Don Matesz: Wheat Myths & The Wheat Belly Grain Brain Challenge

The Arab Bedouins traditionally consumed the
majority of energy from whole wheat bread

A recent large meta-analysis of prospective cohort studies predominantly carried out in countries where dietary fiber is derived largely from cereal fiber, in particular wheat, found that an increment of 10 grams of dietary fiber a day was associated with a 20-34%, 9% and 11% decreased risk of death from heart disease, cancer and all-causes combined, respectively.1 Similarly, recent meta-analyses have found that whole grain intake is associated with a significantly lower risk of type II diabetes, weight gain, cardiovascular disease and colorectal cancer.2 3 This data casts significant doubt on the claims that the intake of whole-grains, including whole wheat are primary causes of these conditions and diseases.

Don Matesz, author of Powerd By Plants: Natural Selection & Human Nutrition has been releasing a series of informative videos where he challenges the claims about the modernization of wheat and it being a primary cause of multiple chronic diseases and conditions. In one notable video, Don provides strong evidence that there is actually less gluten content in modern wheat, and that the intake of gluten has decreased significantly in the United States over the last century. In another video Don describes the very high intake of wheat bread in the traditional Mediterranean diet, and how bread intake was correlated with a lower rate of mortality in the Seven Countries Study, consistent with the studies described above. He is a also doing 30 day challenge where he will be consuming one pound of whole-grain wheat products, and 2-3 serving of soy products for 30 days to see whether he develops a 'wheat belly' or a 'grain brain'. Head over to his blog or YouTube channel to view his progress, or see some of the videos below.

Wheat Belly Grain Brain Challenge D5 & 6 | Wheat vs. Meat: The Mediterranean Evidence

Wheat Belly Grain Brain Challenge D7 | Does Modern Wheat Have More Gluten?

Wheat Belly Grain Brain Challenge D9 | Is Commercial Wheat Loaded With Toxic Pesticides?

While Don is only doing a 30 day challenge, a number of healthy populations have traditionally consumed similar or even greater quantities of wheat throughout their entire lives. One example described previously are the Arab Bedouins, who traditionally consumed the great majority of their dietary intake from whole wheat bread (approx. 750 grams in addition to other wheat products).4 5 Obesity, diabetes and heart disease were all exceptionally rare in this population when they adhered to their traditional whole wheat based diet, and have become far more common since the transition towards a westernized diet.4 6 It is past time to cast aside the unsubstantiated claims made by fad diet promoters about the adverse health effects of modern wheat and whole grains.

Saturated Fat and Heart Disease Meta-Analyses: Were Scientists Wrong?

Was it Ancel Keys or the low carb advocates
who fabricated data on saturated fat?

In a previous review, Clearing up the Confusion Surrounding Saturated Fat, I examined several important flaws and omissions in two meta-analysis studies which are frequently cited as evidence against the hypothesis that dietary saturated fat increases the risk of heart disease. The earlier study was published in 2010 by Siri-Tarino and colleagues in the American Journal of Clinical Nutrition, and the more recent study published by Chowdhury and colleagues in the Annals of Internal Medicine. These studies were both cited in a recent Time magazine article by Bryan Walsh as evidence to "eat butter" for health. In this earlier review I focused primarily on how the studies included in these meta-analyses, as well many other studies actually provide support for the hypothesis that saturated fat increases the risk of fatal forms of heart disease.

Although a number of prominent diet-heart researchers identified many serious flaws and omissions in these meta-analyses that cast doubt on the validity of the researchers conclusions, there are several other critical flaws related to how the estimates were derived for these meta-analyses that have not received adequate attention.1 2 3 4 5 This review will examine how a number of erroneous estimates may have biased the results and primary findings of these meta-analyses. Of particular concern, is in regards to how Siri-Tarino and colleagues derived negative estimates for three studies for which the original peer reviewed publications found positive associations between saturated fat and risk of heart disease. These studies and the estimates published in the meta-analysis by Siri-Tarino and colleagues are described in the table below. 

Study Name                                Risk Ratio (RR)    95% Confidence Interval (95% CI)

Framingham Heart Study6         0.92                       0.68, 1.24

Honolulu Heart Study7               0.86                       0.67, 1.12

Lipid Research Clinics Study8    0.97                       0.80, 1.18

Note: The risk ratio represents high vs low intake of saturated fat in relation to coronary heart disease. An estimate below 1 suggests a benefit of higher intake, and vice-versa. The estimates are considered statistically significant only if both the lower and upper 95% confidence intervals are on either side of 1.

The estimates published in the meta-analysis by Siri-Tarino and colleagues for all three of the abovementioned studies suggest a non-significant trend towards a benefit of saturated fat intake, greatly contrasting the findings from the original peer reviewed publications.9 This warrants an investigation into how Siri-Tarino and colleagues derived these negative estimates.

The Framingham Heart Study

Contrary to other studies included in the meta-analysis, the Framingham study reported estimated risk ratios for low vs high intake, rather than high vs low intake of saturated fat. Among the younger cohort in this study, 10% vs 15% of intake was associated with a 22% decreased risk of coronary heart disease (RR=0.78 [95% CI, 0.61-1.00]).6 Conversely this benefit of low intake was not observed among the older cohort (RR=1.06 [95% CI, 0.86-1.30]). Nevertheless, both of these estimates were controlled for serum cholesterol, which is expected to have biased these findings against showing an adverse effect of saturated fat. 

The tables in the meta-analysis clearly show that rather than converting the risk ratios for low vs high intake to appropriately reflect high vs low intake, Siri-Tarino and colleagues simply reported the estimates for 10% vs 15% of intake as representing 15% vs 10% of intake of saturated fat. The combined estimate for the younger and older groups in this cohort should therefore have been reported as RR=1.09 [95% CI, 0.81-1.47], and not as RR=0.92 [95% CI, 0.68-1.24], which was the estimate reported in the meta-analysis. The estimate provided in the meta-analysis for this study is clearly erroneous and biased the meta-analysis against showing an adverse effect of saturated fat.

The Honolulu Heart Study

In the original peer reviewed publication from the 10 year follow-up of the Honolulu Heart Study, a high intake of saturated fat was associated with a highly statistically significant increased risk of incidence of combined myocardial infarction (heart attack) and coronary heart death.7 This was despite over-adjustment for serum cholesterol. However, when combined with the incidence of the soft end points, angina and coronary insufficiency, the association was only statistically significant in the univariate analysis which did not control for serum cholesterol. The authors of this paper however, warned about misinterpreting the results for these soft end points, asserting:

When interpreting these results about whether the nutrients relate differently to the different manifestations of coronary heart disease, one should keep several problems in mind. The diagnostic certainty of the soft end points (angina pectoris or coronary insufficiency) is much less than that of the hard end points (myocardial infarction or coronary heart disease death).This could result in attenuation of a true relationship.

