Alcohol trial collapses

Pounding one alcoholic drink after another is bad for your health. Things get murkier when it comes to ‘‘moderate’’ drinking. What’s the limit? Can a health-conscious person serenely order a second round?

The alcohol industry has long embraced the notion that alcohol in moderation won’t harm you and indeed is good for you.

Many studies have shown that people who drink any kind of alcohol in moderation have lower rates of heart disease than people who abstain or who drink heavily. But the evidence is stubbornly ambiguous.

As reported in the Lancet earlier this year, a survey of the health of nearly 600,000 drinkers in 19 countries found that very moderate drinking – about one drink a day – lowers the rate of certain kinds of heart attacks but raises the risk of other cardiovascular problems. There’s no net benefit in life expectancy, the study found.

Alcohol research is notoriously bedevilled by ‘‘confounding effects’’. The most obvious is that the non-drinking population includes people who can’t drink because of health problems. Meanwhile, healthy people are free to drink.

‘‘People who drink moderately are healthier than people who don’t drink. But that doesn’t mean the drinking caused them to be healthier,’’ says University of Minnesota social epidemiologist Toben Nelson.

This issue was supposed to be clarified by the 10-year, US$100 million Moderate Alcohol and Cardiovascular Health trial, which started to enrol participants earlier this year.

It would have looked at 7800 people on multiple continents, all older than 50 and at risk of heart disease. Teetotallers and heavy drinkers would have been ineligible.

The volunteers would have been randomly assigned into two groups, one that consumed a single drink every day for six years and one that abstained from alcohol every day for six years.

The goal was to see whether drinking a little bit lowered the rate of heart disease.

But NIH terminated the project in June, saying the trial’s results would not be credible. The majority of the funding for the study was to have come from the alcohol industry, funnelled through a nonprofit foundation.

The foundation was supposed to be a firewall between industry and researchers, but an investigation found that researchers had engaged in extensive communication with industry before the trial was approved.

The NIH investigation also found flaws with the study design. It didn’t have enough participants, and it didn’t last long enough, said Michael Lauer, deputy director for extramural research at the National Institutes of Health. Cancer, for example, can take years to become detectable.

The study also did not include women at high risk of getting breast cancer. That’s because research has shown that any alcohol consumption, even a drink a day, increases breast cancer risk. But the decision not to include such women also could have skewed the results of the study.

The NIH report said the trial ‘‘could show benefits while missing the harms’’.

Emails published by the NIH suggest that backers of the trial expected to show that moderate drinking has a health benefit. Researchers are supposed to have what is known as ‘‘equipoise’’ going into a trial. That means ‘‘you are approaching a question with a completely neutral attitude’’, Lauer said.

‘‘This is not open-ended research. This is marketing research,’’ said Marion Nestle, a professor emerita of food science at New York University.

The trial’s principal investigator, Kenneth Mukamal, an epidemiologist at Harvard, did not respond to an interview request. But he released a statement saying he stood ‘‘forcefully behind the scientific integrity’’ of the trial.

The volunteers would have been randomly assigned into two groups, one that consumed a single drink every day for six years and one that abstained.