THURSDAY, April 19, 2007 (HealthDay News) -- Heavy drinking during the college years takes it toll on the heart, research suggests.
In a new study, college students who regularly drank to excess had above-normal levels of C-reactive protein (CRP), a blood marker for systemic inflammation long linked to cardiovascular illness.
But the news was not all bad. Moderate drinkers actually had lower, healthier CRP readings than those who drank little or no alcohol, the study found.
"In a sense, I was surprised," said study co-author Elizabeth Donovan, an undergraduate biology and nutrition science major at the College of Saint Benedict (CSB) in St. Joseph, Mich.
"Although in older people high C-reactive protein levels are associated with an increased risk for cardiovascular disease, I wasn't so sure this would apply to a younger population," she noted. "But if C-reactive protein levels are predictive of future risk for cardiovascular disease twenty or thirty years down the road, then it appears college-age individuals may be beginning this dangerous pattern -- which is a clear reason to be concerned about heavy drinking."
Donovan conducted her research with faculty advisor and co-author Amy Olsen, a professor of nutrition. They are presenting their findings in Chicago this week at the American Heart Association's Conference on Arteriosclerosis, Thrombosis and Vascular Biology.
According to the American Heart Association (AHA), CRP levels rise when body-wide inflammation kicks in following an injury or infection. Inflammation is thought to play a critical role in atherosclerosis, the build-up of fatty deposits on the lining of the arteries.
Although the exact link, if any, between high CRP levels and heart disease remains unclear, an AHA review of recent studies suggests that patients with elevated CRP are more likely to suffer an initial or recurrent heart attack or stroke. They are also less likely to survive these attacks. As well, high CRP levels raise the risk that arteries will close back up following surgical intervention.
Using AHA standards for assessing CRP-associated risk, Donovan and Olson defined low risk for cardiovascular disease as having less than one milligram of CRP per liter of blood. A CRP level of between one and three milligrams was interpreted as bearing moderate risk, while anything above three milligrams was equated with high risk.
The researchers then asked 25 college-age men and women to complete surveys concerning their drinking habits, smoking habits, medication use, and recent weight loss -- behaviors which can affect CRP levels.
The students were then categorized into one of three groups: non-drinkers (consumed one or less drinks per week); moderate drinkers, (two to five drinks a day over the course of one or two days per week); and heavy drinkers, (three or more drinks a day, at least three days a week). Heavy drinkers also included people who binge-drank, consuming five or more drinks at one time, at least two or more days per week.
Blood tests revealed that, overall, the students were at low risk of heart disease, with an average CRP of 0.9 milligrams per liter of blood.
However, heavy drinkers had a CRP average of 1.25 mg, suggesting they were at moderate risk for future heart disease.
On the other end of the scale, moderate drinkers fell into the low-risk group, with CRP averaging just 0.58 milligrams/liter.
Infrequent drinkers and non-drinkers were in the middle, with an average CRP of 0.85 milligrams/liter.
Overweight male students and male and female students with a family history of heart disease had higher CRP readings. Students who ate relatively high levels of fruits and vegetables had lower CRP levels than those who did not, the researchers found.
Donovan's team emphasized that any link between heavy drinking in youth and long-range cardiovascular risk needs further corroboration.
"I don't think this study is enough to say for sure whether cardiovascular disease risk goes up for young people who drink heavily," Donovan cautioned. She noted that the relatively small study did not track student health over a long period of time but rather relied exclusively on a self-report of current drinking habits.
One expert expressed little surprise at the study findings.
"During flu season, we know heart attacks peak, because plaque is already sitting there, quietly, until inflammation sets in," noted Dr. Karol Watson, an assistant professor of cardiology and co-director of the Program in Preventive Cardiology at the University of California, Los Angeles. "So here, alcohol also gets thrown in as one of many acute 'insults' to our bodies which can provoke inflammation."
"Raising C-reactive protein is definitely not a good thing," added Watson. "And if you have arteriosclerotic plaque, any inflammation -- any acute elevation of C-reactive protein -- can destabilize the situation enough so you could have a heart attack or stroke. Of course, because this study was done with young, healthy people, it's unlikely any of them have underlying vascular disease. But you never know that for sure."
For more on C-reactive protein, head to the American Heart Association.