In the meta-analysis by Siri-Tarino and colleagues, the estimates for the 10 year follow-up of the Honolulu Heart Study were derived not from a peer reviewed publication, but rather from a separate data set obtained from the NHLBI. The primary reason that these estimates provided in the meta-analysis greatly contrasted with that of the peer reviewed publication can likely be explained by difference in the inclusion criteria of the participants. The tables in the meta-analysis show that the data used was based on 1177 cases of coronary heart disease from 8006 participants. However, in the peer reviewed publication there was a total of only 456 cases of coronary heart disease from 7088 participants.  Due to several important factors, the researchers of the original peer reviewed publication excluded 918 of the total 8006 participants from their analysis, asserting:

Men who reported that their intake was atypical for the day covered by the 24 hour recall, or who could not recall their intake, were excluded from the present analyses (n=502). Additionally, all men assessed as being prevalent cases of coronary heart disease (n=301), stroke (n=111), or cancer (n=49) were excluded from the analyses.

It is therefore evident that more than 60% of coronary events included in the meta-analysis for this particular study occurred in participants who had pre-existing disease at study baseline and/or reported unreliable dietary intake. As these additional participants made up less than 12% of the population, yet experienced more than 60% of the total events, this suggests the likelihood that these events occurred primarily among the participants with pre-existing cardiovascular disease, rather than the healthy participants reporting unreliable dietary intake. It should be noted that Siri-Tarino and colleagues clearly stated that one of the inclusion criteria for the meta-analysis was that “study participants were generally healthy adults at study baseline”, suggesting that the data they selected did not meet their own criteria.

When considering the fact that the estimate for this study used in the meta-analysis was negatively associated with coronary heart disease, rather than positively associated as was the case in the peer reviewed publication, this suggests that the participants excluded in the peer reviewed publication who experienced coronary events, largely being those with pre-existing disease, were reporting a lower intake of saturated fat. This is concerning considering the evidence that people who are diagnosed of being at risk of cardiovascular disease tend to limit saturated fat intake post-diagnosis. For example, in the earliest study included in the meta-analysis, participants diagnosed with high cholesterol had a tendency to reduce intake of saturated fat in order to improve risk factors.10 It should therefore not be surprising that participants with established cardiovascular disease likely reported a lower intake of saturated fat in this study, suggesting that a lower reported intake was only a marker of more disease, rather than a cause of it. This phenomenon is known as reverse causality, and is one of the important reasons why participants with pre-existing disease are either excluded, or examined separately from healthy participants in such studies. The inclusion of such data in a meta-analysis could significantly distort the findings. 

It is not entirely clear why a null estimate was reported for this study in the more recent meta-analysis published by Chowdhury and colleagues. However, the sample size described in supplement section of the meta-analysis paper suggests that the estimates were based on the same misleading data used by Siri-Tarino and colleagues, and not the original peer reviewed publication.11

The Lipid Research Clinics Study

In the Lipid Research Clinics study, it was observed that among the younger cohort that a 1% increased intake of energy from saturated fat was associated was a statistically significant 11% increased risk of death from coronary heart disease (RR=1.11 [95% CI, 1.04-1.18]).8 However, similar to the Framingham study, this study also included over-adjustments for serum cholesterol and the adverse effect of a high intake of saturated fat was not apparent among the older cohort (RR=0.96 [95% CI, 0.88-1.05]).

In the meta-analysis by Siri-Tarino and colleagues, the estimate for both the younger and older cohorts combined using the random-effects model was reported as RR=0.97 [95% CI, 0.80-1.18]. It is clear that this estimate is erroneous. When using the random-effects model for two estimates, the estimate with the narrowest confidence intervals should carry more weight, and therefore the combined estimate should have been much closer to the estimate for that of the younger cohort. The estimate for a 1% increase of energy from saturated fat should have been reported as RR=1.04 [95% CI, 0.90-1.19]. Similar to the abovementioned studies, this erroneous estimate biased the meta-analysis against showing an adverse effect of saturated fat.

Reanalysis of the Data

The use of erroneous estimates for several studies included in the meta-analysis by Siri-Tarino and colleagues warrants a reanalysis of the original data. I therefore performed a revised meta-analysis of the same 16 prospective cohort studies included in this meta-analysis. The methods used to derive the estimates have been described previously, and were mostly consistent with those used by Siri-Tarino and colleagues. For the Honolulu Heart Study, I derived the estimates based on only the hard coronary end points due to the concern of the accuracy of the estimates for the soft end points being less certain. As the exact P-value was not available for this publication, and indicated only as being between 0.01 and 0.001, I chose to derive the corresponding standard error using a P-value of 0.01, as this was the most conservative estimate.7

In a meta-analysis based on the 16 studies included in the meta-analysis published by Siri-Tarino and colleagues, dietary saturated fat intake was associated with a statistically significant 16% increased risk of coronary heart disease (Fig. 1).

FIGURE 1. Risk ratios and 95% CIs for fully adjusted random-effects models examining associations between saturated fat intake in relation to incidence of coronary heart disease. ¹Studies that included adjustments for serum or LDL cholesterol. SAT, saturated fat intake.

I also carried out an updated meta-analysis, including prospective cohort studies published up until November 2014 that provided the necessary data to derive risk ratios and the corresponding 95% confidence intervals. If a study was published multiple times, the estimate for the longest period of follow-up was used. A total of 21 studies were included, including recent publications not included in either the meta-analyses by Siri-Tarino and colleagues, and Chowdhury and colleagues.7 8 9 12 13 14 15 16 17 18 19 20 21 22 23 24 25 In a meta-analysis of 21 studies, dietary saturated fat was associated with a statistically significant 15% increased risk of coronary heart disease (Fig. 2).

FIGURE 2. Risk ratios and 95% CIs for fully adjusted random-effects models examining associations between saturated fat intake in relation to incidence of coronary heart disease. ¹Studies that included adjustments for serum or LDL cholesterol. SAT, saturated fat intake.

