CHAMPAIGN, Ill. — Does being young and in shape help women recover from a night of drinking? Researchers from the University of Illinois Urbana-Champaign say the answer is apparently no. Their findings reveal that the rate at which women clear alcohol from their bloodstream depends on lean body mass and age, with older women and obese women actually eliminating alcohol 52 percent faster than younger women and those at a slimmer weight.
“We believe the strong relationship we found between participants’ lean body mass and their alcohol elimination rate is due to the association that exists between lean body mass and lean liver tissue – the part of the liver responsible for metabolizing alcohol,” says research group leader M. Yanina Pepino, a professor of food science and human nutrition, in a university release.
In this study, researchers conducted a secondary data analysis from two studies performed at the University of Illinois and Indiana University. The original studies used similar methods in order to estimate the rate that alcohol breaks down in the body. The analysis included 143 women between the ages of 21 and 64, representing body mass indices (BMI) from healthy to morbid obesity. Of the group, 19 women received a type of bariatric surgery.
In 102 women, the team measured the proportions of lean and fat tissue in their bodies and calculated their BMI. Based on their BMI, the women were divided into these three groups: normal weight (BMI:18.5-24.9), overweight (BMI: 25-29.9), and obese (BMI: >30).
As expected, the team found that women with a higher BMI had more fat mass as well as more lean mass. The group with obesity had 52.3kg of lean mass, compared to 47.5kg in the group with normal weight.
Both studies used an alcohol clamp technique where participants received an IV infusion of alcohol at a controlled rate with computer assistance. Personalized infusion rates were calculated based on age, height, weight, and gender before being programmed to reach a target blood alcohol concentration (BAC) of 0.06 percent within 15 minutes and maintain it for two hours. Researchers took breath samples using a breathalyzer at regular intervals throughout the experiments to estimate BAC and give feedback to the system.
“We found that having a higher fat-free body mass was associated with a faster alcohol elimination rate, particularly in women in the oldest subgroups,” says Neda Seyedsadjadi, a postdoctoral fellow at the university and the first author of the study.
“The average alcohol elimination rates were 6 grams per hour for the healthy weight group, 7 grams for the overweight group, and 9 grams for the group with obesity,” the researcher adds. “To put this in perspective, one standard drink is 14 grams of pure alcohol, which is found in 12 ounces of beer, 5 ounces of table wine or 1.5 ounces shot of distilled spirits.”
These findings help researchers better understand alcohol metabolism and physiological factors that could impact it. The work is also unique in that it gives insight on alcohol metabolism in women who have had weight loss surgery. Researchers have long understood that these surgeries alter women’s response to alcohol but they weren’t sure about how quickly they were able to clear alcohol from their blood.
Previously, studies have found that these patients metabolize alcohol slower post-surgery, but this study shows that this may be due to the surgery reducing their lean body mass. Weight loss surgery independently didn’t have any effects alcohol elimination rates.
The findings care published in the journal Alcoholism Clinical and Experimental Research.