PHILADELPHIA (CBS)—In one of the largest studies conducted on the long-term effects of alcohol consumption, it was concluded that heavy drinking may lead to a significant cognitive decline in middle-aged men (average age 56), but women’s brains seemed to be protected against the negative effects, for reasons that are not completely clear.
The study measured cognitive decline in two ways, a decrease in the brain’s processing speed and efficiency along with memory deterioration.
The data researchers used came from the Whitehall II cohort study, which began in the mid-1980s. About 10,000 British civil servants agreed to complete lifestyle questionnaires and undergo physical exams for nearly a 20-year span.
The study design allowed researchers to track the effects of drinking alcohol over long periods of time.
It found that middle-aged men, who drank about 1.2 fluid ounces or more of alcohol a day for 10 years, experienced greater memory loss and more significant slowing of executive function compared to “occasional” or “moderate” drinkers who consumed between .03 and 1.1 ounces a day.
To break it down, a typical shot of 80-proof whiskey is 1.5 fluid ounces but only 0.6 fluid ounces is pure alcohol. So a heavy drinker, according to this study, drank at least two shots of booze a day.
If the study participants were wine or beer drinkers, then they drank at least 10 fluid ounces of wine or 24 fluid ounces of beer a day to reach the same level.
The type of alcohol consumed made no difference in the study’s results.
Heavy drinking for women was defined differently due to the differences in how the genders metabolize alcohol.
To qualify as a heavy drinker in this study, a woman had to drink at least 0.6 fluid ounces of alcohol a day, translating to about half of the male level.
However, heavy drinkers among women didn’t show nearly the same level of brain decline as men, and the reason for that may be estrogen.
A study conducted in 2001 by University of California-Davis researchers showed that estrogen acts as a guard of brain cell health and higher levels of the hormone are linked to a reduced risk of developing Alzheimer’s disease. So it is suggested that estrogen may also act as a hormonal shield against alcohol’s harmful effects.