Estudios científicos

Isolated and joint effects of tobacco and alcohol consumption on risk of Alzheimer's disease


The roles of smoking and alcohol on the development of Alzheimer's disease (AD) remain unclear. We performed a case-control study on the effects of both exposures before the age of onset of the disease in the cases (and same reference age for their age-matched controls) on disease risk. Interviews were conducted with population controls (n=246) and relatives of cases (n=176) identified through local Alzheimer's Disease Associations. Logistic regression models were built adjusting by gender, age, residence, education, economic situation, employment, and history of dementia in close relatives. Risk of AD was unaffected by any measure of tobacco consumption. Alcohol consumers showed a lower risk of AD than never consumers (adjusted odds ratio, aOR = 0.53, 95% CI 0.32, 0.88), with differences by gender (women aOR =0.48, 95% CI 0.27, 0.84; men aOR=0.80, 95% CI 0.23, 2.80). Mean daily total consumption of alcohol and time consuming alcohol showed increasingly protective dose-response relationships in women. Lower AD risk was observed in alcohol drinkers of both genders who never smoked (aOR= 0.37, 95% CI 0.21, 0.65). All these associations were independent of the presence of apolipoprotein E4 allele(s) in the cases. Although the sample was small for some analyses addressing these interactions, our results suggest a protective effect of alcohol consumption, mostly in non-smokers, and the need to consider interactions between tobacco and alcohol consumption, as well as interactions with gender, when assessing the effects of smoking and/or drinking on the risk of AD.

Comentarios divulgativos:

El tabaquismo y el alcohol en el desarrollo de la enfermedad de Alzheimer (EA) siguen sin estar claros. Se realizó un estudio de caso-control sobre los efectos de ambas exposiciones antes de la aparición de la enfermedad. Se realizaron entrevistas con los individuos control de la población (n = 246) y familiares (n = 176). El riesgo de AD no fue afectado por el consumo de tabaco. Los consumidores de alcohol mostraron un menor riesgo de padecer Alzheimer los abstemios. Aunque la muestra era pequeña para hacer frente a algunos análisis de estas interacciones, nuestros resultados sugieren un efecto protector del consumo de alcohol, sobre todo en los no fumadores y la necesidad de considerar las interacciones entre el tabaco y el consumo de alcohol, así como las interacciones con el sexo, al evaluar los efectos de fumar y / o beber en el riesgo de padecer Alzheimer.