In 1983, when AIDS was beginning to run rampant and was little understood, a lifetime ban on blood donations by any man who'd had sex with another man since 1977 made sense. The ban would help prevent transmission of the virus that causes AIDS. Today, it no longer makes sense. It's time to end the lifetime ban.

A Food and Drug Administration advisory panel will begin a two-day meeting Tuesdayon whether to change the ban. An advisory group for the Department of Health and Human Services suggested the outright ban should be changed to a 12-month deferral for any man who has had sex with another man, and the FDA will consider that recommendation. It would be an improvement, but it still doesn't address whether such donations threaten the safety of our blood supply.

Questionnaires filled out by blood donors ask men whether they've had sex with another man, but not whether they are monogamous or use condoms. No one, however, is asked whether he or she has had unprotected heterosexual sex in the past decade or the past day. That's important because 28 percent of AIDS infections are caused by heterosexual sex, and a quarter of victims are women.

The blood supply is quite safe, and that safety is not entrusted to the hope that people will be honest in filling out pre-donation questionnaires. Every pint donated is tested thoroughly, and the only danger is in the period, at most three weeks, when a donor could have contracted AIDS but it cannot yet be detected in his or her blood. To the extent that this is a concern, it's a concern with blood from any donor.

The rules should change both because more donors are needed and because the lifetime ban is based on homophobia rather than science or risk. A 2010 study found that if the ban were changed to a 12-month deferral, about 53,000 more men would begin donating. A full lifting of the ban could increase blood donations by 2 to 4 percent.

The American Medical Association, America's Blood Centers and the American Red Cross are just a few of the organizations supporting a change. As a first step, a 12-month deferral is an improvement. But in the long run, the donation deferrals ought to be based on whether donors practice unsafe sex, and not whether they're gay.