Hold on to the fibre. Contrarian philosophy is often mistaken for wisdom.
For many, the emergence of scientific evidence pointing towards the health benefits of eating plants (and the dangers of an omnivorous or “near-carnivorous” diet (1)) is taken as a personal affront. Because food is a personal experience best enjoyed, it is understandable that an intuitive response to plant-diet positivity may unfortunately be taken personally.
Beyond the science, the plant diet has been linked with concerns on animal cruelty and even global warming, which provides additional venom to the debate on why we should make our diets sustainable. As such the vegan diet is possibly perceived as “pure” as far as ethics and nutrition, in an almost holistic manner. Whereas concerns about animal rights and global warming are both logical and altruistic, it may not be clear that it is still possible to be an unhealthy vegan.
This is a point made clear by Dr T. Colin Campbell in his book “Whole: Rethinking the Science of Nutrition” (2). The clearest issue with many vegan foods currently being promoted is that the more processing plants go through, the more fibre and minerals may be removed. Fibre induces stomach, kidney and liver detoxification (3). Ultra-processing food removes fibre (4), and a lack of fibre is linked to multiple cancers and chronic diseases (3). Also, many components are often added to highly processed foods, and the disproportionate amounts of these added fats, salts/sugars and others are a sin unto themselves (4).
However contrarians (or possibly the unknowing) simply make false equivalencies. Platforms with a following (and some loose references to research) have equated orange juice to a “popular soda beverage”, despite the knowledge of 100% orange juice having health benefits according to health surveys (5, 6) and pilot clinical studies (7, 8, 9).
As far as nutrition is concerned, large population studies on the “vegan diet” have predominantly focused on the consumption of unprocessed “whole plant foods” (1,10). The prevailing exception has been the effect of 100% fruit/plant juice beverages, and although most fibre content has been removed, these juices maintain amazing health value (8), as described previously.
The epidemiology studies about veganism or whole plant diets often face the rebuttal that “correlation is not causation”. For example, vegans could tend to be more health conscious than omnivores and exercise more (providing an alternate cause for correlation between vegans and health parameters). But between vegans, vegetarians and omnivores; vegans have the lowest risk of developing hypertension and metabolic diseases, even after you statistically account/control for amount of exercise etc (11).
The correlation-causation talking point fundamentally demands for experimental evidence of cause. In other words, what is the step-by-step proof of the mechanism behind good health caused by a vegan diet? The previously mentioned study of vegans and hypertension is not a mechanistic breakdown of causation, but shows a strong correlation. Not only do many studies focus on identified phytonutrients and mechanisms (12), but possible mechanisms for omnivorous toxicity have suggested heme iron (13), excessive IGF-1 induction (14) and heterocyclic amines from specific cooking processes as causes (15).
Ultimately, a slightly over-academic debate is lost on a patient who can pragmatically implement sound nutritional research and may lower their risk of cardiovascular disease and metabolic disease after just 7 days of adopting a “low-fat, starch-based, vegan diet” (16). The science is crucial, but let’s not forget to help people.
Disclaimer: If you have medical concerns, please consult your doctor before implementing the opinions in this article.
N. Baiden PhD.
1. Chen, J., Campbell, T. C., Li, J., and Peto, R. (1990) Diet, Life-Style, and Mortality in China: A Study of the Characteristicsof 65 Chinese Counties, Oxford University Press, Cornell University Press, and People’s Medical Publishing House
2. Campbell, T. C., and Jacobson, H. (2013) Whole: Rethinking the Science of Nutrition, BenBella Books, Inc.
3. Kieffer, D. A., Martin, R. J., and Adams, S. H. (2016) Impact of Dietary Fibers on Nutrient Management and Detoxification Organs: Gut, Liver, and Kidneys. Advances in Nutrition 7, 1111–1121
4. Moubarac, J.-C., Bortoletto Martins, A. P., Claro, R. M., Levy, R. B., Cannon, G., and Monteiro, C. A. (2013) Consumption of ultra-processed foods and likely impact on human health. Evidence from Canada. Public Health Nutrition 16, 2240–2248
5. O’Neil, C. E., Nicklas, T. A., Rampersaud, G. C., and Fulgoni, V. L., III. (2012) 100% Orange juice consumption is associated with better diet quality, improved nutrient adequacy, decreased risk for obesity, and improved biomarkers of health in adults: National Health and Nutrition Examination Survey, 2003–2006. Nutrition Journal 11
6. Chang, S.-C., Cassidy, A., Willett, W. C., Rimm, E. B., O’Reilly, E. J., and Okereke, O. I. (2016) Dietary flavonoid intake and risk of incident depression in midlife and older women. American Journal of Clinical Nutrition 104, 704–714
7. Ko, S. H., Choi, S. W., Ye, S. K., Cho, B. L., Kim, H. S., and Chung, M. H. (2005) Comparison of the antioxidant activities of nine different fruits in human plasma. Journal of Medicinal Food 8, 41–46
8. Morand, C., Dubray, C., Milenkovic, D., Lioger, D., Martin, J. F., Scalbert, A., and Mazur, A. (2011) Hesperidin contributes to the vascular protective effects of orange juice: a randomized crossover study in healthy volunteers. American Journal of Clinical Nutrition 93, 73–80
9. Hyson, D. A. (2015) A Review and Critical Analysis of the Scientific Literature Related to 100% Fruit Juice and Human Health. Advances in Nutrition 6, 37–51
10. Tonstad, S., Stewart, K., Oda, K., Batech, M., Herring, R. P., and Fraser, G. E. (2013) Vegetarian diets and incidence of diabetes in the Adventist Health Study-2. Nutrition Metabolism and Cardiovascular Diseases 23, 292–299
11. Appleby, P. N., Davey, G. K., and Key, T. J. (2002) Hypertension and blood pressure among meat eaters, fish eaters, vegetarians and vegans in EPIC-Oxford. Public Health Nutrition 5, 645–654
12. McCarty, M. F. (1999) Vegan proteins may reduce risk of cancer, obesity, and cardiovascular disease by promoting increased glucagon activity. Medical Hypotheses 53, 459–485
13. Dixon, S. J., and Stockwell, B. R. (2014) The role of iron and reactive oxygen species in cell death. Nature Chemical Biology 10, 9–17
14. Allen, N. E., Appleby, P. N., Davey, G. K., Kaaks, R., Rinaldi, S., and Key, T. J. (2002) The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans. Cancer Epidemiology Biomarkers & Prevention 11, 1441–1448
15. Shaughnessy, D. T., Gangarosa, L. M., Schliebe, B., Umbach, D. M., Xu, Z., MacIntosh, B., Knize, M. G., Matthews, P. P., Swank, A. E., Sandler, R. S., DeMarini, D. M., and Taylor, J. A. (2011) Inhibition of Fried Meat-Induced Colorectal DNA Damage and Altered Systemic Genotoxicity in Humans by Crucifera, Chlorophyllin, and Yogurt. Plos One 6
16. McDougall, J., Thomas, L. E., McDougall, C., Moloney, G., Saul, B., Finnell, J. S., Richardson, K., and Petersen, K. M. (2014) Effects of 7 days on an ad libitum low-fat vegan diet: the McDougall Program cohort. Nutrition Journal 13