The coffee diterpenes cafestol and kahweol raise serum cholesterol in humans. Each 10 mg of cafestol consumed per day elevates cholesterol by 5 mg/dL (0.13 mmol/L). Diterpene levels in various coffee brews were examined. Scandinavian boiled coffee contained (mean f SD) 3.0 f 2.8 mg, French press coffee 3.5 f 1.2 mg, and TurkisWGreek coffee 3.9 f 3.2 mg of cafestol per cup. Consumption of five cups per day of any of these coffee types could thus elevate serum cholesterol by 8-10 mgl dL. Italian espresso coffee contained 1.5 f 1.0 mg of cafestol per cup, five cups theoretically raising cholesterol by 4 mg/dL. Brewing time had little effect of diterpenes. Brewing strength increased diterpenes in boiled, French press, and espresso coffee but not in TurkisWGreek coffee. Diterpenes in instant, drip filtered, and percolated brews were negligible. Regular and decaffeinated coffees had similar diterpene contents. High chronic intake of French press coffee or TurkisldGreek coffee could increase serum cholesterol and thus coronary risk similar to that reported previously for Scandinavian boiled coffee.

▪ Abstract  Some coffee brewing techniques raise the serum concentration of total and low-density-lipoprotein cholesterol in humans, whereas others do not. The responsible factors are the diterpene lipids cafestol and kahweol, which make up about 1% (wt:wt) of coffee beans. Diterpenes are extracted by hot water but are retained by a paper filter. This explains why filtered coffee does not affect cholesterol, whereas Scandinavian “boiled,” cafetiere, and Turkish coffees do. We describe the identification of the cholesterol-raising factors, their effects on blood levels of lipids and liver function enzymes, and their impact on public health, based on papers published up to December 1996.

Caffeine is partly responsible for the homocysteine-raising effect of coffee. Coffee, but not caffeine, affects homocysteine metabolism within hours after intake, although the effect is still substantial after an overnight fast.

No abstract

Drinking large quantities of paper-filtered coffee raises fasting plasma concentrations of total homocysteine in healthy individuals.

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

The coffee diterpene cafestol occurs in both robusta and arabica beans. It is present in unfiltered coffee brews and raises serum concentrations of cholesterol, triacylglycerols, and alanine aminotransferase in humans. The effects are linear with the cafestol dose. Unfiltered coffee also contains the related compound kahweol, which occurs only in the major coffee strain arabica. The activity of kahweol is unknown. In a randomized, double-blind crossover study, we gave 10 healthy male volunteers either pure cafestol (61-64 mg/d) or a mixture of cafestol (60 mg/d) and kahweol (48-54 mg/d) for 28 d. Relative to baseline values, cafestol raised mean (+/-SEM) total serum cholesterol concentrations by 0.79 +/- 0.14 mmol/L (31 +/- 5 mg/dL), low-density-lipoprotein (LDL) cholesterol by 0.57 +/- 0.13 mmol/L (22 +/- 5 mg/dL), fasting triacy-glycerols by 0.65 +/- 0.12 mmol/L (58 +/- 11 mg/dL), and alanine aminotransferase by 18 +/- 2 U/L (all P < 0.01). Relative to cafestol alone, the mixture of cafestol plus kahweol increased total cholesterol by another 0.23 +/- 0.16 mmol/L (9 +/- 6 mg/dL) (P = 0.08), LDL cholesterol by 0.23 +/- 0.16 mmol/L (9 +/- 6 mg/dL) (P = 0.09), triacylglycerols by 0.09 +/- 0.10 mmol/L (8 +/- 9 mg/dL) (P = 0.20), and alanine aminotransferase by 35 +/- 11 U/L (P = 0.004). Thus, the effect of cafestol on serum lipid concentrations was much larger than the additional effect of kahweol, and the hyperlipidemic potential of unfiltered coffee mainly depends on its cafestol content. Both cafestol and kahweol raised alanine aminotransferase concentrations, and their hyperlipidemic effect thus seems not to be coupled with their effect on liver cells.

Coffee beans and some types of coffee brew-not the regular types of coffee prepared with a paper filter or with soluble coffee granules-contain the diterpenes cafestol and kahweol. Cafestol and kahweol raise the serum concentration of cholesterol and triglycerides in humans, and they also appear mildly to affect the integrity of liver cells. Both effects are transient after withdrawal of the diterpenes, and it is as yet unsure whether these effects are associated. Patients at increased risk of heart disease who drink large amounts of coffee should be advised to select brews low in diterpenes.