There's been an awful lot of media coverage in recent weeks about the "dangers" for meat eaters and those consuming eggs and so on. For example, a film "What the Health" (from the makers of another documentary called Cowspiracy) is making waves. The film in its words "exposes the collusion and corruption in government and big business that is costing us trillions of healthcare dollars, and keeping us sick". The movie claims that eating eggs is as bad as smoking and blames a non-vegetarian diet on obesity, diabetes, cancer and premature death!
Really? So a little off topic but since your overall diet, including wine, is key to your health I thought it was about time that FermentedGrape.com delved into this controversy and established the facts from fiction.
Does the clinical evidence out there, as opposed to a bunch of opinions from zealot vegan physicians, support the view that you clear your fridge of meat and dairy?
The 2017 film is film directed by Kip Andersen and Keegan Kuhn, produced and partly funded by vegans and features many interviews with vegan doctors and advocates. Its executive producer is Hollywood star, Joaquin Phoenix, who happens to be a vegan.
From the film's website, "Kip Andersen’s awakening as a filmmaker came as a result of An Inconvenient Truth. After seeing the film, he dramatically changed his lifestyle and believed he was doing everything he could to help the planet. But his life took a different direction when he found out animal agriculture is the leading cause of environmental destruction. Together with Keegan Kuhn he co-produced his first film, Cowspiracy: The Sustainability Secret, which became an overnight viral success and ignited the environmental movement. Following this success, he was invited to speak in front of the European Parliament and a new cut, executive produced by Leonardo DiCaprio, was exclusively released on Netflix in September 2015."
Anti meat campaigners used to focus on highlighting abuses of animal welfare but there is now a new direction of portraying meat and dairy to be as deadly as burning tobacco.
The claims in this film are not supported by the available clinical evidence and instead the producers rely on two vegan promoting organisations "Physicians Committee for Responsible Medicine (PCRM)" and "Nutritionfacts.org".
The PCRM has been involved in several pieces of research looking at diet, veganism vs meat. For example, the Los Angeles times reported on "Study finds plant-based diets lead to weight loss". This article was based on a paper originally published called, "Position of the Academy of Nutrition and Dietetics: Vegetarian Diets, DianaCullum-Dugan, published Journal of the Academy of Nutrition and Dietetics, Volume 115, Issue 8, August 2015, Pages 1347.
The original paper stated that plant based diets significantly reduced weight better than meat based diets and “There was no significant weight-loss difference between studies using ovo-lacto-vegetarian diets and those using vegan diets” An ovo-lacto vegetarian (or lacto-ovo vegetarian) is a vegetarian who does not eat meat, but does consume some animal products such as eggs and dairy.
“It is the position of the Academy of Nutrition and Dietetics that appropriately planned vegetarian, including vegan, diets are healthful, nutritionally adequate, and may provide health benefits for the prevention and treatment of certain diseases. These diets are appropriate for all stages of the life cycle, including pregnancy, lactation, childhood, adolescence, older adulthood, and for athletes. Plant-based diets are more environmentally sustainable than diets rich in animal products because they use fewer natural resources and are associated with much less environmental damage.”
But there is controversy around this publication!
Looking at Sciencedirect.com it has the following statement attached to the clinical paper, "This article has been removed at the request of the Academy Positions Committee (APC) of the Academy of Nutrition and Dietetics. The APC became aware of inaccuracies and omissions in the position paper that could affect recommendations and conclusions within the paper. After further review, the APC decided it was appropriate to remove this paper for major revision."
Do vegans and vegetarians really live longer?
From this Times newspaper on 5th August 2017,
- Alice Howarth, a cancer researcher, said: “While it is true that diet plays an important role in diseases including cancer and diabetes, the claims in this film vastly overstate and misrepresent the scientific understanding. "What the Health" overwhelms the viewer with scaremongering ‘facts’ which do not hold up to scientific investigation.”
