A Systematic Review of the Association Between Vegan Diets and Risk of Cardiovascular Disease

Abstract

Background Plant-based diets are gaining attention globally due to their environmental benefits and perceived health-protective role. A vegan diet may have cardiovascular benefits; however, evidence remains conflicting and insufficiently assessed. Objectives We evaluated the utility of the vegan diet in cardiovascular disease (CVD) prevention. Methods We conducted a systematic review of studies evaluating the association between vegan diets and cardiovascular outcomes. We searched 5 databases (Ovid MEDLINE, EMBASE, Web of Science, Scopus, and OpenGrey) through 31 October 2020. Four investigators independently screened the full texts for inclusion, assessed quality, and extracted data from published reports. Results Out of the 5729 identified records, 7 were included, comprising over 73,000 participants, of whom at least 7661 were vegans. Three studies, with at least 73,426 individuals (including at least 7380 vegans), examined risks of primary cardiovascular events (total CVD, coronary heart disease, acute myocardial infarction, total stroke, hemorrhagic stroke, and ischemic stroke) in individuals who followed a vegan diet compared to those who did not. None of the studies reported a significantly increased or decreased risk of any cardiovascular outcome. One study suggested that vegans were at greater risk of ischemic stroke compared to individuals who consumed animal products (HR, 1.54; 95% CI, 0.95–2.48). Yet in another study, vegans showed lower common carotid artery intima-media thickness (0.56 ± 0.1 mm vs. 0.74 ± 0.1 mm in controls; P < 0.001), and in 3 studies of recurrent CVD events, vegans had 0–52% lower rates. Furthermore, endothelial function did not differ between vegans and nonvegans. Using the Grading of Recommendations Assessment, Development and Evaluation approach, evidence was deemed to be of low to very low strength/quality. Conclusions Among the Western populations studied, evidence weakly demonstrates associations between vegan diets and risk of CVDs, with the direction of associations varying with the specific CVD outcome tested. However, more high-quality research on this topic is needed. This study was registered at PROSPERO as CRD42019146835.

Therapeutic Potential of Nutritional Food for Healthy Cardiovascular System-Molecular Mechanism

“…The results of this study demonstrate that low carbohydrate diets may be used for much longer periods in obese subjects with high total cholesterol levels, as well as in patients with normocholesterolemia [79]. In studies of vegan diets, lower BMI, lower serum total cholesterol, lower glucose levels, lower in ammation levels, and lower blood pressure were associated with decreased cardiometabolic risk factors [80]. A study examined the adequacy of vegan diets in European populations and their macro-and micronutrient intakes.…”

The Effect of a Vegan Diet on the Cardiovascular System

“…On the other hand, according to some studies, a vegan diet may be related to reduced intake of protein, vitamins, or minerals, and thus should also be evaluated in terms of harmful effects. The research on veganism is contradictory and inadequately evaluated [ 53 ]. The vast majority of studies on health effects of vegan and plant-based diets were short term and cannot give accurate data on cardiovascular outcomes, which has mostly been estimated based on the changes in biomarker concentrations.…”

“…In contrast, lower intake of n-3 long-chain polyunsaturated fatty acids (i.e., DHA and EPA), vitamins (i.e., vitamin B12 and D), specific nutrients, including selenium, zinc, iodine, and calcium, as well as higher levels of essential amino acids (i.e., homocysteine), may explain some of the unfavorable CV effects associated with vegan diets, such as the potential increased risk of ischemic stroke [ 72 ]. One study has found that vegans and vegetarians had a higher risk of ischemic stroke than people who ate animal products (HR, 1.54; 95 percent CI, 0.95–2.48) [ 53 ].…”

The Accumulation and Molecular Effects of Trimethylamine N-Oxide on Metabolic Tissues: It’s Not All Bad

“…These foods and nutrients may or may not be directly linked to CVD independent of TMAO production [ 8 , 69 , 81 ]. Diets high in plant products, including the Mediterranean, vegetarian, and vegan diets are associated with lower circulating TMAO [ 50 , 82 , 83 , 84 ]. However, even healthy diets containing fish, vegetables, and whole-grain products, which measured high levels of long-chain unsaturated fatty acids can increase serum TMAO levels in patients with at cardiometabolic risk [ 85 ].…”