Decades ago we started to get the first inklings that a plant-based diet may be protective against diabetes. Studies going back half a century found that those eating meat one or more days a week had significantly higher rates of diabetes, and the more frequently meat was eaten, the more frequent the disease. And this is after controlling for weight. Even at the same weight, those eating plant-based had but a fraction of the diabetes rates, and if anything, vegetarians should have had more diabetes just because they appear to live so much longer so had more time to develop these kinds of chronic diseases–but no–apparently lower rates of death and disease.

Fast forward 50 years to the Adventist-2 study, looking at 89,000 people and we see a stepwise drop in the rates of diabetes as one eats more and more plant-based, down to a 78% lower prevalence among those eating strictly plant-based. Protection building incrementally as one moved from eating meat, to eating less meat, to just fish, to no meat, and then to no eggs and dairy either.

We see the same thing with another leading killer, high blood pressure. The greater the proportion of plant foods, the lower the rates of hypertension. The same with excess body fat. The only dietary group not on average overweight were those eating diets composed exclusively of plant foods, but again this same incremental drop with fewer and fewer animal products. This suggests that it’s not black and white, not all or nothing; any steps one can make towards eating healthier may accrue significant benefits.

Followed over time, vegetarian diets were associated with a substantially lower incidence of diabetes–fewer new cases–indicating the potential of these diets to stem the current diabetes epidemic.

What about eating a really healthy diet with just a little meat? Or is it better to eat none at all? We have new insight this year from Taiwan. Asian diets in general tend to be lower in meat and higher in plant foods compared with Western diet, but whether a diet completely avoiding meat and fish would further extend the protective effect of a plant-based diet wasn’t known, until now.

Traditionally, Asian populations have had low rates of diabetes, but a diabetes epidemic has since emerged, and appears to coincide with increased meat, animal protein, and animal fat consumption, but the Westernization of Asian diets also brought along a lot of fast food and junk. So these researchers at the national university didn’t want to just compare those eating vegetarian to typical meateaters; they compared Buddhist vegetarians to Buddhist nonvegetarians eating traditional Asian diets. Even the omnivores were eating a predominantly plant-based diet, consuming little meat and fish, with the women eating the equivalent of about a single serving a week, and men eating a serving every few days. That’s just 8% of the meat intake in the U.S., 3% for the women. The question: is it better to eat 3% or 0%?

Again, both groups were eating healthy–zero soda consumption, for example, in any group. Despite the similarities in their diet, and after controlling for weight, family history, exercise, and smoking the men eating vegetarian had just half the rates of diabetes, and the vegetarian women just a quarter of the rates. So even in a population consuming a really plant-based diet with little meat and fish, true vegetarians who completely avoided animal flesh, while eating more healthy plant foods, had lower odds for prediabetes and diabetes after accounting for other risk factors. They wanted to break it up into vegan versus ovo-lacto like in the Adventist-2 study, but there were no cases at all of diabetes found within the vegan group.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.

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