- Gunter Kuhnle, associate professor in nutrition and health, University of Reading, said: “Apart from a few very specific dietary components (fibre, fats) for which there is a clear link with health, it appears that the old and boring recommendation of a balanced diet is still the best.
So what's the story from the literature evidence? Is being a vegetarian or vegan better for you?
There is no clear evidence of any difference in overall risk of death (mortality) between vegetarians and non-vegetarians. However a plant based diet (vegan and vegetarian) seems to be associated with a lower risk of some cancers, heart disease and diabetes.
A rather good review was published in Critical Reviews in Food, Science and Medicine journal, "Vegetarian, vegan diets and multiple health outcomes: A systematic review with meta-analysis of observational studies" in February 2016.
In summary, "With regard to prospective cohort studies, the analysis showed a significant reduced risk of incidence and/or mortality from ischemic heart disease (RR 0.75; 95% CI, 0.68 to 0.82) and incidence of total cancer (RR 0.92; 95% CI 0.87 to 0.98) but not of total cardiovascular and cerebrovascular diseases, all-cause mortality and mortality from cancer."
In the 2012 study, Cardiovascular disease mortality and cancer incidence in vegetarians: a meta-analysis and systematic review. seven studies with a total of 124,706 participants were included in this analysis. All-cause mortality in vegetarians was 9% lower than in nonvegetarians (RR = 0.91; 95% CI, 0.66-1.16). But the average may be a 9% reduction, but the variability is huge from a 44% reduction, to a 16% increase in mortality for a vegetarian diet.
Individual studies as opposed to these meta-analyses, show a confusing pattern.
In the "Mortality in British vegetarians: results from the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford)" published in 2009 the authors concluded that "The mortality of both the vegetarians and the non-vegetarians in this study is low compared with national rates. Within the study, mortality from circulatory diseases and all causes is not significantly different between vegetarians and meat eaters, but the study is not large enough to exclude small or moderate differences for specific causes of death, and more research on this topic is required."
In the study Vegetarian dietary patterns and mortality in Adventist Health Study 2. mortality was shown to be up to 15% less in the vegans versus meat eaters. It was shown that "There were 2570 deaths among 73,308 participants during a mean follow-up time of 5.79 years. The mortality rate was 6.05 (95% CI, 5.82-6.29) deaths per 1000 person-years. The adjusted hazard ratio (HR) for all-cause mortality in all vegetarians combined vs nonvegetarians was 0.88 (95% CI, 0.80-0.97). The adjusted HR for all-cause mortality in vegans was 0.85 (95% CI, 0.73-1.01); in lacto-ovo-vegetarians, 0.91 (95% CI, 0.82-1.00); in pesco-vegetarians, 0.81 (95% CI, 0.69-0.94); and in semi-vegetarians, 0.92 (95% CI, 0.75-1.13) compared with nonvegetarians. "
What about nutritional problems with vegetrian and vegan diets?
"Although a high consumption of red meat, which is rich in haeme iron and saturated fat, may increase the risk of cardiovascular disease and some types of cancer, this does not apply to white meat and fish. In fact, the most important protective effect would seem to be derived from the consumption of unrefined vegetable products (whole-grain cereals, vegetables, fruits, nuts and legumes) and fish. In other words, a prudent, omnivorous diet with moderate amounts of animal products, in which red meat is partly replaced by white meat and fish (especially fatty fish), together with the consumption of ample amounts of unrefined vegetable products, is thought to be just as protective as a vegetarian diet. On the other hand, the omission of meat and fish from the diet increases the risk of nutritional deficiencies. A vegan diet, in particular, leads to a strongly increased risk of deficiencies of vitamin B12, vitamin B2 and several minerals, such as calcium, iron and zinc."
