Association between carbohydrate intake and fatty acids in the de novo lipogenic pathwayin serum phospholipids and adipose tissue among 63-year old men

• AbstractBackground: Fatty acid composition in blood and adipose tissue is useful to reflect dietary fatquality, although the utility of even-chain saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) has been debated. Since SFA also can be produced via de novo lipogenesis (DNL), and desaturated to MUFA, it has been proposed that these fatty acids may reflect carbohydrate-induced DNL. We aimed to test the hypothesis that high carbohydrate intake, especially sugars, is related to SFA and MUFA in serum and adipose tissue.Methods: Validated 7-day food records were collected and fatty acid composition in serum phospholipids (PL) and adipose tissue (AT) were measured in 63-year-old men (n=299). Stearoyl-CoA desaturate (SCD) activities in AT and PL were estimated by the palmitoleic acid (16:1) to palmitic acid (16:0) ratio. Associations of dietary carbohydrate, disaccharides,  monosaccharides, carbohydrate-to-fiber ratio, and alcohol with the sum of even-chain SFA, 16:0, 16:1, and SCD activity were assessed using linear regression models with and without adjustment for BMI. Non-linear trends were evaluated using restricted cubic splines. In a subsample (n=81) with RNA measured in AT biopsies, associations of dietary carbohydrate and alcohol with SCD gene expression were assessed using linear regression models.Results: In BMI-adjusted models, intake of carbohydrates was inversely associated with palmitic acid in PL (P=0.005). Disaccharide intake was non-linearly associated with 16:1 and SCD activity in PL (P for nonlinear trend ≤0.02), with the lowest values observed in the mid tertile. Alcohol intake was linearly associated with 16:0 in PL (P<0.001) and with 16:1 (P<0.001) and SCD activity (P ≤0.005) in AT. Alcohol intake was non-linear associated (P≤0.02) with 16:1 and SCD activity in PL; with initially stable levels at lower intakes that rapidly increased at intakes above median. In the subsample, we found no associations between carbohydrate intake and SCD gene expression (P ≥0.08).Conclusion: In this Swedish population, we found no evidence to suggest that higher carbohydrate intake or sugar-rich foods or beverages is reflected by higher SFA in PL and AT.Instead, alcohol was consistently associated with higher SFA and MUFA.

Nyckelord

fatty acid

saturated fatty acids

carbohydrate

phospholipid

Kostvetenskap

Food, Nutrition and Dietetics

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)