Health experts have long warned about the risks of drinking too much alcohol. Now, a new study has found evidence suggesting that drinking alcohol, even in moderate amounts, may still have unwanted impacts.
The research found that moderate drinking of alcohol is associated with changes in brain structure and higher risk of worsening brain function.
In a new study that spanned 30 years, researchers looked at the brain of more than 500 middle-aged heavy drinkers, moderate drinkers, and teetotalers, and found that those who consumed more alcohol had a greater risk of hippocampal atrophy, a condition that affects the brain's hippocampus.
The hippocampus is a small region of the brain involved in memory and spatial navigation. The hippocampus also plays a part in the formation of long-term memory. Any damage in this part of the brain can cause disorientation and memory loss, and lead to conditions such as amnesia, dementia, and Alzheimer's disease. Hippocampal atrophy causes cognitive and memory dysfunction as a result of hippocampal degeneration.
Hippocampal Atrophy In People Who Drink Alcohol
The people with the highest risk drank more than 30 units of alcohol a week on average, but researchers also found that those who drank moderately consuming between 14 and 21 units of alcohol per week were far more at risk to have hippocampal atrophy than those who abstain from drinking alcohol.
"We were surprised that the light to moderate drinkers didn't seem to have that protective effect," said study author Anya Topiwala of the University of Oxford. "These are people who are drinking at levels that many consider social drinkers, so they are not consuming a lot."
The findings support the lowering of drinking limits under Britain's guidelines and pose questions about the limits currently recommended in the United States, which suggest that up to 24. 5 units of alcohol weekly is safe for men.
In the study, the researchers found higher odds of brain structure changes in participants who consumed just 14 to 21 units per week.
"Alcohol consumption, even at moderate levels, is associated with adverse brain outcomes including hippocampal atrophy," the researchers wrote in their study, which was published in The BMJ British Medical Journal, on June 6.
"These results support the recent reduction in alcohol guidance in the UK and question the current limits recommended in the US."
A unit is equivalent to 10 milliliters of pure alcohol. A large beer has about 2 units; a bottle of wine, 9; and a 25-milliliter spirit shot has 1 unit of alcohol.
The researchers also found that drinking more was associated with poorer white matter integrity, a factor considered critical for cognitive functioning.
Topiwala and colleagues, however, noted that the observational study does not prove a cause and effect relationship albeit the findings may have important public health implications. Other experts, on the other hand, said that moderate drinkers need not give up the booze solely because of the report.
Eric Rimm, of Harvard T.H. Chan School of Public Health, said that many other lifestyle factors such as diet were not taken into account in the study.