Tag Archives: fatty acids

FOOD-official-meatFor over a decade now, a debate has been raging within the nutrition science community. One side views saturated fat as generally unhealthy; they recommend replacing these fats, at least to some degree, with omega-6 polyunsaturated fats. The other side views saturated fat as health-supportive, or at least health-neutral; likewise, they regard omega-6 as somewhat unhealthy and typically recommend decreasing its consumption. So, who has it right? The truth seems to be grey and somewhere in between.

 

The Modern Diet

Americans have largely followed the US government’s dietary advice for the past 40 years. For example, following official dietary advice in the 80s to reduce fat in our diets, we decreased our fat consumption from 45 to 34% of calories, on average, while increasing our carbohydrate consumption from 39 to 51% of calories [i].

We made these changes because doing so – or so we were told – would decrease cardiovascular disease (CVD), which was and still remains the number one cause of death in the western world.

However, there are also different types of fats (see Figure 1) and both international and US government guidelines have made recommendations about the types of fats we should consume. Current recommendations suggest reducing saturated fat to a maximum of 10% of total calories while increasing omega-6 to somewhere between five and 10% of total calories  [ii], [iii].

Figure 1. The basic types of fat.

Different Types of Fats

 

As a population, we’re pretty much within these recommended zones. We get 11% of our calories from saturated fat and 8% from polyunsaturated fat (primarily the omega-6 variety)[iv], [v].

CVD mortality has declined since its peak in the 1950s, but CVD prevalence remains very high. For example, the total number of inpatient cardiovascular operations and procedures increased 28% between 2000 and 2010 (from 5.9 million to 7.6 million procedures) [vi]. Moreover, prevalence of metabolic syndrome, a precursor to CVD, has reached a staggering 34% of the population [vii].

If the advice to replace saturated fat with omega-6 was designed to reduce CVD, then what went wrong? Was the advice misguided? Let’s look at the evidence.

 

The Pro-PUFA Studies

Numerous recently published meta-analyses support the conclusion that replacing saturated fat with polyunsaturated fat (though not necessarily omega-6) leads to modest CVD risk reductions. For example:

 

  • Mozaffarian D, et al. (2010) pooled data from 8 randomized controlled trials (RCTs) encompassing 13,614 participants and 1,042 coronary heart disease (CHD) events. They determined that for every 5% caloric increase in polyunsaturated (PUFA) fat there is a corresponding 10% decrease in CHD risk [viii].

Study Limitations: PUFA consumption for this study included both omega-6 and omega-3. Therefore, it’s possible the positive results may have been primarily from omega-3; negative effects from omega-6 could have been masked.

 

  • Hooper L, et al. (2015) pooled data from 13 long-term RCTs encompassing 53,300 participants. They found “a small but potentially important reduction in cardiovascular risk when saturated fat intake was lowered,” particularly by replacing saturated fat with PUFAs, but not by replacing it with carbohydrates [ix]. However, the study found no clear effect of reducing saturated fat on total mortality.

Study Limitations: Among these RCTs, omega-6 and omega-3 PUFAs were grouped together. Therefore, analyzing the individual impact of either PUFA was not possible.

 

  • Farvid MS, et al. (2014) conducted a meta-analysis of 11 studies pertaining to omega-6 (LA) intake and CHD. They concluded “a 5% of energy increment in LA intake replacing energy from saturated fat intake was associated with a 9% lower risk of CHD events and a 13% lower risk of CHD deaths”.

Study Limitations: (1) Whereas this study did specifically measure omega-6, it didn’t account for the ratio of omega-6 to omega-3 (referred to as “n-6/n-3” hereafter), (2) the meta-analysis only included observational studies, not RCTs, and (3) the meta-analysis measured cardiovascular disease mortality, but not all-cause mortality.

 

  • Yanping Li, et al. (2015) conducted a meta-analysis of two observational studies, the first of which followed 85,000 women for 24 years and the second of which followed 43,000 men for 30 years. In total, 7,667 cases of CHD were documented. The authors concluded that replacing 5% of the energy intake from saturated fats with equal energy from PUFAs was associated with a 25% reduced risk of CHD [xi].

Study Limitations: (1) The study was observational (no RCTs were included), (2) the study didn’t account for the n-6/n-3 ratio, and (3) the data was derived from food frequency questionnaires.

 

  • Wu JH, et al. (2015) conducted a cohort study of 2,792 older US adults (mean age, 74). To avoid the problems associated with food frequency questionnaires, they analyzed circulating omega-6 (LA only) blood levels, an objective biomarker of LA consumption[xii]. Those within the highest quintile of circulating LA had 13% lower all-cause mortality than those in the lowest quintile. Interestingly, when the authors stratified subjects based on combined LA and omega-3 PUFA concentrations, those in the highest quintile had a 54% lower all-cause mortality risk compared to those in the lowest quintile.

Study Limitations: This study was designed better than most, but didn’t completely demonstrate how changes to the n-6/n-3 ratio affect mortality.

 

The Anti-PUFA Studies

Christopher Ramsden, MD is a clinical investigator for the National Institutes of Health. During the past decade, Ramsden has been among the most prominent scientists challenging the mainstream narrative that omega-6 should replace saturated fat. Through a series of studies, most of which were published by the British Medical Journal, Ramsden and his colleagues have put forth an important antithesis [xiii], [xiv], [xv]. Some of their conclusions include:

  • Increasing omega-3 relative to omega-6 significantly reduces the risk of heart disease.
  • Diets rich in omega-6 increase risks of all CHD endpoints, while increasing all-cause mortality risk.
  • Substituting dietary omega-6 LA in place of SFA increases all-cause mortality risk, as well as risks from coronary heart disease.
  • Benefits previously attributed to greater intake of total PUFAs may be specifically attributable to omega-3 and not to omega-6 LA.