The findings from these meta-analyses presented here are compatible with the findings from a broad range of evidence described previously. This includes findings from randomized controlled trials showing an adverse effect of saturated fat on blood cholesterol and arterial function, as well as the demonstrated unequivocal causal relationship between diets rich in cholesterol and saturated fat, and the development of atherosclerosis in nonhuman primates, among dozens of other animal species. Furthermore, these findings are supported by numerous ecological studies, including the Seven Countries Study. 

The estimates of this meta-analysis are clearly stronger than that of the Siri-Tarino and Chowdhury meta-analyses, neither of which produced statistically significant estimates. One of the primary reasons for these contrasting estimates was due to the correction of the estimates for several studies described above. These contrasting estimates can also in part be explained by the correction of erroneous estimates for the confidence intervals reported in the Siri-Tarino meta-analysis for the Ireland-Boston Diet Heart Study, and in the Chowdhury meta-analysis for the EPIC-Greece study. It is clear that in the original peer reviewed publications that the estimates in these studies were statistically significant to the 95% confidence level, yet non-statistically significant estimates were reported in the meta-analyses for these studies, biasing against showing an adverse effect of saturated fat.13 20

Another important difference in the meta-analyses presented here, is that the estimates for studies reporting estimates as a 1% increase of energy were transformed to represent a 5% increase of energy from saturated fat. In the Siri-Tarino meta-analysis the researchers either simply reported the estimates for a 1% increase, or transformed the estimates to represent a similarly small increase of energy. Similarly, Chowdhury and colleagues multiplied the estimates from these studies by the power of 2.18, effectively representing the effect of an increase of only a 2.18% increase of energy. The researchers rational for this was that this equation would be expected to show the effect of mean top vs bottom third of intake. While this equation may be suitable for some studies using different scales of measurement, it requires a leap of faith to assume a difference of only 2.18% of energy represents high vs low intake in these studies. Reporting estimates as a 5% increase of energy, as was done here would make differences for high vs low intake much more comparable to that of the other included studies, while still being moderately conservative. As the studies that reported estimates as a 1% increase of energy were more likely to show a positive relationship between saturated fat and coronary heart disease, failing to transform the estimates to represent a sufficient change in intake may result in minimizing the statistical power of these studies, and in-turn biasing a meta-analysis against showing an adverse effect of saturated fat.

Conflicts of Interest

The meta-analyses published by Siri-Tarino and colleagues and Chowdhury and colleagues contained erroneous estimates for several positive studies which in-turn biased against showing an adverse effect of saturated fat. Given the fact that these researchers were well informed in this area of research, it is difficult to accept that they were simply unaware of any of the issues described here. In the meta-analysis by Siri-Tarino and colleagues there was clear evidence of potential conflicts of interest. The meta-analysis was funded in part by the National Dairy Council, and the senior researcher, Ronald Krauss had reported receiving grants from the National Dairy Council, the National Cattleman’s Beef Association and the Robert C. and Veronica Atkins Foundation. Similarly, several of the researchers of the meta-analysis by Chowdhury and colleagues have reported receiving grants from the food industry. Suggestive evidence of these researchers intention to downplay the role of saturated fat on fatal heart disease have also been described previously.

Although receiving grants from a particular industry does not necessarily negate the findings of a study, when errors are made that bias the study results in favor of the concerned industry, the intentions of the researchers should be questioned. The lines of evidence described here lends support to the likelihood that these researchers put their own interests before that of the general public, driving the public to follow dangerous dietary patterns at the hands of fad diet advocates who promote these studies.

Putting Data into Context

It is important to note that the influence that saturated fat has on the risk of disease is not primarily determined by intake per se, but by which foods saturated fat is substituted for. As the intake of dietary fiber was universally low among participants in these studies, this suggests that participants consuming diets lower in saturated fat were substituting saturated fat primarily with lean animal foods and heavily processed foods.26 In addition, as dietary fiber was associated with a decreased risk of coronary heart disease in a number of these studies, the estimates described here therefore could be a significant underestimation of the effect of replacing saturated fat with more healthful, fiber rich foods.26 Furthermore, in the studies included in this meta-analysis, the difference for high vs low intake of saturated fat was relatively low, often only ranging between about 5% and 10% of energy. This suggests that individuals following popular diets which emphasize far greater intakes of saturated fat than recommended levels may be at a much greater risk.

It is also important to note that the effect that a particular food has on the risk of coronary heart disease cannot be fully explained by the amount of one particular nutrient, but rather by multiple nutrients that likely operate together in a complex manner to modify the risk of disease. Therefore, it would be more appropriate to compare the substitution of different foods, rather than focusing entirely on substituting single nutrients. Focusing attention on recommending healthy dietary patterns that are naturally low in saturated fat, while rich in dietary fiber and other beneficial nutrients; primarily, minimally processed, plant-based diets would likely be a more effective measure to improve overall dietary quality, resulting in greater improvements to heart health compared to the more contemporary reductionist approach of focusing on modifying single nutrients. The effectiveness of such a diet was recently demonstrated again by Caldwell Esselstyn in a follow-up of 200 high-risk patients. In this study, coronary artery disease was either arrested or reversed in the great majority of adherent patients, clearly contrasting that of any other peer-reviewed study of similar size.27

This review demonstrates that the conclusions of several meta-analysis studies which suggest that dietary saturated fat unlikely increases the risk of heart disease are misleading, and that the current evidence supports the recommendations to replace foods rich in saturated fat with minimally refined plant based foods. Recommendations based on the findings of these meta-analyses made by the media and low carb advocates to consume more saturated fat rich foods are therefore unsubstantiated and likely dangerous. While it may make an interesting read being told that scientists, such as Ancel Keys have intentionally deceived us into believing that saturated fat-rich foods are unhealthy, it is appears that it may actually be the authors of such articles who lack in the way of honesty. 

Study acronyms: ATBC, Alpha-Tocopherol Beta Carotene Study; BLSA, Baltimore Longitudinal Study of Aging; EPIC-Greece, European Prospective Investigation into Cancer Greece; EUROASPIRE, European Action on Secondary and Primary Prevention through intervention to reduce events; FHS, Framingham Heart Study; GPS, Glostrup Population Study; HHS, Honolulu Heart Study; HLS, Health and Lifestyle Survey; HPFS, Health Professionals' Follow-Up Study; IBDH, Ireland-Boston Diet Heart Study; IIHD, Israeli Ischemic Heart Disease Study; JACC, Japan Collaborative Cohort Study; JPHC, Japan Public Health Center Based Study; KIHD, Kuopio Ischaemic Heart Disease Risk Factor Study; LRC, Lipid Research Clinics; MALMO, Malmo Diet and Cancer Study; NHS, Nurses' Health Study; SHS, Strong Heart Study; WES, Western Electric Study.

