Objective: Earlier studies and trials have shown a serum cholesterol raising effect of unfiltered coffee, which is reduced by about 80% in filtered coffee. Recent cross-sectional studies and trials, however, have indicated that filtered coffee may have a more pronounced serum cholesterol raising effect than previously anticipated. The objective of this controlled study was to assess the effects of the intake and abstention of filtered brewed coffee on blood lipids.
Design: A prospective, controlled study with four consecutive trial periods. The first and third periods were 3 weeks of total coffee abstention. The second and fourth periods consisted of 4 weeks with the subjects consuming 600 ml filter brewed coffee/day.
Setting: Free-living population. Volunteers.
Subjects: A total of 121 healthy, nonsmoking men and women aged 29-65 y.
Interventions: Not applicable.
Main outcome measures: Serum total cholesterol, serum HDL cholesterol, serum triglycerides, serum lipoprotein (a) (Lp(a)), blood pressure and heart rate.
Results: The two coffee abstention periods were associated with a decline in serum cholesterol of 0.22 mmol/l (95% CI -0.31, -0.13) and 0.36 mmol/l (95% CI -0.46, -0.26), respectively. Filtered coffee/day 600 ml increased serum cholesterol by 0.25 mmol/l (95% CI 0.15, 0.36) and 0.15 mmol/l (95% CI 0.04, 0.26) during the two coffee drinking periods.
Conclusions: Coffee abstention for 3 weeks decreased total serum cholesterol by 0.22-0.36 mmol/l. A volume of 600 ml (about four cups) of filtered coffee/day during 4 weeks raised total serum cholesterol by 0.15-0.25 mmol/l.