Some of the problems with the studies used to justify increased omega-6 consumption, according to Ramsden and his colleagues, include:

  • Failure to distinguish between trials that selectively increased omega-6 and those that substantially increased omega-3
  • Failure to acknowledge that omega-6 and omega-3 replaced not only SFAs, but large amounts of trans-fats in many trials used in the pro-PUFA meta-analyses
  • Failure to provide the specific compositions of the diets (particularly with respect to omega-6 and trans-fat) used in the pro-PUFA meta-analyses
  • Failure to analyze the impact of n-6/n-3 ratios


The Middle Ground

As you can see, the consumption of saturated fat and omega-6 are controversial, partly because we lack rigorous studies specifically designed to test the optimal balance between saturated fat, omega-6, and omega-3. This was precisely the conclusion of a 2015 Cochran review by Al-Khudairy L, et. al. [xvi].

The authors sought RCT data demonstrating the effectiveness of increasing or decreasing omega-6 for the prevention of cardiovascular disease. Additionally, they wanted to assess the impact of total omega-3 consumption and the n-6/n-3 ratio.

Unfortunately, “very few trials were identified with a relatively small number of participants randomized.” They concluded, (1) there is currently insufficient evidence to recommend either increased or decreased omega-6 consumption, and (2) larger, better RCTs on this topic are needed.

 

Conclusion

In Part 1 of this article series, we’ve seen that many critical questions about optimal saturated- and polyunsaturated fat consumption levels haven’t yet been answered by science. While we wait for better RCTs to be conducted, we can gain deeper insights and a better understanding of this issue by examining the fat consumption patterns of our Paleo ancestors. Be sure to check out Part II of this series, where we’ll do just that.

 

References

[i] Cohen E, et al. (2015). Statistical review of US macronutrient consumption data,

1965–2011: Americans have been following dietary guidelines, coincident with the rise in obesity. Nutrition, 31. Retrieved from (link).

[ii] US Department of Health and Human Services and U.S. Department of Agriculture. (Dec 2015). 2015–2020 Dietary Guidelines for Americans. 8th Edition. Retrieved from (link).

[iii] FAO. (2010). Fats and fatty acids in human nutrition: Report of an expert consultation. Rome: Food and Agriculture Organization of the United Nations. Retrieved from (link).

[iv] Ervin RB, et al. Centers for Disease Control. (Nov 2004). Advanced Data from Vital Health Statistics. Retrieved from (link).

[v] Wright JD, et al. Centers for Disease Control. (Nov 2010). Trends in Intake of Energy and Macronutrients in Adults. From 1999–2000 Through 2007–2008. NCHS Data Brief, 49. Retrieved from (link).

[vi] Mozaffarian D, et al. (2015). Heart Disease and Stroke Statistics—2015 Update. Circulation, 131. Retrieved from (link).

[vii] Aguilar M, et al. (2015). Prevalence of the Metabolic Syndrome in the United States, 2003-2012. JAMA, 313(19). Retrieved from (link).

[viii] Mozaffarian D, et al. (2010) Effects on Coronary Heart Disease of Increasing Polyunsaturated Fat in Place of Saturated Fat: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. PLoS Med, 7(3). Retrieved from (link).

[ix] Hooper L, et al. (Jun 2015). Reduction in saturated fat intake for cardiovascular disease. Cochrane Database Syst Rev., 10(6). Retrieved from (link).

Farvid MS, et al. (Oct 2014). Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies. Circulation, 130(18). Retrieved from (link).

[xi] Yanping Li, et al. (Oct 2015). Saturated Fats Compared With Unsaturated Fats and Sources of Carbohydrates in Relation to Risk of Coronary Heart Disease. Journal of the American College of Cardiology, 66(14). Retrieved from (link).

[xii] Wu JH, et al. (Oct 2015). Circulating Omega-6 Polyunsaturated Fatty Acids and Total and Cause-Specific Mortality: The Cardiovascular Health Study. Circulation, 130(15). Retrieved from (link).

[xiii] Ramsden CE, et al. (2010). n-6 Fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. British Medical Journal, 104(11). Retrieved from (link).

[xiv] Ramsden CE, et al. (2013). Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. British Medical Journal, 346. Retrieved from (link)

[xv] Ramsden CE, et al. (Apr 2016). Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73). British Medical Journal, 353. Retrieved from (link).

[xvi] Al-Khudairy L, et al. (2015). Omega 6 fatty acids for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev., 16(11). Retrieved from (link).

Inuit | The Paleo Diet

The Inuit have long been used as a shining example that low carbohydrate approaches to diet can work.1 2 3 4 In fact, traditionally they consumed very little vegetables or any other typically Western foods, and subsisted mainly on fish, sea mammals, and land animals.5 And despite this diet (which would horrify most mainstream dieticians) the Inuit traditionally had very low rates of disease.6

By contrast, the traditional Western diet has been correlated with a plague of health issues.7 8 9 As a further example of just how nutritionally poor the Western diet can be, one third of all cancer deaths have been linked to continued intake of low quality foods – which are everyday staples of the Western diet.10

Interestingly, when consumed in a very low carbohydrate version, a Paleo Diet looks very similar – if not identical – to the traditional Inuit diet. Since this way of eating is higher in fat than most North American diets, it is commonly presumed (erroneously) that high fat diets must somehow be “bad.”11 12 What gets (purposely) left out of these arguments is the fact that the type of fat consumed is very important.13 14 15 16 17 Consuming omega-3 fatty acids is highly beneficial for health – while consuming industrial trans fat is pretty much the worst thing you can do for your health.18

To bring all this background knowledge to a head, new research published last week, showed that the Inuit have special mutations in genes involved in fat metabolism.19 These genetic mutations may allow them to thrive on their very low carbohydrate diet. This is thought provoking because these genetic mutations are found in nearly 100% of the Inuit. By contrast, only a mere 2% of Europeans exhibit the same mutations. This means that those of us from European ancestry may synthesize omega-3 polyunsaturated fatty acids differently than the Inuit.

