The Older Brain on Drugs: Substances That May Cause Cognitive Impairment

Alcohol Use and Cognitive Impairment Among Older Adults

Alcohol is the most commonly used recreational drug in older adults. Among 40,556 U.S. adults age 60 years and older, 52.8% of men and 37.2% of women were current drinkers.^[4] Drinking guidelines suggest that a safe amount of alcohol intake for individuals over age 65 would be no more than seven drinks per week and no more than four at one sitting for both men and women (see Table 1 ).^[5]

Cognitive function in adults has been shown to have a J-shaped relationship with level of alcohol intake (see Figure 1). Several studies have shown that light to moderate drinkers have generally superior cognitive function than abstainers and heavy drinkers.^[6,7,8,9] Particularly, the cardiovascular benefits of flavonoids in red wine have been hypothesized to preserve cognitive function, although protective socioeconomic factors may also be of importance in the wine-drinking population groups studied.^[10,11] In contrast, moderate to heavy drinking has been shown to increase risk of cognitive impairment, particularly in older adults.^[12]

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Figure 1.

Cognitive Impairment and Chronic Daily Alcohol Use Patterns

Alcohol use poses an additional risk to older adults with illness in terms of adverse interactions between alcohol and both prescribed and OTC medications, especially psychoactive medications such as benzodiazepines, anticonvulsants, and antidepressants.^[13] In a survey of 83,321 older outpatients, 19% of those taking prescription medications known to adversely interact with alcohol reported concomitant alcohol use.^[14]

The acute cognitive effects of alcohol use are well known, but less well studied are the long-term effects of chronic alcohol use on brain function, particularly among older individuals.^[13] Alcohol intoxication can cause cognitive effects such as disinhibition, ataxia, and short-term memory impairment.^[15] Historically, the Wernicke-Korsakoff syndrome was considered to entirely explain the dangers of chronic alcohol overuse, but current data indicate that alcohol-induced dementia may be linked to other causes as well.^[16]

Geriatrics and Aging. 2008;11(5):284-289. © 2008  1453987 Ontario, Ltd.