Drinking alcohol has been tied in the past to a higher risk of high blood pressure, but in a new analysis of past studies, researchers found that a drink or two a day seemed to protect even those with hypertension from heart disease and death.
People with high blood pressure who have never been drinkers shouldn't start now based on the evidence from studies like these, said senior author Qi-Qiang He of the School of Public Health/Global Health Institute at Wuhan University in China.
Observational studies only include data on what people do in their lives and what happens to them, and can't say for sure that one action, like drinking alcohol, causes a particular result.
Analysing and comparing drinkers
The new meta-analysis combines the data from nine previous studies involving a total of nearly 400,000 people with high blood pressure. In all of the studies, alcohol consumption, including wine, beer and spirits, was recorded, as were cases of heart disease, stroke, heart failure and death from any cause.
The researchers divided the participants into four groups: occasional or never drinkers, those who drank about 10 grams of ethanol – pure alcohol – per day, and those who drank 20 or 30 grams of ethanol per day.
In the U.S., a five-ounce glass of wine, a 12-ounce bottle of beer and a 1.5-ounce shot of liquor each contain about 14 grams of alcohol.
Overall, He's team found that cardiovascular disease, heart attacks, strokes and other risks went down as alcohol consumption went up, according to the results published in Mayo Clinic Proceedings.
This study included relatively few heavy drinkers, and other studies have found that the heart risk decline disappears for very heavy drinkers or binge drinkers, the authors caution.
Read: Heart disease – the risk factors
For all causes of death, the risk was lowest among those who drank between eight and 10 grams of alcohol per day, and the risk was higher for those who drank more or did not drink at all. Light to moderate drinkers were about 18 percent less likely to die over the course of a study than people who did not drink.
"This was firstly found true in people with normal blood pressure," He told Reuters Health by email.
Alcohol health benefits unclear
In the general population, some studies suggest that alcohol consumption might enhance heart rate variability or keep plaque from building up inside arteries, but the mechanism is still not clear, He said.
If anything, beneficial effects of alcohol should be even more pronounced for people without high blood pressure, said Dr. Franz H. Messerli a cardiology expert at the Icahn School of Medicine at Mount Sinai in New York.
"One to 2 drinks daily is said to be the goldilocks amount of alcohol," Messerli told Reuters Health by email.
But even these small amounts of alcohol have been associated with an increased risk for high blood pressure, he said.
"We don't know whether moderate drinking is truly cardioprotective or if it is merely a marker of a healthy lifestyle," Messerli said.
Moderate alcohol drinkers also tend to be part of the healthiest subset of the social landscape, he said.
Read: Light drinking lowers stroke risk in women
"Non-drinkers are usually older, eat a less healthy diet and exercise less than moderate drinkers," he noted.
Messerli agreed that the study results should not be taken as encouragement for non-drinkers to take up drinking.
Suggesting that people start having a few drinks here and there to reduce their risk of various heart problems may actually lead to binge drinking which increases the risk of stroke, Messerli said.
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Image: Two glasses of red wine from Shutterstock
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