While the initial buzz of this paper was high, in practice it really doesn’t change anything we know about consuming a healthy Paleo Diet. Omega-3 fatty acids, like those found in wild-caught fish, are still extremely beneficial for our health. In fact, researchers have found that omega-3 fatty acids have widely beneficial anti-inflammatory properties.20 This proves beneficial for inflammatory and autoimmune diseases, in addition to maintaining good health for those without specific health conditions. The advice to consume omega-3 fatty acids is great for mitigating coronary heart disease, depression, aging, and cancer.21

Beyond this, arthritis, Crohn’s disease, ulcerative colitis and lupus erythematosis are autoimmune diseases which may be helped by adequate omega-3 consumption.22 Of the omega-3 fatty acids available, DHA (docosahexaenoic acid) is the best, for a variety of reasons.23 24 Look for foods naturally high in DHA (such as wild-caught fish) and avoid inflammatory seed oils – like those commonly used by most major restaurants. This crucial step will help you stay healthy in the long term – no matter what genes and ancestry you may have.

REFERENCES

[1] Dewailly E, Mulvad G, Sloth pedersen H, Hansen JC, Behrendt N, Hart hansen JP. Inuit are protected against prostate cancer. Cancer Epidemiol Biomarkers Prev. 2003;12(9):926-7.

[2] Bjerregaard P, Dewailly E, Young TK, et al. Blood pressure among the Inuit (Eskimo) populations in the Arctic. Scand J Public Health. 2003;31(2):92-9.

[3] Mulvad G, Pedersen HS, Hansen JC, et al. The Inuit diet. Fatty acids and antioxidants, their role in ischemic heart disease, and exposure to organochlorines and heavy metals. An international study. Arctic Med Res. 1996;55 Suppl 1:20-4.

[4] O’keefe JH, Harris WS. From Inuit to implementation: omega-3 fatty acids come of age. Mayo Clin Proc. 2000;75(6):607-14.

[5] Kuhnlein HV. Nutrition of the Inuit: a brief overview. Arctic Med Res. 1991;Suppl:728-30.

[6] Stefansson V. The friendly arctic. The MacMillan Co, NY. 1921.

[7] Manzel A, Muller DN, Hafler DA, Erdman SE, Linker RA, Kleinewietfeld M. Role of “Western diet” in inflammatory autoimmune diseases. Curr Allergy Asthma Rep. 2014;14(1):404.

[8] Myles IA. Fast food fever: reviewing the impacts of the Western diet on immunity. Nutr J. 2014;13:61.

[9] Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 2002;56(8):365-79.

[10] American Cancer Society. Cancer facts & figures 2004. Atlanta: American Cancer Society, 2004.

[11] Guldstrand MC, Simberg CL. High-fat diets: healthy or unhealthy?. Clin Sci. 2007;113(10):397-9.

[12] Schwingshackl L, Hoffmann G. Comparison of effects of long-term low-fat vs high-fat diets on blood lipid levels in overweight or obese patients: a systematic review and meta-analysis. J Acad Nutr Diet. 2013;113(12):1640-61.

[13] Abumrad NA, Piomelli D, Yurko-mauro K, Merrill A, Clandinin MT, Serhan CN. Moving beyond “good fat, bad fat”: the complex roles of dietary lipids in cellular function and health: session abstracts. Adv Nutr. 2012;3(1):60-8.

[14] Simopoulos AP. Omega-3 fatty acids in health and disease and in growth and development. Am J Clin Nutr. 1991;54(3):438-63.

[15] Daley CA, Abbott A, Doyle PS, Nader GA, Larson S. A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef. Nutr J. 2010;9:10.

[16] Loef M, Walach H. The omega-6/omega-3 ratio and dementia or cognitive decline: a systematic review on human studies and biological evidence. J Nutr Gerontol Geriatr. 2013;32(1):1-23.

[17] Swanson D, Block R, Mousa SA. Omega-3 fatty acids EPA and DHA: health benefits throughout life. Adv Nutr. 2012;3(1):1-7.

[18] Ip C. Review of the effects of trans fatty acids, oleic acid, n-3 polyunsaturated fatty acids, and conjugated linoleic acid on mammary carcinogenesis in animals. Am J Clin Nutr. 1997;66(6 Suppl):1523S-1529S.

[19] Fumagalli M, Moltke I, Grarup N, et al. Greenlandic Inuit show genetic signatures of diet and climate adaptation. Science. 2015;349(6254):1343-7.

[20] Wall R, Ross RP, Fitzgerald GF, Stanton C. Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids. Nutr Rev. 2010;68(5):280-9.

[21] Harris WS, Dayspring TD, Moran TJ. Omega-3 fatty acids and cardiovascular disease: new developments and applications. Postgrad Med. 2013;125(6):100-13.

