Fumiaki Imamura, University of Cambridge School of Clinical Medicine
Amanda Fretts, University of Washington - Seattle Campus
Matti Marklund, Uppsala Universitet
Andres V. Ardisson Korat, Harvard T.H. Chan School of Public Health
Wei-Sin Yang, National Taiwan University
Maria Lankinen, University of Eastern Finland
Waqas Qureshi, Wake Forest University School of Medicine
Catherine Helmer, University of Bordeaux
Tzu-An Chen, Baylor College of Medicine
Kerry Wong, Cancer Council Victoria
Julie K. Bassett, Cancer Council Victoria
Rachel Murphy, University of British Columbia Faculty of Medicine
Nathan L. Tintle, Dordt CollegeFollow
Chaoyu Ian Yu, University of Washington School of Health
Ingeborg A. Brouwer, Vrije Universiteit Amsterdam
Kuo-Liong Chien, National Taiwan University
Alexis C. Frazier-Wood, Baylor College of Medicine
Liana C. del Gobbo, Stanford University School of Medicine
Luc Djousse, Brigham and Women's Hospital
Johanna M. Geleijnse, Wageningen University
Graham G. Giles, Cancer Council Victoria
Janette de Goede, Wageningen University
Vilmunder Gudnason, Icelandic Heart Association Research Institute
William S. Harris, University of South Dakota
Allison Hodge, Cancer Council Victoria
Frank Hu, Harvard T.H. Chan School of Public Health
InterAct Consortium
Albert Koulman, University of Cambridge School of Medicine
Markku Laakso, Uppsala Universitet
Lars Lind, Uppsala Universitet
Hung-Ju Lin, National Taiwan University Hospital
Barbara McKnight, University of Washington School of Public Health
Kalina Rajaobelina, University of Bordeaux
Ulf Riserus, Uppsala Universitet
Jennifer G. Robinson, University of Iowa College of Public Health
Cecilia Samieri, University of Bordeaux
David S. Siscovick, The New York Academy of Medicine
Sabita S. Soedamah-Muthu, Wageningen University
Nona Sotoodehnia, University of Washington - Seattle Campus
Qi Sun, Harvard T.H. Chan School of Public Health
Michael Y. Tsai, University of Minnesota
Matti Uusitupa, University of Eastern Finland
Lynne E. Wageknecht, Wake Forest School of Medicine
Nick J. Wareham, University of Cambridge School of Clinical Medicine
Jason HY Wu, University of South Wales
Renata Micha, Tufts University
Nita G. Forouhi, University of Cambridge School of Clinical Medicine
Rozenn N. Lemaitre, University of Washington - Seattle Campus
Dariush Mozaffarian, Tufts University
Fatty Acids and Outcomes Research Consortium

Document Type


Publication Date



Mathematics, Statistics, and Computer Science


fatty acids, biochemical markers, dairy products, fat content, food consumption, diabetes



We aimed to investigate prospective associations of circulating or adipose tissue odd-chain fatty acids 15:0 and 17:0 and trans-palmitoleic acid, t16:1n-7, as potential biomarkers of dairy fat intake, with incident type 2 diabetes (T2D).

Methods and findings

Sixteen prospective cohorts from 12 countries (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan) performed new harmonised individual-level analysis for the prospective associations according to a standardised plan. In total, 63,682 participants with a broad range of baseline ages and BMIs and 15,180 incident cases of T2D over the average of 9 years of follow-up were evaluated. Study-specific results were pooled using inverse-variance±weighted meta-analysis. Prespecified interactions by age, sex, BMI, and race/ethnicity were explored in each cohort and were meta-analysed. Potential heterogeneity by cohort-specific characteristics (regions, lipid compartments used for fatty acid assays) was assessed with metaregression. After adjustment for potential confounders, including measures of adiposity (BMI, waist circumference) and lipogenesis (levels of palmitate, triglycerides), higher levels of 15:0, 17:0, and t16:1n-7 were associated with lower incidence of T2D. In the most adjusted model, the hazard ratio (95% CI) for incident T2D per cohortspecific 10th to 90th percentile range of 15:0 was 0.80 (0.73±0.87); of 17:0, 0.65 (0.59± 0.72); of t16:1n7, 0.82 (0.70±0.96); and of their sum, 0.71 (0.63±0.79). In exploratory analyses, similar associations for 15:0, 17:0, and the sum of all three fatty acids were present in both genders but stronger in women than in men (pinteraction < 0.001). Whereas studying associations with biomarkers has several advantages, as limitations, the biomarkers do not distinguish between different food sources of dairy fat (e.g., cheese, yogurt, milk), and residual confounding by unmeasured or imprecisely measured confounders may exist.


In a large meta-analysis that pooled the findings from 16 prospective cohort studies, higher levels of 15:0, 17:0, and t16:1n-7 were associated with a lower risk of T2D.


Copyright: © 2018 Imamura et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Source Publication Title

PLoS Medicine





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