Research On Meat And Health

Consumption of Unprocessed Red Meat Is Not a Risk to Health
from World Farmers’ Organisation (WFO) Scientific Council

A synopsis of five significant, recent and broad-scale scientific investigations on the health risks and health benefits of red meat consumption indicates that there is no convincing scientific evidence for assertions about harmful health effects of unprocessed red meat intake. If at all, the data very slightly lean toward an association of red meat consumption and protective health benefits. Overall, any of the statistical associations of up to 100 grams of red meat consumption per capita per day are so weak that they should be considered neutral. It is notable that less than 1% of the global population consumes more than 85 grams of red meat per day. From a global public health perspective, then, red meat consumption above the threshold of 85 grams is so negligible as to be irrelevant. National governments and supranational organizations such as the EU and UN, and their initiatives such as this year’s UN Food Systems Summit, as well as international business and consumer associations, would be wrong to assume that a scientific consensus exists to justify policies to reduce red meat consumption in the general population for health reasons.

Associations of unprocessed and processed meat intake with mortality and cardiovascular disease in 21 countries [Prospective Urban Rural Epidemiology (PURE) Study]: a prospective cohort study
by Romaina Iqbal, et al

In a large multinational prospective study, we did not find significant associations between unprocessed red meat and poultry intake and mortality or major CVD.

Controversy on the correlation of red and processed meat consumption with colorectal cancer risk: an Asian perspective (full paper)
by Sun Jin Hur, et al

We conducted an in-depth analysis of prospective, retrospective, case-control and cohort studies, systematic review articles, and IARC monograph reports, which revealed that the IARC/WHO report weighted the results of studies based in Western countries more and that the correlation between intake of processed meat products and colorectal cancer incidence in Asians is not clearly supported. Among 73 epidemiological studies, approximately 76% were conducted in Western countries, whereas only 15% of studies were conducted in Asia. Furthermore, most studies conducted in Asia showed that processed meat consumption is not related to the onset of cancer. Moreover, there have been no reports showing significant correlation between various factors that directly or indirectly affect colorectal cancer incidence, including processed meat products types, raw meat types, or cooking methods.

Red meat and colon cancer: A review of mechanistic evidence for heme in the context of risk assessment methodology
by Claire Kruger & Yuting Zhou

In conclusion, the methodologies employed in current studies of heme have not provided sufficient documentation that the mechanisms studied would contribute to an increased risk of promotion of preneoplasia or colon cancer at usual dietary intakes of red meat in the context of a normal diet.

Meat intake and cause-specific mortality: a pooled analysis of Asian prospective cohort studies
by Jung Eun Lee, et al

Ecological data indicate an increase in meat intake in Asian countries; however, our pooled analysis did not provide evidence of a higher risk of mortality for total meat intake and provided evidence of an inverse association with red meat, poultry, and fish/seafood. Red meat intake was inversely associated with CVD mortality in men and with cancer mortality in women in Asian countries.”

No association between meat intake and mortality in Asian countries
by Dominik D Alexander

After pooling data across the cohorts, Lee et al (3) observed no significant increases in risk of all-cause mortality comparing the highest with the lowest intake categories of total meat, red meat, poultry, or fish. In contrast, most associations were in the inverse direction with significant decreased risks for poultry (among men and women) and fish (women), with a nearly significant decreased risk with greater intakes of red meat in women (upper CI: 1.00). Similar patterns of associations (most indicating a decreased risk) were observed for cause-specific mortality; comparing the highest with the lowest intake categories, significant decreased risks of CVD mortality with red meat (men) and cancer mortality with red meat and poultry (women) were observed. The only significant positive association in the overall analyses was for the highest category of fish intake and cancer mortality. Little effect modification was apparent after stratification by educational level and by BMI.