[22] Robinson DR, Knoell CT, Urakaze M, et al. Suppression of autoimmune disease by omega-3 fatty acids. Biochem Soc Trans. 1995;23(2):287-91.

[23] Horrocks LA, Yeo YK. Health benefits of docosahexaenoic acid (DHA). Pharmacol Res. 1999;40(3):211-25.

[24] Conquer JA, Holub BJ. Dietary docosahexaenoic acid as a source of eicosapentaenoic acid in vegetarians and omnivores. Lipids. 1997;32(3):341-5.

Omega-3 vs. Omega-6: Rethinking the Hypothesis

When you’re eating a meal, you’re probably not thinking about macronutrients, like carbohydrates, fats and proteins. The vast majority of individuals following a Western diet aren’t consciously thinking is this food essential to the human body? It is important to note, however, that while there is no such thing as an “essential carbohydrate,”1 there are “essential fats.”2 Essential in the sense that the human body cannot make these fats endogenously,3 and therefore, must be obtained via diet or supplementation.4 Within the class of essential fats, we have omega-3, which has different forms such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (E’PA).5 However, omega-3 is more commonly known to the general populace as “fish oil.”

Omega 3 fatty acids are long chain in structure and found in a variety of foods.6 The action of these long chain fatty acids is commonly called “anti-inflammatory,” though this is a misnomer.7 They are simply less inflammatory than omega-6 fatty acids. Omega-3 FAs and omega-6 FAs compete for the same enzyme to eventually be converted into anti-inflammatory prostaglandins (PGE3) and less inflammatory leukotrienes and into pro-inflammatory prostaglandins (PGE2) and more inflammatory leukotrienes, respectively.8 This paper then goes on to declare, it is the ratio of omega-6 to omega-3 that is vital to reduce or promote the overall inflammatory state of the body.9,10,11 When we look to the habits of hunter-gatherers, the ratio of omega-6 to omega-3 has been estimated at 2:1 or 3:1.12 This is in contrast to the modern diet, which has been estimated at 10:1, or even 25:1.13

With this evidence, it is assumed that emulating the ratio of hunter-gatherers is correct, if we want to improve bio-markers of health.14 Certainly the theory that an inflammatory diet, full of omega-6 rich vegetable oils and very little omega-3 would likely lead to health problems, makes basic sense.15 However, newer research suggests both omega-6 and omega-3 FAs reduce the risk of heart disease, and the ratio of these fatty acids is “not useful and can be misleading.”16 One study reported that omega-6 FAs do not inhibit the beneficial effects of omega-3 FAs, and the combination of both fatty acids leads to the greatest reduction in levels of inflammation.17

However, the real issue here is that omega-3 FAs bind to G coupled-protein receptors, and cause broad anti-inflammatory effects.18 If you remove the omega-3 FAs from your diet, inflammation returns. This means that adequate omega-3 intake alone, regardless of omega-6 intake, is enough to stop inflammation in the body. The same is apparent when you look at the biochemical pathway of omega-6 and omega-3 FAs. They compete for the same enzyme19 through a process known as competitive inhibition.20

The best method of action to pursue, is to simply follow a Paleo Diet and eat plenty of fish rich in omega-3. If you want to avoid dietary intake of omega-3, and obtain the requirements solely from a supplement, DHA is preferable to all other forms of omega-3, since it can be retro converted into EPA.21 Only in the context of a very inflammatory diet (like the standard Western diet) does the ratio of omega-3 to 6 matter. Another case where the ratio would be of utmost importance, is if you aren’t getting any omega-3 FAs at all. This isn’t to say that the omega-3 to omega-6 ratio is completely irrelevant, but if you’re consuming a Paleo Diet, you will likely be getting the right amounts of these essential fatty acids for optimal health.

References

1. Westman EC. Is dietary carbohydrate essential for human nutrition?. Am J Clin Nutr. 2002;75(5):951-3.

2. Insel, Paul. Nutrition: Custom Edition. 4th Edition. Jones & Bartlett Learning, 2010; 182.

3. Chang CY, Ke DS, Chen JY. Essential fatty acids and human brain. Acta Neurol Taiwan. 2009;18(4):231-41.

4. Singh M. Essential fatty acids, DHA and human brain. Indian J Pediatr. 2005;72(3):239-42.

5. Wainwright PE. Dietary essential fatty acids and brain function: a developmental perspective on mechanisms. Proc Nutr Soc. 2002;61(1):61-9.

6. Meyer BJ, Mann NJ, Lewis JL, Milligan GC, Sinclair AJ, Howe PR. Dietary intakes and food sources of omega-6 and omega-3 polyunsaturated fatty acids. Lipids. 2003;38(4):391-8.

7. Foitzik T, Eibl G, Schneider P, Wenger FA, Jacobi CA, Buhr HJ. Omega-3 fatty acid supplementation increases anti-inflammatory cytokines and attenuates systemic disease sequelae in experimental pancreatitis. JPEN J Parenter Enteral Nutr. 2002;26(6):351-6.

8. Macsai MS. The role of omega-3 dietary supplementation in blepharitis and meibomian gland dysfunction (an AOS thesis). Trans Am Ophthalmol Soc. 2008;106:336-56.

9. Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 2002;56(8):365-79.

10. Gómez candela C, Bermejo lópez LM, Loria kohen V. Importance of a balanced omega 6/omega 3 ratio for the maintenance of health: nutritional recommendations. Nutr Hosp. 2011;26(2):323-9.

11. Simopoulos AP. The omega-6/omega-3 fatty acid ratio, genetic variation, and cardiovascular disease. Asia Pac J Clin Nutr. 2008;17 Suppl 1:131-4.

