Vegetarian Nutrition (VN) for Disease Prevention (2022-23)
Vegetarian Nutrition for Disease Prevention Umbrella Review
Lifestyle behaviors, including dietary patterns, play an important role in the prevention of cardiovascular and other diseases. Several observational studies have suggested that those following vegetarian, including vegan, dietary patterns may have a lower risk of certain diseases. A vegetarian dietary pattern is one that does not include intake of flesh products such as meat, poultry or fish, and a vegan diet additionally does not include other animal products such as dairy products or eggs. Understanding the benefits and harms of vegetarian and vegan diets for presumably healthy adults in the general population can help inform nutrition practitioners working with adult clients who follow or are interested in following vegetarian or vegan diets.
Several current systematic reviews report on the impact of vegetarian diets compared to non-vegetarian diets on a range of outcomes. Therefore, an overview of systematic reviews, also called an umbrella review, was conducted to answer the research question: In presumably healthy adults in the general population, what are the relationships between vegetarian, including vegan, diets compared to non-vegetarian diets on:
- Health Outcomes: incidence of cardiovascular disease, type 2 diabetes, cancer, bone fractures and cardiovascular events;
- Nutrient Status: concentrations of vitamin B12, calcium, hemoglobin, ferritin, iodine, vitamin D, omega-3s, BMI, bone density, muscle mass/lean body mass, fat mass; and
- Other Biomarkers: blood pressure and concentrations of LDL-cholesterol, triglycerides, and c-reactive protein.
Key findings:
- This umbrella review analyzed and summarized findings from 27 systematic reviews published from 2018 to January 2023. Evidence describing relationships between vegetarian diets and outcomes for adults in the general population was primarily observational.
- Moderate certainty of evidence described vegetarian diets, including vegan diets, reduced cardiovascular disease incidence compared to non-vegetarian diets.
- Low and very low certainty of evidence described several other potential benefits of following a vegetarian and/or vegan diets, including reduced risk of cardiovascular disease mortality, reduced blood pressure, blood lipids, BMI and c-reactive protein concentrations.
- However, low and very low certainty evidence also described some potential harms of following vegetarian diets for adults in the general population, including lower bone mineral density, and increased risk of fractures and lower vitamin B12 and vitamin D concentrations for those following vegan diets.
Use the links on the left to access the results of the review.