20.
37.Lang KS, Fillon S, Schneider D, Rammensee HG, Lang F. Stimulation of TNF alpha expression by hyperosmotic stress. Pflugers Arch. 2002 Mar;443(5-6):798-803.
38.Ip WK, Medzhitov R. Macrophages monitor tissue osmolarity and induce inflammatory response through NLRP3 and NLRC4 inflammasome activation. Nat Commun. 2015 May 11;6:6931.
39.Foss JD, Kirabo A, Harrison DG. Do high-salt microenvironments drive hypertensive inflammation? Am J Physiol Regul Integr Comp Physiol. 2017 Jan 1;312(1):R1-R4
40.Binger KJ, Gebhardt M, Heinig M et al. High salt reduces the activation of IL-4- and IL-13-stimulated macrophages. J Clin Invest. 2015 Nov 2;125(11):4223-38
41.Min B, Fairchild RL. Over-salting ruins the balance of the immune menu.  J Clin Invest. 2015 Nov 2;125(11):4002-4.
42.Amara S, Tiriveedhi V. Inflammatory role of high salt level in tumor microenvironment (Review).  Int J Oncol. 2017 May;50(5):1477-1481
43.Amara S, Alotaibi D, Tiriveedhi V. NFAT5/STAT3 interaction mediates synergism of high salt with IL-17 towards induction of VEGF-A expression in breast cancer cells. Oncol Lett. 2016 Aug;12(2):933-943
44.Amara S, Zheng M, Tiriveedhi V. Oleanolic acid inhibits high salt-induced exaggeration of warburg-like metabolism in breast cancer cells. Cell Biochem Biophys. 2016 Sep;74(3):427-34.
45.Amara S, Whalen M, Tiriveedhi V. High salt induces anti-inflammatory MΦ2-like phenotype in peripheral macrophages. Biochem Biophys Rep. 2016 Sep;7:1-9
46.Amara S, Ivy MT, Myles EL, Tiriveedhi V. Sodium channel γENaC mediates IL-17 synergized high salt induced inflammatory stress in breast cancer cells. Cell Immunol. 2016 Apr; 302:1-10
47.Davies RJ, Sandle GI, Thompson SM. Inhibition of the Na+,K(+)-ATPase pump during induction of experimental colon cancer. Cancer Biochem Biophys. 1991 Aug;12(2):81-94.
48.Thompson, Davies RJ.  A high potassium diet prevents transepithelial depolarization in experimental colon cancer. In: Vitamins and Minerals in the Prevention and Treatment of Cancer, (Maryce M. Jacobs, Ed.), CRC Press, Boston, 1991, p 263.
49.Fine BP, Hansen KA, Walters TR, Denny TN.  Dietary sodium deprivation inhibits cellular proliferation: evidence for circulating factor(s). In: Vitamins and Minerals in the Prevention and Treatment of Cancer, (Maryce M. Jacobs, Ed.), CRC Press, Boston, 1991, p 276.
50.Fine BP, Ponzio NM, Denny TN, Maher E, Walters TR. Restriction of tumor growth in mice by sodium-deficient diet. Cancer Res. 1988 Jun 15;48(12):3445-8.
51.Davies RJ, Daly JM. Potassium depletion and malignant transformation of villous adenomas of the colon and rectum. Cancer. 1984 Mar 15;53(6):1260-4.

 

Vitamin E | The Paleo Diet

Symptoms of vitamin E deficiency are rare, but according to at least four national surveys, most Americans consume less than the government’s Recommended Daily Allowance (RDA) of this essential nutrient.1 The authors of an August 2015 study published in PLOS-One call vitamin E a “shortfall nutrient” because over 90% of Americans consume insufficient quantities and because low vitamin E status has been linked to multiple health consequences, including increased total mortality.2

Vitamin E is clearly important, but can the Paleo diet provide adequate levels? After all, some of the most frequently cited “best dietary sources” aren’t Paleo compliant. Are supplements necessary? The RDA for males and females above 14 years of age is 15 mg daily. The following table shows vitamin E values for 100 grams of various foods and their corresponding RDAs.

Vitamin E

The foods highest in vitamin E are predominantly seeds/nuts and their oils. Seed oils are excluded from the Paleo diet, however, primarily because they contain excessive amounts of polyunsaturated fatty acids (PUFAs). Almonds, hazelnuts, and sunflower seeds are good Paleo vitamin E sources. Fruits and vegetables are also good, but they contain very low amounts. Those small amounts accumulate, however, so collectively they are indeed significant.

