We all know that excessive alcohol use can have detrimental effects on health and well-being, but we've also been told that a glass of red wine here and there can be good for your heart. Two recent studies show that both are true. 

The bad news is that drinking too much alcohol can accelerate the aging process and even lead to cancer. e! Science News reports on a study presented at the 101st annual meeting of the American Association for Cancer Research, which recently took place in Washington, D.C. Researchers from the University of Milan, Italy, revealed that the link between alcohol consumption, cancer and aging starts at the cellular level with the shortening of telomeres. 

A telomere is a region of repetitive DNA found at the end of a chromosome. Telomeres are essential to the genetic stability of cells, and they protect the ends of chromosomes from fusing into rings or binding with other DNA. Although telomeres shorten naturally with age, scientists have long speculated that excessive use of alcohol can hasten the process, thereby increasing cancer risk.

To prove this, the scientists studied two groups of individuals who were similar in age, diet, amount of physical exercise, and other lifestyle factors. The study found that 22 percent of the people in one group consumed four or more alcoholic beverages per day, while only 4 percent of the other group drank that much. After measuring serum DNA in both groups' participants, researchers found that telomere length was dramatically shortened in those who consumed large amounts of alcohol, revealing a direct link between alcohol abuse and cancer at the cellular level. 

Now for the good news: Researchers at Johns Hopkins have discovered that drinking red wine may protect the brain from stroke damage. Sylvain Doré, Ph.D., a professor at Johns Hopkins University School of Medicine, induced an ischemic stroke in mice two hours after feeding them resveratrol, a compound found in the skins and seeds of red grapes. Mice that had received the resveratrol suffered significantly less brain damage than those that did not. Doré says his study demonstrates how resveratrol increases levels of heme oxygenase, an enzyme known to shield nerve cells in the brain from damage. Simply put, the elevated enzyme levels produced by resveratrol consumption enable the brain to better protect itself when a stroke hits.

Before you sign up for a wine club or pick up a resveratrol supplement at the health food store, take heed: Doré insists that more research is needed to determine what kind of red wine is best, and how much of the compound might be optimal to protect the brain.

As is often the case, it all seems to come down to moderation: A glass of red wine here and there can boost your body's ability to protect itself from disaster, but overdo it — you might make yourself vulnerable to disease.