For a beverage that doesn’t enjoy the healthiest of reputations, coffee has been the subject of quite a few studies that link its consumption with benefits for health. Specifically, there has been several studies now that link coffee drinking with a reduced risk of cardiovascular disease (e.g. heart disease) or diabetes. Now there is some talk that coffee may have benefits for long-term brain health too. Just recently saw the publication of a study which has linked coffee consumption with a reduced risk of dementia including Alzheimer’s disease [1].
This study, published in the Journal of Alzheimer’s disease, analysed the relationship between coffee drinking and dementia risk in a group of 1409 individuals followed for an average of 21 years. The results showed that coffee drinking in middle age was associated with relative protection from dementia in later life, even after so-called ‘confounding factors’ (including lifestyle factors associated with dementia risk) were accounted for. Individuals drinking 3-5 cups of coffee a day were found to have only about a third of the risk of developing dementia compared to individuals drinking little or no coffee.
So-called ‘epidemiological’ studies of this nature are perhaps good for showing associations between things, but that does not mean that one is causing the other. In other words, we cannot conclude from this study that coffee drinking actually protects against dementia, only that its drinking is associated with protection. However, there are a number of effects that coffee has in the body that could behind any genuinely protective effect.
To begin with, coffee is rich in substances called ‘antioxidants’ which might help protect brain cells from damage wreaked by ‘free radicals’. Also, as we know, coffee consumption is also associated with a reduced risk of diabetes, and diabetes is a risk factor for dementia (essentially because it increases the risk of ‘vascular dementia’ which causes impaired blood supply to the brain). It is also possible that coffee may provide some protection against dementia through its ability to deliver caffeine to the body: an animal study has found that giving caffeine to mice with Alzheimer’s disease improved their brain function [2]. It also reduced the production of the protein beta-amyloid, deposits of which are typically found in the brains of Alzheimer’s disease sufferers. On top of this, we also have other epidemiological evidence linking coffee consumption with reduced dementia (Alzheimer’s disease) risk in humans [3].
While we don’t have definitive proof that coffee drinking reduces dementia risk, the current evidence is at least encouraging. And as a whole, I think it adds to growing evidence linking coffee consumption with benefits for health.
References:
1. Eskelinen MH, et al. Midlife Coffee and Tea Drinking and the Risk of Late-Life Dementia: A Population-Based CAIDE Study. J Alzheimers Dis. 2009;16(1):85-91.
2. Arendash GW, et al. Caffeine protects Alzheimer’s mice against cognitive impairment and reduces brain beta-amyloid production. Neuroscience. 2006;142(4):941-52.
3. Barranco Quintana JL, et al. Alzheimer’s disease and coffee: a quantitative review. Neurol Res. 2007;29(1):91-5.
