A vegan diet is one of the healthiest dietary patterns available, but it is not definitively “the healthiest.” Vegan eating delivers clear advantages for heart health and diabetes prevention, yet it also introduces real nutritional gaps that require active management. Whether a vegan diet outperforms other well-planned diets depends largely on what you eat, what you supplement, and which health outcome you’re measuring.
Where Vegan Diets Excel
The strongest evidence in favor of vegan eating centers on cardiovascular health and blood sugar control. In clinical trials, plant-based diets reduce LDL cholesterol by about 10% on average, a shift that meaningfully lowers heart disease risk over time. Prospective studies of more than 120,000 vegetarians found a 25% reduced risk of ischemic heart disease compared to meat eaters, with stricter plant-based patterns generally showing the greatest benefit.
The metabolic advantages are equally striking. In a large long-term cohort study, the prevalence of type 2 diabetes was 49% lower among vegans and 46% lower among lacto-ovo vegetarians compared to non-vegetarians. That’s a substantial gap, and it holds up even after accounting for body weight differences. Vegan diets tend to be higher in fiber and lower in saturated fat, both of which improve how the body handles insulin.
Vegan diets also appear to benefit the gut. Cross-sectional research shows that vegans and vegetarians harbor greater bacterial diversity in their intestines than omnivores, with significantly higher counts of Bacteroidetes, a group of bacteria associated with fiber metabolism and reduced inflammation. Greater microbial diversity is consistently linked with better overall health.
Where Vegan Diets Fall Short
The most well-documented risk is vitamin B12 deficiency. Some studies estimate that 52% of vegans have deficient B12 levels, compared to just 1% of omnivores. Across multiple countries, subnormal B12 status affects 50 to 70% of people following vegetarian or vegan diets. B12 is essential for nerve function and red blood cell production, and prolonged deficiency can cause irreversible neurological damage. Supplementation is not optional on a vegan diet; it’s a requirement.
Bone health is another area of concern. Multiple prospective cohort studies have found that vegan diets are associated with increased fracture risk, driven partly by lower intakes of calcium, vitamin D, and protein, and partly by lower body weight (which is protective for bones through mechanical loading). Evidence suggests that supplementing calcium and vitamin D together, along with eating protein-rich plant foods, can reduce this elevated risk.
Protein quality matters more than most people realize. Scientists score protein sources based on how well the body can digest and use their amino acids. On this scale, soy scores high (91 out of 100), comparable to whey (85). But most other plant proteins score considerably lower: pea protein comes in at 70, and wheat protein at just 48. By contrast, pork scores 117. This doesn’t mean you can’t get enough protein on a vegan diet, but it does mean you need to combine multiple protein sources and eat larger quantities to match what animal proteins deliver in smaller servings.
Vegan vs. Other Healthy Diets
When researchers compare vegan diets head-to-head with other well-studied patterns, no single diet consistently wins. A meta-analysis of more than 2 million people found that strict adherence to a Mediterranean diet reduced overall mortality by 10% and cardiovascular disease incidence by 9%. The vegetarian data showed a 25% reduction in ischemic heart disease specifically, but the two patterns have never been directly compared in a randomized trial for cardiovascular outcomes.
All-cause mortality data complicate the picture further. One large U.S. prospective study found that pescatarians (fish-eating vegetarians) had the lowest mortality risk, with a hazard ratio of 0.81 compared to omnivores. Lacto-ovo vegetarians showed essentially no difference from omnivores (0.99), and vegans actually trended toward slightly higher mortality (1.27), though this result was not statistically significant. These numbers don’t mean veganism is dangerous. They likely reflect the challenge of maintaining nutritional adequacy without careful planning, something that washes out in populations where supplementation and dietary variety are common.
Not All Vegan Diets Are Equal
One of the biggest misconceptions is that “vegan” automatically means “healthy.” A growing body of research shows that the quality of plant-based foods matters enormously. Analysis from Imperial College London found that plant-based ultra-processed foods were linked with a 7% increase in cardiovascular disease risk compared to unprocessed plant-based foods. Vegan burgers, packaged snacks, and sugary plant-based desserts can be just as harmful as their animal-based counterparts.
The distinction between a whole-food vegan diet built around vegetables, legumes, nuts, seeds, and whole grains versus one relying on processed meat substitutes and refined carbohydrates is arguably more important than the distinction between vegan and omnivore. A poorly planned vegan diet can be nutritionally worse than a thoughtful omnivorous one, and vice versa.
What About Children?
Vegan diets in children require especially careful attention. Systematic reviews of the available evidence show that vegan children tend to be similar to, or somewhat below, omnivorous children in height, weight, and BMI. The risk of stunting and being underweight exists, though the percentage affected is relatively small. Bone mineral content is notably reduced in vegan children compared to omnivores, with markers suggesting a higher rate of bone turnover that may signal stress on developing bones. Iron stores also tend to be lower, with vegan children showing reduced ferritin concentrations.
Preliminary data suggest that children who drink plant-based milk instead of cow’s milk may end up shorter, though this area still has limited long-term data. For families raising children on vegan diets, careful supplementation of B12, vitamin D, calcium, and iron, along with attention to adequate protein and calorie intake, is essential for supporting normal growth.
The Bottom Line on Vegan Health
A well-planned vegan diet ranks among the healthiest dietary patterns for preventing heart disease and type 2 diabetes, and it promotes a more diverse gut microbiome. But calling it “the healthiest diet” overstates the evidence. It carries real risks for B12 deficiency, bone fractures, and inadequate protein quality that don’t exist with other healthy eating patterns like pescatarian or Mediterranean diets. The healthiest diet is less about a specific label and more about the underlying pattern: abundant whole plant foods, adequate protein from varied sources, minimal ultra-processed food, and smart supplementation to fill any gaps.