12. Cordain L, Eaton SB, Sebastian A, et al. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr. 2005;81(2):341-54.

13. Yan L, Bai XL, Fang ZF, Che LQ, Xu SY, Wu D. Effect of different dietary omega-3/omega-6 fatty acid ratios on reproduction in male rats. Lipids Health Dis. 2013;12:33.

14. Apte SA, Cavazos DA, Whelan KA, Degraffenried LA. A low dietary ratio of omega-6 to omega-3 Fatty acids may delay progression of prostate cancer. Nutr Cancer. 2013;65(4):556-62.

15. Kang JX, Liu A. The role of the tissue omega-6/omega-3 fatty acid ratio in regulating tumor angiogenesis. Cancer Metastasis Rev. 2013;32(1-2):201-10.

16. Anton SD, Heekin K, Simkins C, Acosta A. Differential effects of adulterated versus unadulterated forms of linoleic acid on cardiovascular health. J Integr Med. 2013;11(1):2-10.

17. Pischon T, Hankinson SE, Hotamisligil GS, Rifai N, Willett WC, Rimm EB. Habitual dietary intake of n-3 and n-6 fatty acids in relation to inflammatory markers among US men and women. Circulation. 2003; 108(2): 155-160.

18. Oh DY, Talukdar S, Bae EJ, et al. GPR120 is an omega-3 fatty acid receptor mediating potent anti-inflammatory and insulin-sensitizing effects. Cell. 2010;142(5):687-98.

19. Babcock TA, Novak T, Ong E, Jho DH, Helton WS, Espat NJ. Modulation of lipopolysaccharide-stimulated macrophage tumor necrosis factor-alpha production by omega-3 fatty acid is associated with differential cyclooxygenase-2 protein expression and is independent of interleukin-10. J Surg Res. 2002;107(1):135-9.

20. Oleñik A, Mahillo-fernández I, Alejandre-alba N, et al. Benefits of omega-3 fatty acid dietary supplementation on health-related quality of life in patients with meibomian gland dysfunction. Clin Ophthalmol. 2014;8:831-6.

21. Conquer JA, Holub BJ. Dietary docosahexaenoic acid as a source of eicosapentaenoic acid in vegetarians and omnivores. Lipids. 1997;32(3):341-5.

Nuts | The Paleo Diet

Do you find yourself having difficulty shedding weight on your Paleo regime? Or perhaps you’re still experiencing GI distress or frequent breakouts even though you’ve cut out the gluten, the dairy and the legumes.

Too many nuts, or the wrong type of nuts could be causing the problem.

Nuts can indeed be a part of the Paleo Diet when eaten in moderation: “in moderation” being the key takeaway message.

Since nuts are high in inflammatory Omega-6 and low in anti-inflammatory Omega-3, they should be regarding more as a garnish than a regular, go-to source of dietary fat.

The fats we should rely on regularly are raw avocados, coconut oil and extra virgin olive oil, as well as the fats we find with our protein sources, like wild salmon or the occasional fattier cut of grass fed meat, like a nice rib-eye.

Are All Nuts Created Equal?

Not at all.

We must factor in not only the type of nut, but also how the nut might be processed.

  • Raw, sprouted nuts are best, whereas you should steer clear of those found in large canisters, roasted in peanut oil. By soaking nuts and allowing them to sprout, we can reduce the amount of phytates we consume when we eat a handful of them with an apple as a snack, for example.
  • Surprisingly, almonds, which we see in abundance in many forms and varieties, have one of the worst Omega 3:6 ratios, with virtually no detectable Omega-3s!
  • Walnuts, Macadamias and Brazil Nuts, however, rank as the top three in their ratio which is more favorable, but still not ideal.

Don’t make the common mistake of buying a huge vat of nuts and bringing them to the office to “snack on” throughout the day. Far too often this ends in too many calories, an unbalanced macronutrient profile and an upset stomach.

How many nuts are too many nuts?

Simply put, if you’re eating any nuts more often than as the occasional garnish, it may be too much. Because they’re easy to purchase, easy to eat and require zero preparation, many people make the mistake of making them their go-to snack for the office or home, and end up consuming hundreds of extra calories each day without even realizing it.

But why are some nuts ok, but not some grains or some legumes?

It comes down to portion sizes and frequency. We’re only meant to be eating a small portion, as a garnish, on occasion, whereas with pasta, bread or bagels, the amount eaten in the typical Standard American Diet is closer to cupfuls.

A good example of how many nuts to eat might include a tablespoon of raw walnuts on a salad or a handful of raw almonds with an apple, some sliced turkey and spinach made into a wrap a couple times per week is the way to go.

Eating a vat of salted nuts, roasted in peanut oil that you purchased on sale at Costco each week is the wrong approach.

Are Nuts for Everyone?

Certain populations may need to be even more careful with nuts, such as those with autoimmune conditions. While some can tolerate nuts and seeds others cannot. The best approach is to go nut-free for a month on top of the standard Paleo Diet and then test to see if you react.

Storing

Because of their high fat content, nuts kept in the freezer can be eaten in that state. They won’t freeze into a rock-solid piece of ice the way a piece of lean chicken or veggies would.

Rather than following the budget friendly strategy of buying in bulk, only to find that two pound bag of organic raw walnuts still sitting in your cupboard two months later and not tasting so great, keeping them in the freezer proves to be cost-effective too, as nothing will spoil and go to waste.

