麻豆传媒

That glass of red wine with dinner probably won't protect you from an early grave, according to an updated meta-analysis on the longevity impact of alcohol.

Compared with never-drinkers, "low-volume" drinkers who kept daily alcohol intake under two drinks (1.3 to 24 g ethanol) each day didn't see any reduction in the risk for death from any cause (relative risk 0.93, 95% CI 0.85-1.01), found researchers led by Jinhui Zhao, PhD, a scientist and senior data analyst at the University of Victoria's Canadian Institute for Substance Use Research, in British Columbia.

A typical 12-oz beer or 5-oz glass of wine in the U.S. contains about 14 g of pure ethanol.

"Medium-volume" consumers who threw back about three drinks per day (25 to 44 g of ethanol) also didn't see any significant protection or harm from their habits when compared with nondrinkers (RR 1.05, 95% CI 0.96-1.14), the group reported in .

"Our study gives strong grounds for scepticism regarding the comforting idea that alcohol in moderation is good for health," co-author Tim Stockwell, PhD, also of the University of Victoria, told 麻豆传媒 by email, adding that there continues to be controversy on this topic.

"The idea that alcohol is beneficial in moderation has a profound influence on global, national, and regional estimates of alcohol's impact on health and safety," he explained. "It also has profound implications for guidelines prepared by health authorities for alcohol drinkers wishing to reduce health risks."

While low or moderate alcohol intake didn't appear to increase the risk for death in this study, it was consistent with others in suggesting there also weren't any actual health benefits, said Timothy K. Brennan, MD, MPH, chief of clinical services for the Addiction Institute of Mount Sinai in New York City.

"No alcohol is best," he told 麻豆传媒. "Drinking less is always better for our bodies than drinking more."

"It is clear from this study -- and many others -- that heavy drinking not only increases the likelihood of developing a variety of diseases, but it also increases the risk of dying," noted Brennan, who wasn't involved with the study.

Drinking any more than about three drinks in a typical day started to catch up with folks, the researchers found.

People considered "high volume" drinkers in the study -- this included those who drank anywhere between 45 to 64 g of ethanol each day -- saw a 19% higher relative risk for all-cause mortality (RR 1.19, 95% CI 1.07-1.32).

Following an upward pattern, consumers of more than about 4.5 drinks a day (65 g ethanol) saw the highest risk for an early death, with a 35% higher risk for all-cause mortality compared with lifetime abstainers from booze (RR 1.35, 95% CI 1.23-1.47).

Even when compared with just the occasional drinker -- those who keep it under one drink a week -- high and higher-volume drinkers still saw significantly higher risks for death.

But the "safe" threshold for drinking was lower for women.

When just looking at data on females, even medium-volume drinking wasn't without health risks. Women drinking around two to three servings (25 to 44 g of ethanol) daily saw a 21% higher risk of death from any cause compared with women who completely abstained from alcohol (RR 1.21, 95% CI 1.08-1.36). On top of that, high- and higher-volume female drinkers had a 34% and 61% increased risk for death, respectively.

Overall, Brennan advised that men limit their alcohol intake to two drinks per day or less and women should limit their intake to one drink per day or less.

While all ages generally saw the same pattern -- higher all-cause mortality linked with more than three drinks per day -- the magnitude of this risk was more pronounced for those under age 56. Because of this, the researchers suggested future studies home in on this younger age group.

The fully adjusted models took into consideration factors like abstainer biases, age, sex, study country, drinking patterns, lifestyle factors, and more.

Data on over 4.8 million individuals and 425,564 deaths were compiled as part of this updated systematic review and meta-analysis, which included 107 studies in more than 20 countries published from 1980 to 2021.

These findings support those from two prior meta-analyses conducted by the same research group. In 2016, suggesting that low-volume daily drinking might help stave off death from any cause, but this risk reduction disappeared after adjustment for abstainer biases and quality-related study characteristics. A year later, the researchers found mixed results when looking at the .

As the third installment in their series, the current meta-analysis was able to incorporate the last few years of new data. "Our study summarized results from every published study on the topic canvassing the life experiences of nearly 5 million individuals," said Stockwell.

"Our focus is on the validity of the hypothesis that alcohol in moderation is beneficial for health," he added.

However, the group said that the available research on the topic is still riddled with drinker misclassification errors, as 86 of the studies included former drinkers or occasional drinkers in the abstainer group used for comparison. Only 21 of these studies were actually free of abstainer biases.

"The importance of controlling for former drinker bias/misclassification is highlighted once more in our results which are consistent with prior studies showing that former drinkers have significantly elevated mortality risks compared with lifetime abstainers," Zhao's group said.

For example, they found former drinkers carried a 26% higher risk for death from any cause than lifelong abstainers (RR 1.26, 95% CI 1.12-1.42). This lends support to the notion of "sick quitters," or former drinkers who quit due to health reasons.

Stockwell also pointed out how studies of older people are the most biased toward finding health benefits from moderate drinking.

"One of the reasons for this is that older people who continue to drink tend to be particularly robust and healthy, while those who stop drinking often do so because they have become unwell," he explained.

"Being able to continue drinking at an older age is a sign -- not a cause -- of good health," said Stockwell.

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