A study published in the Journal of the Academy of Nutrition and Dietetics dives into the role of plant-based diets, particularly vegetarian and vegan dietary patterns. A systematic review was performed to explore vegetarian and vegan diet patterns
Twenty-seven systematic reviews exploring vegetarian dietary patterns in generally healthy adults revealed moderate-quality evidence linking these diets to reduced cardiovascular disease (CVD) incidence. Lower-quality evidence suggests additional benefits, such as decreased CVD mortality, overall cancer incidence, blood pressure, certain blood lipid levels, and C-reactive protein concentrations, as well as lower BMI. Low bone mineral density, increased fracture risk, and deficiencies in vitamin B12 and D—especially among vegans—highlight the need for careful dietary planning.
In disease management, particularly for individuals with CVD, CVD risk factors, or type 2 diabetes mellitus (T2DM), vegetarian and vegan diets show moderate-quality evidence for reducing BMI and hemoglobin A1c levels. These diets are also potentially beneficial in lowering diabetes medication needs, although the supporting evidence is of very low quality. Among individuals with existing CVD, plant-based diets performed similarly to therapeutic nonvegetarian diets in controlling blood pressure, lipid profiles, and other clinical outcomes, though most evidence was of low or very low quality.
The Plant-Based Diet Index (PDI) distinguishes between healthful (hPDI) and unhealthful (uPDI) plant-based patterns. Diets high in whole, nutrient-dense foods—such as fruits, vegetables, legumes, and nuts—are associated with reduced risks of T2DM, CVD, obesity, and inflammation. In contrast, diets high in refined grains, sweetened beverages, and processed plant foods may increase chronic disease risk. High hPDI scores are also associated with a more diverse and beneficial gut microbiota, which supports immune, metabolic, and gastrointestinal health.
Plant-based proteins, though sometimes less digestible than animal proteins, can meet all essential amino acid requirements when a variety of sources are consumed. Foods like tofu, beans, and whole grains contribute to adequate protein intake, muscle synthesis, and gut health. Soy products, in particular, offer high-quality protein and are linked to improved cardiometabolic outcomes and reduced cancer risk. Additionally, plant sources of omega-3 fatty acids—such as flaxseeds and walnuts—support inflammation control and cell health.
The study suggests that vegetarian and vegan diets may play a significant role in improving health outcomes related to cardiometabolic diseases. However, these diets may also present challenges, including potential nutrient deficiencies. RDNs and NDTRs are encouraged to offer vegetarian and vegan dietary options to adults who are interested and could benefit from them. Furthermore, the Academy of Nutrition and Dietetics advocates for policies that promote equitable access to plant-based foods in various settings, including schools, childcare programs, and federal assistance programs.
