April 22, 2005
Beer, Red Wine Both Boost Blood Pressure
But red wine's other effects may still make it heart-healthy
HealthDay News -- Raise a glass to higher blood pressure: A new study finds that beer and wine both boost it slightly, and by about the same amount.
"Our study reinforces the ideas that it is alcohol, and not a specific beverage type, that leads to increases in blood pressure," said Renate R. Zilkens, a research fellow in the School of Medicine and Pharmacology at the University of Western Australia.
But the finding shouldn't stop anyone from having the occasional drink -- one expert believes mild to moderate alcohol consumption is probably still good for the cardiovascular system, overall.
In the study, Zilkens and her colleagues assigned 24 healthy, nonsmoking men aged 20 to 65 with normal blood pressure and no heart disease history to four different groups for four weeks: no alcohol; 13 ounces (about a half-bottle) of red wine a day; 13 ounces of de-alcoholized red wine; or 37 ounces (3 cans) of beer per day. Each man took a turn in each of the four groups.
The researchers tracked each man's blood pressure with 24-hour monitoring, performed ultrasound measures of blood vessel functioning and took urine and blood samples.
They found that drinking beer boosted systolic pressure (the top number in a reading) by 2.9 millimeters of mercury while wine increased it by 1.9 millimeters. The alcohol-free red wine had no effect on blood pressure, however.
"The quantity of red wine and beer that was consumed by the men in this study has similar amounts of alcohol in them, -- that is, about 40 grams -- which is equal to four standard drinks in Australia," Zilkens said.
Beer increased sleeping heart rate by 5 beats per minute, while wine boosted it 4.4 beats, the researchers noted.
Based on their findings, Zilken's team conclude that it is alcohol, not some other ingredient specific to either wine or beer, that boosts blood pressure. They stress that, right now, the findings apply only to men with otherwise normal blood pressure.
So does these findings negate the heart-healthy benefits many recent studies have found for moderate consumption of alcohol, especially red wine?
Not necessarily, Zilkens said. "The study cannot exclude the possibility that red wine has some health property making it better than beer," she said. "But at this point in time, the evidence has not been gathered to justify promoting red wine ahead of beer."
And wine drinkers, Zilkens and others suspect, may just be healthier to begin with.
"The public needs to be aware that there are other lifestyle factors (such as healthier diet, exercise, income) which characterize many wine drinkers, and it is likely that it is these factors which are responsible for less cardiovascular disease in some populations of wine drinkers," she said.
Still, mild to moderate alcohol consumption might still help prevent cardiovascular disease, according to Dr. Ralph L. Sacco, a professor of neurology and epidemiology at Columbia University and Mailman School of Public Health, at the Neurological Institute of NewYork Presbyterian Hospital.
"The amount of blood pressure elevation in these healthy white men may not have adverse health consequences," he said. "I think the study helps us understand that the beneficial vascular effects of alcohol are unlikely to be explained by a reduction in blood pressure."
Compounds in red wine may have antioxidant effects that help relax the blood vessels, he added.
"Although there was a slight increase in blood pressure," Sacco noted, "there was no change in other vascular functional assessments. There may be other beneficial mechanisms operating that would negate any of the potentially small adverse effects of wine on blood pressure. The beneficial effects of mild-to-moderate alcohol consumption probably outweigh the potential adverse effects of a small increase in blood pressure."
The American Heart Association defines alcohol in moderation as no more than two drinks daily for men no more than one drink per day for women. And it cautions that drinking too much can have adverse cardiovascular effects, including raising the levels of certain blood fats and increasing calorie intake.
To learn more about alcohol, wine and cardiovascular disease visit the American Heart Association.