The short answer is yes. The Mayo Clinic team summarized its findings with these instructions for doctors:
"Physicians should encourage patients to limit animal products when possible, and substitute red meat and processed red meat with plant-based foods."
They drew this conclusion from a review of six other reviews of studies examining the relationship between meat-eating and mortality. This meta-review, if you will, contained data from than 3.3 million people in total. The sheer scope of the investigation allowed researchers to pick up on trends despite variability between individual studies.
Most memorably, one of the studies found that long-term vegetarianism was associated with a 3.6-year increase in life expectancy. Another found that meatless diets cut the risk of type 2 diabetes mellitus in half. Low-meat diets (meat less than once per week but more than once per month) still decreased diabetes risk by one quarter to one third.
Hopefully doctors will help spread the word: less meat means a longer and healthier life.
Written by Cameron Meyer Shorb