Coca-Cola used to call its drink "the ideal brain tonic," proving that companies put marketing ahead of reality even in the long-ago days of Way Back When.

But while soda will actually rot your brain, there's another beverage that really can protect it -- and it's something many of us already enjoy at the end of the day: Booze.

I've told you before how alcohol can boost your health and well-being and slash your disease risk, and a new study confirms that a moderate drinking habit can even save your brain from the ravages of dementia.

Researchers tracked 3,202 Germans over the age of 75 who did not have dementia at the start of the three-year study. Roughly half didn't drink at all, while 25 percent sipped less than one a day, 13 percent enjoyed between one and two, and 12 percent drank even more than that.

Overall, the researchers found that the moderate drinkers -- those who had a glass or two a day -- were 30 percent less likely to develop dementia during the study period than non-drinkers.

These healthy drinkers also had a 40 percent lower risk of the most frightening cognitive disorder of all: Alzheimer's disease.

Wine was the most popular drink, followed by beer... but the researchers wrote in Age and Ageing that there were no significant differences in the types of booze -- just between moderate drinkers and nondrinkers.

Other studies have also found that drinking can protect the brain and lower the risk of dementia. Research published in 2009 found that seniors who enjoyed between eight and 14 drinks a week were 37 percent less likely to develop dementia than nondrinkers.

Another study published last year found that women who have a drink or two a day have a 52 percent lower risk of Alzheimer's, while men can lower the odds by 20 percent.

Think that's all? Not even close -- there's actually been more than 70 studies on this over the years, and most of them have reached a similar conclusion.

Just remember: Too much booze can actually hurt your brain, not save it. Heavy drinkers have a higher risk of dementia, and by some estimates alcohol abuse plays a role in up to 10 percent of all cases.

Keep it moderate, however, and you won't just protect your brain. A healthy drinking habit can lower the risk cardiovascular disease, diabetes and some forms of cancer.

Drinkers are also happier, wealthier, smarter -- and they even live longer, too.