Plant-based nutrition – emphasizing consumption of vegetables, whole grains, nuts, seeds, legumes, and fruits – can prevent, treat, or reverse certain chronic diseases in adults based on current best research evidence.
The chronic diseases studied most include obesity, high body mass index, hypertension, type 2 diabetes, coronary artery disease, and hyperlipidemia. Plant-based diets, however, are not a cure-all and should not be substituted for existing medication or therapy unless supervised by a physician.
Statements Based on Research Evidence
Individuals who report eating more plants have lower body mass index (BMI) and lower blood levels of total cholesterol, LDL cholesterol, fasting glucose, C reactive protein, and inflammatory profiles than do individuals who report eating fewer plants in their diet. Strong evidence based on over 700,000 subjects in population and cohort studies.
Plant-based diets can reverse existing coronary artery disease (evidenced by angiography) and can reduce body weight, oral diabetic medication needs, and blood levels of total cholesterol, LDL cholesterol, fasting glucose, c reactive protein (CRP), and hemoglobin A1c. Moderate evidence based on randomized trials and cohort studies that are mostly short-term (weeks to months) and have varying rates of adherence to plant-based diets over time.
Individuals who report eating more plants are less likely to develop hypertension, ischemic heart disease, type 2 diabetes, colon cancer, gastrointestinal cancer, and cancer overall in subsequent decades. Moderate evidence based on population and cohort studies that lose some subjects over time and have diverse methods and outcomes (e.g., are heterogeneous).
Individuals who report eating more plants are less likely to die from cardiovascular disease, ischemic heart disease, cerebrovascular disease, some cancers (pancreatic, lymphatic, hematopoietic), and from all-cause mortality. Moderate evidence based on population and cohort studies that lose some subjects over time and have diverse methods and outcomes.
Individuals who eat exclusively plant-based diets have lower rates of obesity, hypertension, type 2 diabetes, and cardiovascular disease than those who eat plant-based diets with some animal products. Weak evidence based on population and comparative studies with minorities of participants on exclusively plant-based diets and with variations in how these diets are defined.
The evidence mostly supports increased consumption of plants as beneficial, in contrast to simply removing animal products from the diet. Within the category of plant-based diets there is some evidence that eating only plants is best, with growing evidence that a whole food plant-based diet has more benefits than one that contains refined plant foods.
Many different plant-based diets have been used in research studies, making it difficult to generalize results and raising concerns in some cases (e.g., highly restrictive low-fat diets) about the ability of individuals to adhere to these diets for long periods of time.
Some of the observed health benefits of plant-based diets may be due to other lifestyle interventions that often accompany these diets, such as smoking cessation, limited alcohol consumption, stress reduction, and a greater emphasis on exercise and fitness.
We support the American Medical Association’s resolution from 2017 to “call on US hospitals to improve the health of patients, staff, and visitors by providing a variety of healthful food, including plant-based meals and meals that are low in fat, sodium, and added sugars”