Health Benefits of a Vegan Diet: Current Insights

Abstract

: To assess the health bene fi ts of a vegan diet, observational studies of diabetes (non-insulindependent;NIDDM),cancer,mortality,gutmicrobiota,hypertension,lipids,andoverweight were examined. Utilizing PRISMA items to identify articles and assess their quality for inclusion, 44 studies were screened into the review. In two separate studies, vegans did not have a reduced risk of diagnosis of “ any ” cancer, nor of speci fi c cancers when the effects of BMI were adjusted. When datawereaggregated,therewasareducedriskofanycancer.Veganshadlowertotalcholesteroland LDL-C levels compared to omnivores, and in some cases other dietary groups. In the US, there was areduced riskofadiagnosisofNIDDMandinWesterncountries,veganshad lowerBMI.Research support for reduced risk of diagnosis of female cancers, improved mortality rates, lower blood pressure, lower triglycerides, and a healthier microbiome for vegans compared to omnivores was inconsistent. There was no evidence that reduced speci fi c cancer incidence rates were lower in vegans although inadequate sample sizes had hampered these analyses. In vegans, HDL-C levels were either lower or not signi fi cantly different from omnivores. Geographic location was a strong moderatorwiththemostcompellingevidenceforthehealthadvantagesofavegandietcomingfrom the US, whereas in Taiwan, India and Vietnam, there was much less evidence of its bene fi t. In some instances, sex moderated the association between adopting the diet and health outcomes. speci fi c the diet, dietary comparison groups utilized in studies may alsoaffectresults.Althoughavegandietisassociatedwithsomehealthbene fi ts,thelevelofsupport for the bene fi t varied according to the health outcome being measured, with evidence emerging that BMI is an important mediator and geography and to a lesser extent sex are important moderators.