Booze inhibits more than just your judgement: it impairs your immune system’s ability to fight off pathogens, according to a study published last week in the journal BMC Immunology. Researchers exposed human monocytes, a type of white blood cell vital for a functioning immune system, to an amount of alcohol equivalent to a blood alcohol concentration of 0.1 (around the legal level in most states). Compared to booze-free cells, monocytes exposed to both short- and long-term levels of alcohol produced significantly less type 1 interferons, chemicals the help recruit immune cells to stage an antiviral response (and also have anti-tumor activity). Excessive drinking has long been thought to interfere with the body’s ability to fight disease, and boozing is an important risk factor for hepatitis C and barrier to treatment in HIV. But not much had been known about the mechanisms behind the effect.

But the findings of the study weren’t all so cut and dry. For instance, cells bathed in alcohol for only a few hours showed a notable decrease in the production of tumor necrosis factor-alpha, an chemical that’s helpful in fighting pathogens but is also associated with inflammatory-related chronic conditions like rheumatoid arthritis and inflammatory bowel syndrome. Monocytes exposed to near constant levels of alcohol for a week, however, showed the opposite: a significant increase in TNF-a. More research will be required to pin down the health-related effects of these chemical fluctuations.

Reference: Maoyin Pang, Shashi Bala, Karen Kodys, Donna Catalano and Gyongyi Szabo. Inhibition of TLR8- and TLR4-induced Type I IFN induction by alcohol is different from its effects on inflammatory cytokine production in monocytes. BMC Immunology, 2011. DOI: 10.1186/1471-2172-12-55

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