Effects of low-dose alcohol consumption on postural control with a particular focus on the role of the visual system

There is clear evidence that vision contributes to stabilizing posture and that large quantities of alcohol affect balance. It has, however, not yet been investigated whether and how the consumption of low doses of ethanol affects postural control and the visual system. The purpose of this study was therefore to assess the influence of low-dose alcohol intake on balance. After having performed stability tests in a sober condition, 26 healthy males were instructed to consume 0.32 g of ethanol/kg body weight. At predefined time points, blood samples were collected and stability index scores were calculated using computerized dynamic posturography. Thirty minutes after ethanol intake, blood alcohol levels reached a mean peak of 0.037%. Whereas the ability to maintain balance significantly deteriorated during eyes-open testing, it surprisingly did not decrease during eyes-closed testing. Apparently, the visual system is particularly affected by ethanol and plays a major role in maintaining postural stability.