Coffee as a Prophylaxis Against Liver Cancer
Even those drinking one cup of coffee each day seem to reap significant protection against hepatocellular cancer. Researchers from the Istituto di Ricerche Farmacologiche “Mario Negri,” Milan, Italy, found that among the 10 studies evaluable for the link between coffee consumption and protection from liver cancer, which tested populations ranging from Japan to Southern Europe, the results concurred.
The researchers pointed out, however, that each study defined low, moderate, and high consumers of coffee differently. For example, three cups could be considered low-to-moderate daily consumption in one study but be treated as high daily consumption in another (dependent on the daily number of cups usually drunk by that population). In any case, if a person has only one cup a day, he or she has a 30% lower risk of hepatocellular carcinoma than non–coffee drinkers. If they have higher consumption rates, the risk is 55% less than controls. For each additional one cup per day consumed, the relative risk was 0.77 from the case–control studies evaluated, 0.75 from the cohort studies, and 0.77 overall. The multivariate-adjusted odds ratios for
daily coffee drinkers vs. nondrinkers
HCV = Hepatitis C virus.Adapted from Wakai K, Kurozawa Y, Shibata A, et al: Liver cancer
Odds of Dying
From Liver Cancer
All Coffee Drinkers
HCV-Positive Coffee Drinkers
HCV-Negative Coffee Drinkers
risk, coffee, and hepatitis C virus infection: A nested case-control
study in Japan. Br J Cancer 2007;97:426-428.
A separate case–control study from Japan found that the odds of dying from hepatocellular cancer in people who were regular coffee drinkers was cut significantly. In fact, the greatest reduction in risk was in patients with hepatitis C virus infection.
Previous reports indicated that heavy coffee consumption may cut colon cancer risk by 50% in women. The basis for a link between coffee and cancer protection is not yet understood, but the weight of evidence is considerable. However, the link between coffee and other cancers may be more insidious (e.g., cervical cancer). Don’t go buying that Starbucks’ stock just yet.
Bravi F, Bosetti C, Tavani A, et al: Coffee drinking and hepatocellular carcinoma risk: A metaanalysis.
Wakai K, Kurozawa Y, Shibata A, et al: Liver cancer risk, coffee, and hepatitis C virus infection: a nested case-control study in Japan.
Br J Cancer 2007;97:426-428.
Will a Daily Vitamin Prevent Liver Cancer as Well?
Clinical studies are beginning to separate the myths from facts with regard to dietary foods, and vitamin and mineral supplements. Investigators have recently addressed whether some commonly held beliefs about the foods and vitamins we ingest. In late August, a group of researchers from Beijing, China, and the United States participated in a joint randomized, double-blind study to determine whether vitamin or mineral supplements can prevent primary liver cancer.
The study participants included 29,450 healthy adults from Linxian, China. After randomization, the study group was given a vitamin-mineral combination and instructed to take the supplement daily for 5.25 years (ending in May 1991). The supplement contained one of four combinations: (1) retinol and zinc, (2) riboflavin and niacin, (3) ascorbic acid and molybdenum, and (4) beta-carotene, alpha-tocopherol, and selenium, all at doses equal to or twice the U.S. recommended daily allowance. Some patients were randomized to receive all four supplement combinations daily.