Moderate Alcohol Use May Slow Progression to Dementia

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May 21, 2007 — A single alcoholic drink every day or less may significantly delay progression to dementia in individuals with mild cognitive impairment (MCI), a study published in the May 22, 2007, issue of Neurology suggests.

Investigators at the University of Bari in Italy found patients with MCI who had up to 1 drink per day — mostly wine — developed dementia at an 85% slower rate than their abstemious counterparts.

According to study authors Vincenzo Solfrizzi, MD, PhD, and Francesco Panza, MD, PhD, whereas many studies have assessed alcohol consumption and cognitive function in the elderly population, this is the first to examine how alcohol consumption affects the rate of progression from MCI to dementia.

Lifetime Alcohol Exposure
Study subjects were participants in the Italian Longitudinal Study on Aging (ILSA) and included 1445 individuals aged 65 to 84 years who were cognitively healthy at study outset and evaluated for MCI risk factors. Of these subjects, a group of 121 who subsequently developed the condition were evaluated for progression to dementia.

Participants underwent clinical and laboratory evaluations that included screenings for coronary artery disease, hypertension, type 2 diabetes, and stroke.

In addition, all subjects completed a questionnaire that gathered information on demographic characteristics, body weight and weight history, smoking habits, and current medication use. In addition, blood samples were taken to determine serum total cholesterol levels.

Study subjects underwent the Mini-Mental State Examination to evaluate global cognitive function. Episodic memory was tested with the Babcock Story Recall Test, and the Activities of Daily Living scale was used to determine functional status.

Beer or wine consumption was assessed according to daily consumption in the previous year and quantified according to 3 categories: half a glass (0.125 L), 2 glasses (0.25 L), and 4 glasses (0.50 L).

Investigators collected data on "superalcoholic" consumption by asking participants how often they consumed "shots" of spirits in the previous year. A single shot was considered equivalent to 1 standard drink. In addition, investigators calculated subjects' lifetime alcohol exposures.

Among the overall study group, wine accounted for 75% of alcohol intake; beer, 2%; and superalcoholic beverages, 22.1%. In addition, alcohol consumption was higher among men than women.

No Link to Increased MCI Risk
Adjusted analyses showed there was no association between alcohol consumption and increased MCI risk. However, based on previous research, including the Rotterdam Study, which showed light to moderate alcohol consumption was associated with a reduced risk for dementia, the authors speculate that a longer follow-up period in the current study likely would have revealed a similarly positive relationship between moderate alcohol consumption and MCI risk.

At a median follow-up of 3.5 years, 14 subjects with MCI developed dementia. Adjusted analysis showed that light drinking (0.1 - 1 drink/day) was associated with a significantly lower rate of progression to dementia compared with no alcohol consumption (hazard ratio , 0.15; 95% CI, 0.03 - 0.77).

Furthermore, compared with alcohol derived from other sources, alcohol derived from wine was also significantly associated with a lower rate of progression to dementia.

The authors also report there was no significant association between higher levels of drinking, classified as 1 or more drinks per day, and the rate of progression to dementia in patients with MCI compared with nondrinkers.

The mechanism by which low to moderate alcohol consumption may protect against progression of MCI to dementia is not clear. However, the authors speculate it may be through the effects of alcohol consumption on the cerebral vasculature. They point out that some evidence suggests moderate alcohol consumption may be protective against ischemic stroke and vascular dementia via a reduction in vascular risk factors.

This study was supported by ILSA and the Associazione per la Formazione e la Ricerca in Geriatria.

Neurology. 2007;68:1790-1799.


Source: http://www.medscape.com/viewarticle/556984?src=mp