Serum pentadecanoic acid (15:0), a short-term marker of dairy food intake, is inversely associated with incident type 2 diabetes and its underlying disorders123

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ABSTRACT

Background:

Growing evidence suggests that dairy consumption is associated with lower type 2 diabetes risk. However, observational studies have reported inconsistent results, and few have examined dairy’s association with the underlying disorders of insulin resistance and β-cell dysfunction.

Objective:

We investigated the association of the dairy fatty acid biomarkers pentadecanoic acid (15:0) and trans-palmitoleic acid (trans 16:1n−7) with type 2 diabetes traits by evaluating 1) prospective associations with incident diabetes after 5 y of follow-up and 2) cross-sectional associations with directly measured insulin resistance and β-cell dysfunction.

Design:

The study analyzed 659 adults without diabetes at baseline from the triethnic multicenter Insulin Resistance Atherosclerosis Study (IRAS). Diabetes status was assessed by using oral-glucose-tolerance tests. Frequently sampled intravenous-glucose-tolerance tests measured insulin sensitivity (SI) and β-cell function [disposition index (DI)]. Serum fatty acids were quantified by using gas chromatography. Logistic and linear regression models were adjusted for demographic, lifestyle, and dietary variables.

Results:

Serum 15:0 was a significant biomarker for total dairy intake in the IRAS cohort. It was associated with a decreased incident diabetes risk (OR: 0.73, P = 0.02) and was positively associated with log SI (β: 0.84, P = 0.03) and log DI (β: 2.21, P = 0.02) in fully adjusted models. trans 16:1n−7 was a marker of total partially hydrogenated dietary fat intake and was not associated with outcomes in fully adjusted models.

Conclusions:

Serum 15:0, a marker of short-term intake of this fatty acid, was inversely associated with diabetes risk in this multiethnic cohort. This study may contribute to future recommendations regarding the benefits of dairy products on type 2 diabetes risk.

Keywords

dairy
epidemiology
fatty acids
nutrition
type 2 diabetes

Cited by (0)

1

From the Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada (IDS and AJH); Lipomics, a Division of Metabolon Inc., West Sacramento, CA (SMW); the Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC (ADL); the Division of Public Health Sciences, School of Medicine, Wake Forest University, Winston-Salem, NC (LEW); Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO (MJR); the Division of Clinical Epidemiology, University of Texas Health Sciences Center, San Antonio, TX (SMH and CL); the Department of Medicine and Dalla Lana School of Public Health, University of Toronto, Toronto, Canada (AJH); and Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, Canada (AJH).

2

Supported by a contribution from the Dairy Research Cluster Initiative (Dairy Farmers of Canada, Agriculture and Agri-Food Canada, the Canadian Dairy Network, and the Canadian Dairy Commission). IDS is supported by the University of Toronto Banting & Best Diabetes Centre, Tamarack Graduate Award in Diabetes Research, and Dairy Farmers of Canada (Ontario Student Opportunity Trust Funds).

3

Address correspondence to AJ Hanley, Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, FitzGerald Building, 150 College Street, Toronto, ON, Canada M5S 3E2. E-mail: [email protected].

4

Abbreviations used: DI, disposition index; FFQ, food-frequency questionnaire; FSIGT, frequently sampled intravenous-glucose-tolerance test; IRAS, Insulin Resistance Atherosclerosis Study; SI, insulin sensitivity index; TFA, trans fatty acid.