Differences in carotid to femoral pulse wave velocity and carotid intima media thickness between vegetarian and omnivorous diets in healthy subjects: a systematic review and meta-analysis

Background: Arterial stiffness and atherosclerosis are known risk factors for cardiovascular morbidity and mortality. Vegetarian diets have been associated with cardiovascular benefits, including improvements in metabolic parameters. However, the impact of a vegetarian diet on cardiovascular parameters, specifically arterial stiffness and atherosclerosis, in healthy individuals remains unclear. Thus, this study aims to analyze differences in arterial stiffness and atherosclerosis between vegetarian and omnivorous diets in healthy subjects. Methods: A systematic review and meta-analysis were conducted following established guidelines. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched for studies examining the association between vegetarian and omnivorous diets with arterial stiffness and atherosclerosis. Cross-sectional studies reporting carotid to femoral pulse wave velocity (cf-PWv) as a measure of arterial stiffness and carotid intima media thickness (c-IMT) as a measure of atherosclerosis were included. Data were synthesized using random effects models, and sensitivity analyses, meta-regressions, and assessment of publication bias were performed. Results: Ten studies were included in the systematic review, and seven studies were included in the meta-analysis. The pooled analysis demonstrated that individuals following a vegetarian diet had differences in the levels of arterial stiffness (cf-PWv) compared to those following an omnivorous diet (MD: -0.43 m s-1; 95% CI: -0.63, -0.23). Similarly, atherosclerosis (c-IMT) was found to be different in individuals adhering to a vegetarian dietary pattern (MD = -29.86 mm; 95% CI: -58.41, -1.32). Conclusions: Our findings suggest that a vegetarian diet is associated with improved arterial stiffness and reduced atherosclerosis in healthy individuals. These results support the inclusion of a well-balanced vegetarian dietary pattern in the prevention and management of cardiovascular diseases. However, further research is needed to explore the effects of a vegetarian diet on arterial health in diverse populations and to assess long-term cardiovascular outcomes.