Vegans have measurably lower rates of heart disease, type 2 diabetes, and certain cancers compared to meat eaters. But they also face higher fracture risk and a serious likelihood of vitamin B12 deficiency if they don’t supplement. The honest answer is that a well-planned vegan diet offers significant health advantages, while a poorly planned one creates real vulnerabilities.
What matters most isn’t whether you eat animal products, but the overall quality of what you eat. A vegan diet built around whole grains, legumes, vegetables, and nuts consistently outperforms the average omnivorous diet on nearly every health marker. A vegan diet built around chips, white bread, and processed meat alternatives tells a different story.
Heart Disease and Blood Pressure
Cardiovascular health is where vegan diets show their strongest advantage. Vegan men have roughly half the risk of dying from ischemic heart disease compared to non-vegetarians. That’s a striking reduction, and it holds up even after researchers adjust for exercise habits, age, and sex. Vegetarians and pescatarians also benefit, but with a more modest 13% reduction in ischemic heart disease rates.
Blood pressure follows a similar pattern. Vegans have about 63% lower odds of developing hypertension compared to non-vegetarians. A randomized trial using identical twins, one eating vegan and the other omnivorous, found that the vegan twins saw significant improvements in LDL cholesterol, insulin levels, and body weight over the study period. Using identical twins is a powerful design because it eliminates genetic differences as a confounding factor.
Type 2 Diabetes Risk
Vegans develop type 2 diabetes at dramatically lower rates. In a study of over 41,000 people followed for two years, vegans had about 62% lower odds of developing type 2 diabetes compared to non-vegetarians, even after controlling for body weight and other variables. A separate analysis found vegans had roughly half the rate of diabetes compared to omnivores.
The weight factor matters here. Vegans tend to carry less body fat, which itself reduces diabetes risk. But even after adjusting for BMI, the protection persists. The high fiber content of plant-based diets likely plays a role by improving how the body processes blood sugar, and the absence of certain compounds found in red and processed meat may also contribute.
Cancer: A Mixed Picture
Cancer prevention is where the vegan advantage gets more nuanced. Vegan men are 35% less likely to develop prostate cancer, a finding from a large U.S. cohort study that held up even after adjusting for body weight. No other form of vegetarian diet showed this same protection. There was also a trend toward lower risk of advanced, more dangerous forms of prostate cancer, though that link was less statistically clear.
For colorectal cancer, however, vegetarian diets as a whole are linked to lower risk, but vegan diets specifically don’t show additional protection beyond what vegetarians achieve. The American Institute for Cancer Research notes that it’s the overall dietary pattern, rich in fiber, fruits, and vegetables, low in processed meat, that drives cancer protection rather than the complete elimination of animal products.
Weight and Metabolic Health
Vegans consistently weigh less than omnivores. Clinical trials confirm that plant-based diets lead to greater weight loss, improved cholesterol, better blood sugar regulation, and lower blood pressure. The identical twin trial is particularly compelling: with genetics held constant, the vegan diet produced measurable improvements in weight, LDL cholesterol, and insulin levels in just weeks.
These findings aren’t limited to short-term interventions. A two-year dietary trial among African Americans randomized to either a vegan or low-fat omnivorous diet also found improvements in body weight and cardiovascular risk factors in the vegan group.
Bone Health Is a Real Concern
This is where the vegan health story takes a turn. The large EPIC-Oxford study, which followed tens of thousands of people over many years, found that vegans had a 43% higher risk of total fractures and more than double the risk of hip fractures compared to meat eaters. That translates to roughly 15 additional hip fractures per 1,000 vegans over a 10-year period. Leg fractures were also about twice as common.
These elevated risks persisted even after adjusting for BMI and lifestyle factors. Lower calcium and protein intake likely contribute, along with lower vitamin D levels in some vegan populations. If you eat a vegan diet, paying attention to calcium (through fortified foods or supplements), vitamin D, and adequate protein is not optional for long-term bone health.
B12 Deficiency Is Nearly Universal Without Supplements
Vitamin B12 is found naturally only in animal products, and the consequences of going without it are serious: nerve damage, cognitive problems, and a type of anemia that can become irreversible. About 52% of unsupplemented vegans have deficient B12 levels, compared to just 1% of omnivores. Across multiple countries, 50 to 70% of vegans and vegetarians have subnormal B12 status.
The fix is simple. A daily supplement of at least 4 micrograms, or regular consumption of B12-fortified foods like nutritional yeast, plant milks, or breakfast cereals, maintains adequate levels. This is the single most important supplement for anyone eating a fully vegan diet.
Iron: Smaller Gap Than Expected
Iron deficiency is often cited as a vegan concern, and plant-based iron is indeed harder for the body to absorb. But the actual gap in anemia rates is smaller than many people assume. In a U.S. study, 13% of vegan women were anemic compared to 10% of non-vegetarian women. In China, the difference was wider: 30% versus 10%. The variation suggests that diet composition, not just the absence of meat, determines iron status.
Pairing iron-rich plant foods (lentils, spinach, tofu, fortified cereals) with vitamin C significantly boosts absorption. Cooking in cast iron and avoiding tea or coffee with meals also helps, since tannins interfere with iron uptake.
Protein Quality Differs by Source
Not all plant proteins are created equal. Protein quality is measured by how well a food provides the essential amino acids your body needs in the right proportions. On the standard scoring system (PDCAAS), whey protein scores a perfect 1.0. Soy is nearly identical at 0.99. Pea protein drops to around 0.83, and wheat protein falls to just 0.45.
For vegans, this means soy-based foods (tofu, tempeh, edamame) are genuinely excellent protein sources, comparable to dairy. Relying heavily on wheat or rice protein alone would leave gaps. The practical solution is eating a variety of legumes, soy products, nuts, seeds, and whole grains throughout the day, which covers all essential amino acids without needing to combine them at every meal.
Gut Health and Fiber
Vegan diets tend to produce higher levels of butyrate in the gut, a short-chain fatty acid that fuels the cells lining the colon and plays a role in reducing inflammation. Vegans also harbor higher levels of certain beneficial bacterial species associated with butyrate production. Interestingly, overall bacterial diversity at the species level was actually higher in omnivores in one study, though the functional significance of this difference isn’t straightforward. A gut microbiome that efficiently produces protective compounds may matter more than sheer diversity.
Not All Vegan Diets Are Equal
A large meta-analysis of prospective studies found that people who scored highest on a healthy plant-based diet index had a 14 to 15% lower risk of dying from any cause compared to those who scored lowest. But people who scored highest on an unhealthy plant-based diet index, one heavy in refined grains, sugary drinks, and processed snacks, had a 20% higher risk of death. Being vegan while eating mostly processed food is worse than a balanced omnivorous diet.
Even ultra-processed plant foods, though, may not be as harmful as their animal-based equivalents. Replacing dairy milk with soy milk, for example, reduces LDL cholesterol, blood pressure, and markers of inflammation. The research suggests that while whole plant foods are the clear winners, processed plant foods occupy a middle ground that still tends to outperform processed animal products on cardiometabolic measures.
The Bottom Line on Longevity
Greater adherence to a healthy plant-based diet is associated with lower risk of death from all causes and from cardiovascular disease specifically. The relationship isn’t perfectly linear: the biggest mortality reductions come when shifting from a poor diet to a moderately plant-heavy one, with diminishing returns beyond that. Vegans who supplement B12, attend to calcium and vitamin D, eat enough protein from varied sources, and build their diet around whole foods are positioned for genuinely better health outcomes than the average omnivore. Vegans who skip supplements and rely on processed convenience foods may trade one set of health risks for another.