Cancer link to red meat consumption may not exist for Asians: Study
by Pearly Neo

Researchers in Korea have discovered that the link between meat consumption and colorectal cancer may not apply to Asians. The meat-colorectal cancer correlation was first elucidated in a report by the International Agency for Research on Cancer (IARC) in 2015. The Korean researchers carried out a thorough review of over 500 studies that had previously been conducted on meat consumption and cancer. These included cohort and case-control analyses, prospective and retrospective studies, other review articles, as well as IARC monograph reports. Of these, 73 human epidemiological studies were selected for more in-depth analysis.

“The aim was to investigate the relationship between meat intake and colorectal cancer risk from an Asian, particularly Korean, perspective,” ​said the authors. “[We found] that approximately 76% [of the studies] were conducted in Western countries, whereas only 15% of studies were conducted in Asia. Furthermore, most studies conducted in Asia showed that processed meat consumption is not related to the onset of cancer.”​ “[As such], the correlation between intake of processed meat products and colorectal cancer incidence in Asians is not clearly supported,” ​they concluded. The study also reported that there do not exist any conclusive reports proving a significant correlation between meat consumption and colorectal cancer, whether it involves processed meats, raw meats or the relevant cooking methods.

Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium
by Bradley C. Johnston, et al

Recommendations: The panel suggests that adults continue current unprocessed red meat consumption (weak recommendation, low-certainty evidence). Similarly, the panel suggests adults continue current processed meat consumption (weak recommendation, low-certainty evidence). […]

Contemporary dietary guidelines recommend limiting consumption of unprocessed red meat and processed meat. For example, the 2015–2020 Dietary Guidelines for Americans recommend limiting red meat intake, including processed meat, to approximately 1 weekly serving (1). Similarly, United Kingdom dietary guidelines endorse limiting the intake of both red and processed meat to 70 g/d (2), and the World Cancer Research Fund/American Institute for Cancer Research recommend limiting red meat consumption to moderate amounts and consuming very little processed meat (3). The World Health Organization International Agency for Research on Cancer has indicated that consumption of red meat is “probably carcinogenic” to humans, whereas processed meat is considered “carcinogenic” to humans (4). “These recommendations are, however, primarily based on observational studies that are at high risk for confounding and thus are limited in establishing causal inferences, nor do they report the absolute magnitude of any possible effects. Furthermore, the organizations that produce guidelines did not conduct or access rigorous systematic reviews of the evidence, were limited in addressing conflicts of interest, and did not explicitly address population values and preferences, raising questions regarding adherence to guideline standards for trustworthiness (5–9). […]

In our assessment of causal inferences on unprocessed red meat and processed meat and adverse health outcomes, we found that the absolute effect estimates for red meat and processed meat intake (13, 16) were smaller than those from dietary pattern estimates (14), indicating that meat consumption is unlikely to be a causal factor of adverse health outcomes (Table 1).

Should dietary guidelines recommend low red meat intake?
by Frédéric Leroy & Cofnas

3. Meat eating and chronic disease: evaluation of the evidence
3.1. Evidence from observational studies needs to be interpreted with care

As a first point of concern, the input data obtained from food frequency questionnaires should be interpreted prudently as they can be problematic for a variety of reasons (Schatzkin et al., 2003; Archer et al., 2018; Feinman, 2018). Social desirability bias in food reporting is just one example, as reported consumption can be affected by the perceived health status of certain foods. Not all self-defined vegetarians avoid meat, which is suggestive of a considerable risk for underreported intake in health-conscious groups (Haddad & Tanzman, 2003).

