The U.S. government is considering a proposal to redefine the definition of moderate alcohol consumption in its federal Dietary Guidelines. It may sound like a small change, but it's an important marker.
Every five years, the departments of Agriculture and Health and Human Services review the U.S. Dietary Guidelines under congressional mandate. The goal is to update the national nutritional guidelines according to the latest scientific research. Such guidelines can have important effects on federal programs. Before the formal guidelines are published, a committee of appointed external experts gathers to draft recommendations for any changes. The 13-member committee that reviewed the 2010 guidelines released their report June 15.
The basic upper threshold for moderate alcohol intake hasn't changed since the third version of the Dietary Guidelines for Americans was published in 1990: Up to one drink per day for women and two for men. But one of the suggestions by the advisory committee for the 2010 version, due out later this year, is to define moderation as an average daily intake of up to one drink for women and two for men, with no more than three drinks for women on a single day and four for men.
That "average" is a small semantic change, but a notable one as it has the potential to influence the focus of future research on the ways and patterns in which people consume alcohol.
Alcohol has at times been a contentious issue in the guidelines. The 1990 version included a statement that alcohol had "no net health benefit." The 1995 guidelines dropped that phrase in the wake of research pointing to alcohol's association with a lower risk of heart disease. Subsequent versions have further detailed alcohol's complex relationship with chronic disease, cancers and mortality, noting some positive aspects to moderate consumption (a lower risk of heart disease and diabetes among others) and some negative (a higher risk of breast and colon cancers).
There were few surprises in the 2010 recommendations other than the shift in wording of the daily recommendation. The change is part of an effort by the committee to understand alcohol consumption patterns. Epidemiological studies often draw conclusions about alcohol intake from data tallied by drinks per week, month or even year. In addition, the committee found that most U.S. citizens do not drink every day. An average of one drink a day might mean seven on Friday. That can complicate using data gleaned from these epidemiological studies to make a recommendation for a responsible daily use of alcohol, and the proposed new wording of the recommendation is meant to reflect an average over a week or month.
Another striking thing about the 2010 committee report in regard to alcohol is where the mention of alcohol is absent. The 2005 guidelines lumped alcohol in with added sugars and saturated fats as "discretionary calories" that should be limited. In the committee's proposed key recommendations for 2010, alcohol is purposely not included in that category, with the report stating that, "alcohol makes a very minor contribution to overall energy intake in the diets of most Americans." The report, however, does say that alcohol is one thing people looking to cut calories out of their diet might consider.
Marion Nestle, professor of nutrition at New York University and a committee member for the 1995 Dietary Guideline review believes this shift is not surprising given the focus of the 2010 report on mitigating obesity, especially obesity in children. "[Alcohol] raises other kinds of issues," she said. "But its role in obesity is unclear except with people who consume lots of it and it didn't factor in as a major issue in a report which is trying to deal as well as it can with obesity."
The role of alcohol in relationship to weight gain is not yet fully understood. The report notes that epidemiological studies suggest that moderate consumption of alcohol does not lead to increased weight gain, but the research is inconclusive as to whether that comes from lifestyle choices or some sort of metabolic process. This is one of the areas that the committee members recommend for further research.
Public comments on the committee's report will be accepted until July 15, with the final version of the 2010 Guidelines expected to be published by the end of the year.