Probably the best Paleo vitamin E source is olive oil. One tablespoon packs 1.9 mg, which is 10% of the RDA. You can add a few tablespoons of olive oil on salads or cooked vegetables, or use it for cooking. Olive oil becomes even more attractive when you consider its relatively low levels of PUFAs.

We should note that vitamin E functions primarily as an antioxidant, which means it protects against cellular damage by scavenging for free radicals. PUFAs have a high propensity to oxidize and oxidation creates free radicals. Therefore, high levels of PUFAs can negate vitamin E’s benefits. If we refer back to our chart, we see that many foods rich in vitamin E are also PUFA-rich.

Back in 1988, Brazilian scientists theorized that total vitamin E content is not the best indicator of vitamin E activity for vegetable oils. Using high-pressure liquid chromatography, they analyzed various oils for vitamin E activity and determined that high PUFA content offsets vitamin E activity and that oil refinement causes vitamin E losses upwards of 22%, especially during steam deodorization.3 They proposed that for vitamin E, unrefined oils beat their refined counterparts and that the ratio of vitamin E to PUFA better indicates vitamin E potential compared to absolute vitamin E levels.

A British Journal of Nutrition study published this month (October 2015) reiterates the same point: “The vitamin E requirement will increase with an increase in PUFA consumption and with the degree of unsaturation of the PUFA in the diet.”4 Another just-published study is also raising interest about vitamin E, particularly for its conclusion that those who have metabolic syndrome (about one-third of the US population) don’t absorb vitamin E as effectively as those who are healthy.5 Lead author of this latter study, Richard Bruno, commented, “Dietary requirements of nutrients are generally defined only in the context of what a healthy person needs, but considering that two-thirds of Americans are overweight or obese, a healthy person might not be representative of our society. This work tells us that at least one-third of Americans have higher vitamin E requirements than healthy people.”6

With all this in mind, one might conclude that supplementation is the best way to maintain adequate vitamin E levels. In the 1980s, scientists began to understand how free radicals contribute to atherosclerosis, cancer, vision loss, and various other chronic conditions. This sparked interest in the preventative potential of antioxidant supplements, particularly vitamin E. Several observational studies, including the Nurses’ Health Study, suggested 20 – 40% reductions in heart disease risk among people taking vitamin E supplements.7

Follow-up randomized controlled trials, however, dampened enthusiasm for vitamin E supplements, both for heart disease and cancer prevention. One meta-analysis even concluded that high-dose vitamin E supplementation may increase all-cause mortality and should be avoided.8 For those who are interested, the Harvard School of Public Health has an excellent summary on the history of research on vitamin E supplementation.

In conclusion, supplementation may provide benefits for certain conditions, but food sources of vitamin E are widely considered to be superior. Many of the richest food sources, however, are high-PUFA seed oils. High levels of PUFAs counteract vitamin E’s antioxidant capacity. It’s best to eliminate vegetable seed oils from your diet. The Paleo Diet provides plenty of vitamin E via olive oil, small quantities of seeds and nuts, and large amounts of vegetables.

References

1. National Institutes of Health, Office of Dietary Supplements. (June 2013). Vitamin E Fact Sheet for Health Professionals.

2. McBurney, M., et al. (August 19, 2015). Suboptimal Serum α-Tocopherol Concentrations Observed among Younger Adults and Those Depending Exclusively upon Food Sources, NHANES 2003-2006. PLOS-One.

3. Desai, D., et al. (June 1988). Vitamin E content of crude and refined vegetable oils in Southern Brazil. The Journal of Food Composition and Analysis, 1(3).

4. Raederstorff, D., et al. (October 2015). Vitamin E function and requirements in relation to PUFA. British Journal of Nutrition, 114(8).

5. Mah, E., et al. (October 7, 2015). α-Tocopherol bioavailability is lower in adults with metabolic syndrome regardless of dairy fat co-ingestion: a randomized, double-blind, crossover trial. American Journal of Clinical Nutrition [epub ahead of print].

6. Caldwell, E. (October 7, 2015). Metabolic syndrome leads 1 in 3 Americans to need more vitamin E. Ohio State University (Press Release).

7. Institute of Medicine. (2000). Dietary reference intakes for vitamin C, vitamin E, selenium, and carotenoids. National Academies Press.

8. Miller, ER., et al. (January 4, 2005). Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Annals of Internal Medicine, 142(1).

Olive Oil | The Paleo Diet

Dr. Cordain,

First of all, I can’t thank you enough for The Paleo Diet you wrote. I must have “sold” your book and made like 30+ people buy it. Inspired by your book, I not only helped change my life and that of my girlfriend, but also saved my mother’s life whose liver function was deteriorating through requesting that she goes off most ridiculous medications and shift to a Paleo diet.

