Abstention from filtered coffee reduces the concentrations of plasma homocysteine and serum cholesterol - a randomized controlled trial

Background: Elevated concentrations of plasma total homocysteine (tHcy) and serum total cholesterol are risk factors for ischemic heart disease (IHD). Previous studies showed that the consumption of very high doses of unfilte red coffee increases tHcy and total cholesterol. Objective: A prospective intervention study was performed to assess the eff ects of coffee consumption on the concentrations of tHcy and total choleste rol by using doses and brewing methods common in southeastern Norway. Design: The study was an unblinded, controlled trial with 191 healthy, nons moking, coffee-drinking volunteers aged 24-69 y randomly assigned to 3 grou ps who were asked to consume for 6 consecutive weeks no coffee, 1-3 cups (a pproximate to 175-525 mL)/d, or greater than or equal to4 cups(approximate to 700 mL)/d prepared in the manner to which they were accustomed. Blood sa mples were drawn when the subjects were randomly assigned and at 3 and 6 wk of the trial. Dietary data were collected by questionnaire. Results: Ninety-seven percent of the participants reported being regular co nsumers of caffeinated filtered coffee. Abstention from coffee for 6 wk was associated with a decrease in the tHcy concentration of 1.08 mu mol/L and a decrease in the total cholesterol concentration of 0.28 mmol/L in partici pants who had been drinking on average 4 cups of filtered coffee daily for the past year. Adjustments for several possible confounders did not alter t he results. Conclusion: Abstention from filtered coffee in doses that are commonly cons umed was associated with lower concentrations of tHcy and total cholesterol .