Comparison of effect of cafetiere and filtered coffee on serum concentrations of liver aminotransferases and lipids: six month randomised controlled trial

Abstract

Objective: To study the effects of prolonged intake of cafetiere coffee, which is rich in the diterpenes cafestol and kahweol, on serum aminotransferase and lipid concentrations. Design: Randomised parallel controlled trial. Subjects: 46 healthy men and women aged 19 to 69. Intervention: Consumption of five to six strong cups (0.9 litres) a day of either cafetiere (22 subjects) or filtered coffee (24 subjects) for 24 weeks. Main outcome measures: Mean changes in serum aminotransferase and lipid concentrations. Results: Cafetiere coffee raised alanine aminotransferase concentration by up to 80% above baseline values relative to filtered coffee. After 24 weeks the rise was still 45% (9 U/l (95% confidence interval 3 to 15 U/l), P = 0.007). Alanine aminotransferase concentration exceeded the upper limit of normal in eight of the 22 subjects drinking cafetiere coffee, being twice the upper limit of normal in three of them. Cafetiere coffee raised low density lipoprotein cholesterol concentrations by 9–14%. After 24 weeks the rise was 0.26 mmol/l (0.04 to 0.47 mmol/l) (P = 0.03) relative to filtered coffee. Triglyceride concentrations initially rose by 26% with cafetiere coffee but returned close to baseline values within six months. All increases were reversible after the intervention was stopped. Conclusions: Daily consumption of five to six cups of strong cafetiere coffee affects the integrity of liver cells as suggested by small increases in serum alanine aminotransferase concentration. The effect does not subside with prolonged intake. High intakes of coffee brews rich in cafestol and kahweol may thus be responsible for unexplained increases in this enzyme activity in apparently healthy subjects. Cafetiere coffee also raises low density lipoprotein cholesterol concentration and thus the risk of coronary heart disease. Key messages This randomised study found that cafetiere coffee also increased alanine aminotransferase and low density lipoprotein cholesterol concentrations, and they were still raised after six months of daily intake. Filtered coffee had no effect The increase in liver enzyme activity could be innocuous, but the increase in cholesterol concentration may increase coronary risk and could be a reason to advise patients to drink filtered coffee

Diterpenes from coffee beans decrease serum levels of lipoprotein(a) in humans: results from four randomised controlled trials

“…The present ®ndings contradict our previous observation in a cross-sectional study that Norwegian boiled-coffee drinkers had higher Lp(a) levels than ®lter coffee drinkers (Urgert et al, 1996b).…”

“…The effects on serum lipids and liver enzymes have been reported elsewhere (Weusten-van der Wouw et al, 1994;Urgert et al, 1996a;Urgert et al, 1997a).…”

“…Bias due to hormone intake or drug therapy (Berglund, 1995) is thus unlikely. Furthermore, changes in dietary intakes, body mass, and alcohol use were minimal and similar for the control and treatment groups within each study (Weustenvan der Wouw et al, 1994;Urgert et al, 1996a;Urgert et al, 1997a). Therefore, it is unlikely that the reductions in Lp(a) levels were due to anything else than treatment with coffee diterpenes.…”

“…Short-term intake of coffee diterpenes raises serum levels of alanine amino transferase (Weusten-van der Wouw et al, 1994;Van Rooij et al, 1995;Urgert et al, 1996a), which may point at disturbed hepatocyte integrity (Keil, 1990). The alterations in serum lipids and lipoprotein levels caused by coffee diterpenes may also be due to effects on liver cell metabolism.…”

“…They are responsible for the cholesterol-raising effect of Scandinavian boiled coffee (Weusten-van der Wouw et al, 1994;Heckers et al, 1994). Cafestol and kahweol strongly affect lipid metabolism with short-term intake (Bak & Grobbee, 1989;Aro et al, 1987;van Dusseldorp et al, 1991;Ahola et al, 1991;Aro et al, 1990;Urgert et al, 1996a) as well as in life-long consumers of un®ltered coffee (Bùnaa et al, 1988;Stensvold et al, 1989;Weusten-van der Wouw et al, 1994;Pietinen et al, 1990;Lindahl et al, 1991). We recently found that consumption of boiled coffee was also associated with Lp(a) levels; the median Lp(a) level in Norwegians who were life-long consumers of boiled coffee was 65% higher than in matched ®lter coffee drinkers (Urgert et al, 1996b).…”