Vegetarian Diet may lower LDL-C, HbA1c and body weight among high risk CVD patients

Vegetarian diet consumption can effectively reduce the cardiometabolic risk factors like low-density lipoprotein cholesterol (LDL-C), hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and body weight in people with or at high risk of cardiovascular diseases (CVDs). The vegetarian diet was greatly effective in glycemic control and had a synergistic effect in patients at high risk of CVD and type 2 diabetes as per a recent study that was published in the journal JAMA Network Open. 

Cardiovascular diseases (CVDs) continue to be the dominant contributor to disease burden and rising healthcare costs globally, despite significant therapeutic advances. A higher risk of CVD morbidity and mortality is mechanistically associated with poor nutrition. Recent guidelines suggest that various forms of vegetarian diets have become popular due to the health and environmental benefits. Plant based diets are known to improve the cardiometabolic risks but their effect on patients at high risk of cardiovascular diseases (CVDs) is inconclusive. Hence researchers conducted a meta-analysis to assess the association of vegetarian diets with major cardiometabolic risk factors, including low-density lipoprotein cholesterol (LDL-C), hemoglobin A1c (HbA1c), systolic blood pressure (SBP), and body weight in people with or at high risk of CVDs. 

Eligible trials where vegetarian diets were delivered to adults with cardiovascular risks were included. Cardiovascular risk factors like LDL-C, HbA1c or SBP were included. Data like the demographics, study design, sample size, and diet description were independently extracted by two reviewers and risk of bias assessment was performed. Assessing the mean changes in LDL-C, HbA1c, and SBP between the two groups was the main outcome of measurement. Mean changes in LDL-C, HbA1c, SBP, and body weight were assessed by random-effects model. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to evaluate the overall certainty of evidence. 

Key findings:

• Twenty RCTs involving 1878 participants with a mean age range of 28-64 years were included, and mean duration of intervention was 25.4 weeks (range, 2 to 24 months).
• Four studies targeted people with CVDs, 7 focused on diabetes, and 9 included people with at least 2 CVD risk factors.
• Consumption of vegetarian diets for an average of 6 months was associated with decreased LDL-C, HbA1c, and body weight by 6.6 mg/dL, 0.24%, and 3.4 kg, respectively, but the association with SBP was not significant (−0.1 mm Hg) when compared to all other diets.
• The GRADE assessment showed a moderate level of evidence for LDL-C and HbA1c reduction.

Thus, vegetarian diet was associated with significant reductions in LDL-C, HbA1c, and body weight, beyond standard therapy, in patients with or at high risk of CVDs. This study is crucial for the development of clinical guidelines in the management of cardiometabolic risk factors. 

Further reading: Wang T, Kroeger CM, Cassidy S, et al. Vegetarian Dietary Patterns and Cardiometabolic Risk in People With or at High Risk of Cardiovascular Disease: A Systematic Review and Meta-analysis. JAMA Netw Open. 2023;6(7):e2325658. doi:10.1001/jamanetworkopen.2023.25658