In a 2006 review, "Health effects of vegetarian and vegan diets" they stated that "Cohort studies of vegetarians have shown a moderate reduction in mortality from IHD but little difference in other major causes of death or all-cause mortality in comparison with health-conscious non-vegetarians from the same population. Studies of cancer have not shown clear differences in cancer rates between vegetarians and non-vegetarians. More data are needed, particularly on the health of vegans and on the possible impacts on health of low intakes of long-chain n-3 fatty acids and vitamin B(12). Overall, the data suggest that the health of Western vegetarians is good and similar to that of comparable non-vegetarian.
In a Swiss study published in 2017, Micronutrient status and intake in omnivores, vegetarians and vegans in Switzerland. the authors state that, "Despite substantial differences in intake and deficiency between groups, our results indicate that by consuming a well-balanced diet including supplements or fortified products, all three types of diet can potentially fulfil requirements for vitamin and mineral consumption."
Claims from What the Health film under scrutiny
Claim: Eating one egg a day is as bad as smoking five cigarettes a day.
One of the scientific papers on which the film bases this claim does not mention eggs. It looks at cholesterol, from which the effect of eggs has been inferred. A second looked at the link between egg yolk and plaque in carotid arteries, not life expectancy.
Claim: The risk of heart disease is 50 per cent for meat eaters, 45 per cent for vegetarians and 4 per cent for vegans.
Experts agree that vegetarians seem to have a lower risk of heart disease but this claim, made on the documentary’s Facebook page, above, refers to a 1994 study that did not include vegans and does not show any statistically meaningful risk reduction.
Claim: One serving of processed meat a day increases risk of developing diabetes by 51 per cent.
Fact Of two papers picked out by the film-makers to illustrate this, only one has the figure cited, which refers to relative risk, rather than absolute risk. Alexandra Freeman, of the Winton Centre for Risk and Evidence Communication, said: “An ‘increase’ can be made to look huge, but if it’s an increase from a tiny value to another tiny value then that puts a whole different perspective on it.”
Summary - do vegetarians and vegans really live longer?
In summary, there seems to be good evidence that plant based diets which avoid meat mean that your risk of heart disease, stroke, obesity and diabetes is lower. However, the impact on overall mortality is less clear cut, with several large meta-analyses clearly stating that there is no different in risk of death in vegetarians, vegans and carnivores. Also, it seems that with the right level of dietary supplementation there are no serious effects on health from practicing a vegan or vegetarian diet.
However, as a meat lover myself, I personally advocate a balanced omnivore diet, relating to the Mediterranean diet with a good balance of fresh and good quality, meats, fish, vegetables, pulses and fruit (see also the "French Paradox"). If possible using organic ingredients, quality over quantity.
Also throw in a good dose of exercise, at least 3 times a weak vigorous, no smoking and a couple of glasses of red wine a day and I think you have the perfect balance of a delicious and nutritious diet and health as well as happiness. Lets face it you can't beat a good steak and a glass of red wine even if a salad/vegetable diet may be slightly better for you, you'll probably die at the same age as your vegetarian friend and be less happy on the way if you can cope with all the animal welfare challenges! Lets face it the food industry needs to look after animals better and not treat them like commodities which they are at the moment. Less but better quality meat please!
More information on clinical studies and further reading
Beneficial effects of vegetarian and vegan diets on health outcomes have been supposed in previous studies.
Aim of this study was to clarify the association between vegetarian, vegan diets, risk factors for chronic diseases, risk of all-cause mortality, incidence, and mortality from cardio-cerebrovascular diseases, total cancer and specific type of cancer (colorectal, breast, prostate and lung), through meta-analysis.
A comprehensive search of Medline, EMBASE, Scopus, The Cochrane Library, and Google Scholar was conducted.
