Circulating Biomarkers of Dairy Fat and Risk of Incident Diabetes Mellitus Among US Men and Women in Two Large Prospective Cohorts

How long before your doctor and nutritionist have updated your stroke diet protocol? I bet you don't even have a diet protocol that is specific enough to follow. Saying to follow the Mediterranean diet is not a protocol because there is nothing specific about it.
http://circ.ahajournals.org/content/early/2016/03/22/CIRCULATIONAHA.115.018410.abstract

1. Mohammad Y. Yakoob1;
2. Peilin Shi2;
3. Walter C. Willett1;
4. Kathryn M. Rexrode3;
5. Hannia Campos1;
6. E. John Orav3;
7. Frank B. Hu1;
8. Dariush Mozaffarian4*

+ Author Affiliations

1. ¹Harvard School of Public Health, Boston, MA
2. ²Friedman School of Nutrition Science & Policy, Tufts University, Boston, MA
3. ³Brigham and Women's Hospital and Harvard Medical School, Boston, MA
4. ⁴Harvard School of Public Health, Boston, MA; Friedman School of Nutrition Science & Policy, Tufts University, Boston, MA

1. ↵* Tufts University, Friedman School of Nutrition Science & Policy, Dean's Office, 150 Harrison Ave., Boston, MA 02111 dariush.mozaffarian@tufts.edu

Abstract

Background—In prospective studies, relationship of self-reported consumption of dairy foods with risk of diabetes mellitus is inconsistent. Few studies have assessed dairy fat, using circulating biomarkers, and incident diabetes. We tested hypothesis that circulating fatty acid biomarkers of dairy fat, 15:0, 17:0, and t-16:1n-7, are associated with lower incident diabetes.

Methods and Results—Among 3,333 adults aged 30-75 years and free of prevalent diabetes at baseline, total plasma and erythrocyte fatty acids were measured in blood collected in 1989-90 (Nurses' Health Study) and 1993-94 (Health Professionals Follow-Up Study). Incident diabetes through 2010 was confirmed by validated supplementary questionnaire based on symptoms, diagnostic tests, and medications. Risk was assessed using Cox proportional hazards, with cohort findings combined by meta-analysis. During mean±SD follow-up of 15.2±5.6 years, 277 new cases of diabetes were diagnosed. In pooled multivariate analyses adjusting for demographics, metabolic risk-factors, lifestyle, diet, and other circulating fatty acids, individuals with higher plasma 15:0 had 44% lower risk of diabetes (quartiles 4 vs. 1, HR=0.56, 95%CI=0.37-0.86; P-trend=0.01); higher plasma 17:0, 43% lower risk (HR=0.57, 95%CI=0.39-0.83, P-trend=0.01); and higher t-16:1n-7, 52% lower risk (HR=0.48, 95%CI=0.33-0.70, P-trend <0.001). Findings were similar for erythrocyte 15:0, 17:0, and t-16:1n-7, although with broader CIs that only achieved statistical significance for 17:0.

Conclusions—In two prospective cohorts, higher plasma dairy fatty acid concentrations were associated with lower incident diabetes. Results were similar for erythrocyte 17:0. Our findings highlight need to better understand potential health effects of dairy fat; and dietary and metabolic determinants of these fatty acids.