Vegetarian Diets and Quality of Life: Cause or Effect?

Very few would argue that simply excluding flesh from the diet will guarantee optimal health and longevity. However, the CBS Atlanta recently featured a concerning article, Study: Vegetarians Less Healthy, Lower Quality Of Life Than Meat-Eaters, suggesting that diets that exclude flesh promotes poor health. This article which has gathered much attention describes the findings of a cross-sectional survey from Austria that was published in PLoS One.1 This study has previously been addressed by Don Matesz in an very informative post. However, due to very serious omissions made by the CBS Atlanta, I felt that it was necessary to also address this study.

Vegetarian Diets and Perceived Health: Cause or Effect? 

It cannot be emphasized enough how important it is to recognize that this study, based on the Austrian Health Interview Survey (AT-HIS) examined dietary patterns after the subjects had developed health problems. Many vegetarians are not born into vegetarianism, but adopt a vegetarian diet later in life. Therefore, it is important to address why the vegetarians in this study adopted a flesh free diet. This important limitation was acknowledged by the Austrian researchers, who asserted:

Potential limitations of our results are due to the fact that the survey was based on cross-sectional data. Therefore, no statements can be made whether the poorer health in vegetarians in our study is caused by their dietary habit or if they consume this form of diet due to their poorer health status. We cannot state whether a causal relationship exists, but describe ascertained associations.

More importantly, in regards to causation the researchers asserted:

Our results have shown that vegetarians report chronic conditions and poorer subjective health more frequently. This might indicate that the vegetarians in our study consume this form of diet as a consequence of their disorders, since a vegetarian diet is often recommended as a method to manage weight and health.

The researchers suggested that if anything, it was not a flesh free diet that caused a higher rate of a number of health problems, but rather that it was poor health that caused these subjects to adopt a flesh free diet. This is similar to the phenomenon where former smokers report poorer perceived health than current smokers, because they quit smoking with the intention of alleviating poor health.2 This phenomenon is often referred to as reverse causality. 

Unfortunately, Benjamin Fearnow, the author of the article in the CBS Atlanta ignored the evidence suggesting that these results were the result of reverse causality, and instead suggested that a flesh free diet was actually the cause of a number of health problems:

...the vegetarian diet — characterized by a low consumption of saturated fats and cholesterol that includes increased intake of fruits, vegetables and whole-grain products — carries elevated risks of cancer, allergies and mental health disorders.

It is important to note that the Austrian Health Interview Survey did not measure food intake in actual detail. Subjects who reported consuming a flesh free diet were simply assumed to be consuming a diet poor in dietary cholesterol and saturated fat. However, in this study 36% of the vegetarian subjects were classified as lacto-ovo vegetarians, and 55% pescetarians (allowing fish, dairy and eggs). Only 9% were classified as vegans.1 Therefore, up to 91% of the subjects classified as vegetarians consumed dairy and eggs, being the richest sources of saturated animal fat and cholesterol, respectively. The CBS Atlanta failed to mention even the definition of a vegetarian diet used in this study, yet alone the breakdown of subjects in each category of vegetarian diet.

Vegetarian Diets and Cancer

At the time of the report, it was observed that 4.8% of the subjects of the Austrian Health Interview Survey classified as vegetarians had cancer, as opposed to 1.8% of the subjects following an omnivorous diet rich in meat. Unfortunately, no details were provided as to what portion of the studied population adopted a flesh free diet after diagnosis. However, data from previous studies suggest that cancer patients are highly motivated to adopt a plant based diet. As described previously: 

The results of a recent study from the Netherlands illustrates the critical importance of considering reverse causality in research on plant-based diets. The researchers found that 75% of the vegetarian participants with cancer adopted a vegetarian diet after diagnosis, consistent with previous research which found that cancer survivors are highly motivated to adopt a more plant-based diet with the intention of improving poor health.3 4

If the 75% figure from the study from the Netherlands is to be considered representative of this Austrian population, this would suggest that only 1.2% of the vegetarians adopted a flesh free diet prior to diagnosis of cancer. This is lower than the 1.8% figure for omnivores following a meat rich diet, but similar to that of the omnivores following a diet low in meat. Unfortunately, due to the lack of reliable data these estimates should be taken with a grain of salt. 

Prospective (forward-looking) studies which measure diet before diseases are diagnosed are much less likely to be complicated by reverse causality than cross-sectional studies, and therefore considered to be more appropriate for determining causality. I previously carried out a meta-analysis of 5 prospective cohort studies comparing the rates of cancer incidence in vegetarians compared to health conscious omnivores. For this review, I updated the meta-analysis to include the rates of major cancers in the Adventist Mortality and Adventist Health studies. In addition, I limited the inclusion criteria to studies that provided estimates specifically for subjects classified as either vegans, or lacto-ovo vegetarians.

In a meta-analysis including 7 prospective cohort studies, vegetarians had a statistically significant 9% lower risk of cancer incidence compared to health conscious omnivores (Fig. 1).5 6 7 8 9 It is important to note that meat intake was relatively low in the omnivorous group in these studies, especially taking into account that a significant portion of the omnivorous subjects were actually classified as semi-vegetarians. This suggests the difference in cancer incidence may be greater when compared to regular meat eaters.

FIGURE 1. Risk ratios and 95% CIs for fully adjusted random-effects models examining associations between vegetarian diets in relation to cancer incidence. ¹Mortality from cancers of the breast, colorectal, lung, prostate and stomach combined. VEG, vegetarian diet.

The finding of a decreased risk of cancer in vegetarians may be explained, in part, by a diet devoid in heme iron. Controlled feeding trials have established that NOCs (N-nitroso compounds) arising from heme iron in meat forms potentially cancerous DNA adducts in the human digestive tract, likely in part, explaining the significant association between heme iron and an increased risk of colorectal cancer in recent meta-analyses of prospective cohort studies.10 11 12 Heme iron has also been associated with numerous other cancers.

