Understanding the Link between Dairy Foods and Type 2 Diabetes: An Investigation Using Dairy Fatty Acid Biomarkers
Year: 2018
Type: dissertation
Study design: Observational Study
Abstract: Increasing evidence points to an inverse association between dairy intake and type 2 diabetes (T2DM) risk, however results from studies relying on self-reported questionnaires to assess dairy intake have been inconsistent and few have looked at dairy’s effect on T2DM’s underlying disorders, namely insulin sensitivity and β-cell dysfunction. Dairy (non low-fat options) contains high amounts of saturated (SFA) and naturally occurring trans fatty acids (TFA), yet recent studies suggest that different types of SFA and TFA have different metabolic effects, with dairy-derived fatty acids potentially being protective. Nonetheless, there are limited data on dairy fatty acids’ impact on the underlying pathophysiology of T2DM. In my doctoral research I (1) measured baseline dairy fatty acids 15:0, t16:1n9, c9,t11 CLA, and t18:1n11 in the 4 serum FA pools [phospholipid (PL), cholesteryl ester (CE), triglyceride (TG), and non-esterified (NEFA)], and identified factors that modify their distribution across serum pools; (2) evaluated longitudinal associations of dairy fatty acids with insulin sensitivity and β-cell function over 6 years; and (3) applied statistical methods for combining biomarker and self-reported dietary intake data to evaluate associations of dairy intake on 6yr incident dysglycemia prediction. Data from 444 adults at high risk for T2DM were analyzed. Insulin sensitivity and β-cell dysfunction were calculated from 75g oral glucose tolerance tests. Study 1 showed that proportions of dairy fatty acids differ by pool. Dairy intake was associated with PL and CE fatty acids, while higher circulating TG fatty acids were markers of dysmetabolism. In study 2, PL and CE fatty acids were positively associated insulin sensitivity and β-cell dysfunction longitudinally, while TG fatty acids were negatively associated. Study 3 demonstrated that in models with multiple biomarkers, principal components analysis combining dietary and biomarkers discriminated dysglycemia status better than individual measures alone. Overall, these results highlight the complex distribution of dairy fatty acids in serum and the heterogeneity of their associations with T2DM pathogenesis.
Source: TSpace (University of Toronto)
Author: Ingrid D. Santaren
Language: English
Topic: Nutritional Studies and Diet
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2974435218