Coffee drinking has been shown to lower the risk of developing Parkinson's Disease, a neurological disorder which causes tremors and disability in about one in 200 older people.
The more coffee one drinks, up to a maximum of 28 oz a day, the lower the Parkinson's risk, according to a US study published yesterday in the Journal of the American Medical Association.
Dr G. Webster Ross, from the department of veterans affairs, Honolulu, and colleagues studied data from a 30-year, follow-up study of 8,004 men. They found disease incidence went down as the amount of coffee consumed during mid-life went up.
The incidence "declined consistently with increased amounts of coffee intake, from 10.4 [cases] per 10,000 person-years in men who drank no coffee to 1.9 [cases] per 10,000 person-years in men who drank at least 28 oz a day", the authors report.
This five-to-one higher risk faced by those who don't drink coffee was reduced when smoking habits were included. Yet even when tobacco use was taken into account the risk for coffee drinkers was still two to three times lower.
The researchers believe it is the caffeine and not other nutrients, such as niacin , which influenced the risk. "The relationship between caffeine and Parkinson's Disease was unaltered by intake of milk and sugar," the authors added.
The research team did not deal with any negative impact on health which might arise due to caffeine intake.
Parkinson's is a significant source of illness and health service demand. Incidence is also expected to increase because people are living longer.
The progressive neurological disorder causes permanent nerve damage which leads to muscle tremors, stiffness and weakness. Eventually the person becomes disabled and while drugs can be used to treat the symptoms the damage cannot be reversed. Pope John Paul II suffers from Parkinson's Disease, which affects his speech and severely limits his movements.
"The observational nature of the study design prevents concluding that coffee or caffeine directly protect against development of Parkinson's Disease," the authors cautioned.
