Daily, moderate drinking could almost halve the risk of developing Alzheimer’s disease or other types of dementia, according to new research.
The finding adds to a growing body of evidence for the health benefits of moderate drinking which is already known to protect against heart disease and stroke.
The adverse effect of excess alcohol is beyond question. Besides destroying the liver, several studies have shown that exessive drinking can be toxic to the brain. Alcoholics can end up with a shrunken brain, which is linked to dementia. There is even a medical condition called alcoholic dementia．
Scientists at Erasmus University in Rotterdam, the Netherlands, conducted a six-year study of 5,395 people aged 55 and over who did not have signs of dementia. They were asked whether they ever drank alcohol. Those who said yes were quizzed on how often they drank and details on their consumption of specific drinks such as wine, beer, spirits and fortified wine such as sherry and port.
The men mostly drank beer and liquor, while women preferred wine and fortified wine. The researchers also checked whether participants’ drinking habits had changed over the preceding five years or whether they had engaged in binge drinking-more than six drinks in one day.
Everyone was categorized according to how much they drank. Four or more glasses of alcohol perday were considered heavy drinking.
By the end of the study in 1999, 197 of the participants had developed Alzheimer’s or another form of dementia. Those who fared best were people who drank between one and three drinks a day. They had a 42 percent lower risk of developing dementia than the nondrinkers.
Those who weren’t daily drinkers but had more than one drink per week had a 25 percent lower risk and those who drank less than a glass a week were 18 percent less likely than nondrinkers to develop dementia. Heavy drinkers, who numbered 165-mostly men-were 1 1/2 times more likely to get vascular dementia and slightly more likely than nondrinkers of ending up with Alzheimer’s.
Researchers suggested the blood-thinning and cholesterol-lowering properties of ethanol in alcohol may ward off dementia, which is often caused by a blood vessel problem.
Another possibility, the study speculated, is that low levels of alcohol could stimulate the release acetylcholine, a brain chemical believed to facilitate learning and memory.