People who put in long extra hours at work every week are more prone to drink to excess than people who limit their week to the normal 40 or so hours, a study suggests.

Researchers analyzing data covering more than 400,000 workers found those working for at least 49 hours a week were around 13 percent more likely to exhibit "risky alcohol use" than those who worked 35 to 40 hours weekly.

Defined as more than 21 drinks weekly for men and 14 drinks weekly for women, the behavior is deemed risky because it can subject a person to elevated risks of health problems including heart or liver disease, stroke and cancer, the researchers report in the British Medical Journal.

Looking for a link between work hours and alcohol consumption, researchers analyzed the available published studies.

"The meta-analysis supports the longstanding suspicion that among workers are subjected to long working hours, alcohol can seem like a fast acting and effective way to dull work-related aches and pains and smooth the transition between work life and home life," wrote Cassandra Okechukwu of the Harvard School of Public Health in an editorial accompanying the published analysis.

In one survey analyzed in the study, a third of employees reported they had come to work suffering from a hangover, and 15 percent said they had been drunk while at work.

The problem of long work hours and risky drinking habits cuts across socioeconomic lines, the researchers found, pushing both the factory worker and the high-level CEO toward more alcohol consumption if they regularly put in long hours.

However, just having a job -- being employed as opposed to unemployed -- has been associated with reduced rates of alcohol consumption, and also better odds of recovering from alcohol misuse if it does occur, suggesting a delicate balance between work behaviors and drinking behaviors, the researchers emphasize.

"Any exposure associated with avoidable increases in disease or health damaging behavior, or both, warrants careful examination," Okechukwu says. "Indeed these findings could add impetus to further regulation of working hours as a public health intervention."

That might be difficult, the researchers note.

In the European Union, directive encouraging employers to limit working hours to 48 hours are often ignored.

And in the United States, where there are few polices regulating work hours, enacting any laws to do so would prove difficult.

 "I don't want to make policy recommendations," Okechukwu says. "In the U.S., we're not even there yet."