Alcohol Consumption Habits May Threaten GI Health

22/05/06 Many studies have evaluated the risks and benefits of alcohol intake, with some concentrating on potential benefits while others focus on the risks of abuse. According to new research presented at Digestive Disease Week 2006 (DDW), the volume of alcohol ingested and how it is mixed with other beverages can affect the health of the gastrointestinal (GI) system. DDW is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.

"Many factors come into play when managing a healthy lifestyle. In this case, patterns of alcohol consumption may significantly affect digestive health," said Lee Kaplan, M.D., Ph.D., associate professor of medicine, Harvard Medical School and director of the Massachusetts General Hospital Weight Center. "Researchers explore a variety of drinking methods to differentiate which patterns are most harmful and which may have some beneficial protective effects."

Artificially Sweetened, Compared to Regular Mixers, Accelerate Gastric Emptying and the Rate of Alcohol Absorption

When alcohol is mixed with beverages such as orange juice or soda, the rate of alcohol absorption into the blood stream depends not only on the individual, but also the "mixer." Researchers at the Royal Adelaide Hospital in Australia analyzed alcoholic beverages mixed with diet or regular soda (with sucrose) to determine the rate of gastric emptying and blood alcohol response. They found that alcohol combined with sugar-free mixers were processed through the stomach and entered the blood stream much more quickly than alcohol with regular mixers.

Researchers analyzed eight male volunteers who consumed orange-flavored vodka beverages with both a diet mixer and regular mixer. Participants were monitored to track the rate at which the mixer was emptied from the stomach and their subsequent blood alcohol concentration (BAC) levels.

From this study, the team discovered that the substitution of artificial sweeteners for sucrose in mixed alcoholic beverages may have a substantial effect on the rate of gastric emptying and the blood alcohol response. The time to empty half of the diet drink from the stomach was 21 minutes, compared to regular drinks which took 36 minutes for the same degree of emptying. Peak blood alcohol concentrations were substantially greater with diet drinks at an average of 0.05 percent, while regular drinks measured at 0.03 percent BAC.

"Today, more and more people are shifting personal preferences by choosing 'diet' drinks as a healthier alternative," said Chris Rayner, M.D., of Royal Adelaide Hospital and lead author of the study. "What people do not understand is the potential side effects that diet mixed alcoholic drinks may have on their body's response to alcohol."

Moderate Alcohol Consumption Protects Against Colorectal Adenomas

In illnesses from cardiovascular disease to cancer, studies on alcohol consumption have revealed a wide spectrum of risks and benefits. Researchers from the University of North Carolina took a closer look at the effects of alcohol consumption on the risk of colorectal adenomas (polyps) and found that, surprisingly, moderate amounts of alcohol may have a protective effect against colorectal adenomas, a potential precursor to colorectal cancer.

Although previous analyses have identified an increased risk of colon cancer in conjunction with excessive alcohol consumption, only a few have examined in-depth the relationship between the amount of alcohol intake and the corresponding risk of colorectal adenomas and cancers.

To evaluate risk factors for colorectal adenomas, researchers implemented a case-control study of 725 eligible patients -- 203 case and 522 controls. After undergoing a colonoscopy, participants were divided into five groups based on the average number of alcoholic drinks consumed per week: 1) 0 drinks per week; 2) >0 and <2 drinks per week; 3) 2 to <7 drinks per week (moderate drinkers); 4) 7 to <14 drinks per week; and 5) =14 drinks per week. The results were adjusted for the effects age, gender, body mass index (BMI), use of non-steroidal anti-inflammatory medications, race, and smoking status. When compared to non-drinkers and heavy drinkers, moderate drinkers (between >0 and <2 and 2 to<7 drinks per week) had the lowest adjusted probability of having an adenoma. Using moderate drinkers (>0 and <2 drinks per week) as the reference group, researchers found that non-drinkers were 41 percent more likely to have a colorectal adenoma. Patients consuming 7 to 14 drinks per week were 65 percent more likely to have an adenoma, and those consuming more than 14 drinks per week were two and a half times more likely to have an adenoma.

"Consuming alcohol within a moderate limit may be beneficial to the colon, but we cannot assume that the rate of alcohol consumption is the only factor," said Gregory Austin, M.D., of the University of North Carolina and lead study author. "It is vital that researchers take a broader approach into understanding the development of colorectal adenomas and the range of effects that various lifestyle choices or habits may have."