"Liver holiday" may do drinkers some good

NEW YORK (Reuters Health) - For men who drink regularly and heavily, taking a break from alcohol for a couple days each week may benefit their health, according to Japanese researchers.

The study included 89,000 middle-aged men and women who were followed for up to 13 years. At study entry 68 percent of the men and 11 percent of the women were regular drinkers. The analysis was confided to the men because the number of female drinkers was so small.

The investigators found that men who drank relatively heavily on most days of the week had a heightened risk of dying from any cause. In contrast, men who drank roughly the same amount alcohol each week, but drank less frequently, showed no increase in their mortality risk.

The findings, which appear in the American Journal of Epidemiology, give some credibility to the widespread social belief in Japan that a “liver holiday,” a few days off from drinking each week helps counter the ill effects of alcohol.

However, the findings don’t suggest that a few binges each week will do no harm, the study’s lead author cautioned.

“This does not mean you can drink a lot as long as you have a ‘liver holiday,’” Dr. Tomomi Marugame, of the National Cancer Center in Tokyo, told Reuters Health.

There was no evidence, the researcher said, that a liver holiday protected study participants who drank the most heavily -- downing more than 750 grams of alcohol per week - the equivalent of about 50 glasses of wine each week.

In addition, Marugame pointed out that numerous studies have pointed out the hazards of binge-drinking, which is typically defined as having five or more drinks in one sitting.

Still, Marugame’s team notes in the report, the findings suggest that the liver holiday belief has some merit.

Among men who reported being heavy drinkers -- defined as 300 grams or more of alcohol per week -- only those who drank on at least five days out of the week had a higher risk of dying during the study period. Compared with their peers who drank a few times per month, these men were up to 55 percent more likely to die.

Men who drank just as much, but took a few days off each week, had no increase in mortality risk, unless their drinking reach excessively high amounts.

It’s not clear why those few days each week might make a life-or-death difference, Marugame said. One possibility, according to the researcher, is that heavy drinkers who partake every day may be more persistently exposed to acetaldehyde, a byproduct of alcohol metabolism that is thought to promote cancer.

On top of this, Marugame noted, about half of Japanese individuals are believed to be deficient in an enzyme that processes acetaldehyde in the body, which would routinely increase their exposure to the substance.

SOURCE: American Journal of Epidemiology, April 2007.