In June 2013, institute staff drew up a business plan making the case for the industry’s financial support of the study. “Once the data are released into the public domain via publication,” it said, “the industry can use that information to make or bolster whatever arguments and claims they choose.”

It continued, “At that point, the N.I.A.A.A. and the N.I.H. are out of the process.”

If the study failed to find health benefits in moderate drinking but provided no evidence of harm, the results still would be a boon for the beverage makers. The findings would counter a 2014 World Health Organization edict that no level of alcohol consumption is safe because it raises the risk of cancer.

Indeed, on Feb. 26, 2015, Dr. Mukamal and alcohol institute staff weighed in on an email to an industry group, editing it to say that one of the important findings of the study “will be showing that moderate drinking is safe.”

Image Dr. Kenneth Mukamal Credit... Kayana Szymczak for The New York Times

“As we discussed, this will be the first R.C.T., i.e. ‘gold standard’ evidence of this,” they added, “and it is important to answer statements made by W.H.O. and others that ‘no level of alcohol is safe’ with certainty.” (R.C.T. refers to a randomized controlled trial.)

Alcohol, which is classified as a carcinogen, is linked to a slight increase in breast cancer risk at even one drink a day. One of the main criticisms of the alcohol trial from the start was that it was not large enough, and would not last long enough, to detect a rise in cancers, which are slow-growing, among drinkers.

Barry S. Kramer, director of cancer prevention at the National Cancer Institute, who reviewed the trial design as part of the advisory committee’s report, agreed with this assessment. “The trial is set to show the benefit while missing the harm” of alcohol consumption, he wrote.