Nonalcoholic Red Wine Might Help Lower Blood Pressure
THURSDAY Sept. 6, 2012 -- While some say it's not as flavorful as the real thing, drinking nonalcoholic red wine might help lower blood pressure in men at high risk for heart disease.
Middle-aged and older men who drank moderate amounts of de-alcoholized red wine daily for four weeks had drops in systolic (top number) and diastolic (bottom number) blood pressure, according to a small new study by Spanish researchers.
"In the context of a healthy diet and a healthy lifestyle, daily consumption of de-alcoholized red wine can help prevent hypertension," said study author Gemma Chiva-Blanch, at the department of internal medicine at the Hospital Clinic of Barcelona.
The study was published online Sept. 6 in the journal Circulation Research.
The nonalcoholic wine drinkers also showed increased levels of nitric oxide -- a molecule in the blood that previous studies have linked with improving blood-vessel health and lowering blood pressure.
While some studies have shown that moderate alcohol consumption lowers the risk of cardiovascular disease, others suggest red wine in particular is beneficial, possibly because it's rich in polyphenols, which are antioxidants linked with lowering blood pressure.
Though it is well-documented that binge and heavy drinking are bad for blood pressure, the effect of moderate alcohol consumption has been unclear, the authors said.
The study "compares the effects of red wine and a nonalcoholic red wine with identical composition -- except for the alcohol content -- in the same subjects," Chiva-Blanch said. The scientists also analyzed gin's effect.
Participants were 67 men aged 55 or older who either had type 2 diabetes or more than three risk factors for cardiovascular disease, such as smoking, high blood pressure, high cholesterol, being overweight or obese, or a family history of premature coronary heart disease.
After an initial two-week abstinence period, they were separated into three groups assigned to a different beverage: three ounces of gin, 10 ounces of red wine or 10 ounces of nonalcoholic red wine. After four weeks of daily consumption, the men rotated to a new beverage, and so forth with the third beverage.
After each rotation, researchers measured blood pressure, heart rate, and nitric oxide levels in the blood, and then a statistical analysis was performed.
They found a reduction in blood pressure after the men drank red wine but it was not statistically significant, and gin consumption did not reduce blood pressure. However, after the men drank the alcohol-free red wine, blood pressure levels dropped significantly. Systolic blood pressure levels decreased by about 6 mmHg, and diastolic blood pressure levels dropped by 2 mmHg.
In theory, the authors said those changes could reduce the risk of heart disease by 14 percent and cut the chance of a stroke almost 20 percent.
Mayo Clinic cardiologist Dr. Sharonne Hayes said the new research is "a hypothesis-generating study" that needs more investigation.
"Gin, Mai Tais, wine, beer -- a lot of studies would suggest that when it all comes down to it, it's the alcohol. But then there was a rise of interest in polyphenols -- resveratrol in red wine and grapes. But most of those studies showed that giving polyphenols by themselves showed no benefit or change. So the thinking has circled back to maybe it's just the alcohol," Hayes said.
She noted that the study was small, with no control group. She said it's known that blood pressure goes up when alcohol is withdrawn, even if the person is not a heavy drinker, and she speculated that the two-week "wash-out" period before the study could have influenced the results.
"So I have problems with the methods in this study. It's intriguing; it's suggestive, but not definitive. It needs to be explored. The methods may not be enough to allow us to extrapolate this to say that alcohol or de-alcoholized wine is better for you," Hayes said, adding that lowering blood pressure for a few weeks also doesn't indicate that cardiovascular risk will decrease long-term. "But to be fair, the authors say this, too," she added.
American Heart Association president Donna Arnett said the research is interesting because it looks at a specific type of drinking.
"This is that in-between phase of solidly moderate drinking. So in that way it offers something new," said Arnett, who is also an epidemiologist at the University of Alabama at Birmingham.
While the research holds promise, Arnett said she is concerned about the methodology. She noted, "They didn't have a 'wash-out' period between the interventions and that's important because it lets people stabilize and return to their blood pressure value before the intervention. It is possible that there is a carryover effect from one of the drinking periods to the next. That had me concerned from a study-design perspective."
Hayes said it would be intriguing to study other groups: a mixed-sex group, a younger group including patients with lower risk factors and women in perimenopause.
"High blood pressure is an important issue in women. And we now know there are sex differences in responses to alcohol intake," Hayes said.
The authors of an editorial that accompanies the study said there is growing evidence that the chemicals in red wine confer health benefits beyond alcohol, and the new research adds to it.
"However, numerous issues need to be resolved in order to clearly assess the preventive or therapeutic potential of red wine constituents," wrote Huige Li and Ulrich Forstermann, with the department of pharmacology at Johannes Gutenberg University Medical Center in Mainz, Germany.
Chiva-Blanch noted that while this study showed de-alcoholized red wine seems to have "exclusive" effects in blood pressure, "when talking about other cardiovascular risk factors such as low HDL cholesterol, de-alcoholized red wine has no effects."
She also pointed out that other research shows red wine consumption has protective effects in atherosclerosis and cholesterol.
Would people be willing to swap their cabernets and Chiantis for an alcohol-free version, if the health benefits were confirmed?
Mayo Clinic's Hayes isn't sure. She said nonalcoholic red wine lacks the body and fullness of real red wine.
"People drink for other reasons that are complex and personal -- whether it's how you feel or it's about the complex taste. If we found that drinking de-alcoholized red wine was truly therapeutic, that it actually lowered blood pressure, I think people would probably take it as medicine," Hayes said.
Chiva-Blanch said, "It depends on the health awareness of the population. People who care about their health would be willing to switch to nonalcoholic drinks, while others would not."
Visit the U.S. Centers for Disease Control and Prevention to learn more about alcohol and public health.
Posted: September 2012