Vegetarian Diets and Heart Disease

In the Austrian Health Interview Survey, it was suggested that subjects classified as vegetarians were more likely to have had a history of heart attacks. It is important to note however, that, plant-based diets, poor in saturated fat and cholesterol have for long been adopted by individuals at risk of coronary heart disease. For example, it is known that in studies carried out as far back as the late 1950s, subjects with unfavorable blood cholesterol levels tended to limit intake of dietary cholesterol and saturated fat in order to improve cardiovascular risk factor.13

I previously carried out a meta-analysis of 7 prospective cohort studies comparing the rate of death of coronary heart disease of vegetarians compared to health conscious omnivores. For this review, I examined the incidence of coronary heart disease, and limited the inclusion criteria to studies that provided estimates specifically for subjects classified as either vegans, or lacto-ovo vegetarians. In a meta-analysis including 7 prospective cohort studies, vegetarians had a statistically highly significant 24% lower risk of coronary heart disease compared to health conscious omnivores (Fig. 2).5 6 7 14 15  

FIGURE 2. Risk ratios and 95% CIs for fully adjusted random-effects models examining associations between vegetarian diets in relation to coronary heart disease incidence. VEG, vegetarian diet.

The degree of reduction in risk of mortality from coronary heart disease observed in vegetarians in these cohort studies was generally in proportion to the expected reduced risk based on the differences in levels of total and non-HDL cholesterol, and blood pressure. This is supported by evidence from prospective cohort studies which found that diets characterized as being low in saturated fat and rich in dietary fiber decrease the risk of death from coronary heart disease. These findings are also supported by a recent meta-analysis of clinical trials and observational studies that found that vegetarian diets are associated with lower blood pressure and a lower risk of hypertension.16 Interestingly, the rates of hypertension tended to be lower in the vegetarians in the Austrian Health Interview Survey, suggesting that if the subjects adopted a vegetarian diet as a means to control hypertension, they were likely successful doing so.  

Vegetarian Diets and Mental Heath

In the Austrian Health Interview Survey, it was observed that subjects classified as vegetarians had a higher rate mental illnesses, defined as anxiety disorder or depression. Unfortunately, no data was provided as to what portion of the subjects adopted a vegetarian diet after developing these conditions. These findings have appealed to proponents of Paleoloithic diets who hypothesize that humans have a dietary requirement for meat in order to maintain large brains and mental health. However, in Powered By Plants: Natural Selection & Human Nutrition, Don Matesz examines an extensive body of research that casts considerable doubt on the hypothesis that meat is required to maintain mental health and is responsible for the evolution of the large human brain.

The findings from a number of clinical trials cast doubt on the hypothesis that an appropriately designed flesh free diet has adverse effects on, and that flesh rich diets, poor in carbohydrate have beneficial effects on overall mental health.

• Sacks and colleagues carried out a crossover trial to examine the effects of adding 250 g/day of beef isocalorically to the diet on blood cholesterol of vegetarians. As expected, during the meat phase total cholesterol and systolic blood pressure increased significantly. However, it was also observed that the participants experienced increased anger, anxiety, confusion, depression, and fatigue and less vigor compared to the vegetarian phase.17
• Beezhold and Johnston compared the mood scores of participants assigned to either a vegetarian diet, excluding all animal foods except dairy to participants assigned to either a omnivorous diet, or a diet that included fish, but excluded meat and poultry. The researchers found that the vegetarian group demonstrated significantly improved mood scores compared to both the omnivorous and fish groups.18
• Schweiger and colleagues compared the effects of a vegetarian diet and an omnivorous diet on global mood scores. They found that the vegetarian group demonstrated significantly better global mood, and that carbohydrate intake associated with better global mood.19
• Kieldsen-Kragh examined the effects of a vegetarian diet on rheumatoid arthritis. The researchers hypothesized that the participants may find the vegetarian diet too restrictive, and that therefore adherence to the diet would impose psychological distress on the them. However, contrary to their expectations, the vegetarian group demonstrated significantly improved physiological health, and were less anxious and depressed compared to the omnivorous group.20
• Brinkworth and colleagues examined the effects of a very low-carbohydrate diet and a low-fat diet on body weight and mood and cognitive function. Although there was no statistical difference in terms of weight loss between the groups, the participants assigned to the low-fat group demonstrated significantly improved mood scores compared to the participants assigned to the low-carbohydrate diet.21
• Holloway and colleagues carried out a crossover trial to examine the effects of a high-fat, low-carbohydrate diet on alterations to heart and brain function. The researchers found that the participants not only demonstrated significantly impaired cardiac health, but also impaired attention, memory recall speed, and mood while following the high-fat, low-carbohydrate diet.22
• Halyburton and colleagues examined the effects of a low and high-carbohydrate diet on mood and cognitive function. Although, unlike other studies, the researchers found that mood was similar in both groups, participants assigned to the low-fat diet demonstrated improved speed of processing compared to the participants assigned to the low-carbohydrate group.23

Mass Media as a Source of Health Information

The article featured in the CBS Atlanta is just one example of many studies that are misinterpreted, likely intentionally by the mass media. Unfortunately, the mass media is certainly not a reliable source for health information, as their primarily concern is to publish news that appeal to their targeted audience. In this case it was meat eaters who desired to hear negative things about vegetarian diets. This is likely why many important studies do not receive appropriate media attention,  and why consumers are either left in the dark or simply confused about health information.

Although there is convincing evidence of the health benefits of an appropriately planned diet that either excludes or significantly limits the intake of flesh, such findings cannot be extrapolated to all diets that exclude flesh. The definition of a vegetarian diet only provides information as to what foods an individual restricts, and not which foods are included. This is why the emphasis of a healthy diet also needs be on which foods are included, not only on those that are excluded. Future research in this area should address what foods vegetarians are substituting meat with,  the length of adherence to a vegetarian diet, and whether subjects adopted a vegetarian diet in order to alleviate poor health. This would allow for a considerably more meaningful interpretation of the effects of vegetarian diets.

Powered By Plants: Natural Selection & Human Nutrition - New Book by Don Matesz

I am proud to share the news that Don Matesz has released the book Powered By Plants: Natural Selection & Human Nutrition. Here is a brief description of the book:

In Powered By Plants: Natural Selection & Human Nutrition, Don Matesz proposes that a plant-based diet powered human evolution. Challenging anthropologists and advocates of low-carbohydrate and 'paleo' diets who claim that we require meat in our diet because meat-eating drove human evolution, Matesz cites a large body of evidence indicating that the human organism has numerous heritable anatomical, physiological, and biochemical features primarily adapted to acquisition or metabolism of whole plant foods, but lacks the heritable features expected as evidence of evolution primarily driven by meat consumption. While natural selection appears to have favored a human biology that thrives on a plant-based diet, sexual selection may explain the apparent paradox that we are athletically capable of hunting but highly susceptible to diseases caused by the luxury of meat consumption.  Matesz surveys human biology from head-to-toe, and, backed by hundreds of references, shows that our sensory, locomotive, manual, digestive, and reproductive systems, and our nutrient metabolism, are all adapted to a whole foods plant-based diet. This evidence indicates that consumption of animal products promotes disease because it conflicts with basic human biology. 

