Plant-Based Diets Linked to Lower Risk of Heart Disease and Cancer, Review Finds

A sweeping analysis of two decades of medical research has found that people who eat vegetarian or vegan diets tend to have measurably lower rates of heart disease and cancer—two of the leading causes of death and disability worldwide. The conclusion comes from an umbrella review, a kind of scientific synthesis that collects and organizes findings from dozens of smaller studies and meta-analyses published between 2000 and 2023. Researchers led by Angelo Capodici, a medical doctor at the University of Bologna in Italy, examined 48 separate reviews to reach their findings, published in PLOS ONE.

The health advantages associated with plant-based eating were consistent across several markers. People following vegetarian or vegan diets showed better cholesterol profiles and improved blood sugar control. Their body mass index tended to be lower. Markers of inflammation in their bodies were reduced compared to those of people who eat meat. Most significantly, they faced a lower risk of developing both cancer and cardiovascular disease, and had lower mortality rates from heart-related conditions.

But the researchers were careful not to oversimplify the mechanism. They noted that vegetarians and vegans typically did more than simply avoid meat. They also consumed fewer refined grains, less added fat, fewer sweets and processed snacks, and drank fewer calorie-laden beverages than omnivores. They ate a wider variety of plant foods overall. This suggests that an omnivore might achieve similar health gains not by eliminating meat entirely, but by reducing processed foods and added sugars—a distinction that matters for how people interpret the findings.

The work arrives at a moment when plant-based eating has gained significant cultural traction. Over the past decade, millions have adopted vegetarian or vegan diets for reasons ranging from personal health to environmental concern to cost savings. That shift has generated a corresponding surge in research data, giving scientists like Capodici's team more material to analyze than ever before. The umbrella review approach allowed them to synthesize that expanding body of evidence into a coherent picture.

Yet the researchers stopped short of recommending universal adoption of plant-based diets. Individual nutritional needs vary substantially, they emphasized. Pregnant women following plant-based diets, for instance, did not show significantly lower rates of gestational diabetes or hypertension in the studies examined. Plant-based eating can also create risks of vitamin and mineral deficiencies if not carefully planned. People with allergies, gastrointestinal conditions, or other health complications may require a more tailored dietary approach.

Capodici and his colleagues called for more targeted research to understand precisely why plant-based diets correlate with better health outcomes. The findings of their umbrella review are only as strong as the original studies they synthesized, and that limitation warrants caution. Rather than encouraging wholesale dietary shifts at a population level, the researchers suggested that future work should narrow down the specific mechanisms at play—which components of plant-based eating drive the benefits, and for whom those benefits are most pronounced.

The implication is clear: diet appears to be a powerful lever for preventing chronic disease, perhaps more powerful than previously understood. But pulling that lever requires precision. For some people, the answer may be a fully plant-based diet. For others, it may be reducing processed foods while keeping some animal products. The science suggests the direction to move; individual circumstances determine the path.