WEDNESDAY, Aug. 22, 2018 (HealthDay News) -- Could a habit of consistent "moderate" drinking -- a little more than two drinks a day for men, and slightly less for women -- actually help your heart?
That's the suggestion from a new study of more than 35,000 British and French adults whose health and drinking habits were tracked for a decade. The investigators found that consistent, moderate tippling was tied to better heart health than abstaining from alcohol altogether.
Still, researchers from University College London (UCL) cautioned that many other lifestyle factors might explain the findings, and they found only an association -- not a definite cause-and-effect relationship.
One U.S. expert who wasn't involved in the study echoed that sentiment.
"There is a suggestion that small, consistent intake of alcohol may have a protective effect on the development of coronary heart disease. But whether the beneficial effects are attributed to the alcohol or overall healthy lifestyle patterns -- such as communal eating, physical activity or social support -- remains unclear," said Dr. Eugenia Gianos. She directs women's heart health at Lenox Hill Hospital in New York City.
As reported Aug. 22 in BMC Medicine, a team led by UCL's Dr. Dara O'Neill analyzed data from six studies involving more than 35,000 adults in the United Kingdom and France, over a 10-year period.
During that time, nearly 5 percent developed heart disease, and 0.9 percent of those people died from heart problems, the findings showed.
When it came to drinking habits, consistency appeared to be the key to heart risk, the researchers said.
Those who consistently drank moderate amounts of alcohol had a lower risk of heart disease than those whose drinking levels ebbed and flowed over time. Consistent moderate drinkers also had a lower risk compared to people who'd drank in the past but had since given it up, and those who never drank, O'Neill's group found.
Age and gender appeared to be factors, too.
"When we split the sample by age, we found that the elevated risk of [heart disease] among 'inconsistently' moderate drinkers was observed in participants aged over 55, but not those aged below," O'Neill said in a journal news release.
"It may be that the older group experienced lifestyle changes, such as retirement, which are known to co-occur with increases in alcohol intake and that these could have played a role in the differing risk," O'Neill added.
Also, among the long-time non-drinkers, abstention appeared to raise heart risks for women, but not for men, the study found.
And in one unexpected finding, consistent heavy drinkers were found to have the lowest incidence of a cardiovascular event -- crises such as a heart attack or stroke.
However, the researchers cautioned that this could be a statistical fluke.
Because surveys often fail to capture enough heavy drinkers to achieve statistical significance, "interpretation of the absence of [an unhealthy] effect among heavy drinkers in the current study should be done very cautiously, particularly in light of the known wider health impact of heavy alcohol intake levels," O'Neill said.
For her part, Gianos stressed that the jury is still out on the effect of even moderate drinking on a person's overall health.
For example, she said, "there are also studies showing increased breast cancer risk with alcohol intake and well-established negative effects of heavy alcohol intake, so we still cannot recommend that people who do not drink should begin to do so for the potential protective effects."
Dr. Cathy Grines directs cardiology at North Shore University Hospital in Manhasset, N.Y. She noted that "it has long been shown that moderate alcohol consumption (such as two glasses of wine for men, one for women) have beneficial effects on the heart. For example, individuals who live in France have a rich, butter-laden diet and higher rates of smoking, yet have lower risk of cardiovascular disease, which is proportional to [their] moderate alcohol drinking."
Theories abound as to the connection, Grines said, but the "reduction in the risk of cardiovascular disease is thought to be due, in part, to beneficial effects of alcohol on cholesterol and thinning the blood."
What's new about O'Neill's study is the emphasis on drinking consistency, she added.
"The protective effects of alcohol went away if one did not drink the same amounts regularly," Grines noted. "Many of us believe that we are 'detoxing' and helping ourselves by having periods of abstinence, but that [may be] a false assumption."
The U.S. Centers for Disease Control and Prevention offers heart disease prevention tips.