Age-related differences in the effects of ethanol on performance and behaviour in healthy men.

Four age groups of healthy men; 20-29, 30-39, 40-49, and 50-59 years (N = 12 per group), drank 0.68 g of ethanol/kg body weight as neat whisky in the morning after an overnight (10 hr) fast. The concentration of ethanol in fingertip blood, various signs and symptoms of intoxication, body-sway (open and closed eyes), hand-tremor, positional alcohol nystagmus (PAN) and roving ocular movements (ROM) were measured at 30-60 min intervals after drinking. Body-sway and hand-tremor increased with advancing age in tests made before the ingestion of alcohol (P < 0.05). After drinking alcohol, body-sway and hand-tremor increased in the four age groups (P < 0.05), being most pronounced at or near the time of reaching the peak blood alcohol concentration (BAC). The initial impairment subsided when the post-absorptive phase of ethanol kinetics commenced. At 60 min post-drinking, body-sway was most pronounced in men aged 40-49 years when their eyes were closed (P < 0.05). Otherwise, age-related differences in alcohol impairment in the other age groups were not statistically significant. Positional alcohol nystagmus (PAN) developed mainly during the acute phase of intoxication, decreasing in intensity as the time after drinking progressed. Roving ocular movements (ROM) were most apparent during the post-absorptive phase (120-420 min). We conclude that the acute effects of a moderate dose of ethanol on sensory and motor functions are not much different in men aged between 20 and 59 years.