Secondly, diets are difficult to disentangle from other lifestyle factors. It has been shown that Western-style meat eating is closely associated with nutrient-poor diets, obesity, smoking, and limited physical activity (Alexander et al., 2015; Fogelholm et al., 2015; Grosso et al., 2017; Turner & Lloyd, 2017). Given the fact that health authorities have been intensely promoting the view that meat is unhealthy, health-conscious people may be inclined to reduce intake. Typically, the associations between meat eating and disease tend to be higher in North American than in European or Asian cohort studies, indicating the presence of lifestyle bias and the need for cross-cultural assessments (Wang et al., 2016; Grosso et al., 2017; Hur et al., 2018). A pooled analysis of prospective cohort studies in Asian countries even indicated that red meat intake was associated with lower cardiovascular mortality in men and cancer mortality in women (Lee et al., 2013). Likewise, when omitting Seventh-Day Adventist studies from meta-analyses, the beneficial associations with cardiovascular health for vegetarian diets are either less pronounced or absent indicating the specific effects of health-conscious lifestyle rather than low meat consumption as such (Kwok et al., 2014; FCN, 2018). This is important, as Seventh-Day Adventism has had considerable influence on dietary advice worldwide (Banta et al., 2018).

As a third point, the relative risks (RRs) obtained from observational studies are generally low, i.e., much below 2. In view of the profusion of false-positive findings and the large uncertainty and bias in the data due to the problems mentioned above (Boffetta et al., 2008; Young & Karr, 2011), such low RR levels in isolation would not be treated as strong evidence in most epidemiological research outside nutrition (Shapiro, 2004; Klurfeld, 2015). Relationships with RRs below 2, which are susceptible to confounding, can be indicative but should always be validated by other means, such as randomized controlled trials (RCTs) (Gerstein et al., 2019). The association between meat eating and colorectal cancer, for instance, leads to an RR estimate below 1.2, whereas for the association between visceral fat and colorectal neoplasia this value equals 5.9 (Yamamoto et al., 2010). The latter provides a robust case that is much more deserving of priority treatment in health policy development. […]

3.2. Intervention studies have not been able to indicate unambiguous detrimental effects

As stated by Abete et al. (2014), epidemiological findings on meat eating “should be interpreted with caution due to the high heterogeneity observed in most of the analyses as well as the possibility of residual confounding”. The interactions between meat, overall diet, human physiology (including the gut microbiome), and health outcomes are highly intricate. Within this web of complexity, and in contrast to what is commonly stated in the public domain (Leroy et al., 2018a), the current epidemiological and mechanistic data have not been able to demonstrate a consistent causal link between red meat intake and chronic diseases, such as colorectal cancer (Oostindjer et al., 2014; Turner & Lloyd, 2017).

RCTs can play an important role in establishing causal relationships, and generally provide much stronger evidence than that provided by observational data. However, even RCTs are not fail-safe and can also be prone to a range of serious flaws (Krauss, 2018). Intervention studies that overlook the normal dietary context or use non-robust biomarkers should be interpreted with caution, and do not justify claims that there is a clear link between meat and negative health outcomes (see Turner & Lloyd, 2017; Kruger & Zhou, 2018). The available evidence generally suggests that interventions with red meat do not lead to an elevation of in vivo oxidative stress and inflammation, which are usually cited as being part of the underlying mechanisms triggering chronic diseases (Mann et al., 1997; Hodgson et al., 2007; Turner et al., 2017). Even in an epidemiological cohort study that was suggestive of an inflammatory response based on an increased CRP level, this effect became non-significant upon adjustment for obesity (Montonen et al., 2013). Moreover, a meta-analysis of RCTs has shown that meat eating does not lead to deterioration of cardiovascular risk markers (O’Connor et al., 2017). The highest category of meat eating even paralleled a potentially beneficial increase in HDL-C level. Whereas plant-based diets indeed seem to lower total cholesterol and LDL-C in intervention studies, they also increase triglyceride levels and decrease HDL-C (Yokoyama et al., 2017), which are now often regarded as superior markers of cardiovascular risk (Jeppesen et al., 2001).

