381 Protein Source – Plant or Animal? [8 Aug 2016]

An interesting study was published last week in JAMA Internal Medicine. The study examined data from two previous epidemiologic studies involving over 130,000 health professionals, average age 49, to see if source of protein – animal or plant – has an influence on health and longevity.

The study found that (after factoring out known risk factors) eating more animal protein (meat) was weakly associated with slightly higher mortality, particularly cardiovascular, while eating more plant protein was more strongly associated with a lower mortality.

Curiously these associations only occurred in people with at least one unhealthy lifestyle factor – smoking, heavy alcohol intake, overweight, or physically inactive. For those with a healthy lifestyle the source of protein did not affect mortality. The type of meat was also significant – replacing plant protein for processed meat had a greater reduction of mortality than replacing unprocessed red meat. And there was no association found with fish or poultry and mortality. Note that this is an observational study and does not necessarily show a causal relationship.

How to account for the lack of effect of protein source on the healthy lifestyle group? One possible explanation is that the healthy lifestyle people may have had more fibre and healthier plant foods in their diet, made healthier choices of animal protein (less processed meat, more poultry and fish), and cooked it in a healthier manner (not deep-fried or burned).

This study was limited to older adult health professionals and may not apply to other age or socio-economic groups. For example previous studies have shown that children and adolescents do better on animal protein from red meat (in moderation) as it provides significant and easily absorbed amounts of protein and micronutrients such as iron, zinc and Vitamin A which are crucial to growth and development, and may even help prevent chronic disease in adulthood.

In conclusion, it appears that increasing plant sourced protein may be especially helpful if you smoke, drink too much, are overweight or inactive, or if you have a chronic disease such as diabetes, coronary heart disease, or kidney disease.

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.