The study, published in Lancet medical journal, combined results from 83 studies conducted in 19 countries, tracking nearly 600,000 people who drank alcohol.
The researchers found a higher risk of stroke, heart failure and other problems in people who drank heavily. That may partly reflect that alcohol can elevate blood pressure and alter cholesterol levels, the study explained.
Its findings indicate that countries, including Canada, have drinking guidelines that are too loose.
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Canada’s Low-Risk Alcohol Drinking Guidelines suggest that women shouldn’t consume more than two drinks a day or 10 a week. Men should limit drinking to three per day and 15 per week.
The guidelines estimate that if all Canadians abide by those markers, alcohol-related deaths in the country would be reduced by roughly 4,600 each year.
The U.S. government currently recommends no more than seven drinks a week for women. The recommendation for men is 14 drinks.
The study estimates that 40-year-old men who drink as much as the current U.S. guidelines can expect to live one to two years less than men who have no more than seven drinks per week.
“What this is saying is, if you’re really concerned about your longevity, don’t have more than a drink a day,” David Jernigan, a Johns Hopkins University alcohol researcher, explained to The Associated Press.
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How accurate is this study?
Like most health studies, this one has its limitations and shortcomings.
This research is not built to make firm conclusions about cause and effect, Vancouver-based registered dietitian Desiree Nielsen explained to Global News.
“As much as they try and account for different variables, we can’t say definitively that having more than seven drinks a week is going to lead to a lower life expectancy for an individual,” she said.
“That’s based on so many factors — their genetic ability to metabolize alcohol, their other overall health and wellness, whether they eat well, exercise, whether they manage their stress.”
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A dietitian’s recommendations
Nielsen explains that because Canada’s daily recommendations are similar to those suggested by the study, there’s no harm in continuing to follow them. But those concerned about their intake should consult a doctor or dietitian.
“I feel that people should speak with their health-care professional to determine their own individual risk factors,” Nielsen said, adding that not all research applies to everyone.
The dietitian recommends that Canadians try to go a few days or weeks without alcohol if they are looking to feel “more energetic.” She adds that Canada’s recommendations are based on daily consumption, so the weekly amount shouldn’t all be consumed at once.
“From a health perspective, what you’re not supposed to do is save up all your drinks for the weekend,” she said. “For better health, keep your daily drinking moderate.”
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How do you balance all the studies?
Several studies have linked excessive alcohol consumption to increased risks of health problems in the past, but some studies have also noted some benefits to drinking moderately.
Nielsen explains that nutritional research is about slowly building consensus over an issue through several studies — that takes time.
“One study comes out saying one thing and other researchers try to replicate those results, and they may or may not. It takes time for a body of evidence to accumulate,” she explained.
“It’s really important for us not to kind of flip-flop or worry about changing our entire lives based on one study.”
— With files from The Associated Press