Without question, this is one of the most well researched books on the topic of evolutionary nutrition, containing hundreds of high quality relevant references. Throughout this book Don Matesz critically examines many of the claims published in peer reviewed journals by prominent proponents of the so-called Paleo diet. Matesz ultimately concludes that the hypothesis brought forward by these proponents that humans evolved and thrived on a predominantly meat based diet is over-simplistic and is in disagreement with a broad spectrum of evidence. Matesz demonstrates this by examining dozens of factors that cast doubt on the hypothesis that Paleolithic humans were the successful hunters that these proponents have made them out to be. For example, Matesz points out the relatively low hunting success rate and low energy return from hunting by modern African hunter-gatherers, casting doubt on whether Paleolithic humans who used more primitive weapons would have had a greater rate of success. Another important point raised is the known high rate of dehydration and hyperthermia among modern day athletes running long distances in warm climates despite being supplied with water throughout their races, suggesting that Paleolithic humans living in warm African climates who had fewer reliable sources of water would have unlikely relied on persistence hunting to provide any significant portion of their diet. 

In this book, Matesz also examines the natural occurring pathogens found in animal foods, demonstrating that these are found in similar quantities in both intensively farmed livestock and wild game, and provides a significant amount of evidence for their role in human disease. This book is an essential read for anyone interested in evolutionary nutrition, and highly recommended for anyone interested in health in general.

Don Matesz has studied the topic of evolutionary nutrition for the best part of two decades, and his extensive knowledge on this topic allowed him to be selected as a presenter for the first ever Ancestral Health Conference. Read about Matesz's fascinating decision to return to a plant-based diet after 14 years of following a Paleo diet, and his struggle with ill-health caused by this former diet in his blog post Farewell to Paleo.

Click here for the paperback copy and here for the digital copy. A sample of the book can be viewed on Amazon.

Other recommended reading by Don Matesz

Response to The Miracle Cure for Losing Weight

Phytates: Antinutrients or Essential Nutrients?

Grass-Fed Animal Products Prevent Obesity and Cardiovascular Disease?

Iron, Oxidation, Inflammation, and Aging

Wheat Belly: Fat or Flat

Wheat Again

Grass-Fed Animal Foods and Diseases of Civilization: Cardiovascular Disease in Ancient Civilizations

Vilhjalmur Stefansson was an Artic explorer known for his observations on the traditional living Inuit-Eskimo, which he lived together with in the winter of 1906-1907 in the Mackenzie Delta of Canada. Stefansson asserted that during this time he subsisted on traditional Inuit fare, based almost exclusively on flesh. In part based on less than extensive observations of the health of the Inuit, Stefansson hypothesized that a number of chronic and degenerative diseases, including cancer are diseases of civilization which can be prevented by adherence to a pre-modern diet and lifestyle. However, Stefansson did not suggest that only flesh based dietary patterns, such as that consumed by the traditional living Inuit, but also primarily vegetarian diets, such as that consumed by the Hunza may protect against such diseases.1 

The term diseases of civilization, which Stefansson has contributed to the popularization of is frequently referred to by proponents of Low-Carb, Paleo, Primal and Weston A. Price Foundation type diets. Many of these proponents have extrapolated limited suggestive evidence that obesity, type 2 diabetes, coronary heart disease, certain cancers, and a number of other chronic and degenerative diseases were uncommon during the Paleolithic period to suggesting that foods derived from naturally raised, grass-fed animals, as was consumed by Paleolithic humans must therefore somehow provide protection against these so-called diseases of civilization. Many of these proponents have also claimed that a vast number of scientific studies that have been used as evidence to conclude that animal foods increase the risk of such diseases have been complicated by confounding of other unhealthy foods and lifestyle factors, or by the use of unnaturally raised animal foods. This series of posts will examine the evidence to help determine whether these claimed confounding variables can actually explain the evidence linking animal foods with certain chronic and degenerative diseases, often referred to as diseases of civilization, but also as western diseases, lifestyle diseases and diseases of affluence.

In 1928, Stefansson and his colleague Karsten Anderson participated in a monitored experiment partly funded by the meat industry in which they consumed a flesh exclusive diet for the period of one year. Although the researchers concluded that these two men were in good health throughout the experiment, Anderson experienced a severe elevation in blood cholesterol, with measurements as high as 800 mg/dl on one occasion, which returned to pre-experiment levels after resuming a higher carbohydrate diet.2 A glucose tolerance test carried out immediately after the termination of the meat based experiment showed a marked rise in blood sugar in both men compared to a subsequent test carried out after resuming a higher carbohydrate diet. Glucose was detected in the urine of Anderson in the test following the meat based experiment, a marker of untreated diabetes. This abnormality was not detected in the subsequent test after resuming a higher carbohydrate diet.3

Short-term experiments such as this cannot provide adequate insight into the long-term consequences of following such a diet, as it can take many decades for diseases caused by exposure to harmful substances to become clinically significant. For example, the greatest risk of excess death from radiation-related solid cancers among the atomic bomb survivors of Hiroshima and Nagasaki was more than half a century after exposure.4 Furthermore, other flesh based experiments have resulted in considerably more unfavorable outcomes. For example, in 1906, Russell noted an even earlier experiment: 

A recent instance occurred in South Africa, where about twenty natives out of some hundreds who were supplied with a large amount of flesh, as an experiment, by mine-owners, died, and many others were ill.5

Cardiovascular Disease in Ancient Civilizations

The traditional living Inuit's were certainly
not immune from atherosclerosis

If a diet rich in naturally raised animal foods provides protection against cardiovascular disease as many proponents of Low-Carb type diets claim, it would be expected that traditional living populations consuming such a diet, particularly those living prior to the rapid westernization of the globe would demonstrate evidence of superior cardiovascular health compared to those populations who subsisted primarily on starchy staples, including grains, legumes and tubers. Populations who have inhabited the arctic, where scant plant matter is available throughout most parts of the year, such as the Inuit and Aleut were forced to subsist almost exclusively on hunted marine animals for extensive periods of time.1 6 This should make these populations suitable to study the hypothesis that naturally raised animal foods protect against cardiovascular disease.

