According to a recent research, even light-to-moderate drinking is linked to brain damage. Researchers evaluated data from more than 36,000 participants and discovered a relationship between drinking and decreased brain capacity that starts at less than one alcohol unit per day (about half a beer) and increases with each successive drink.
Using a dataset of over 36,000 participants, the study discovered that increasing from one to two drinks per day was connected to brain alterations comparable to two years of ageing. Drinking more heavily was linked to a higher toll. Heavy drinking and the brain have an unhealthy connection, according to scientists. People who drink excessively have structural and size changes in their brains, which are linked to cognitive deficits.
However, a recent research suggests that even moderate alcohol usage, such as a few beers or glasses of wine a week, may pose a danger to the brain. Light-to-moderate alcohol intake was linked to decreases in total brain capacity, according to a study performed by a team from the University of Pennsylvania that looked at data from over 36,000 participants.
The researchers discovered that the association became stronger as the amount of alcohol consumed increased. For instance, among 50-year-olds, increasing average daily drinking from one alcohol unit (about half a beer) to two units (a pint of beer or a glass of wine) causes brain alterations comparable to two years of aging. At the same age, going from two to three alcohol units was like aging three and a half years. The results were published in the journal Nature Communications.
“Because we have such a huge sample size, we can identify minor correlations even between consuming half a beer and one beer per day,” says Gideon Nave, a corresponding author on the research and a faculty member at Penn’s Wharton School. He worked alongside former postdoctoral researcher and co-corresponding author Remi Daviet, who is now at the University of Wisconsin-Madison, as well as Perelman School of Medicine colleagues Reagan Wetherill and Henry Kranzler, as well as other researchers.
“These results contradict scientific and regulatory standards on safe drinking limits,” adds Kranzler, who is the director of the Penn Center for Addiction Studies. “For example, although the National Institute on Alcohol Abuse and Alcoholism advises that women consume no more than one drink per day on average, men’s recommended limits are twice as high, exceeding the consumption level linked to lower brain capacity in the research.”
The relationship between drinking and brain health has been studied extensively, with mixed findings. While there is strong evidence that heavy drinking causes structural changes in the brain, including significant reductions in gray and white matter throughout the brain, other studies have suggested that moderate alcohol consumption may have no effect, or even that light drinking may benefit the brain in older adults.
However, these previous studies lacked the power of massive datasets. Nave, Daviet, and colleagues have previously undertaken research utilizing the UK Biobank, a dataset of genetic and medical information from half a million British middle-aged and older persons, to look for patterns in large amounts of data. In the present work, they utilized biomedical data from this resource, especially brain MRIs from over 36,000 people in the Biobank, which can be used to determine white and gray matter volume in various brain areas.
“Having this dataset is like having a more powerful microscope or telescope,” Nave explains. “With a higher resolution, you can see patterns and correlations that you couldn’t perceive previously.”
It was necessary to adjust for confounding factors that may muddy the association in order to acquire an understanding of probable connections between drinking and the brain. Age, height, handedness, sex, smoking status, socioeconomic position, genetic heritage, and county of residency were all taken into account. They also adjusted the brain-volume data to account for the size of the whole head.
The Biobank’s volunteer members had answered survey questions on their alcohol usage levels, which ranged from total abstinence to an average of four or more units per day. When the researchers divided the subjects into groups based on their average consumption levels, they saw a subtle but noticeable pattern: the gray and white matter volume that would ordinarily be predicted by the individual’s other features was lowered.
Rising from zero to one alcohol unit per day had no effect on brain volume, but going from one to two or two to three units per day was linked to gray and white matter decreases.
“It’s not linear,” Daviet explains. “The more you drink, the worse it becomes.”
Even when the heavy drinkers were excluded from the analysis, the correlations persisted. The scientists discovered that the reduced brain volume was not restricted to a single brain area.
The researchers compared the changes in brain size associated with drinking to those associated with aging to get a feel of the effect. According to their calculations, each extra unit of alcohol drank each day resulted in a larger aging impact on the brain. While moving from zero to a daily average of one alcohol unit was related with a half-year of aging, going from zero to four drinks was associated with more than ten years of aging.
The authors plan to utilize the UK Biobank and other big datasets in future research to address further concerns about alcohol usage. “We’re intrigued if drinking one beer a day is better than drinking none during the week and seven on the weekend,” Nave explains. “We haven’t looked into it yet, but there’s some evidence that binge drinking is bad for the brain.”
They’d also want to be able to prove causality rather than correlation, which might be achievable with new longitudinal biological datasets that track young individuals as they grow older.
“We may be able to look at these impacts over time and pull out causal linkages using genetics and other methods,” Nave adds.
While the researchers stress that their study focused only on correlations, they believe the results may cause drinkers to reassess their consumption levels.
“There’s some evidence that drinking has an exponential impact on the brain,” Daviet explains. “As a result, one extra drink in a day may have a greater effect than any of the prior drinks consumed that day. As a result, cutting down on that last drink of the night might have a significant impact on brain aging.”
“The folks who can profit the most by drinking less are the ones who are currently drinking the most,” Nave explains.
Reagan R. Wetherill is a research assistant professor of psychiatry at the Perelman School of Medicine at the University of Pennsylvania.
At Penn’s Perelman School of Medicine, Henry R. Kranzler is the Benjamin Rush Professor of Psychiatry and the head of the Penn Center for Studies of Addiction.
Gideon Nave is the Carlos and Rosa de la Cruz Assistant Professor of Marketing and the Wharton Neuroscience Initiative at Penn’s Wharton School.
Remi Daviet is an assistant professor of marketing at the University of Wisconsin-Wisconsin Madison’s School of Business.
The paper’s initial author was Daviet, and co-corresponding authors were Wetherill, Nave, and Daviet.
Kanchana Jagannathan, Nathaniel Spilka, and Henry R. Kranzler of the Perelman School of Medicine at the University of Pennsylvania; Gökhan Aydogan of the University of Zurich; and Philipp D. Koellinger of the University of Wisconsin-Madison were also coauthors.