Based on the above, we conclude that there is a lack of robust evidence to confirm an unambiguous mechanistic link between meat eating as part of a healthy diet and the development of Western diseases. It is paramount that the available evidence is graded prior to developing policies and guidelines, making use of quality systems such as GRADE (Grading of Recommendations Assessment, Development and Evaluation; Guyatt et al., 2008). One of the founders of the GRADE system has issued a public warning that the scientific case against red meat by the IARC panel of the WHO has been overstated, doing “the public a disservice” (Guyatt, 2015). The IARC’s (2015) claim that red meat is “probably carcinogenic” has never been substantiated. In fact, a risk assessment by Kruger and Zhou (2018) concluded that this is not the case. Such hazard classification systems have been heavily criticized, even by one of the members of the IARC working group on red meat and cancer (Klurfeld, 2018). They are accused of being outmoded and leading to avoidable health scares, public funding of unnecessary research and nutritional programs, loss of beneficial foods, and potentially increased health costs (Boyle et al., 2008; Anonymous, 2016; Boobis et al., 2016).

3.3. A scientific assessment should not overlook conflicting data

Dietary advice that identifies meat as an intrinsic cause of chronic diseases often seems to suffer from cherry-picking (Feinman, 2018). One example of a fact that is typically ignored is that hunter-gatherers are mostly free of cardiometabolic disease although animal products provide the dominant energy source (about two-thirds of caloric intake on average, with some hunter-gatherers obtaining more than 85% of their calories from animal products; Cordain et al., 2000, 2002). In comparison, contemporary Americans obtain only about 30% of calories from animal foods (Rehkamp, 2016).

Whereas per capita consumption of meat has been dropping over the last decades in the US, cardiometabolic diseases such as type-2 diabetes have been rapidly increasing. Although this observation does not resolve the question of causality one way or the other, it should generate some skepticism that meat is the culprit (Feinman, 2018). Moreover, several studies have found either that meat intake has no association with mortality/morbidity, or that meat restriction is association with various negative health outcomes (e.g., Key et al., 2009; Burkert et al., 2014; Kwok et al., 2014; Lippi et al., 2015; Hur et al., 2018; Iguacel et al., 2018; Yen et al., 2018). As another example of conflicting information, the epidemiological association pointing to a potential role of the meat nutrient L-carnitine in atherosclerosis via trimethylamine N-oxide (TMAO) formation (Koeth et al., 2013), is contradicted by intervention studies (Samulak et al., 2019) and epidemiological data showing that fish intake, being by orders of magnitude the largest supplier of TMAO (Zhang et al., 1999), improves triglycerides and HDL levels (Alhassan et al., 2017). […]

5. Meat avoidance leads to a loss of nutritional robustness

Diets poor in animal source foods can lead to various nutritional deficiencies, as already described more than a century ago for the case of pellagra (Morabia, 2008), a condition which remains relevant today for poorly planned vegan diets (Ng & Neff, 2018). Advocates of vegetarian/vegan diets usually admit that these diets must indeed be “well-planned” in order to be successful, which involves regular supplementation with nutrients such as B12. However, realistically, many people are not diligent about supplementation, and will often dip into deficient or borderline-deficient ranges if they do not obtain nutrients from their regular diet. In such cases, general malnutrition (Ingenbleek & McCully, 2012), poorer health (Burkert et al., 2014), and nutrient limitations (Kim et al., 2018) may be the result, as found in various countries, such as Denmark (Kristensen et al., 2015), Finland (Elorinne et al., 2016), Sweden (Larsson & Johansson, 2002), and Switzerland (Schüpbach et al., 2017). For example, a substantial number of vegetarians and vegans are in the deficient or borderline-deficient range for B12 (Herrmann & Geisel, 2002; Herrmann et al., 2003), despite the fact that the need for B12 supplementation is well-publicized (see also Herbert, 1994; Hokin & Butler, 1999; Donaldson, 2000; Elmadfa & Singer, 2009; Gilsing et al., 2010; Obersby et al., 2013; Pawlak et al. 2013, 2014; Pawlak, 2015; Woo et al., 2014; Naik et al., 2018). B12 deficiency is particularly dangerous during pregnancy (Specker et al., 1988, 1990; Bjørke Monsen et al., 2001; Koebnick et al., 2004), childhood (Rogers et al., 2003) and adolescence (van Dusseldorp et al., 1999; Louwman et al., 2000).

