Women who drink 15 grams or less of alcohol a day (the equivalent of one drink of any alcoholic beverage) at midlife may be healthier when older than women who do not drink at all, who consume more than two drinks a day, or who consume four drinks or more at the one time. A study led by Qi Sun from the Harvard School of Public Health and the Brigham and Women's Hospital in Boston, USA, and published in this week's PLoS Medicine suggests that in women, regular, moderate alcohol consumption during middle age (average age 58 years) is related to good overall health -- that is, having no major chronic diseases, such as heart disease or diabetes, and no major cognitive and physical impairment, or mental health limitations -- in those who live to 70 years and beyond. The authors define this good overall health as "successful aging."

The authors used information from periodic food frequency questionnaires given to the 121,700 female nurses enrolled in the US Nurses' Health Study (which began in 1976) to assess the alcohol consumption of the nurses during middle age. The authors then included in their analysis the vast majority (98.1%) of participants who were not heavier drinkers (45 g/d) when middle-aged and examined the health status in the 13,984 women who lived to 70 years and over.

After discounting other factors, such as smoking, that might affect their health status, the authors found that women who drank 5-15 g of alcohol per day (between a 1/3 and 1 drink per day) had about a 20% higher chance of good overall health when older compared to non-drinkers. Furthermore, women who drank alcohol regularly had a better chance of good overall health when older than occasional drinkers: compared to women who didn't drink, women who drank five to seven days a week had almost 50% greater chance of good overall health when older.

The authors conclude: "These data suggest that regular, moderate consumption of alcohol at midlife may be related to a modest increase in overall health status among women who survive to older ages."

They add: "The 2010 US Department of Agriculture dietary guidelines note that moderate alcohol consumption of up to one drink per day for women and up to two drinks per day for men may provide health benefits in some people. Our data support this recommendation and provide novel evidence suggesting that light-to-moderate alcohol consumption at the levels of one to two drinks/day or slightly less at midlife may benefit overall health at older ages in US women."