Eighty-six cross-sectional and 10 cohort prospective studies were included. The overall analysis among cross-sectional studies reported significant reduced levels of body mass index, total cholesterol, LDL-cholesterol, and glucose levels in vegetarians and vegans versus omnivores. With regard to prospective cohort studies, the analysis showed a significant reduced risk of incidence and/or mortality from ischemic heart disease (RR 0.75; 95% CI, 0.68 to 0.82) and incidence of total cancer (RR 0.92; 95% CI 0.87 to 0.98) but not of total cardiovascular and cerebrovascular diseases, all-cause mortality and mortality from cancer. No significant association was evidenced when specific types of cancer were analyzed. The analysis conducted among vegans reported significant association with the risk of incidence from total cancer (RR 0.85; 95% CI, 0.75 to 0.95), despite obtained only in a limited number of studies.
This comprehensive meta-analysis reports a significant protective effect of a vegetarian diet versus the incidence and/or mortality from ischemic heart disease (-25%) and incidence from total cancer (-8%). Vegan diet conferred a significant reduced risk (-15%) of incidence from total cancer.
Key TJ1, Appleby PN, Spencer EA, Travis RC, Roddam AW, Allen NE.
Am J Clin Nutr. 2009 May;89(5):1613S-1619S. doi: 10.3945/ajcn.2009.26736L. Epub 2009 Mar 18.
Few prospective studies have examined the mortality of vegetarians.
We present results on mortality among vegetarians and nonvegetarians in the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford).
We used a prospective study of men and women recruited throughout the United Kingdom in the 1990s.
Among 64,234 participants aged 20-89 y for whom diet group was known, 2965 had died before age 90 by 30 June 2007. The death rates of participants are much lower than average for the United Kingdom. The standardized mortality ratio for all causes of death was 52% (95% CI: 50%, 54%) and was identical in vegetarians and in nonvegetarians. Comparing vegetarians with meat eaters among the 47,254 participants who had no prevalent cardiovascular disease or malignant cancer at recruitment, the death rate ratios adjusted for age, sex, smoking, and alcohol consumption were 0.81 (95% CI: 0.57, 1.16) for ischemic heart disease and 1.03 (95% CI: 0.90, 1.16) for all causes of death.
The mortality of both the vegetarians and the nonvegetarians in this study is low compared with national rates. Within the study, mortality from circulatory diseases and all causes is not significantly different between vegetarians and meat eaters, but the study is not large enough to exclude small or moderate differences for specific causes of death, and more research on this topic is required.
Vegetarian dietary patterns and mortality in Adventist Health Study 2. Orlich MJ1, Singh PN, Sabaté J, Jaceldo-Siegl K, Fan J, Knutsen S, Beeson WL, Fraser GE.
JAMA Intern Med. 2013 Jul 8;173(13):1230-8. doi: 10.1001/jamainternmed.2013.6473.
Some evidence suggests vegetarian dietary patterns may be associated with reduced mortality, but the relationship is not well established.
To evaluate the association between vegetarian dietary patterns and mortality.
Prospective cohort study; mortality analysis by Cox proportional hazards regression, controlling for important demographic and lifestyle confounders.
Adventist Health Study 2 (AHS-2), a large North American cohort.
A total of 96,469 Seventh-day Adventist men and women recruited between 2002 and 2007, from which an analytic sample of 73,308 participants remained after exclusions.
Diet was assessed at baseline by a quantitative food frequency questionnaire and categorized into 5 dietary patterns: nonvegetarian, semi-vegetarian, pesco-vegetarian, lacto-ovo-vegetarian, and vegan.
MAIN OUTCOME AND MEASURE:
The relationship between vegetarian dietary patterns and all-cause and cause-specific mortality; deaths through 2009 were identified from the National Death Index.
There were 2570 deaths among 73,308 participants during a mean follow-up time of 5.79 years. The mortality rate was 6.05 (95% CI, 5.82-6.29) deaths per 1000 person-years. The adjusted hazard ratio (HR) for all-cause mortality in all vegetarians combined vs nonvegetarians was 0.88 (95% CI, 0.80-0.97). The adjusted HR for all-cause mortality in vegans was 0.85 (95% CI, 0.73-1.01); in lacto-ovo-vegetarians, 0.91 (95% CI, 0.82-1.00); in pesco-vegetarians, 0.81 (95% CI, 0.69-0.94); and in semi-vegetarians, 0.92 (95% CI, 0.75-1.13) compared with nonvegetarians. Significant associations with vegetarian diets were detected for cardiovascular mortality, noncardiovascular noncancer mortality, renal mortality, and endocrine mortality. Associations in men were larger and more often significant than were those in women.
