Changes in Lipoproteins, Plasma Fatty Acid Profiles, and MicroRNA Following Four Months of Daily Almond Consumption (P08-098-19)

Abstract

Abstract Objectives To determine the effects of chronic almond consumption on blood lipoproteins, circulating fatty acids and microRNA profiles. Methods This study was a sixteen week two arm parallel randomized controlled trial. Participants received 20% of their daily calories from almonds or a calorie and fiber-matched control snack. Blood was collected at baseline, two months (midpoint), and four months (endpoint). Blood lipid panels were performed at all three time points and non-esterified fatty acid composition of fasting plasma was analyzed at the Western Human Nutrition Research Center. Total RNA was isolated from plasma samples and amplified by PCR using purchased microRNA primers, selected based on literature review and relevant biological pathways. Lipoprotein data were analyzed using repeated measures ANOVA and lipidomics data were compared using the standard least squares approach. Results Twenty eight subjects completed the study protocol. There were no significant differences within or between groups for total cholesterol, HDL, or triglycerides. Time by treatment effects were significant for LDL in the treatment group at endline (−13.2 ±6.5 mg/dL, P = 0.048). There were no differences in concentration or profile found in plasma fatty acid profile and these amounts were largely unchanged by diet treatment. In analysis of non-esterified fatty acids, there was a weak time by treatment effect for calendic acid (18:3, n-6) that is not significant after comparison for multiple corrections. microRNA is being investigated as a potential driver of this change in LDL and results are pending. Conclusions This pilot investigation found a small but significant difference in LDL concentrations from baseline following 4 months of daily almond consumption. Findings that there is no difference by treatment in non-esterified plasma fatty acids suggest that this difference is not driven through fatty acid signaling. Post-transcriptional regulation of gene expression through microRNA is a line of inquiry that is currently being explored. Funding Sources Almond Board of California, Jastro Shields Research Grant.