For an easy to make treat, rinse, then freeze some organic grapes or a sliced banana. Paired with a handful of macadamias and topped with a dash of cinnamon and ginger, this makes an incredibly decadent “something sweet” way to finish a meal, far more representative of True Paleo than any treat.

Zero processing and loads of flavor is the way to go.

For a special occasion, create the decadent Raw Chocolate Covered Walnuts with Berries.

Verdict on Monounsaturated Fats | The Paleo Diet

If SFA (saturated fatty acids) are bad for us then why does our body store excess calories that way?

Saturated fat consumption was likely unrestricted among ancient hunter gatherer populations. For the purpose of efficiency and conservation, entire animals would be consumed.

The USDA and other major government nutrition advocates claim that excess saturated fat intake will lead to exceedingly high cholesterol levels and coinciding health problems. Currently, there are no confirmed studies demonstrating the correlation of increased saturated fat intake with a higher risk for cardiovascular mortality. Saturated fat intake might increase LDL cholesterol initially, but it produces protective HDL cholesterol simultaneously.

The Inuit people of North America subsist on a diet that is extremely high in saturated fats, and the majority of the population does not exhibit cardiovascular diseases. The body does indeed store excess carbohydrates as saturated fat, but this is simply for the purpose of future energy expenditure. Saturated fat should not be feared, and is a vital fatty acid for maintaining consistent energy levels while following a Paleo lifestyle.

Bottom line: Saturated fats should be consumed in moderation along with other leaner cuts of meat.

Kyle Cordain
The Paleo Diet Team

There has been extensive debate within the Paleo community recently surrounding the validity of certain cooking oils while following The Paleo Diet.

Hunter-gatherers would have not had access to most cooking oils available to modern society. That being said, animal fats were likely consumed and used as a substitute for cooking oils that are commonly consumed today. Grilling eliminates the need for cooking with oil in pans, but grilling food for every meal is not very realistic for the average individual following a contemporary Paleo Diet.

However, there are a number of common cooking oils that should never be consumed while following The Paleo Diet. These include:

  • Soybean Oil: Often partially hydrogenated and is highly inflammatory due to the disproportionately high ratio of omega-6 to omega-3 fatty acids.
  • Canola Oil: Derived from the unpalatable rapeseed plant, the oil is stripped of erucic acid to make it edible. Canola oil is often praised for its omega-3 content, but health practitioners often fail to account for the quick degradation of omega-3 fatty acids within the oil due to the 500 degree temperature that is required to manufacture the oil.
  • Cottonseed Oil: Derived from an inedible plant that is used in the textile industry, the oil is used in numerous processed foods including margarine, ice cream, bread, and packaged oysters. As with Canola, Cottonseed also has an unhealthy fatty acid profile and should be avoided at all costs.

Other cooking oils to avoid for rancidity, inflammatory properties, and an unbalanced fatty acid profile:

  • Safflower Oil
  • Sunflower Seed Oil
  • Sesame Seed Oil
  • Peanut Oil
  • Corn Oil
  • Vegetable OilGrape Seed Oil
Despite the overwhelming majority of unhealthy oils that are available for purchase at your average grocery store, there is still hope! Swap out the bad for the oils permitted when following The Paleo Diet.

  • Olive Oil: Fantastic for sauteing and as a salad dressing. It is fairly resistant to high heat, which makes it less prone to rancidity. It primarily consists of monounsaturated fats, which are considered safe and healthy.
  • Coconut Oil: While the tropical, shelf-stable oil is relatively high in saturated fats, the saturated fat content should not be a concern and allows for the oil to remain stable at high temperatures. Coconut oil is also very rich in a medium chain fatty acid known as Lauric Acid, which is recognized for its antimicrobial and antifungal properties.
  • Animal Fat: Realistically, this is the closest to a hunter-gatherer cooking fat or oil. Grass-fed beef tallow is preferred. Duck fat is also allowed. However, be careful when consuming fat from pork or chicken, as both contain significantly higher quantities of polyunsaturated fats.

Although there are numerous toxic and potentially lethal species of mushroom species, you should not be worried about consuming the mushrooms you find at your choice grocer. In all likelihood, our hunter-gatherer ancestors likely indulged in various types of mushrooms on a semi-regular basis, knowing the distinct properties to exclude poisonous species. Mushrooms are also relatively low on the glycemic index and are rich in selenium, potassium, riboflavin, niacin – all optimal for your health. Let the mushroom hunting adventures ensue!

Kyle Cordain
The Paleo Diet Team

Mushroom Sauté

Cooking Oils | The Paleo Diet

3 – 4 Servings

Ingredients

  • 2 cups fresh mushrooms, sliced thin
  • ½ sweet onion, sliced thin
  • 2 fresh garlic cloves, pressed
  • 2 tbsp extra virgin olive oil
  • ¼ cup red wine
  • 2 leaves fresh basil finely chopped
  • 1 sprig fresh rosemary, minced, stem removed
  • Grass-Fed Beef or Buffalo Steaks

Directions

1. In large fry pan, saute onions and garlic in olive oil over medium heat until onions are tender.

2. Stir in mushrooms and remaining ingredients.

3. Reduce heat to low and simmer for 5 minutes.

4. Serve over fresh grass-fed beef or buffalo steaks.

Grain Brain

Hi Loren,

I was hoping I could induce you to correct a statement made about your work in a recent post in The Atlantic. It’s by a senior editor, a medical doctor, James Hamblin, who’s doing a take-down of Perlmutter’s Grain Brain couched as a piece of journalism. In it he quotes David Katz of Yale, commenting about the paleolithic diet and your work.

