In the recent flurry of publicity over low-carbohydrate diets, some diet promoters have depicted beer as an unhealthful source of fattening carbohydrates. Not so, says a brewing expert at the University of California, Davis.

Rather, beer, in moderation, can be part of a "low-carb" diet and potentially a good source of soluble fiber and prebiotic substances that promote digestion, reports Charles Bamforth, chair of the Department of Food Science and Technology.

"Certainly obesity and the serious health problems it creates should be of great concern to everyone in the United States and other developed nations," said Bamforth. "But to erroneously claim that beer is high in carbs does a disservice to health-conscious individuals."

Bamforth directs the brewing program at UC Davis, where he holds the Anheuser-Busch Endowed Professorship of Malting and Brewing Science. The findings of his review of brewing and nutrition research related to carbohydrate content will appear in the November Journal of the Institute of Brewing.

"The message for consumers," Bamforth said, "is that the only sustainable and sensible way to lose weight and avoid weight gain is to focus on the calorie content of all foods and beverages, including beer," Bamforth said. "And they should remember that, contrary to popular thought, beer is not comprised merely of empty calories. Rather, it can contain significant levels of vitamins, antioxidants, minerals and fiber."

Beer and carbs

Low-carbohydrate diets, including the Atkins and South Beach diets, have become popular in recent years as a trendy way to lose or manage weight. Such "low-carb" diets stress avoiding carbohydrate-rich foods, including cereals and cereal-derived products. Because beer is made from malted cereal grains, it was quickly labeled as a high-carb beverage and thus incompatible with a low-carb diet.

In his research review, Bamforth notes that Arthur Agatson, who developed the South Beach Diet, originally labeled beer as "the most fattening of all alcoholic beverages" due to its use of the sugar maltose. Agatson later retracted that claim and lifted his ban on beer when it was brought to his attention that maltose is removed by the fermentation process. But by that time, the brewing industry already had begun marketing "low carb" beers, which, according to federal standards, must contain no more than seven grams of carbohydrate per serving.

While the low-carb movement created a new marketing niche for the brewing industry, it also created the impression that regular beers were high in carbohydrate.

"In truth, the majority of beers on the market contain relatively low levels of carbohydrates," Bamforth said. "Furthermore, alcoholic drinks that contain mixers such as ginger ale, cola, tonic and tomato juice are far more charged with carbohydrate than is beer."

He added that there is little experimental data available from the research community to define the healthfulness of beer. And in the absence of guidelines in the popular dietary press, most consumers are left with an unhealthy image of beer.

Bamforth stresses that the interaction of foods in the body is quite complex and equally difficult to quantify with existing measurements. Two such systems have been developed to rank the carbohydrate content of various foods. The first is the "glycemic index," which rates carbohydrate-containing foods according to their immediate effect on blood sugar. The second is the more refined "glycemic load" system, which takes into consideration that some foods might contain a lot of carbohydrates, but those carbohydrates might not have an immediate impact on blood sugar, and vice versa. For technical reasons, neither system lends itself to describing how the carbohydrates in beer and other alcoholic beverages impact the human body, Bamforth says.

Beer and Calories

Because there is no direct method for quantifying how the carbohydrates in beer impact weight and overall human health, Bamforth suggests that consumers are better advised to consider the calories in beer. In doing so, it is important to realize that alcohol contributes more to beer's calorie content than do carbohydrates.

"Therefore, brewers who are developing beers with dieters in mind will want to aim for the lowest alcohol content that can be achieved without compromising flavor and other quality characteristics," he said.

He notes that the link between alcohol consumption and body weight is still puzzling to nutritionists.

"The scientific literature features conflicting data as to whether there truly is a simple correlation between beer intake and body-mass index," Bamforth said. "The beer belly probably has more to do with the French fries and sausages eaten alongside, than the beer."