Other potentially challenging micronutrients for people on plant-based diets include (but are not limited to) iodine (Krajcovicová-Kudlácková et al., 2008; Leung et al., 2011; Brantsaeter et al., 2018), iron (Wilson & Ball, 1999; Wongprachum et al., 2012; Awidi et al., 2018), selenium (Schultz & Leklem, 1983; Kadrabová et al., 1995), and zinc (Foster et al., 2013). Even if plant-based diets contain alpha linolenic acid, this may not (as noted) prevent deficiencies in the long-chain omega-3 fatty acids EPA and DHA (Rosell et al., 2005), which can pose serious risks in pregnancy and for growing children (Burdge et al., 2017; Cofnas, 2019).

Risks of nutritional deficiency are also documented by an extensive list of clinical case reports in the medical literature, with serious and sometimes irreversible pathological symptoms being reported for infants (e.g., Shinwell & Gorodisher, 1982; Zengin et al., 2009; Guez et al., 2012; Bravo et al., 2014; Kocaoglu et al., 2014; Goraya et al., 2015), children (e.g., Colev et al., 2004; Crawford & Say, 2013), adolescents (e.g., Chiron et al., 2001; Licht et al., 2001; O’Gorman et al., 2002), and adults (e.g., Milea et al., 2000; Brocadello et al., 2007; De Rosa et al., 2012; Førland & Lindberg, 2015). The latter reports commonly refer to failure to thrive, hyperparathyroidism, macrocytic anemia, optic and other neuropathies, lethargy, degeneration of the spinal cord, cerebral atrophy, and other serious conditions. Although the direction of causality is not clear, meat avoidance is statistically associated with eating disorders and depression (Zhang et al., 2017; Barthels et al., 2018; Hibbeln et al., 2018; Matta et al., 2018; Nezlek et al., 2018) and may mirror neurological problems (Kapoor et al., 2017).

Our main concern is that avoiding or minimizing meat consumption too strictly may compromise the delivery of nutrients, especially in children and other vulnerable populations. Evidently, health effects of plant-based approaches depend largely on the dietary composition (Satija et al., 2016). Yet, the more restricted the diet and the younger the age, the more this will be a point of attention (Van Winckel et al., 2011). According to Cofnas (2019), however, even realistic vegetarian diets that include diligent supplementation can put children at risk for deficiencies and thereby compromise health in both the short and long term. There is some direct and indirect evidence that the elevated phytoestrogen intake associated with low-meat diets may pose risks for the development of the brain and reproductive system (Cofnas, 2019). Moreover, attempts to introduce dietary modifications that are also compatible with vegan philosophy often pose a medicosocial challenge (Shinwell & Gorodischer, 1982). In our opinion, the official endorsement of diets that avoid animal products as healthy options is posing a risk that policy makers should not be taking. As stated by Giannini et al. (2006): “It is alarming in a developed country to find situations in which a child’s health is put at risk by malnutrition, not through economic problems but because of the ideological choices of the parents”.

Related posts:

Dietary Risk Factors for Heart Disease and Cancer
Blue Zones Dietary Myth
Eat Beef and Bacon!
Are ‘vegetarians’ or ‘carnivores’ healthier?
Vegetarianism is an Animal-Based Diet
Being “mostly vegan” is like being “a little pregnant.”
Plant-Based Nutritional Deficiencies
True Vitamin A For Health And Happiness
Hubris of Nutritionism
Ancient Greek View on Olive Oil as Part of the Healthy Mediterranean Diet
Wild-Caught Salmon and Metabolic Health
Early Research On the Industrial Diet
Amish Paradox
Moral Panic and Physical Degeneration
Health From Generation To Generation
Ancient Atherosclerosis?

Are ‘vegetarians’ or ‘carnivores’ healthier?

