Almond consumption for 8 weeks differentially modulates metabolomic responses to an acute glucose challenge compared to crackers in young adults

Abstract

This study investigated the dynamic responses to an acute glucose challenge after 8 weeks of almond or cracker consumption (clinicaltrials.gov ID: NCT03084003). Young adults (n = 73, age: 18-19 years, BMI: 18-41 kg/m²) participated in an 8-week randomized, controlled, parallel-arm intervention and were assigned to consume either almonds (2 oz/d, n = 38) or an isocaloric control snack of graham crackers (325 kcal/d, n = 35) daily. Twenty participants from each group underwent a 2-hour oral glucose tolerance test (oGTT) at the end of the intervention. Metabolite abundances in the oGTT serum samples were quantified using untargeted metabolomics, and targeted analyses for free PUFAs, total fatty acids, oxylipins, and endocannabinoids. We hypothesized that 8-week almond consumption would differentially modulate the metabolomic response to a glucose challenge compared to crackers. Multivariate, univariate, and chemical enrichment analyses were conducted to identify significant metabolic shifts. Findings exhibit a biphasic lipid response with higher levels of unsaturated triglycerides earlier in the oGTT followed by lower levels later in the almond vs cracker group (p-value <.05, chemical enrichment analyses). Almond (vs cracker) consumption was also associated with higher AUC_{120 min} of aminomalonate, and oxylipins (P-value <.05), but lower AUC_{120 min} of l-cystine, N-acetylmannosamine, and isoheptadecanoic acid (P-value <.05). Additionally, the Matsuda Index in the almond group correlated with AUC_{120 min} of CE 22:6 (r = -0.46; P-value <.05) and 12,13 DiHOME (r = 0.45; P-value <.05). Almond consumption for 8 weeks leads to dynamic, differential shifts in response to an acute glucose challenge, marked by alterations in lipid and amino acid mediators involved in metabolic and physiological pathways.