As part of the study, which was published Wednesday in the BMJ, researchers looked at people's weekly alcohol intake from the Whitehall II study, which tracks disease and social behaviors in a group of British civil servants for 30 years.
They also question the current limits recommended in the U.S. which suggest that up to 24.5 units a week is safe for men, as the research suggests increased odds of hippocampal atrophy at just 14-21 units a week. Tests included asking participants to name as many words as they could that start with the same letter in one minute.
However, the researchers behind the new study note that the USA guidelines allow a higher limit for men of 24.5 units per week.
Even after the effects of factors such as sex, age, education, social class, physical and social activity, smoking, stroke risk and medical history were taken into account, the study found connections between those with higher alcohol intake and declining brain health.
On the other hand, the study found, people's drinking habits were not tied to their performance on other tests of mental acuity, including short-term memory. The study did not look at heavy, abusive drinking, but that already is firmly linked with brain damage and dementia, she noted.
Canada's Low-Risk Alcohol Drinking Guidelines say to reduce long-term health risks, no more than two drinks a day, five times a week or 10 drinks total a week for women are recommended and no more than three drinks a day, five times a week or 15 drinks total a week are recommended for men.
The researchers examined images of the participants' brains - which enabled them to explore correlations between average alcohol use, cognition and brain structure. Red wine was linked to heart health, and research showed that moderate drinkers actually enjoyed some real benefits. The issue is that brain scans have failed to show any protective effect caused by any degree of alcohol consumption.
The researchers note this is an observational study, so they can not draw any conclusions relating to cause and effect.
The study is still in its early stages, and the researchers have still not found enough evidence to confirm how often you should be drinking.
The report reviewed data on more than 12 million women from dozens of studies conducted around the world and found that just one small glass of w... Some also state that as this was exclusively an observational study, it should not conclude "causation".
It seems that "everything in moderation" may no longer be the best rule to drink by. Through these, the researchers were able to analyze the volunteers' brain functions.
In other countries, that threshold is set higher for men: 35 units in Spain, 24.5 in the United States, 21 in Denmark and Ireland, and 19 in New Zealand. Most in this study were men with similar backgrounds, with generally higher IQs than the population as a whole, all factors that can affect the results. "The big fibre tracts in the brain are cabled like electrical wire and the insulation, if you like, on those wires was of a poorer quality in people who were drinking more", said Topiwala.