Higher intake of fish and fat is associated with lower plasma s-adenosylhomocysteine: a cross-sectional study

Several B-vitamins act as co-factors in one-carbon metabolism, a pathway that plays a central role in several chronic diseases. However, there is a lack of knowledge of how diet affects markers in one-carbon metabolism. The aim of this study was to explore dietary patterns and components associated with one-carbon metabolites. We hypothesized that intake of whole-grains and fish would be associated with lower Hcy, and higher SAM:SAH ratio due to their nutrient content. We assessed dietary information using a four-day dietary record in 118 men and women with features of the metabolic syndrome. In addition we assessed whole-blood fatty acid composition and plasma alkylresorcinols. Plasma s-adenosylmethionine (SAM), s-adenosylhomocysteine (SAH), homocysteine (Hcy) and vitamin B12 was included as one-carbon metabolism markers. We used principal component analysis (PCA) to explore dietary patterns and multiple linear regression models to examine associations between dietary factors and one-carbon metabolites. PCA separated subjects based on prudent and unhealthy dietary patterns, but the dietary pattern score was not related to the one-carbon metabolites. Whole grain intake was found to be inversely associated to plasma Hcy (−4.7% (−9.3; 0.0), P = .05) and total grain intake tended to be positively associated with SAM and SAH (2.4% (−0.5; 5.5), P = .08; 5.8% (−0.2; 12.1), P = .06, respectively, per SD increase in cereal intake). Fish intake was inversely associated with plasma Hcy and SAH concentrations (−5.4% (−9.7; −0.8), P = .02 and −7.0% (−12.1; −1.5), P = .01, respectively) and positively associated with the SAM:SAH ratio (6.2% (1.6; 11.0), P = .008). In conclusion, intake and fish and whole-grain appear to be associated with a beneficial one-carbon metabolism profile. This indicates that dietary components could play a role in regulation of one-carbon metabolism with a potential impact on disease prevention.