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If your New Year's resolution is to stop tippling, you may want to reconsider.

Instead, vow to spend 2009 drinking in moderation if you want to keep Alzheimer's at bay, a new report suggests.

People who have one to two alcoholic drinks a day are often at a lower risk of developing Alzheimer's disease and dementia than their teetotalling peers, researchers concluded after analyzing 44 studies about moderate alcohol intake and its effect on the heart and the brain.

More than half of the studies - all published since 1990 and conducted on humans over the age of 60 and animals - found benefits to sipping a regular glass of wine, beer or spirits.

Only a handful of the studies, all reviewed in July, 2007, by a consortium of seven American researchers in Chicago, made negative links.

Lead author Michael Collins of Loyola University Chicago's school of medicine says the report helps physicians and the public understand that moderate alcohol consumption may benefit not only the heart but the brain as well.

"Alcohol in these two different organs is triggering a protective state that uses similar biochemical pathways," he says of findings in the report to be published in the February, 2009, issue of Alcoholism: Clinical and Experimental Research. "With the brain, we're trying to see whether we can understand those pathways."

Research that focuses on the effects of moderate alcohol intake on the brain is slowly emerging, Dr. Collins says.

While no one knows exactly why benefits exist, the studies offer a couple of theories. One is that slight exposure to alcohol whips cells into shape, creating a protective layer in the brain made of proteins that can prevent the onset of dementia and other forms of cognitive decline. Another theory plays on how the well-known cardiovascular benefits of moderate alcohol intake - such as the way it causes muscles and blood streams to relax - can protect against small strokes, which often lead to dementia.

The report mainly focuses on the positive influence moderate alcohol use has on the heart, but also highlights 19 longitudinal cohort studies conducted on human drinkers and non-drinkers between 1997 and 2008 that compared risk factors for cognitive decline, Alzheimer's and dementia. In these studies, 54 per cent of the risk factors were lowest in moderate drinkers.

But, of course, there is a fine line between the good things alcohol can do for your brain and the severe damage it can cause, Dr. Collins is quick to point out.

Heavy drinking over a long period of time is known to cause memory loss and kill brain cells.

"Yes, it's a fine line," he says. "We're not about to say people who don't drink should start drinking. It's just that we're uncovering these fairly beneficial events of a low amount of alcohol on brain cells."

It was while studying the damaging effects alcohol has on the brain that he and his colleagues found the apparent benefits of a little bit of alcohol. While giving a moderate level of alcohol to a sample culture of rat brain cells, Dr. Collins found the cells created a neuroprotectant - a sheath of proteins forming around the neuron. The finding piqued his interest in the cardiovascular benefits of a little bit of alcohol in the blood stream, spurring him to organize the roundtable discussion.

But while moderate alcohol consumption is lauded in this report, some researchers aren't so sure it can work to stop the onset of dementia or Alzheimer's.

Carol Ann Paul researched moderate alcohol intake and brain shrinkage in a study published in the October issue of Archives of Neurology - a report Dr. Collins says was not one of the 44 reviewed. Ms. Paul, currently an instructor in the neuroscience program at Wellesley College in Massachusetts, found that moderate alcohol intake does nothing to protect the brain from shrinkage, a common occurrence in sufferers of dementia.

"While [the report authors are] very confident in their findings about the cardiovascular system, they're much more guarded in their findings about the nervous system," she says. "Whatever dilating effect alcohol has in the bloodstream in the body, it's going to have that same effect in the brain. It's going to be very hard to untangle the effects."