CONCLUSIONS AND RELEVANCE:
Vegetarian diets are associated with lower all-cause mortality and with some reductions in cause-specific mortality. Results appeared to be more robust in males. These favorable associations should be considered carefully by those offering dietary guidance.
Ann Nutr Metab. 2012;60(4):233-40. doi: 10.1159/000337301. Epub 2012 Jun 1.
Huang T1, Yang B, Zheng J, Li G, Wahlqvist ML, Li D.
Prospective cohort studies have examined mortality and overall cancer incidence among vegetarians, but the results have been inconclusive.
The objective of the present meta-analysis was to investigate cardiovascular disease mortality and cancer incidence among vegetarians and nonvegetarians.
Medline, EMBASE and Web Of Science databases were searched for cohort studies published from inception to September 2011. Studies were included if they contained the relative risk (RR) and corresponding 95% CI. Participants were from the UK, Germany, California, USA, the Netherlands and Japan.
Seven studies with a total of 124,706 participants were included in this analysis. All-cause mortality in vegetarians was 9% lower than in nonvegetarians (RR = 0.91; 95% CI, 0.66-1.16). The mortality from ischemic heart disease was significantly lower in vegetarians than in nonvegetarians (RR = 0.71; 95% CI, 0.56-0.87). We observed a 16% lower mortality from circulatory diseases (RR = 0.84; 95% CI, 0.54-1.14) and a 12% lower mortality from cerebrovascular disease (RR = 0.88; 95% CI, 0.70-1.06) in vegetarians compared with nonvegetarians. Vegetarians had a significantly lower cancer incidence than nonvegetarians (RR = 0.82; 95% CI, 0.67-0.97).
Our results suggest that vegetarians have a significantly lower ischemic heart disease mortality (29%) and overall cancer incidence (18%) than nonvegetarians.
Ned Tijdschr Geneeskd. 2003 Jul 5;147(27):1308-13.
In the latest Dutch national food consumption survey (1998) just over 1% of subjects (about 150,000 persons) claimed to be vegetarians; however, a much larger group (6% or approximately 1 million persons) ate meat < or = once a week. Vegetarianism can be subdivided into lacto-vegetarianism (a diet without meat and fish) and veganism (a diet without any animal foods whatsoever, including dairy products and eggs). A recent meta-analysis showed that vegetarians had a lower mortality from ischaemic heart disease than omniovorous subjects; however, cancer mortality and total mortality did not differ. Although a high consumption of red meat, which is rich in haeme iron and saturated fat, may increase the risk of cardiovascular disease and some types of cancer, this does not apply to white meat and fish. In fact, the most important protective effect would seem to be derived from the consumption of unrefined vegetable products (whole-grain cereals, vegetables, fruits, nuts and legumes) and fish. In other words, a prudent, omnivorous diet with moderate amounts of animal products, in which red meat is partly replaced by white meat and fish (especially fatty fish), together with the consumption of ample amounts of unrefined vegetable products, is thought to be just as protective as a vegetarian diet. On the other hand, the omission of meat and fish from the dietincreases the risk of nutritional deficiencies. A vegan diet, in particular, leads to a strongly increased risk of deficiencies of vitamin B12, vitamin B2 and several minerals, such as calcium, iron and zinc. However, even a lacto-vegetarian diet produces an increased risk of deficiencies of vitamin B12 and possibly certain minerals, such as iron. Data from the latest Dutch food consumption survey suggest that 5-10% of all inhabitants of the Netherlands (up to 1 million persons) actually have a vitamin B12 intake below recommended daily levels. In medical practice, the possibility of vitamin B12 deficiency in subjects consuming meat or fish < or = once a week deserves serious consideration. In case of doubt, evaluation is indicated using sensitive and specific deficiency markers such as the levels of methylmalonic acid in plasma or urine. Alternative dietary sources of vitamin B12 instead of meat are fish (especially fatty fish is a good source of vitamin B12), or a vitamin-B12-supplement.