Nutrition studies has been plagued with problems. Most of the research in the past was extremely low quality. Few other fields would allow such weak research to be published in peer-reviewed journals. Yet for generations, epidemiological (observational and correlational) studies were the norm for nutrition studies. This kind of research is fine for preliminary exploration in formulating new hypotheses to test, but it is entirely useless for proving or disproving any given hypothesis. Shockingly, almost all of medical advice and government recommendations on diet and nutrition are based on this superficial and misleading level of results.

The main problem is there has been little, if any, control of confounding factors. Also, the comparisons used were pathetically weak. It turns out that, in studies, almost any dietary protocol or change improves health compared to a standard American diet (SAD) or other varieties of standard industrialized diets based on processed foods of refined carbs (particularly wheat), added sugar (particularly high fructose corn syrup), omega-6 seed oils (inflammatory, oxidative, and mutagenic), food additives (from glutamate to propionate), and nutrient-deficient, chemical-drenched agricultural crops (glyphosate among the worst). Assuming the dog got decent food, even eating dog shit would be better for your health than SAD.

Stating that veganism or the Mediterranean diet is healthier than what most people eat really tells us nothing at all. That is even more true when the healthy user effect is not controlled for, as typically is the case with most studies. When comparing people on these diets to typical meat eaters, the ‘carnivores’ also are eating tons of carbs, sugar, and seed oils with their meat (buns, french fries, pop, etc; and, for cooking and in sauces, seed oils; not to mention snacking all day on chips, crackers, cookies, and candy). The average meat-eater consumes far more non-animal foods than animal foods, and most processed junk food is made mostly or entirely with vegan ingredients. So why do the animal foods get all the blame? And why does saturated fat get blamed when, starting back in the 1930s, seed oils replaced lard as the main source of cooking fat/oil?

If scientists in this field were genuinely curious, intellectually humble, not ideologically blinded, and unbiased by big food and big farm funding, they would make honest and fair comparisons to a wide variety of optimally-designed diets. Nutritionists have known about low-carb, keto, and carnivore diets for about a century. The desire to research these diets, however, has been slim to none. The first ever study of the carnivore diet, including fully meat-based, is happening right now. To give some credit, research has slowly been improving. I came across a 2013 study that compared four diets: “vegetarian, carnivorous diet rich in fruits and vegetables, carnivorous diet less rich in meat, and carnivorous diet rich in meat” (Nathalie T. Burkert et al, Nutrition and Health – The Association between Eating Behavior and Various Health Parameters: A Matched Sample Study).

It’s still kind of amusing that the researchers called carnivorous a “diet rich in fruits and vegetables” and a “diet less rich in meat.” If people are mostly eating plant foods or otherwise not eating much meat, how exactly is that carnivorous in any meaningful and practical sense? Only one in four of the diets were carnivorous in the sense the average person would understand it, as a diet largely based on animal foods. Even then, it doesn’t include a carnivorous diet entirely based on animal foods. Those carnivores eating a “diet rich in meat” might still be eating plenty of processed junk food, their meat might still be cooked or slathered in harmful seed oils and come with a bun, and they might still be washing it down with sugary drinks. A McDonald’s Big Mac meal could be considered as part of a diet rich in meat, just because meat represents the greatest portion of weight and calories. Even if their diet was only 5-10% unhealthy plant foods, it could still be doing severe damage to their health. One can fit in a fairly large amount of carbs, seed oils, etc in a relatively small portion of the diet.

I’m reminded of research that defines a “low-carb diet” as any carb intake that is 40% or below, but other studies show that 40% is the absolute highest point of carb intake for most hunter-gatherers (discussed here with links to references). As high and low are relative concepts in defining carb intake, what is considered a meat-rich diet would be relative as well. I doubt these studied carnivorous “diets rich in meat” are including as high amount of animal foods as found in the diets of Inuit, Masai, early Americans, and Paleolithic humans. So what is actually being compared and tested? It’s not clear. This was further confounded in how vegans, vegetarians, and pescetarians (fish-eaters) were combined into a single group mislabeled as ‘vegetarian’, considering that vegetarians and pescetarians technically could eat a diet primarily animal-based if they so chose (dairy, eggs, and/or fish) and I know plenty of vegetarians who eat more cheese than they do fruits and vegetables. Nonetheless, at least these researchers were making a better comparison than most studies. They did try to control for other confounders such as pairing each person on a plant-based diet with “a subject of the same sex, age, and SES [socioeconomic status]” from each of the other three diets.