I thought perhaps you could take a little time to set both Hamblin and maybe even Katz right. The key section:

“Of course,” Katz added, “Everything about the Paleolithic Era is subject to debate. Most of us don’t know what we had for breakfast yesterday, let alone what people were doing 100,000 years ago. Yeah, I’ve read the same thing that the average life expectancy was between 20 and 40 and, consequently, the diseases of old age didn’t happen because old age didn’t happen. There’s nothing about their diet that we know to be protective against things like Alzheimer’s. That’s just silly.”

Perlmutter has estimated that the Stone Age diet was 75 percent fat, a claim Katz finds “wildly preposterous.” Anthropological research, he pointed out the work of Loren Cordain, suggests that in the age before cooking oil, humans ate mostly plants with a scattering of seeds and nuts. “Virtually nothing in the natural world is that concentrated of a fat source, except maybe for the brain. Maybe if they just ate the brains of animals? They didn’t have oil. They only started adding oil to the diet after the Dawn of Agriculture. What the hell could they possibly have eaten that would be that fatty?'”

This kind of journalism is bad enough when they get the facts vaguely right and just spin them to fit their biases. When they butcher the facts, too, it deserves correcting.

All the best,

Gary Taubes

Gary Taubes is the author of Why We Get Fat (2011), Nobel Dreams (1987), Bad Science: The Short Life and Weird Times of Cold Fusion (1993), and Good Calories, Bad Calories (2007), which is titled The Diet Delusion in the UK. He has won the Science in Society Award of the National Association of Science Writers three times and was awarded an MIT Knight Science Journalism Fellowship. Taubes studied applied physics at Harvard and aerospace engineering at Stanford (MS, 1978). Taubes has written numerous articles for Discover, Science and other magazines. Originally focusing on physics issues, his interests have more recently turned to medicine and nutrition.

Dr. Cordain’s Response:

Hi Gary,

Good to hear from you.  Thanks for forwarding me the article from The Atlantic by James Hamblin, MD. on Perlmutter’s Grain Brain. I came away with a number of impressions:

1.  Both Katz and Perlmutter acknowledge the underlying, evolutionary basis for human nutrition.

2.  Scientists involved in gluten research and Paleo Diets (including myself) were not directly interviewed in this article.  This omission likely fuels Hamblin’s perspective and does not provide equal input for both sides of the argument.

3.  I was not interviewed for this article and the quote you cite below is not mine, but rather appears to be David Katz’s interpretation of our work.  The quote is erroneous as well as being just flat out wrong.  Our group has repeatedly analyzed the composition and macronutrient content of historically studied hunter gatherer diets.1-7 Animal fat has been an integral part of hominid diets since the origins of our genus Homo.  To correct whomever wrote the erroneous quote below, regardless of whether fat comes from either plant or animal food sources, it contains identical caloric densities (9 kcal/g).  In the typical hunter gatherer diet, animal fat would have generally exceeded plant fat on an average daily basis.

Brain contains virtually no fat, but rather is comprised primarily of fatty acids bound to the phospholipid fraction.  A fat (triglyceride) is also technically called an acylglycerol (a glycerol molecule bound to a fatty acid [acyl group] via an ester bond).   Brain contains little or no acylglycerol, but rather structural fatty acids found not in the triglyceride fraction, but in the phospholipids fraction.   There is no doubt that brain, marrow and other fatty (and fatty acid) portions of wild animal carcasses would have been preferred by our hunter gatherer ancestors over lean meats.

Cordially,

Loren Cordain, Ph.D., Professor

REFERENCES

1. Cordain L, Brand Miller J, Eaton SB, Mann N, Holt SHA, Speth JD. Plant to animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. American Journal of Clinical Nutrition, 2000, 71:682-92.

2. Cordain L, Eaton SB, Brand Miller J, Mann N, Hill K. The paradoxical nature of hunter-gatherer diets: Meat based, yet non-atherogenic. Eur J Clin Nutr 2002;56 (suppl 1):S42-S52.

3. Cordain L, The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24.

4. 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.

5. Cordain L. Saturated fat consumption in ancestral human diets: implications for contemporary intakes. In: Phytochemicals, Nutrient-Gene Interactions, Meskin MS, Bidlack WR, Randolph RK (Eds.), CRC Press (Taylor & Francis Group), 2006, pp. 115-126.

6. Ramsden CE, Faurot KR, Carrera-Bastos P, Sperling LS, de Lorgeril M, Cordain L. Dietary fat quality and coronary heart disease prevention: a unified theory based on evolutionary, historical, global and modern perspectives. Curr Treat Options Cardiovasc Med; 2009;11:289-301.

7. Kuipers RS, Luxwolda MF, Janneke Dijck-Brouwer DA, Eaton SB, Crawford MA, Cordain L, Muskiet FA. Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet. Brit J Nutr , 2010 Dec;104(11):1666-87.

Chia Seeds | The Paleo Diet

Hello Dr. Cordain,

Are there any negative effects associated with chia seeds which would make them inappropriate in The Paleo Diet?

Thank you.

