Diabetes

Vegans have the lowest risk of type 2 diabetes

By WhyStopHarmingAnimals.com

Of all the diet groups researchers have tracked, vegans have the lowest rates of type 2 diabetes[1][2][3][4]. They come in below vegetarians, who come in below people who eat meat[1]. The meat side has been measured closely too: the more meat people eat, the more type 2 diabetes they get[5][6][7], and that rise shows up for unprocessed red meat as well as for bacon and sausages[5][6][8].

A staircase in the Adventist data

The cleanest comparisons come from Seventh-day Adventists, a population in which many people avoid meat for religious reasons while living otherwise alike. Among 60,903 Adventists, type 2 diabetes prevalence climbed with each step toward more animal food: 2.9% in vegans, 3.2% in lacto-ovo vegetarians, 4.8% in pesco-vegetarians, 6.1% in semi-vegetarians and 7.6% in non-vegetarians (Diabetes Care, 2009)[1]. Vegans kept about half the risk even after the researchers adjusted for body mass index, so lower weight doesn't account for all of the gap[1].

When the Adventist Health Study-2 went on to count new cases of diabetes, published in the American Journal of Epidemiology, vegans again had the lowest risk of any diet group[2]. A review of vegetarian dietary patterns reached the same result, with vegan diets tied to the lowest incidence of type 2 diabetes[3], and a more recent analysis of plant-based diets and type 2 diabetes risk once more found the lowest risk among vegan participants[4].

More meat, more diabetes

The Adventist data shows a gradient across diet groups[1]. Meta-analyses of meat intake show one by dose[5][7]. The largest pooled 31 cohorts from 20 countries, covering 1.97 million adults (The Lancet Diabetes & Endocrinology, 2024)[5]. Each daily 100 g of unprocessed red meat came with 10% more type 2 diabetes[5], each 50 g of processed meat with 15% more[5], and each 100 g of poultry with 8% more[5]. Chicken is often offered as the safe swap for beef, and in this analysis it carried extra risk as well[5].

An earlier meta-analysis of 12 cohorts, published in Diabetologia in 2009, compared the heaviest meat eaters with the lightest[6]. Red meat came with 21% more type 2 diabetes[6] and processed meat with 41% more[6]. A separate dose-response meta-analysis of meat and fish intake found a linear relationship between type 2 diabetes risk and total meat, red meat and processed meat[7]. A systematic review of red meat found that unprocessed and processed red meat were both associated with higher risk of diabetes and of cardiovascular disease[8], and a review of meat as a diabetes risk factor found the association to be consistent across the research[9].

The unprocessed result matters because the usual defense of meat blames the salt and preservatives in processed products. Plain red meat and poultry go in the same direction, with smaller increases per gram[5].

Which plants count

Cutting out meat only helps if what replaces it is real food[10]. The largest study on this question followed 200,727 people in the Nurses' Health Studies and the Health Professionals Follow-Up Study, with two decades of diet records (PLOS Medicine, 2016). Those whose diets were most plant-based had 20% less type 2 diabetes[10]. On a version of the score that rewarded healthy plant foods, the reduction was 34%[10]. A version weighted toward juice, soda, refined grains and sweets raised risk instead[10]. A diet can be free of meat and still built on sugar, and that kind of diet doesn't protect anyone[10].

A 2017 analysis that ranked twelve food groups (European Journal of Epidemiology) graded the evidence "high" for red and processed meat raising type 2 diabetes risk, alongside sugary drinks[11]. Whole grains and fruit were protective[11], and optimal intakes of the protective foods came with 42% lower risk[11]. In the same analysis, dairy also tracked with lower risk[11]. That result runs against the other findings on animal foods, and it stands as a mixed one.

Why vegans come out ahead

Weight is part of it. Vegan diets are linked with the lowest obesity risk of the patterns studied[12], largely because they carry more fiber and less calorie-dense food. But the Adventist vegans kept about half the risk after adjusting for body mass index, which points to something beyond pounds[1].

A 16-week randomized trial of 244 people offers one lead. On a low-fat vegan diet, fat stored inside the liver fell 34% and fat inside muscle fell 10%[13], and insulin sensitivity improved[13], with none of it changing in the control group[13] (JAMA Network Open, 2020). Fat stored inside muscle cells interferes with insulin signaling, so clearing it lets insulin work better.

What the evidence can and can't say

The prevention evidence is observational. Cohorts adjust for known differences such as body weight, but no one can randomize thousands of people to eat meat or not for twenty years, so some confounding may remain. Dairy is a genuine exception in one large analysis[11].

What makes the case hard to dismiss is how the pieces line up: a step-by-step gradient across diet groups[1], a dose-response for meat across nearly two million adults[5], the same direction for unprocessed meat and poultry[5], and randomized trials in which people who already have diabetes get better blood sugar when animal products come off the plate.