This umbrella review examines the association between plant-based diets and cardiovascular health, as well as cancer risk. The study analyzed reviews, systematic reviews, and meta-analyses published from January 1, 2000, to June 30, 2023, focusing on the impact of animal-free and animal-products-free diets (A/APFDs) on cardiometabolic diseases, cancer, and related mortality. The findings indicate that vegetarian and vegan diets are significantly associated with better lipid profiles, glycemic control, body weight/BMI, inflammation, and lower risks of ischemic heart disease and cancer. Vegetarian diets are also linked to lower mortality from cardiovascular diseases. However, no significant differences in the risk of gestational diabetes or hypertension were found in pregnant women following vegetarian diets. Study quality was generally average, with high heterogeneity in study populations, dietary patterns, and other lifestyle factors limiting the assessment of real benefits. Plant-based diets appear beneficial in reducing cardiometabolic risk factors, as well as cancer risk and mortality. However, caution is advised in recommending A/APFDs broadly due to limited evidence strength caused by study heterogeneity and potential risks of restrictive diets. The review highlights the need for further research on specific markers related to cardiometabolic and cancer risk, such as biochemical, genetic, and epigenetic markers, before widespread adoption of plant-based diets.This umbrella review examines the association between plant-based diets and cardiovascular health, as well as cancer risk. The study analyzed reviews, systematic reviews, and meta-analyses published from January 1, 2000, to June 30, 2023, focusing on the impact of animal-free and animal-products-free diets (A/APFDs) on cardiometabolic diseases, cancer, and related mortality. The findings indicate that vegetarian and vegan diets are significantly associated with better lipid profiles, glycemic control, body weight/BMI, inflammation, and lower risks of ischemic heart disease and cancer. Vegetarian diets are also linked to lower mortality from cardiovascular diseases. However, no significant differences in the risk of gestational diabetes or hypertension were found in pregnant women following vegetarian diets. Study quality was generally average, with high heterogeneity in study populations, dietary patterns, and other lifestyle factors limiting the assessment of real benefits. Plant-based diets appear beneficial in reducing cardiometabolic risk factors, as well as cancer risk and mortality. However, caution is advised in recommending A/APFDs broadly due to limited evidence strength caused by study heterogeneity and potential risks of restrictive diets. The review highlights the need for further research on specific markers related to cardiometabolic and cancer risk, such as biochemical, genetic, and epigenetic markers, before widespread adoption of plant-based diets.