Abstract P484: Systematic Review and Meta-Analysis of Cardiometabolic Effects of Trans Fatty Acids From Dairy Foods

Abstract

As global initiatives to eliminate industrially-produced trans fatty acids (TFA) are implemented, dairy/ruminant-derived foods will become the major dietary TFA source. Such changes warrant better understanding of health effects from ruminant food-TFA consumption. This systematic review and meta-analysis aimed to assess cardiometabolic impacts of TFA from dairy foods, by evaluating findings from randomized controlled trials (RCTs) and prospective cohort studies (PCs). Separate searches for RCTs and PCs were conducted in PubMed and EMBASE databases using PRISMA guidelines. RCTs with at least a three-week intervention among adults compared the impact on blood lipids of regular dairy foods with TFA-enhanced dairy fat/foods produced by altering the cow’s diet. Selected PCs with at least four years of observation analyzed relationships between blood levels of specific TFA, such as vaccenic acid or trans palmitoleic acid (TPA) and risk of cardiovascular diseases (CVD) or type 2 diabetes among adults. A pooled meta-analysis of RCTs using the random effects model was performed for TC, LDL-C, HDL-C, TC/HDL-C, LDL-C/HDL-C, TG, ApoA1, ApoB as continuous variables with a statistical significance of p < 0.05, 95% confidence interval (CI). For PCs, risk estimates and 95% CI using maximally adjusted models for contrasting exposures of circulating TFA levels were tabulated. Among 13 experimental groups from ten RCTs, there were no statistically significant differences in mean difference (MD) and 95% CI for any lipid biomarkers except a slight decrease in HDL-C (MD: -0.05mmol/L; CI: -0.10, 0.00 mmol/L) for TFA-enriched vs regular dairy foods. Among PCs, four found no association of circulating TPA with risk of CVD mortality or incidence and one found no association of circulating vaccenic acid with risk of CVD mortality. Additionally, three of five PCs found no significant association while two found a significant inverse association of TPA and type 2 diabetes. Our findings indicate that consumption of TFA (0.8 - 12.2 g/d) from different types of dairy foods does not confer adverse effects on cardiometabolic health.