Why Be Vegan? And Why Not?

by

Vegan cheese, vegan chocolate, vegan ice cream, vegan pizza, and vegan burgers are just some of the popular plant-based alternatives to food products. Their popularization is a result of the rise in alternative and restrictive diets in the Western world. Among them, vegetarian and vegan diets lead the way, especially the latter.

A vegan diet is a more extreme form of vegetarianism. While vegetarians exclude animal meat from their diet, vegans exclude all animal products.

The reasons for this are minimizing animal suffering, caring for the environment, and the pursuit of health. In the following few sentences, I will try to determine how well-founded these reasons are. As a nutritionist, I will emphasize the nutritional and health aspects of veganism.

Is a plant-based diet healthier?

Vegans have a lower risk of cardiovascular diseases (1). They suffer less frequently from cancer (2). They live longer (3).

These benefits are likely due to lower blood pressure (4), blood glucose (2), cholesterol (5), and triglycerides (6).

So, should we all be vegans?

Not so fast.

One must be very careful in interpreting these (and any other) observations.

In observational studies comparing diets, it is impossible to separate the effect of veganism from the effects of other habits that accompany it. Namely, vegans and vegetarians pay more attention to health than non-vegetarians (7). They also have lower body mass (8), eat more fruits and vegetables, more often prepare food at home (9), smoke less, drink less alcohol, and are more physically active (10). In general, they lead a healthier lifestyle.

We can only guess what the real cause of the observed benefits is. Maybe it is a healthier lifestyle. Maybe it is the exclusion of animal products. Maybe it is the inclusion of more plant foods. The fact that two events occur together does not mean one causes the other. In other words, correlation does not imply causation.

Furthermore, vegan diets are most often compared with non-vegan diets, where the latter includes all others. This means veganism is compared with the average human diet (11). And the average diet is quite poor.

Being vegan requires significant discipline, so among vegans, we rarely find those uninterested in health. Interest in health leads to caring about diet. Caring about diet mostly leads to better quality nutrition. So, on one side, we compare the habits of individuals highly interested in health with those who generally are not.

The real question is: is a healthy vegan diet a better choice than a healthy omnivorous diet?

I am fairly certain it is not.

Vegans are healthier than omnivores. But not because they are vegans.

Risks of a vegan diet

Humans are omnivores. Despite what some herbivores try to convince you, there is no respectable scientist who would agree with them. Evolutionarily, this gave us a great advantage because it allowed us to adapt to various environments in different seasons.

This means we have the nutritional needs of omnivores. It also means that by removing all animal products from our diet, we are likely to deprive our bodies of essential nutrients.

Research confirms this. Nutrients commonly insufficient in vegans include vitamins D and B12, calcium, iron, zinc, and omega-3 fatty acids (12). Two nutrients less often mentioned, but which vegans (and vegetarians) could also lack, are choline and creatine (13). A persistent deficiency of any of these nutrients is linked to negative health outcomes.

Protein intake can also be a problem. Vegans consume up to 50% less protein than omnivores. For a sedentary population maintaining body mass, this intake is sufficient (14). But for physically active individuals or those trying to lose weight healthily, it could be problematic.

In addition to insufficient intake, vegans may have problems with nutrient bioavailability.

Even when protein intake is quantitatively sufficient, the proteins consumed are less digestible, have lower essential amino acid content, and suboptimal quality (15).

Even when omega-3 fatty acid intake is theoretically sufficient, their bioavailability from plant sources is very low.

Even when calcium intake meets recommendations, its absorption could be reduced due to high phytate and oxalate content.

Even when blood levels of vitamin B12 appear adequate, high folate intake in vegans can mask its deficiency.

The Academy of Nutrition and Dietetics (formerly the American Dietetic Association) states that a vegan diet is adequate for all age groups. Well-planned, yes, but the risk of inadequate nutrition is too high for me to recommend veganism. Children in development are especially vulnerable.

For a dietary choice to affect health, one must adhere to it very long, possibly a lifetime. And over 80% of vegetarians and vegans eventually return to consuming animal products (16). This testifies to the unsustainability of this dietary approach.

Gamechangers – vegan athletes

Until recently, vegan and sports nutrition were two separate worlds. Then came the documentary Gamechangers.

I watched the film and was disappointed. Given its popularity, I expected a higher quality and intellectually honest argumentation. I will not dissect the film in detail but will highlight some mistakes indicating its lack of objectivity and bias.

“Gamechangers” defends its thesis based on personal testimonies, anecdotes. And we know how valuable they are in the search for truth. They are not.

