Who gets Parkinson's Disease?
Parkinson’s disease is an indiscriminate condition which mainly affects people over the age of 50, although it has been known to occur very rarely in young adults.
About four million people world-wide are known to have the disease but this figure could be much higher as many people in the early stages put the symptoms down to ageing.
Misdiagnosis is often a problem because many conditions produce some of the same symptoms. Likewise people many are told they have Parkinson’s when in fact the symptoms are due to something completely different.
The average age for the onset of Parkinson’s is usually about 60 and for some unknown reason it is slightly more prevalent among males. Women have a greater risk of developing walking problems while men appear to suffer more from tremors.
It has been suggested that the hormone oestrogen may offer some protection for women up until the menopause. A 2001 study showed a higher rate of the disease among women who’d undergone a hysterectomy.
Certainly the prevalence among both sexes increases with age. About one in 100 people in their 60s and around one in 10 over 80 have Parkinson’s. Research shows that the risk drops significantly after the age of 75 and that the very elderly are at low risk.
The disease rarely develops in people under 50 - young-onset Parkinson’s accounts for just 5% to 10% of diagnosed cases.
The illness has no social or economic boundaries and no race or region of the world have ever been found to escape it. In general Parkinson’s is more common in developed countries simply because people tend to live longer. Some of the highest prevalence rates of the disease can be found in Europe and North America. The lowest have been found in Nigeria, China, Japan and Sardinia. The Parsi community of Bombay bucks the trend by having one of the highest prevalence rates. Researchers believe this could be due to something in the environment or it could suggest a genetic link because the Parsi is a closed community which does not allow marriage with other races.
Some studies have shown that Asians and African Americans are less likely than Caucasians to develop the disease, although the reason for this hasn’t yet been discovered.
Whether Parkinson’s is hereditary is still up for discussion. People with close relatives who developed the disease at a young age have a slightly higher risk of developing it themselves - a 6% risk compared with 2% risk for families with no history of Parkinson’s. This suggests that there may be a genetic link.