Calculating 5,735 total deaths over an average follow-up period of nearly 10 years per person, and crunching the numbers, the researchers discovered that compared with lifelong abstinence from alcohol, drinking at hazardous levels was linked to a heightened risk of death from all causes. Hazardous drinking is 8 to 20 US standard drinks for women and 21 to 49 for men, as defined by the researchers.
And, the more alcohol units drunk each week, the greater the risk of death from cancer -- even when a person drank less than the recommended maximum per week. The recommended weekly maximum, as defined, is 8 standard drinks for women and 12 for men.
However, all the numbers changed when Stamatakis and his colleagues factored exercise into their equations.
Specifically, they looked at the impact of the recommended amount of weekly exercise for adults, which is 150 minutes of moderate aerobic activity. That includes brisk walking, swimming and mowing the lawn, according to the US Department of Health and Human Services
. HHS also advises strength training for all major muscle groups at least twice a week.
Exercising the recommended amount "appeared to wipe off completely" the inflated risk of cancer death resulting from alcohol, said Stamatakis. Similar physical activity also offset the increased risk of all-cause mortality linked to drinking. Exercising more provided slightly better results.
One thing exercise did not moderate, though, was death risk among those who drank at harmful levels --- "over 20 US standard drinks per week for women and over 28 US standard drinks for men," said Stamatakis.
The results also showed that occasional drinking -- drinking alcohol sometimes but not every week -- was associated with a reduced risk of death from cardiovascular disease among physically active people.
"I would have expected that the moderating effect of physical activity would be more pronounced for cardiovascular disease than for cancer mortality risk," noted Stamatakis.
Because it is an observational study, the results only "suggest a relationship" between exercise, drinking and health benefits, said Michael Hyek, senior director of OhioHealth's McConnell Heart Health Center. The researchers relied on self-reported accounts of lifestyle factors, which may or may not be reliable, and they didn't study eating habits or medication use or other factors that might play a role in how exercise plays into health when drinking is involved, noted Hyek, who was not involved in the research.
Still, Stamatakis believes his study gives "yet another reason" to promote physical activity and make the environment more conducive to physical activity and generally empower people to sit less
. "How many more reasons do we need for physical activity to be taken seriously?" he asked.
With this, Hyek has no argument. The benefits of moderate intensity exercise include stress reduction, the prevention, control and reversal of diabetes, and a positive impact on blood pressure, body weight and depression, he explained.
"I know very few chronic medical conditions that exercise will not have a positive impact on," said Hyek. "It's a good thing regardless of what your circumstances are."