Introduction
Coffee drinking in moderation has been proven to be perfectly safe and research in recent years has increasingly shown that coffee/caffeine may also have beneficial/protective effects against the development of certain diseases. Research published since the early 2000′s has suggested coffee drinking may be protective against the development of Parkinson’s disease and Alzheimer’s disease. Both these debilitating illnesses have a dramatic effect on an individual’s quality of life, particularly (though not exclusively) in the later years of life. Alzheimer’s disease alone affects one in ten Briton’s over the age of 85.

Coffee, caffeine and degenerative brain disease
Recently published research has demonstrated that coffee drinking reduces cognitive decline in men and women (1 & 2).

In particular, an area of research that has attracted considerable interest of late is that of the effect of coffee/caffeine consumption on degenerative brain disorders, particularly Parkinson’s disease and Alzheimer’s disease.

The available evidence demonstrates that coffee drinkers have a lower risk of developing Parkinson’s disease (3 – 8 ) and is inversely and significantly associated with risk of Alzheimer’s disease (9 – 11). However, a study which identified 154 cases of Parkinson’s disease, found that while coffee or caffeine consumption lowered disease risk in women who did not use postmenopausal hormones, they raised disease risk in women who used postmenopausal hormones (4). More studies are needed to decide whether the combined use of oestrogen and coffee or caffeine increases Parkinson’s risk.

A study published in 2009 on 1409 individuals demonstrated a 65 – 70% decreased risk of dementia and a 62 – 64% decreased risk of Alzheimer’s disease in participants who consumed 3 – 5 cups of coffee a day during midlife, compared with those who consumed 2 or less cups of coffee a day (12).

Summary
The weight of evidence strongly suggests that coffee drinking may be protective against the development of Parkinson’s disease and Alzheimer’s, however it is acknowledged that further research is required on the biological mechanisms underlying the potentially protective effect before we can state categorically that coffee drinking protects against these debilitating illnesses.

References
1. Van Gelder BM. European Journal of Clinical Nutrition, Volume 61, 2007
2. Ritchie K. Neurology, Volume 69, 2007
3. Hernan MA. Annals of Neurology, Volume 52, 2002
4. Ascherio A. Annals of Neurology, Volume 50, 2001
5. Ross GW. Journal of the American Medical Association, Volume 283, 2000
6. Ascherio A. Neurology, Volume 60, 2003
7. Hu G. Movement Disorders, Volume 15, 2007
8. Saaksjarvi K. European Journal of Clinical Nutrition, 2007
9. Maia L and De Mendonca A, European Journal of Neurology, Volume 9, 2002
10. Lindsay J. American Journal of Epidemiology, Volume 156, 2002
11. Barraco Quintana JL. Neurological Research, Volume 29, 2007
12. M H Eskelinen et al, Journal of Alzheimer’s Disease, Volume 16, 2009