Individuals switching to veganism make many simultaneous changes, both in diet and lifestyle. In sports context, one of the most significant is that they start eating more carbohydrates. The consequence is greater energy availability, which is advantageous for sports performance. The question remains whether the improvement would be the same or greater if, instead of switching to veganism, they had simply adjusted their diet.

The film ruthlessly equates correlation with causation. It highlights how prominent individuals achieved sports success because they quit consuming animal products. But it is equally possible they achieved success despite this. Don’t forget that behind every success are hundreds of failures the film is not interested in showing.

The film creates imaginary theses to more easily refute them. This is a classic straw man argument (17). For example, as a pre-game meal, it compares a kilogram of steak with a vegan meal. It forgets to mention that no normal nutritionist would recommend a pile of meat, especially before competition. It also attacks the idea that protein is the main source of energy. Maybe that was claimed in ancient Greece, but not today. Furthermore, at one point, it compares the human digestive system with that of a carnivore. Again, no one, with some exceptions, claims humans are carnivores or eat like carnivores.

As a result of the documentary, several clients, professional athletes, asked me if they should switch to a vegan diet. After confirming their reason was not ethical, my answer was no. A vegan diet will not necessarily improve your sports performance, and there is a significant risk it could compromise it.

The ethical question of killing animals

Since I am a nutritionist, not a professional ethicist, the focus of this article is on the substantive aspect of veganism, its effect on health and sports performance. However, it is impossible not to mention two basic vegan arguments that do not directly relate to health.

Eating fish and meat requires killing animals, and the production process often involves violence against them. Few would disagree that animal torture must be eradicated and that farming conditions significantly improved. This, of course, requires greater resource consumption, which means higher product prices. But that is a price we, at least in the developed world, could accept to pay.

Let’s not deceive ourselves that plant food production does not cause death and suffering to animals. According to some estimates, wheat farming kills 25 times more sentient animals than livestock grazing (18). We can also assume that animals killed in fields due to harvesting and poisoning die much more slowly and painfully than those slaughtered. In short, there is no free lunch.

But is killing animals for food justified at all, given that we can survive on a plant-based diet? Considering our dominant position in the food chain, I think it is.

Let’s not forget the “agreement” we have with farm animals. In exchange for earlier death, we prolong their lineage. From a strictly Darwinian perspective, this is a very good compromise. Also, the vast majority of those animals would not be alive outside farming. Provided we improve their living conditions, it is not impossible to see the sense in claiming that farming is actually ethical.

Environmental preservation

Environmental preservation is probably the strongest argument vegans and vegetarians use to switch to plant-based diets.

Production of animal products, compared to producing the same amount of plant food, has a greater environmental impact. It causes increased greenhouse gas emissions, energy consumption, water usage, and pesticide use.

But not every plant product is better for the environment than every animal product, nor is it without environmental impact.

Most people on Earth are aware of the current unsustainability of its exploitation. Undoubtedly, we must do everything in our power to keep the planet livable for future generations.

However, eliminating all animal products from the diet is not the only, or most significant, step we can take. We can reduce resource use and improve animal farming methods. We can reduce portions and frequency of animal product consumption. We can reduce food waste. If nothing works, we can recommend vegetarian or even vegan diets to everyone.

The link between human diet and environment is complex. What is best for the environment is not necessarily best for our health, and vice versa. Compromises must be made.

Protecting the environment is not an all-or-nothing game. It is impossible to live without environmental consequences, but it is our duty to ensure those consequences are sustainable.

Good and bad reasons to be vegan

I am not against veganism per se. I am against inhumane treatment of animals. I am against uncontrolled environmental pollution. But I am also against extremism, sensationalism, dogmas, false and pseudo-scientific claims that permeate the vegan movement.

If you decide to be vegan for religious or ethical reasons, or simply because you dislike the taste or smell of animal products, go ahead. But if you do it for health reasons, keep in mind it is not the best way and you accept certain risks. Not every reason is a good reason, no matter how dear it is to us.

I do not claim that a vegan diet cannot be healthy. I do not claim that healthy vegans do not exist. I claim that the mere fact that you do not eat animal products does not make you healthier than an omnivore. Moreover, there is a real possibility it makes you less healthy. In any case, it does not make you morally superior.

Call me old-fashioned and limited, but at this moment I cannot recommend a vegan diet. I see no evidence for the benefits, and the risks are more than present. But I am not closed to the possibility that my stance may change one day.

If you decide to choose a plant-based diet, do it wisely. For a vegan diet to have positive health effects, it needs to be planned even more precisely than an omnivore’s diet.

Regardless of whether you choose a plant-based or omnivorous diet, contact us to ensure your dietary choices do not harm your health.