Dr. Cordain’s Response:

Good question. I would imagine that many of our readers have never even heard of chia seeds much less eaten them. Chia seeds (Salvia hispanica L.) are a member of the Labiatae plant family and are native to southern Mexico and northern Guatemala. The seeds are small, oval shaped; either black or white colored and resemble sesame seeds. These seeds were cultivated as a food crop for thousands of years in this region by the Aztecs and other native cultures. Chia seeds can be consumed in a variety of ways including roasting and grinding the seeds into a flour known as Chianpinolli which can then become incorporated into tortillas, tamales, and various beverages. The roasted ground seeds were traditionally consumed as a semi-fluid mucilaginous gruel (Pinole) when water is added to the flour. In post-Columbian times the most popular use of chia flour was to make a refreshing beverage in which the ratio of seeds to water is decreased, thereby resulting in a less gelatinous consistency to which lemon, sugar or fruit juice are added. The sticky consistency of chia seed Pinole or chia beverages comes from a clear mucilaginous, polysaccharide gel that remains tightly bound to the seeds. This sticky gel forms a physical barrier which may impair digestion and absorption of fat from the seed while also causing a low protein digestibility.

In the past 20 years a revival of interest in chia seeds has occurred primarily because of their high fat content of about 25-39% by weight, of which 50-57% is the therapeutic omega-3 fatty acid and alpha linolenic acid (ALA). In the past 10 years chia seeds have been used as a foodstuff for animals to enrich their eggs and meat with omega-3 fatty acids. So I wholeheartedly approve of feeding chia seeds to animals and then eating the omega-3 fatty acid enriched meat or eggs of these animals.

How about feeding chia seeds to humans – should we consume chia seeds because of their high omega-3 fatty acid (ALA) content? The Table below shows the entire nutrient profile of chia seeds. At least on paper, it would appear that chia seeds are a nutritious food that is not only high in ALA, but also is a good source of protein, fiber, certain B vitamins, calcium, iron and manganese.

Unfortunately, the devil is always in the details…

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

Coconuts | The Paleo Diet

In my newest book, The Paleo Answer, I provide an in-depth discussion on coconut oil. It is extremely high in a saturated fat called lauric acid which scientifically is labeled 12:0, meaning that it is a fatty acid that contains 12 carbon atoms and no double bonds. At one time, many scientists and nutritionists thought that it was unhealthful and promoted atherosclerosis because it raised total blood cholesterol. However, more recent studies show that it actually improves the total blood lipid profile because it also raises HDL (high density lipoprotein) cholesterol. As the total HDL ratio improves, and if it displaces refined carbohydrates, then it reduces triglycerides and small dense LDL, which also reduce the risk for CVD (cardiovascular disease). Studies of traditional societies living in Pacific islands who consume coconuts for their entire lives appear to be free of CVD, but when they begin to “westernize,” this freedom disappears. So, the best information suggests that coconut oil when consumed without western foods (refined sugars, grains, processed foods, etc.) is a healthful oil.

Lauric acid (12:0) appears to be good for gut health because it has antimicrobial activity which promotes healthy gut bacteria and may help to prevent a leaky gut. Further, since lauric acid has a medium chain length, it is relatively stable during cooking and tends not to breakdown with higher heats. Granted, it contains little polyunsaturated fats and no omega-3 fatty acids, but if the diet is balanced and contains meat and fatty fish (salmon, mackerel, sardines, herring), seafood, grass produced meats and free ranging eggs, the omega-3 fatty acid balance should not be adversely affected by coconut oil.

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

Prostate Cancer Omega-3 | The Paleo Diet

By now you’re all familiar with the study published online by Brasky et al. in the Journal of the National Cancer Institute entitled, “Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial.” It was widely publicized in the mass media, showing an increased risk of prostate cancer for men with higher vs lower omega-3 blood levels. Dr. James H O’Keefe, world renowned cardiologist and Director of the Preventive Cardiology Program at Saint Luke’s, colleague, and co-author on a number of my scientific papers, has given this study exceptional thought and attention. I share with you his insightful response to why it is largely irrelevant clinically below.

Dr. Hector Lopez, board-certified specialist in physical medicine and rehabilitation, with a concentration in spine, sports and musculoskeletal medicine with post-graduate training in nutritional biochemistry has also provided an in-depth analysis examining in objective detail what risks, if any, long chain fatty acid present to the prostate in Long-Chain Omega-3 Fatty Acids: Friend or Foe to Prostate? More than meets the eye to recent controversy over omega-3 levels and prostate cancer risk.

Coridally,

Loren Cordain, Ph.D., Professor Emeritus

This was a retrospective case-control study that showed miniscule differences in omega-3 blood levels: 3.62% in the no-cancer control group, 3.66% in the prostate cancer group. For example, a headline in the Huffington Post read: “Omega-3 supplement taken by millions linked to aggressive prostate cancer.” This is blatantly untrue. To have an omega-3 blood level of 3.6 to 3.7% range is compatible with little to no fish consumption, and no fish oil capsule intake in BOTH arms of the study.

Japanese men consume about 8 times more fish than American men, and on average have an omega-3 index of 8 to 10% (over twice as high as either group in this study). Japanese men have a prostate cancer level that is less than one-sixth that is noted in American men. Prior studies from other investigators have suggested if anything lowers rates of prostate cancer, it is with higher intake of fish and omega-3 fatty acids.

Higher omega-3 levels have been consistently and strongly correlated with lower risks for cardiovascular mortality, sudden cardiac death, all-cause mortality and genetic aging at a cellular level (slowing telomere attrition). William Harris PhD, the ‘CodFather’ of omega-3, and I are looking at the GISSI trials to see if we can shed light on this issue with randomized trial data. Stay tuned, we will let you know what it shows. In the meantime, here is Dr. Harris’s in-depth analysis.

Bottom line: In my opinion, this study is largely irrelevant clinically. And on a personal note, I will continue to emulate the Japanese and keep my omega-3 levels at or above 8%.

James H O’Keefe, MD
Director, Preventive Cardiology Program

Affiliates and Credentials