Given how often we hear reports on the health benefits of drinking moderate amounts of alcohol — including wine and beer — I think people may be surprised to hear about a spate of studies showing that even what many would consider moderate alcohol intake (two to three glasses of wine a day, for instance) may raise your susceptibility to infectious diseases while also slowing your body’s ability to repair a bone fracture or heal a wound.

Alcohol Impairment

These findings and others were reported at a recent conference of the Alcohol and Immunology Research Interest Group at Loyola University Medical Center near Chicago. I got an early report on the event from Elizabeth J. Kovacs, PhD, director of the University’s Alcohol Research Program. According to Dr. Kovacs, the findings center on one key fact of biology — alcohol impairs the ability of most immune cells to do their jobs.

Dr. Kovacs explained that all immune cells are produced in the bone marrow — some then get sent to other parts of the body. So it’s not entirely surprising to learn that one group of findings centers on bone health. One of the ongoing studies (by Dr. Kovac’s colleague John J. Callaci, PhD) reveals that excessive alcohol consumption during adolescence may lead to brittle bones later in life, while another study suggests that this also may be true in adults, as alcohol slows fracture repair.

Another form of immune damage:Since specific immune cells “remember” specific viruses, they’re involved in giving us long-term immunity against flu and other diseases. Dr. Kovacs said that research has now demonstrated that moderate drinking increases susceptibility to infection and disease due to weakened immune cells. Other studies link alcohol intake to slow healing, not only from accidental injuries but also surgical procedures.

How Much Is Too Much?

You probably want to know how muchalcohol it takes to cause these problems, but there’s no clear and reliable answer to that question as yet. According to Dr. Kovacs, the National Institutes of Health recommends that women should drink no more than seven drinks a week and men no more than 14 (barring any binge drinking, of course). However, she said, even that amount may not be safe for a person who is taking medication… elderly… ill with hepatitis or diabetes or any of a long list of other sicknesses… or for a woman who is pregnant or for a person who almost never drinks alcohol.

I asked Dr. Kovacs whether there’s anything one can do to reverse the effects alcohol may already have wrought to his/her health. She explained that when you stop drinking, white blood cells that help the body heal itself may recover in a few weeks. But, she said, regarding the damage drinking does to the ability of immune cells to quickly respond to pathogens, the time line is quite different — it can take many months.

I had one more question for Dr. Kovacs — is there any way to fortify the immune system against the effects of alcohol? Not really, she said — noting that while a good diet, exercise and adequate sleep are helpful in supporting your immune system, “even these aren’t a bulwark against alcohol.” Bottom line — let’s take it easy on alcohol.