Contrary to claims of the traditional living Inuit being immune from cardiovascular disease, evidence of severe atherosclerosis has been identified in several frozen mummies of Alaskan Inuit dating back to 400 CE and 1520 CE, both instances predating European contact.7 8 Atherosclerosis has also previously been identified in several artificially prepared mummies of Aleut-Unangan hunter gatherers who lived in the 18th century in the Aleutian Islands in Alaska.9 10 Recently the HORUS study, which examined an additional five recovered mummies of Unangan hunter gatherers who lived in the mid and late 19th century found definite evidence of atherosclerosis in several major arteries in all three who were over the age of 25.11

When considering the findings from all of these Alaskan Inuit and Aleut mummies it becomes evident that these Alaskan natives likely experienced a greater incidence of atherosclerosis, especially given the young mean age compared to the three other ancient populations studied in the HORUS study. Unlike the Alaskan natives, these other three populations, which were the ancient Egyptians, ancient Peruvians and Ancestral Puebloans practiced agriculture and consumed grains. 

In addition to evidence of atherosclerosis from native Alaskan mummies, reports from medical officers provide further evidence of unfavorable rates of cardiovascular disease among the Inuit before the rapid transition to the western diet. In 1940, based on decades of clinical practice and reviewing reports of medical officers dating all the way back 175 years ago, Bertelsen, who is considered the father of Greenland epidemiology stated in regards to the mortality patterns among the Greenland Inuit that: 

...arteriosclerosis and degeneration of the myocardium are quite common conditions among the Inuit, in particular considering the low mean age of the population.12

Bjerregaard and colleagues performed a literature review for studies addressing the incidence of atherosclerosis and cardiovascular disease among the Inuit of Alaska, Canada and Greenland spanning from the 1930s to more recent decades. The researchers found that the incidence of atherosclerosis was generally similar to that of other western populations that suffered from high rates of cardiovascular disease. Mortality from stroke was found to be even higher, and mortality from all cardiovascular diseases combined was found to be similar or even higher among the Inuit. The researchers also found that mortality from coronary heart disease among the Inuit was not significantly different after adjusting for ill-defined causes of cardiovascular death, suggesting that the substantial proportion of cardiovascular deaths being classified as ‘garbage codes’, particularly in Greenland may have hidden a significant portion of deaths from coronary heart disease. The researchers concluded: 

The mortality from all cardiovascular diseases combined is not lower among the Inuit than in white comparison populations. If the mortality from IHD [ischemic heart disease] is low, it seems not to be associated with a low prevalence of general atherosclerosis. A decreasing trend in mortality from IHD in Inuit populations undergoing rapid westernization supports the need for a critical rethinking of cardiovascular epidemiology among the Inuit and the role of a marine diet in this population.12

A similar phenomenon to the misclassification of deaths from coronary heart disease among the Inuit populations has also been observed in France, which may largely explain the so-called French Paradox. Data from the World Health Organization MONICA Project suggests that the official mortality statistics for France significantly underreport deaths from cardiovascular disease compared to other countries, with deaths from coronary heart disease being underestimated by 75%. Other reports suggest that this is likely explained by a much higher rate of French doctors classifying deaths as due to ‘other causes’ than in other countries.13 14

It has been observed that among the Alaskan Inuit a higher intake of saturated fat is associated with elevated blood pressure, insulin resistance, glucose intolerance and carotid atherosclerosis, suggesting that the traditional Inuit foods relatively rich in saturated fat were likely to have been detrimental to the cardiovascular health of the Inuit.15 16 17 It has also been observed that among Alaskan Inuit elevated LDL cholesterol is associated with a greater than fourfold increased risk of cardiovascular disease.18 Furthermore, rheumatic disorders that have been linked to cardiovascular disease, such as gout and rheumatoid arthritis have been found to be just as, or even more common among the Eskimo populations compared to that of the general North American population.19 20 Established risk factors, a number of which are likely adversely affected by the traditional Inuit diet can probably in part explain the evidence of severe atherosclerosis and unfavorable rates of cardiovascular disease observed among the traditional living Inuit and Aleut populations. 

In the HORUS study it was found that two of the four Ancestral Puebloan who lived in southwestern United States dating between 1500 BCE and 500 CE exhibited probable evidence of atherosclerosis, the two other both being under the age of 30. These Ancestral Puebloans were identified as being from a time when they were transitioning from hunter-gatherers to farmer-foragers, and were likely to have relied on hunted animal foods to supply at least a modest portion of their diet. An additional Ancestral Puebloan mummy aged 18-22 found from a later period after a greater transition towards agriculture did not exhibit any evidence of atherosclerosis.11

In the HORUS study the ancient Egyptian mummies exhibited the next greatest frequency of atherosclerosis, with 29 (38%) of the 76 of the mummies exhibiting at least probable evidence of atherosclerosis.11 In their book Protein Power, Michael and Mary Eades assert that the ‘diet of the average [ancient] Egyptian consisted primarily of carbohydrates’, which they suggest was ‘a veritable nutritionist’s nirvana… rich in all the foods believed to promote health and almost devoid of saturated fat and cholesterol'. These authors go on to suggesting that the carbohydrate rich diet of the ‘average Egyptian’ which they describe as being based on whole-grain wheat and barley supplemented by a variety of fruits, vegetables, legumes, nuts and some goats milk is responsible for the atherosclerosis and obesity exhibited by the ancient Egyptian mummies.21

The authors of Protein Power suggest that complex carbohydrates, such as wheat made the ancient Egyptians obese

There is much evidence that casts doubt on these authors description of the diets of the ancient Egyptian mummies. For example, Macko and colleagues have shown that isotope analyses of the amino-acid composition of hair from the ancient Egyptian mummies far more closely resemble that of modern westerners following an omnivorous diet than a vegetarian, and especially vegan diet.22 In addition, David and colleagues showed that evidence from hieroglyphic inscriptions on ancient Egyptian temples suggest that the elites of ancient Egyptian society, being those who were primarily mummified consumed a diet rich in flesh and saturated animal fat. These researchers addressed the confusion surrounding the diet and atherosclerosis of the ancient Egyptian mummies, asserting: 