What were the results? Vegetarians, compared to the most meat-based of the diets, had worse outcomes for numerous health conditions: asthma, allergies, diabetes, cataracts, tinnitus, cardiac infarction, bronchitis, sacrospinal complaints, osteoporosis, gastric or intestinal ulcer, cancer, migraine, mental illness (anxiety disorder or depression), and “other chronic conditions.” There were only a few health conditions where the plant-based dieters fared better. For example, the so-called ‘vegetarians’ had lower rates of hypertension compared to carnivores rich in meat and less rich in meat, although higher rates than those carnivores rich in fruits and vegetables (i.e., more typical omnivores).

This is interesting evidence about the diets, though. If the carnivorous diets were low enough in starchy and sugary plant foods and low enough in dairy, they would be ketogenic which in studies is known to lower blood pressure and so would show a lesser rate of hypertension. This indicates that none of these diets are low-carb, much less very low-carb (ketogenic). The plant-based dieters in this study also had lower rates of stroke and arthritis, these being other health benefits seen on a ketogenic diet, and so this further demonstrates that this study wasn’t comparing high-carb vs low-carb as one might expect from how the diets were described in the paper. That is to say the researchers didn’t include a category for a ketogenic carnivore diet or even a ketogenic omnivore diet, much less a ketogenic ‘vegetarian’ diet as a control. Keep in mind that keto-carnivore is one of the most common forms of those intentionally following a carnivore diet. And keep in mind that plant-based keto is probably more popular right now than keto-carnivore. So, the point is that these unexpected results are examples of the complications with confounding factors.

The only other result that showed an advantage to the ‘vegetarians’ was less urinary incontinence, which simply means they didn’t have to pee as often. I haven’t a clue what that might mean. If we were talking about low-carb and keto, I’d suspect that the increased urination for the ‘carnivorous’ diets was related to decreased water retention (i.e., bloating) and hence the water loss that happens as metabolism shifts toward fat-burning. But since we are confident that such a diet wasn’t included in the study, these results remain anomalous. Of all the things that meat gets blamed for, I’ve never heard of anyone suggesting that it causes most people to urinate incessantly. That is odd. Anyway, it’s not exactly a life-threatening condition, even if it were caused by carnivory. It might have something to do with higher-fat combined with higher-carb, in the way that this combination also contributes to obesity, whereas high-fat/low-carb and low-fat/high-carb does not predispose one to fat gain. The ‘vegetarianism’ in this study was being conflated with a low-fat diet, but all of the four categories apparently were varying degrees of higher carb.

The basic conclusion is that ‘vegetarians’, including vegans and pescetarians, have on average poorer health across the board, with a few possible exceptions. In particular, they suffer more from chronic diseases and report higher impairment from health disorders. Also, not only these ‘vegetarians’ but also meat-eaters who ate a largely plant-based diet (“rich in fruits and vegetables”) consult doctors more often, even as ‘vegetarians’ are inconsistent about preventative healthcare such as check-ups and vaccinations. Furthermore, “subjects with a lower animal fat intake demonstrate worse health care practices,” whatever that exactly means. Generally, ‘vegetarians’ “have a lower quality of life.”

These are interesting results since the researchers were controlling for such things as wealth and poverty, and so it wasn’t an issue of access to healthcare or the quality of one’s environment or level of education. The weakness is that no data was gathered on macronutrient ratios of the subjects’ diets, and no testing was done on micronutrient content in the food and potential deficiencies in the individuals. Based on these results, no conclusions can be made about causal direction and mechanisms, but it does agree with some other research that finds similar results, including with other health conditions such as vegans and vegetarians having greater infertility. Any single one of these results, especially something like infertility, points toward serious health concerns involving deeper systemic disease and disorder within the body.

