A new study was published in February of 2019 which concluded that people who eat completely plant-based are less likely to develop chronic diseases compared with other dietary groups (1). The study was funded by the NIH (National Institutes of Health) and the National Cancer Institute. Participants included 840 members of the Seventh Day Adventist population in Loma Linda, California, one of the Blue Zones of the world where people live much longer than average. Seventh Day Adventists believe strongly in the importance of health. Their religion teaches them to avoid alcohol and smoking, enjoy regular physical activity and to eat a vegetarian or vegan diet although they are allowed to eat meat if they choose. They are generally very health conscious and are a fit group on the whole.
Five different diet patterns among these participants were identified and analyzed by the researchers through blood, urine and adipose tissue (fat) samples and examination of their diet, alcohol intake, smoking habits, physical activity, supplement use and medical history.
The five diets were;
Vegan (consuming eggs, dairy, fish and meats less than once a month)
Lacto-ovo-vegetarian (consuming eggs and dairy more than once a month; consuming fish and other meat less than once a month)
Semi-vegetarian (consuming non-fish meats at least once a month; consuming any meat including fish less than once a week)
Pesco-vegetarian (consuming fish at least once a month; other meats less than once a month)
Non-vegetarian (consuming non-fish meat at least once a month; consuming any meat including fish more than once a week)
The results of this study were very clear. The vegan group, who ate almost completely plant-based foods, came out on top (1).
Compared to the other dietary patterns, vegans showed;
The highest intake of fruits, vegetables, legumes and whole grains
The highest intake of fiber
The lowest risk for cancer, heart disease and hypertension
Higher blood levels of carotenoid antioxidants (including α-carotene, β-carotene, cryptoxanthin, lutein and zeaxanthin) which are associated with lower inflammation
The highest blood levels of enterolactone and equol, compounds that may decrease inflammation. They are the products of the metabolism of isoflavones by beneficial gut bacteria (2). Higher intake of isoflavones is associated with decreased risks of cardiovascular disease, hormone-dependent cancers and menopausal symptoms.
The lowest intake of saturated fatty acids, fats that are associated with increased cardiovascular disease and other chronic health conditions (3)
The lowest intake of arachidonic acid, an inflammatory omega 6 fat
Higher body levels of omega-3 fatty acids. Though these omega-3s were not the long-chain omega 3s (DHA and EPA), the clinical significance of this is not fully understood. Vegans do not show signs of DHA deficiency, nor do they have higher risks of diseases associated with low EPA and DHA. This may be because vegans seem to have increased efficiency in the conversion of short-chain omega-3s to the long-chain form, especially if their intake of omega-6 fatty acids is low (4).
Higher body levels of active vitamin B12, perhaps because vegans are aware of the difficulty of obtaining vitamin B12 from their diet and are taking regular supplements
Lower average BMI. In fact, vegans were the only group in a healthy weight range; all the other dietary groups were overweight on average
This study illustrates clearly that a completely plant-based diet easily provides all the nutrients needed for health (as long as a Vitamin B12 supplement is taken regularly) and are a nourishing approach to preventing chronic disease (1).
The results from the very recent study discussed above can be added to the conclusions of an earlier one, a 2017 investigation from New Zealand known as the BROAD Study (5). It was a randomized controlled trial involving obese or overweight participants who had been diagnosed with one of type-2 diabetes, ischaemic heart disease, hypertension or high cholesterol. The intervention group were transitioned to a whole-food plant-based diet. High-fat foods such as nuts and avocados were discouraged but no restrictions were placed on total calories consumed. No change in exercise was mandated. The control group continued their current lifestyle habits and diet and received normal medical care of their health conditions. The intervention group was followed for one year. The control group was followed for six months.
Results showed that, compared to the control group, the group eating a whole-food plant-based diet had (4);
Significant and sustained weight reductions with BMI decreases of more than 4 points (The control group showed no BMI decreases.)
Larger average reductions in total cholesterol
A 29% decrease in the number of medications required for their conditions (The control group medications increased by 8% over the course of the study.)
The weight of evidence is continuing to grow. Whole-food plant-based diets are a safe and extremely effective option for controlling weight and reducing the risks of many chronic diseases. When it comes to diet, moderation is not the key. Increasing foods from whole plant sources can certainly improve health. However, removing foods from animal sources allows every bite you eat to provide the healthful elements bountiful in plants….fiber, vitamins, minerals, antioxidants and other bioactive substances.
1 Miles, F.L., Lloren, J.L.C., Haddad, E., Jaceldo-Siegl, K., Knutsen, S., Sabate, J., Fraser, G.E. Plasma, Urine, and Adipose Tissue Biomarkers of Dietary Intake Differ Between Vegetarian and Non-Vegetarian Diet Groups in the Adventist Health Study-2. J Nutr. April, 2019; 149(4): 667–675.
3 Sacks, F.M., Lichtenstein, A.H., Wu, J.H.Y., Appel, L.J., Creager, M.A., Kris-Etherton, P.M., Miller, M. Rimm, E.B., Rudel, L.L., Robinson, J.G., Stone, N.J., Van Horn, L.V. Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association. Circulation. 2017 Jul 18; 136(3):e1-e23.
5 Wright, N., Wilson, L., Duncan, B. The BROAD study: A randomised controlled trial using a whole food plant-based diet in the community for obesity, ischaemic heart disease or diabetes. Nutrition and Diabetes 2017; 7, e256.