Choline is involved in the synthesis of phospholipids, including blood lipids, and is the immediate precursor of betaine, which serves as a methyl group donor in a reaction converting homocysteine to methionine. Several cardiovascular risk factors are associated with plasma homocysteine, whereas little is known about their relationship to choline and betaine.We examined the relation of plasma choline and betaine to smoking, physical activity, BMI, percent body fat, waist circumference, blood pressure, serum lipids, and glucose in a population-based study of 7074 men and women aged 47-49 and 71-74 y. Overall plasma concentrations (means 6 SD) were 9.9 6 2.3 mmol/L for choline and 39.5 6 12.5 mmol/L for betaine. Choline and betaine were lower in women than in men and in younger subjects compared with older (P , 0.0001).Multivariate analyses showed that choline was positively associated with serum triglycerides, glucose, BMI, percent body fat, waist circumference (P , 0.0001 for all), and physical activity (P , 0.05) and inversely related to HDL cholesterol (P , 0.05) and smoking (P , 0.0001). Betaine was inversely associated with serum non-HDL cholesterol, triglycerides, BMI, percent body fat, waist circumference, systolic and diastolic blood pressure (P , 0.0001 for all), and smoking (P , 0.05) and positively associated with HDL cholesterol (P , 0.01) and physical activity (P , 0.0001). Thus, an unfavorable cardiovascular risk factor profile was associated with high choline and low betaine concentrations. Choline and betaine were associated in opposite directions with key components of metabolic syndrome, suggesting a disruption of mitochondrial choline dehydrogenase pathway. J. Nutr. 138: 914-920, 2008.

Established dietary predictors of plasma total homocysteine (tHcy) include folate, riboflavin, and vitamins B 6 and B 12 , while information is scarce regarding other dietary components. The aim of this study was to examine the relation between a variety of food groups, food items and nutrients, and plasma tHcy in a large population-based study. The study population included 5812 men and women aged 47 -49 and 71-74 years who completed a 169-item FFQ. tHcy was examined across quartiles of dietary components by multiple linear regression analyses adjusting for age, sex, energy intake, various risk factors for elevated tHcy, as well as for dietary and plasma B-vitamins. Among 4578 non-users of vitamin supplements, intake of vegetables, fruits, cereals, eggs, fish and milk, as well as chicken and non-processed meats were inversely associated with tHcy level. The estimated mean difference in tHcy per increasing quartile of intake ranged from 2 0·11 (95 % CI 2 0·21, 2 0·01) mmol/l for milk to 20·32 (95 % CI 20·42, 20·22) mmol/l for vegetables. Positive associations were found for sweets and cakes. Whole-grain bread was significantly inversely related to tHcy only after additional adjustment for dietary and plasma B-vitamins. The nutrients folate, vitamin B 6 , B 12 , and riboflavin were inversely related to tHcy. Complex carbohydrates were inversely, and fat positively associated with tHcy, also after adjustment for dietary and plasma B-vitamins. In conclusion, food items rich in B-vitamins and with a low content of fat and sugar were related to lower tHcy levels. Eggs, chicken, non-processed meat, fish and milk were inversely associated with tHcy.

In this population of middle-aged and elderly men and women, recruited from an area with relatively low folate intake, neither plasma choline nor betaine was positively associated with consumption of animal products, fruit, or vegetables, but each was positively associated with the intake of specific food items such as eggs (choline) and bread (betaine).