COFFEE CONSUMPTION AND PLASMA TOTAL HOMOCYSTEINE - THE HORDALAND HOMOCYSTEINE STUDY

The health consequences of coffee drinking remain controversial. We re port on an association between coffee consumption and the concentratio n of total homocysteine (tHcy) in plasma, a risk factor for cardiovasc ular disease and for adverse pregnancy outcome. The study population c onsisted of 7589 men and 8585 women 40-67 y of age and with no history of hypertension, diabetes, ischemic heart disease, or cerebrovascular disease. They were recruited from Hordaland county of western Norway in 1992-1993. Daily use of coffee was reported by 89.1% of the partici pants, of whom 94.9% used caffeinated filtered coffee. There was a mar ked positive dose-response relation between coffee consumption and pla sma tHcy, which was stronger than the relation between coffee and tota l serum cholesterol. In 40-42-y-old men, mean tHcy was 10.1 mu mol/L f or nonusers and 12.0 mu mol/L for drinkers of greater than or equal to 9 cups of coffee/d. Corresponding tHcy concentrations in 40-42-y-old women were 8.2 and 10.5 mu mol/L, respectively. Although coffee drinki ng was associated with smoking and lower intake of vitamin supplements and fruit and vegetables, the coffee-tHcy association was only modera tely reduced after these variables were adjusted for. The combination of cigarette smoking and high coffee intake was associated with partic ularly high tHcy concentrations. A strong inverse relation between tea and tHcy concentration in univariate analysis was substantially atten uated after smoking and coffee drinking were adjusted for. The results of the present report should promote future studies on tHcy as a poss ible mediator of adverse clinical effects related to heavy coffee cons umption.