References

  1. Fraser G. Diet, Life Expectancy, and Chronic Disease. Studies of Seventh-Day Adventists and Other Vegetarians. (Fraser G, ed.). New York, NY: Oxford University Press; 2003.
  2. Dinu M, Abbate R, Gensini GF, Casini A, Sofi F. Vegetarian, vegan diets and multiple health outcomes: A systematic review with meta-analysis of observational studies. Crit Rev Food Sci Nutr. 2017;57(17):3640-3649. doi:10.1080/10408398.2016.1138447
  3. Singh PN, Clark RW, Herring P, Sabaté J, Shavlik D, Fraser GE. Obesity and life expectancy among long-lived black adults. Journals Gerontol – Ser A Biol Sci Med Sci. 2014;69(1):63-72. doi:10.1093/gerona/glt049
  4. Farmer B, Larson BT, Fulgoni VL, Rainville AJ, Liepa GU. A Vegetarian Dietary Pattern as a Nutrient-Dense Approach to Weight Management: An Analysis of the National Health and Nutrition Examination Survey 1999-2004. J Am Diet Assoc. 2011;111(6):819-827. doi:10.1016/j.jada.2011.03.012
  5. Kottler BM, Ferdowsian HR, Barnard ND. Effects of Plant-Based Diets on Plasma Lipids. Am J Cardiol. 2009;104(7):947-956. doi:10.1016/j.amjcard.2009.05.032
  6. De Biase SG, Fernandes SFC, Gianini RJ, Duarte JLG. Vegetarian diet and cholesterol and triglycerides levels. Arq Bras Cardiol. 2007;88(1):32-36. doi:10.1590/S0066-782X2007000100006
  7. Bedford JL, Barr SI. Diets and selected lifestyle practices of self-defined adult vegetarians from a population-based sample suggest they are more “health conscious.” Int J Behav Nutr Phys Act. 2005;2(1):4. doi:10.1186/1479-5868-2-4
  8. Burkert NT, Muckenhuber J, Großschädl F, Rásky É, Freidl W. Nutrition and health – The association between eating behavior and various health parameters: A matched sample study. PLoS One. 2014;9(2). doi:10.1371/journal.pone.0088278
  9. Heiss S, Coffino JA, Hormes JM. Eating and health behaviors in vegans compared to omnivores: Dispelling common myths. Appetite. 2017;118:129-135. doi:10.1016/j.appet.2017.08.001
  10. Le LT, Sabaté J, Singh PN, Jaceldo-Siegl K. The design, development and evaluation of the vegetarian lifestyle index on dietary patterns among vegetarians and non-vegetarians. Nutrients. 2018;10(5). doi:10.3390/nu10050542
  11. Clarys P, Deliens T, Huybrechts I, et al. Comparison of nutritional quality of the vegan, vegetarian, semi-vegetarian, pesco-vegetarian and omnivorous diet. Nutrients. 2014;6(3):1318-1332. doi:10.3390/nu6031318
  12. Melina V, Craig W, Levin S. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. J Acad Nutr Diet. 2016;116(12):1970-1980. doi:10.1016/j.jand.2016.09.025
  13. Wallace TC, Blusztajn JK, Caudill MA, Klatt KC, Zeisel SH. Choline: The Neurocognitive Essential Nutrient of Interest to Obstetricians and Gynecologists. J Diet Suppl. August 2019:1-20. doi:10.1080/19390211.2019.1639875
  14. Sobiecki JG, Appleby PN, Bradbury KE, Key TJ. High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: Results from the European Prospective Investigation into Cancer and Nutrition-Oxford study. Nutr Res. 2016;36(5):464-477. doi:10.1016/j.nutres.2015.12.016
  15. Dietary Protein Quality Evaluation in Human Nutrition Report of an FAO Expert Consultation.; 2011. http://www.nutrinfo.com/biblioteca/libros_digitales/fao_protein_quality.pdf. Accessed February 29, 2020.
  16. Faunalytics. Study of Current and Former Vegetarians and Vegans Initial Findings • December 2014.; 2014. https://faunalytics.org/wp-content/uploads/2015/06/Faunalytics_Current-Former-Vegetarians_Full-Report.pdf. Accessed February 15, 2020.
  17. Straw man – Wikipedia. https://en.wikipedia.org/wiki/Straw_man#cite_note-Stephen_Downes-1. Accessed February 21, 2020.
  18. Ordering the vegetarian meal? There’s more animal blood on your hands. https://theconversation.com/ordering-the-vegetarian-meal-theres-more-animal-blood-on-your-hands-4659. Accessed February 8, 2020.