Once is all it takes. At least that’s what a new study from the University of Massachusetts Medical School on binge drinking suggests.
The study published online in PLOS ONE suggests that a single binge drinking event, where blood alcohol concentration rises to 0.08g/dL or above, can bring about an immune response that could potentially impact on the health of an otherwise healthy individual.
In the study, they took 25 healthy individuals (11 men and 14 women) between the age of 21 and 56 and gave them enough alcohol to raise their blood alcohol levels to the National Institute on Alcohol Abuse and Alcoholism defined level of 0.08g/dL. This works out to about 4 drinks for women and 5 drinks for men consumed within the space of around 2 hours, though it depends on body weight.
They then took blood samples every 30 minutes for the first 4 hours and then again at the 24 hour point.
They tested the blood for alcohol content, lipopolysaccharide (LPS) and 16S rDNA. Lipopolysaccharide is a component of Gram-negative bacterial cell walls and is considered a marker for bacterial translocation, which basically means that bacteria crossed the gut membrane, which they shouldn’t normally do. The test for 16S rDNA is a kind of broad spectrum analysis, as this stretch of DNA is present in pretty much all bacteria and would give an idea of other bacteria that had also passed through the gut barrier.
The graphs above (click to enlarge) show the serum (blood) alcohol levels over time (A,B) and the serum endotoxin (the LPS) over time (C,D). Note as well that the levels of both alcohol and endotoxin remained higher in the women than the men for longer.
Previous studies have shown that circulating endotoxin causes a rise in acute phase proteins, which are involved in inflammation. Sure enough, levels of both lipoprotein binding protein and sCD14, which both interact with LPS, increased in the alcohol group while the control remained unchanged. Likewise, the 16s rDNA showed a significant increase in serum DNA levels at the 1, 4 and even 24 hour mark compared with baseline samples from the same individual.
in an in vitro test with the whole blood of the test subjects they added physiologically comparable levels of LPS, i.e. levels that were found in the subjects after drinking and managed to stimulate an inflammatory cytokine response. Inflammatory cytokines, as the name suggests, induce inflammation as part of an immune response.
What was interesting about this study is how so few drinks brought about this effect, whilst the term binge suggests an excessively heavy night out, I think for a great many people 4-5 drinks within 2 hours is fairly common. It would be interesting to see just how little alcohol is required in an average person to bring about detectable levels of endotoxin. And whilst they measured LPS and 16s rDNA to get an idea I would also be interested to see what else makes it through the gut along with the bacteria and what would be the short term and long term effects of these in conjunction with alcohol intake.
The paper can be read for free here