I recently read an article about the effects of alcohol on chronobiology. In this article, there was one line that talked about how flight attendants are at increased risk for cancer and alcoholism because their schedules mess with their daily rhythm. I decided to look around at the literature on this topic. A meta-analysis of flight attendants did indeed show an increased risk of death related to alcoholism, but only for female flight attendants. However, a study of Swedish flight attendants found the opposite effect, males, but not females, had an increased risk of alcohol-related death. The authors of the meta-analysis sided with the first finding and hypothesized that the increase in alcohol-related death may be related to disruption of their circadian rhythm. This was consistent with the other article that I had read on chronobiology. However, the meta-analysis adds a second hypothesis that alcohol may be used as a sleep aid in flight attendants, thereby resulting in increased alcohol dependency.
This is an interesting notion and actually suggests something pretty different from the evidence suggesting that biologically flight attendants are more likely to develop alcohol dependency. Suggesting that they use alcohol to help them to sleep is an interesting interpretation of the data. It’s true that flight attendants probably have issues falling asleep sometimes when their schedule is affected by jet lag and night shifts. But, are flight attendants abusing alcohol in general because they are more prone to alcoholism or do are they more prone to alcoholism because they resort to drastic measures to fall asleep? In addition to an increased risk for alcoholism, flight attendants are at an increased risk for cancer. Disruptions in light/dark cycles can affect the suprachiasmatic nucleus (the major time-keeper of the body), leading to changes in internal clocks. One such internal clock that can be affected is natural killer (NK) cells. As you can imagine, affecting the ability of the body’s NK cells could lead to increased risk for cancer.