Washington, March 5 : Researchers at the National Institutes of Health (NIH) say that quantity and frequency of drinking, not just the average alcohol consumption over time, independently influence the risk of death from different causes.
"Taken together, our results reinforce the importance of drinking in moderation. In drinkers who are not alcohol dependent, the majority of U.S. drinkers, alcohol quantity and frequency might be thought of as modifiable risk factors for mortality," the researchers say.
"These findings underscore the importance of looking at drinking patterns when investigating alcohol-related health outcomes," says Dr. Ting-Kai Li, Director of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the NIH.
In a study, the researchers examined data from a nationwide health survey conducted in 1988. Nearly half of the nearly 44,000 participants of the survey identified themselves as current drinkers who had at least 12 drinks of alcohol during the previous year, and over 2,500 of them had died by the end of 2002.
Epidemiologist Rosalind A. Breslow and statistician Barry I. Graubard compared their causes of death with the alcohol consumption patterns they reported in the survey.
The researchers found that alcohol frequency and quantity had opposite effects on cardiovascular mortality in men.
They said that men who had five or more drinks on drinking day had a 30 per cent greater risk for cardiovascular mortality than those who had just one drink. They also found alcohol quantity to be associated with increased mortality from cancer among men.
However, frequency of drinking was found to be associated with a decreased risk for death from cardiovascular disease among men. Men who reported drinking 120 to 365 days per year had about 20 per cent lower cardiovascular mortality than those who drank just one to 36 days per year.
Among women, frequent drinking was associated with a significantly increased risk of cancer, while increased quantity was associated with risk for mortality from all causes.
Dr. Breslow says that her study is different from the previous studies because it is not based on the average alcohol intake of individuals, which potential differences between people who sometimes drink heavily, and those who consistently drink small amounts of alcohol.
"Average intake makes no distinction between the individual who has seven drinks one day each week, for example, and someone who has just one drink, every day. Our study is the first to look at how both quantity and frequency components of alcohol consumption independently influence cause-specific mortality within a single cohort representing the US population," says Dr. Breslow.
The researchers also note that a given amount of alcohol is less diluted in a woman's body than in a man's because their bodies generally have lesser amount of water. Consequently, when a woman drinks, the alcohol in her bloodstream typically reaches a higher level than a man's even if both are drinking the same amount.
The findings have been published in the journal Alcoholism: Clinical and Experimental Research.