20 Years of Research Links Meat-Free Diets to Lower Risk of Cancer, Heart Disease: Major New Review

A major new review of the past 20 years of scientific research presents some of the strongest evidence yet that plant-based diets can help prevent the two leading causes of death worldwide: cardiovascular disease and cancer.

A joint undertaking between researchers at the University of Bologna in Italy and the Stanford University School of Medicine, the comprehensive review, published last week in PLOS One, looked at meta-analyses from 2000 to 2023 to evaluate the impact of vegetarian and vegan diets on the risk of cancer and cardiometabolic diseases. After pooling data from 48 meta-analyses involving hundreds of thousands of participants across a range of demographics (including children), the researchers noted some overarching trends: Vegetarians and vegans were significantly less likely to develop cardiovascular disease and cancer. They also tended to have better cardiometabolic health overall, with less inflammation, lower blood pressure, lower cholesterol, and leaner BMIs than people who ate meat.

“Overall, vegetarian and vegan diets are significantly associated with better lipid profile, glycemic control, body weight/BMI, inflammation, and lower risk of ischemic heart disease and cancer,” the authors wrote.

Plant-based diets appeared especially beneficial for preventing prostate and gastrointestinal cancers. Among omnivores, those who ate a lot of red processed meats saw a higher risk of gastrointestinal cancers. “Our umbrella review seems consistent with other primary evidence that links the consumption of red processed meats to an increased risk of cancers of the gastrointestinal tract,” the authors noted.

While a number of studies have linked plant-based diets with improved health outcomes, the new PLOS One report is particularly compelling because it’s an umbrella review. Primary research, such as observational studies and randomized clinical trials, gather essential data. Meta-analyses synthesize previously published studies to identify meaningful associations. Umbrella reviews go a step further, synthesizing meta-analyses to offer a comprehensive summary of available evidence.

The authors acknowledge the review’s limitations, such as potential confounding variables within the observational studies. “It should be remarked that, in the majority of the cases, people adopting plant-based diets are more prone to engage in healthy lifestyles that include regular physical activity, reduction/avoidance of sugar-sweetened beverages, alcohol and tobacco,” they noted.

Still, based on their findings, they conclude that plant-based diets are “one of the effective preventive strategies for the two most impactful chronic diseases on human health in the 21st century.”

To learn more about a whole-food, plant-based diet, visit our Plant-Based Primer. For meal-planning support, check out Forks Meal Planner, FOK’s easy weekly meal-planning tool to keep you on a healthy plant-based path.