COFFEE AND ALZHEIMER’S DISEASE
Interest in the possibility that the consumption of coffee or caffeine might protect against the development of Alzheimer’s disease is growing. A retrospective Portuguese study of 54 cases of Alzheimer’s disease and 54 controls recently demonstrated that caffeine intake over the preceding 20 years was inversely and significantly associated with risk of Alzheimer’s disease (1). A prospective Canadian cohort study of 4,615 elderly subjects diagnosed 194 cases of Alzheimer’s disease and showed that coffee consumption was inversely associated with disease risk (2).
In 2007 researchers reviewed all observational studies that evaluated the association between Alzheimer’s disease risk and coffee consumption. (3)Four studies were identified: two case-control studies and two cohorts. These studies were carried out between 1990 and 2002. There was an obvious protective effect of coffee consumption in the pooled estimate. The authors concluded that ‘Although our pooled estimates show that coffee consumption is inversely associated with the risk of Alzheimer’s disease, the four studies had heterogenous methodologies and results.
In 2009 Swedish and Finnish researchers published the results of their work which looked at midlife coffee and tea drinking and the risk of late-life dementia. In a cohort of 1409 individuals after an average follow-up of 21 years, a total of 61 cases were identified as demented, 48 with Alzheimer's disease. In this study coffee drinkers at midlife had a lower risk of dementia and Alzheimer's disease later in life compared with those drinking none or only little coffee. The lowest risk was found in people who drank 3 to 5 cups of coffee per day. Tea drinking was relatively uncommon in this cohort and was not associated with dementia or Alzheimer's disease (4).
Whilst research has continued into this area, further prospective studies evaluating the association between coffee consumption and Alzheimer’s disease are needed before any firm conclusions can be arrived at.
References:
1. Maia, L. and De Mendonca, A. European Journal of Neurology, 9, 377-382, 2002.
2. Lindsay, J. et al. American Journal of Epidemiology, 156, 445-453, 2002.
3. Barraco Quintana, J L et al, Neurological Research, Volume 29, 2007
4. Eskelinen, M H et al, Journal of Alzheimer's Disease, Volume 16, 2009