Further, inspired by your book my girlfriend (Japanese and I) started a company in the center of anti-paleo culture – Japan, a highly civilized country that is rich in processed rice, noodles, extreme amounts of legumes and soy, and extreme amounts of salt and processed food.  She transitioned her existing beauty salon business into the first in Japan true Paleo based nutrition health company. we researched all over Japan and minor stuff that calls itself Paleo here is for instance advocating dairy and beans.

I developed love and passion for people of Japan. They’re extremely polite, clean, educated, and hospitable people. We simply want to spread love and education to the people of Japan, not make gazillion dollars, and thanks to your book.  For instance, I can see now why Asian, and Japanese people in particular are so extremely skinny and not in a good way, ie guys have no muscle mass and mostly much shorter than an average European guy. Much equipment TOP weight in a gym where I work out is typically my warm-up weight in US and I’m by no means a very strong man.

Advancement of our Paleo based nutrition business in Japan can revolutionize this country of over 120 million people, and through it, all of Asia. it’s based in Osaka. JP.

In our further studies we developed a couple of questions that perhaps you can help with.

One is that you mention Lectins in the book as part of bad stuff in legumes.  however i discovered that lectins are richly found in many fruits and vegetables, such as tomatoes or cucumbers for instance.  if its bad in legumes wouldn’t it be also important to research the levels of lectins in other foods supported by Paleo?

Another is the matter of cooking with olive oil.  my understanding is that Omega 3 is easily oxidized substance. that is Olive oil for instance, when broken down at high temperatures can actually become a poisonous broken down cancerogenic substance and no longer have much value of Omega 3 when fried.  is that not the case?  that’s why lots of Omega 3 manufacturers pride themselves in “cold pressed” stuff for instance.

If you plan on writing an updated version of your book in the future, I’d like to volunteer as your “research slave” to help you with any future writing for free. You cannot imagine how many lives you’ve changed or saved with your book. The implementation of your book on real group of people in Japan who are our existing clients can be also used as an amazing research material of impact of Paleo on otherwise “skinny” people. In US we equate skinny with healthy because we’re so fat. but here, many issues arise such as impact to skin quality and beauty, mental health, horrible teeth, diabetes, stomach cancer, high stress and lack of energy, just to name a few, strokes, high cholesterol.

I’d be happy to work with you to supply you all and any research outcomes. we even have doctors lined up in Tokyo and Osaka who can perform pre and post blood tests and other analysis to monitor impact of Paleo on their overall health.

Thank you!

James

Dr. Cordain’s Response:

Hi James,

Many thanks for your wonderful personal story, and for promoting “Paleo” in Japan.  Let me answer your questions:

“One is that you mention Lectins in the book as part of bad stuff in legumes.  however i discovered that lectins are richly found in many fruits and vegetables, such as tomatoes or cucumbers for instance.  if its bad in legumes wouldn’t it be also important to research the levels of lectins in other foods supported by Paleo?”

Indeed, lectins are nearly ubiquitous in almost all plant foods, but unless they can bind gut tissue or get into the bloodstream, they generally have few adverse health effects.  Lectins have been poorly studied in humans, particularly from actual in vivo (in the living body) experiments, so we really don’t know their precise effects, but must rely upon data from animal and tissue (in vitro) studies.  If legumes or beans have been pressured cooked (as have most commercially available canned legumes) then the lectin content is typically low or absent.  Nevertheless, even canned legumes/beans contain other antinutrients which may have adverse health effects such as saponins, protease inhibitors, and others that I have detailed in my new book, The Paleo Answer.

“Another is the matter of cooking with olive oil.  my understanding is that Omega 3 is easily oxidized substance. that is Olive oil for instance, when broken down at high temperatures can actually become a poisonous broken down cancerogenic substance and no longer have much value of Omega 3 when fried.  is that not the case?  that’s why lots of Omega 3 manufacturers pride themselves in “cold pressed” stuff for instance.”.

Actually, olive oil contains virtually no omega three fatty acids (alpha linolenic acid, or 18:3n3), and the predominant fatty is oleic acid (18:1n9), a monounsaturated fatty acid.  For the fatty acid composition of all vegetable oils, see my website: http://thepaleodiet.com/vegetable-oil-fatty-acid-composition/.  The fewer the number of double bonds, the less likely is an oil to break down at high temperatures and yield toxic compound.  Because olive oil contains a single double bond (i.e. is monounsaturated) it is fairly stable under most cooking conditions.  All oils will breakdown under high and long enough heat.  Hence, if you cook with olive oil try to keep the heat low and limit the cooking time.

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

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