Proc Nutr Soc. 2006 Feb;65(1):35-41.
Key TJ1, Appleby PN, Rosell MS.
Vegetarian diets do not contain meat, poultry or fish; vegan diets further exclude dairy products and eggs. Vegetarian and vegan diets can vary widely, but the empirical evidence largely relates to the nutritional content and health effects of the average diet of well-educated vegetarians living in Western countries, together with some information on vegetarians in non-Western countries. In general, vegetarian diets provide relatively large amounts of cereals, pulses, nuts, fruits and vegetables. In terms of nutrients, vegetarian diets are usually rich in carbohydrates, n-6 fatty acids, dietary fibre, carotenoids, folic acid, vitamin C, vitamin E and Mg, and relatively low in protein, saturated fat, long-chain n-3 fatty acids, retinol, vitamin B(12) and Zn; vegans may have particularly low intakes of vitamin B(12) and low intakes of Ca. Cross-sectional studies of vegetarians and vegans have shown that on average they have a relatively low BMI and a low plasma cholesterol concentration; recent studies have also shown higher plasma homocysteine concentrations than in non-vegetarians. Cohort studies of vegetarians have shown a moderate reduction in mortality from IHD but little difference in other major causes of death or all-cause mortality in comparison with health-conscious non-vegetarians from the same population. Studies of cancer have not shown clear differences in cancer rates between vegetarians and non-vegetarians. More data are needed, particularly on the health of vegans and on the possible impacts on health of low intakes of long-chain n-3 fatty acids and vitamin B(12). Overall, the data suggest that the health of Western vegetarians is good and similar to that of comparable non-vegetarian.
Eur J Nutr. 2017 Feb;56(1):283-293. doi: 10.1007/s00394-015-1079-7. Epub 2015 Oct 26.
Schüpbach R1, Wegmüller R1,2, Berguerand C3, Bui M3, Herter-Aeberli I4.
Vegetarian and vegan diets have gained popularity in Switzerland. The nutritional status of individuals who have adopted such diets, however, has not been investigated. The aim of this study was to assess the intake and status of selected vitamins and minerals among vegetarian and vegan adults living in Switzerland.
Healthy adults [omnivores (OVs), n OV = 100; vegetarians (VGs), n VG = 53; vegans (VNs), n VN = 53] aged 18-50 years were recruited, and their weight and height were measured. Plasma concentrations of the vitamins A, C, E, B1, B2, B6, B12, folic acid, pantothenic acid, niacin, biotin and β-carotene and of the minerals Fe, Mg and Zn and urinary iodine concentration were determined. Dietary intake was assessed using a three-day weighed food record, and questionnaires were issued in order to assess the physical activity and lifestyle of the subjects.
Omnivores had the lowest intake of Mg, vitamin C, vitamin E, niacin and folic acid. Vegans reported low intakes of Ca and a marginal consumption of the vitamins D and B12. The highest prevalence for vitamin and mineral deficiencies in each group was as follows: in the omnivorous group, for folic acid (58 %); in the vegetarian group, for vitamin B6 and niacin (58 and 34 %, respectively); and in the vegan group, for Zn (47 %). Despite negligible dietary vitamin B12 intake in the vegan group, deficiency of this particular vitamin was low in all groups thanks to widespread use of supplements. Prevalence of Fe deficiency was comparable across all diet groups.
Despite substantial differences in intake and deficiency between groups, our results indicate that by consuming a well-balanced diet including supplements or fortified products, all three types of diet can potentially fulfill requirements for vitamin and mineral consumption.