But what really stands out is the high rate of mental illness among ‘vegetarians’ (about 10%), twice as high as the average meat-eater (about 5%) which is to say the average Westerner, and that is with the background of the Western world having experienced a drastic rise in mental illness over the past couple of centuries. And the only mental illnesses considered in this study were depression and anxiety. The percentage would be so much higher if including all other psychiatric conditions and neurocognitive disorders (personality disorders, psychosis, psychopathy, Alzheimer’s, ADHD, autism, learning disabilities, etc). Think about that, the large number of people on a plant-based diet who are struggling on the most basic level of functioning, something I personally understand from decades of chronic depression on the SAD diet. Would you willingly choose to go on a diet that guaranteed a high probability of causing mental health struggles and suffering, neurocognitive issues and decline?

To put this study in context, listen to what Dr. Paul Saladino, trained in psychiatry and internal medicine, has to say in the following video. Jump to around the 19 minute mark where he goes into the nutritional angle of a carnivore diet. And by carnivore he is talking about fully carnivore and so, if dairy is restricted as he does in his own eating, it would also mean ketogenic as well. A keto-carnivore diet has never been studied. Hopefully, that will change soon. Until then, we have brilliant minds like that of Dr. Saladino to dig into the best evidence that is presently available.

Here are a couple of articles that come from the BBC. As a mainstream news source, this demonstrates how this knowledge is finally getting acknowledged in conventional healthcare and public debate. That is heartening.

[Text below is from linked articles.]

Why vegan junk food may be even worse for your health
by William Clark, BBC

There’s also the concern that the health risks associated with these kinds of nutrient deficiencies might not show up immediately. It could take years to associate foggy thoughts and tiredness with low B12 levels, infertility with low iron, and osteoporosis brought on by calcium deficiency does not show up until late 40s and 50s in most people, says Rossi.

“People will think about their health now and not their future health,” she says.

How a vegan diet could affect your intelligence
by Zaria Gorvett, BBC

In fact, there are several important brain nutrients that simply do not exist in plants or fungi. Creatine, carnosine, taurine, EPA and DHA omega-3 (the third kind can be found in plants), haem iron and vitamins B12 and D3 generally only occur naturally in foods derived from animal products, though they can be synthesised in the lab or extracted from non-animal sources such as algae, bacteria or lichen, and added to supplements.

Others are found in vegan foods, but only in meagre amounts; to get the minimum amount of vitamin B6 required each day (1.3 mg) from one of the richest plant sources, potatoes, you’d have to eat about five cups’ worth (equivalent to roughly 750g or 1.6lb). Delicious, but not particularly practical. […]

There are small amounts of choline in lots of vegan staples, but among the richest sources are eggs, beef and seafood. In fact, even with a normal diet, 90% of Americans don’t consume enough. According to unpublished research by Wallace, vegetarians have the lowest intakes of any demographic. “They have extremely low levels of choline, to the point where it might be concerning,” he says.

For vegans, the picture is likely to be bleaker still, since people who eat eggs tend to have almost double the choline levels of those who don’t. And though the US authorities have set suggested intakes, they might be way off.

Meat and mental health: a systematic review of meat abstention and depression, anxiety, and related phenomena
by Urska Dobersek et al

Conclusion: Studies examining the relation between the consumption or avoidance of meat and psychological health varied substantially in methodologic rigor, validity of interpretation, and confidence in results. The majority of studies, and especially the higher quality studies, showed that those who avoided meat consumption had significantly higher rates or risk of depression, anxiety, and/or self-harm behaviors. There was mixed evidence for temporal relations, but study designs and a lack of rigor precluded inferences of causal relations. Our study does not support meat avoidance as a strategy to benefit psychological health.