It is important to point out that there was a marked difference between the mainly vegetarian diet most Egyptians ate and that of royalty and priests and their family members whose daily intake would have included these high levels of saturated fat. Mummification was practised by the elite groups in society, ensuring that their remains have survived to provide clear indications of atherosclerosis; by contrast, there is a lack of evidence that the condition existed among the less well-preserved remains of the [mainly vegetarian] lower classes.23

The findings of a lower incidence of atherosclerosis among the lower classes of ancient Egypt who subsisted primarily on a carbohydrate-rich vegetarian diet are consistent with observations in Egypt in the early 20th century. In 1934, Rosenthal asserted:

Of interest is the report of Ismail in Egypt, who has communicated that among his private patients, whose diet is similar to that of the Europeans, the incidence of atherosclerosis is high, while in his hospital practice, composed mainly of natives, who subsist largely on a carbohydrate diet, the incidence of atherosclerosis is low.24

It is clear that the authors of Protein Power have confused the diet of the elites of the ancient Egyptian society, who certainly cannot be considered as the 'average Egyptian' with the largely vegetarian diet of the of the lower classes who exhibit a lack of atherosclerosis, and which scant evidence suggests were obese. The findings from ancient Egyptian mummies do not support the claimed benefits of a low carbohydrate, high saturated fat diet promoted by these authors.

In the HORUS study, despite having the highest mean age, nearly 10 years older than that of the Unangan and Ancestral Puebloans mummies, the ancient Peruvians exhibited the lowest incidence of atherosclerosis, being evident in 13 (25%) of 51 of the mummies. Compared to these other studied ancient populations, the Peruvians likely relied more on staple plant foods, such as corn, beans and tubers, although did consume some domesticated and hunted animals.11

The researchers of the HORUS study suggested that exposure to smoke from fire used for cooking and25

heating may help explain some of the degree of atherosclerosis identified in these ancient populations. However, the description of the use of fire for cooking in ancient Egypt provided by these researchers would apply primarily to the lower classes of ancient Egypt which exhibit a lack of atherosclerosis, rather than the mummified elites that these researchers examined who would typically have had servants to cook for them.

Gout was known to be common among 

the Mongols of the Golden Horde

In regards to the traditional living Inuit and Aleut, it has been suggested that the extensive exposure to seal oil lamps may help explain the relatively severe degree of atherosclerosis in these populations.  These findings should however be considered in light of evidence of atherosclerosis in other populations which have high exposure to hazardous smoke but consume contrasting diets. For example, it has been observed that the Papua New Guinean highlanders have a smoking prevalence of greater than 70% for males and 20% for females while also being exposed to smoke for up to twelve hours a day due to the use of centrally placed open wood fires in their houses which lack both ventilation and chimneys. Despite such a high exposure to hazardous smoke it has been observed that the Papua New Guinean highlanders have among the lowest age-adjusted incidence of atherosclerosis of any studied population. However, unlike the Inuit, the Papua New Guinean highlanders traditionally consumed a plant based diet with carbohydrate supplying more than 90% of total energy intake, predominantly derived from sweet potatoes.26 27

Another population that have historically been documented to subsist almost exclusively on a diet derived from grass-fed, free-ranging animals are the largely nomadic Mongolians. John of Plano Carpini who visited the Mongols in the mid-13th century noted:

[The Mongols] have neither bread nor herbs nor vegetables nor anything else, nothing but meat… They drink mare’s milk in very great quantities if they have it; they also drink the milk of ewes, cows, goats and even camels.28

Smith reviewed the literature regarding the health of the Mongols from the 13th century and noted that a number of unfavorable cardiovascular risk factors, including obesity and gout were both common disorders. Smith went on to state:

Cardio-vascular problems, although not then subject to diagnosis, may be suspected as well.29

In 1925, Kuczynski reported on the nomadic pastoralists of the Kirghiz and Dzungarian Steppes in Central Asia and northern China that were of Mongolian descent. Similar to the observations of the diet of the nomadic Mongols of the 13th century, Kuczynski observed that these nomadic pastoralists subsisted almost exclusively on enormous quantities of meat and milk from grass-fed, free-ranging animals. Other authors have also come to the same conclusions regarding the composition of the diet of the nomadic pastoralists of the Central Asian Steppes. For example, Tayzhanov asserted:

…the people [of the steppe] lived exclusively on meat, fat and sour milk. Bread was added only later and even then some households did not adopt or consume this food.30

Similarly, Barfield asserted:

In good legendary style, the pure Central Asian nomads eat only meat, marrow, and milk products {preferably ferments}. They despise farmers, farming, and grain…31

These findings suggest that the diet of these nomadic pastoralists of the Central Asian Steppes was almost exclusively animal based, virtually devoid of grains, legumes and refined carbohydrates. This should make these populations also suitable to study the hypothesis that naturally raised animal foods protect against cardiovascular disease. However, not only did Kuczynski observe that these nomadic pastoralists suffered from high rates of obesity and gout similar to the Mongols of the 13th century, Kuczynski's observations further extended to the diagnosis of cardiovascular disease and other dietary related disorders. Kuczynski asserted:

They get arteriosclerosis in an intense degree and often at an early age as shown by cardiac symptoms, nervous disordes, typical changes of the peripheral vessels, nephrosclerosis and, finally, apoplectic attacks. Even in men thirty-two years old I frequently observed arcus senilis.32

It was also observed that in the 1960s the prevalence of coronary heart disease among the nomadic pastoralists in Xinjiang in northern China who consumed large quantities of animal fat from grass-fed, free-ranging animals was more than seven times higher than that of other populations both within Xinjiang and throughout China which consumed significantly less animal fat.33 These observations support the suggestion that cardiovascular disease was common among the Mongols of the 13th century who subsisted almost exclusively on a diet based on grass-fed, free-ranging animals.

Dispelling Grass-Fed Fairy Tales

These findings from populations living before the 20th century suggest that similar to the findings from people studied in more modern times, a greater intake of minimally refined plant foods strongly predicts a lower prevalence of atherosclerosis and cardiovascular disease. These findings cast doubt on the hypothesis that foods from organic, naturally raised animals protect against cardiovascular disease compared to staple plant foods. Furthermore, these findings suggest that the traditional living populations that relied predominantly on naturally raised animal based foods suffered from complications related to cardiovascular disease at a relatively young age and are poor role models for health.

Future posts in this series will further address how naturally raised animal foods influence cardiovascular disease, as well as other so-called diseases of civilization.


Please post any comments in the Discussion Thread.