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The Distribution of Fatty Acid Biomarkers of Dairy Intake across Serum Lipid Fractions: The Prospective Metabolism and Islet Cell Evaluation (PROMISE) Cohort |
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| Authors: | Ingrid D Santaren Richard P Bazinet Zhen Liu Luke W Johnston John L Sievenpiper Adria Giacca Ravi Retnakaran Stewart B Harris Bernard Zinman Anthony J Hanley |
| Affiliation: | 1. Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 1 King's College Circle, M5S 1A8, Toronto, ON, Canada;2. Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, 1 King's College Circle, M5S 1A8, Toronto, ON, Canada
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, 61 Queen St. East, M5C 2T2, Toronto, Canada Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria St., M5B 1T8, Toronto, Canada Division of Endocrinology & Metabolism, St. Michael's Hospital, 61 Queen St. East, M5C 2T2, Toronto, Canada;3. Department of Physiology, University of Toronto, 1 King's College Circle, M5S 1A8, Toronto, Canada;4. Department of Medicine, University of Toronto, 1 King's College Circle, M5S 1A8, Toronto, ON, Canada Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, 60 Murray St., M5B 1W8, Toronto, ON, Canada;5. Centre for Studies in Family Medicine, Western Center for Public Health and Family Medicine, Western University, 1465 Richmond St., N6G 2M1, London, ON, Canada |
| Abstract: | Circulating fatty acids (FA) derived largely from dairy consumption have most commonly been measured in total human serum or phospholipid (PL) fractions, and have been used as validated biomarkers of dairy intake in a growing number of epidemiological studies. Nevertheless, measurement and characterization of a wider spectrum of FA biomarkers of dairy across the four major serum lipid fractions is lacking. This study aimed to (1) quantify FA biomarkers of dairy in PL, triacylglycerol (TAG), cholesteryl ester (CE), and unesterified fatty acid (FFA) serum lipid fractions; and (2) identify potential demographic and metabolic factors that may modify the proportions of these FA across serum fractions. Baseline data from 444 adults in the PROMISE cohort were analyzed. FA biomarkers, 15:0, t16:1n-7, 18:2-c9,t11, and t18:1n-7 were quantified from serum. Dairy intake was estimated using the validated Canadian Diet History Questionnaire. Our results show that t18:1n-7 was the most abundant FA biomarker in all fractions except CE, where 18:2-c9,t11 was the most abundant. Positive correlations within fractions, and across FA in the PL, CE, and FFA fractions were found, however, TAG FA were negatively correlated with the other fractions. PL and CE FA were positively associated with dairy intake, and negatively associated with markers of dysmetabolism while, in contrast, these markers were predictors of higher TAG dairy FA. This study is the first to demonstrate distinct proportions of dairy FA in different serum lipid fractions. PL and CE FA marked dairy intake in this cohort, while TAG FA appeared to be markers of dysmetabolism. |
| Keywords: | Dairy Fatty acid biomarker Odd-chain fatty acid Ruminant trans-fatty acid Serum lipid fraction |