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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #358638
Title: Fatty acid biomarkers of dairy fat consumption and incidence of type 2 diabetes: A pooled analysis of prospective cohort studies

Author
item IMAMURA, FUMIAKI - University Of Cambridge
item FRETTS, AMANDA - University Of Washington
item MARKLUND, MATTI - Uppsala University
item ARDISSON KORAT, ANDRES - Harvard School Of Public Health
item YANG, WEI - University Of Eastern Finland
item LANKINEN, MARIA - University Of Eastern Finland
item QURESHI, WAQAS - Wake Forest School Of Medicine
item HELMER, CATHERINE - University Of Bordeaux
item CHEN, TZU - Children'S Nutrition Research Center (CNRC)
item WONG, KERRY - Cancer Council Victoria
item BASSETT, JULIE - Cancer Council Victoria
item MURPHY, RACHEL - University Of British Columbia
item TINTLE, NATHAN - Dordt College
item YU, CHARYU - University Of Washington
item BROUWER, INGEBORG - Vrije University
item CHIEN, KUO - University Of Eastern Finland
item FRAZIER-WOOD, ALEXIS - Children'S Nutrition Research Center (CNRC)
item DEL GOBBO, LIANA - Stanford University School Of Medicine
item DJOUSSE, LUC - Brigham & Women'S Hospital
item GELEIJNSE, JOHANNA - Wageningen University
item GILES, GRAHAM - Cancer Council Victoria
item DE GOEDE, JANETTE - Wageningen University
item GUDNASON, VILMUNDUR - Icelandic Heart Association
item HARRIS, WILLIAM - University Of South Dakota
item HODGE, ALLISON - Cancer Council Victoria
item HU, FRANK - Harvard School Of Public Health
item KOULMAN, ALBERT - University Of Cambridge
item LAAKSO, MARKKU - University Of Kuopio
item LIND, LARS - Uppsala University
item LIN, HUNG - National Taiwan University
item MCKNIGHT, BARBARA - University Of Washington
item RAJAOBELINA, KALINA - University Of Bordeaux
item RISERUS, ULF - Uppsala University
item ROBINSON, JENNIFER - University Of Iowa
item SAMIERI, CECILIA - University Of Bordeaux
item SISCOVICK, DAVID - New York Academy Of Medicine
item SOEDAMAH-MUTHU, SABITA - Wageningen University
item SOTOODEHNIA, NONA - University Of Washington
item SUN, QI - Harvard School Of Public Health
item TSAI, MICHAEL - University Of Minnesota
item UUSITUPA, MATTI - University Of Eastern Finland
item WAGENKNECHT, LYNNE - Wake Forest School Of Medicine
item WAREHAM, NICK - University Of Cambridge
item WU, JASON - University Of New South Wales
item MICHA, RENATA - Friedman School At Tufts
item FOROUHI, NITA - University Of Cambridge
item LEMAITRE, ROZENN - University Of Washington
item MOZZAFFARIAN, DARIUSH - Friedman School At Tufts

Submitted to: PLoS Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2018
Publication Date: 10/10/2018
Citation: Imamura, F., Fretts, A., Marklund, M., Ardisson Korat, A.V., Yang, W.S., Lankinen, M., Qureshi, W., Helmer, C., Chen, T.A., Wong, K., Bassett, J.K., Murphy, R., Tintle, N., Yu, C.I., Brouwer, I.A., Chien, K.L., Frazier-Wood, A.C., Del Gobbo, L.C., Djousse, L., Geleijnse, J.M., Giles, G.G., De Goede, J., Gudnason, V., Harris, W.S., Hodge, A., Hu, F., Koulman, A., Laakso, M., Lind, L., Lin, H.J., McKnight, B., Rajaobelina, K., Riserus, U., Robinson, J.G., Samieri, C., Siscovick, D.S., Soedamah-Muthu, S.S., Sotoodehnia, N., Sun, Q., Tsai, M.Y., Uusitupa, M., Wagenknecht, L.E., Wareham, N.J., Wu, J.J., Micha, R., Forouhi, N.G., Lemaitre, R.N., Mozzaffarian, D. 2018. Fatty acid biomarkers of dairy fat consumption and incidence of type 2 diabetes: A pooled analysis of prospective cohort studies. PLoS Medicine. 15(10):e1002670. https://doi.org/10.1371/journal.pmed.1002670.
DOI: https://doi.org/10.1371/journal.pmed.1002670

Interpretive Summary: National and international guidelines recommend the consumption of dairy products. Additionally, in high income countries recommendations further specify the consumption of fat-reduced dairy products instead of whole-fat products. However, these recommendations are based on the overall desire to reduce fat intake at the population level, instead of the health effects of dairy fat. However, total consumption of dairy products has been related with a lower number of newly diagnosed cases of type 2 diabetes (T2D) suggesting that reducing dairy (even of the high-fat variety) may not be beneficial for health. Typically, studies looking at the effects of dairy consumption on T2D use self-reported questionnaires, which can introduce reporting bias and thus not provide a good assessment. As a result, few studies have used biomarkers (biological markers or things found in the body) to examine the relationship between specific biomarkers reflecting dairy fat consumption and new cases of T2D. To address this limitation, we conducted a study with 16 groups from around the world (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan). Specifically, we developed a strategy for combining all studies to maximize statistical power, generalizability of the study findings, standardize the statistical analysis procedures and methods. We used 3 biomarkers of dairy intake (3 types of fatty acids) for the study analyses. Data from 63,682 individuals with no T2D at the beginning of each study and 15,180 new T2D cases at follow-up (average duration of follow-up assessments across the studies was 9 years) were analyzed. Overall, we found that each biomarker of dairy intake was related to lower risk for developing T2D independent from age, sex, race/ethnicity, socioeconomic status, physical activity, and body mass index (BMI). The results of this study are significant because they provide the strongest evidence to date for relationship of dairy intake to protection from T2D. This information may be useful to clinicians who have to counsel individuals at risk of T2D on the best dietary strategies to adopt, and those who have to make policy decisions on dietary guidelines.

Technical Abstract: 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). Sixteen prospective cohorts from 12 countries (7 from the United States, 7 from Europe, 1 from Australia, 1 from Taiwan) performed new harmonized individual-level analysis for the prospective associations according to a standardized 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 nine years of follow-up were evaluated. Study-specific results were pooled using inverse variance weighted meta-analysis. Prespecified interactions by age, sex, body-mass index (BMI), and race/ethnicity were explored in each cohort and meta-analysed. Potential heterogeneity by cohort-specific characteristics (regions, lipid compartments used for fatty acid assays) was assessed with meta-regression. 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 cohort-specific 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 was present in both genders but stronger in women than in men (p interaction<0.001). While 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 sixteen prospective cohort studies, higher levels of 15:0, 17:0 and t16:1n-7 were associated with a lower risk of T2D.