1) Age

Epidemiological studies show both men and women have an increasing risk of Parkinson's disease with increasing age.   Because of this, some antiaging dietary supplements such as antioxidants like vitamin E and vitamin C or lifestyle such as calorie restriction may help reduce the risk of the disease.

2) Gender

Men are more likely than women to develop Parkinson's disease.   Could this mean that male sex hormones like testosterone may play a role in the development of Parkinson's disease?  Or female sex hormones such as estrogen have a protective effect against the disease?

3) Tobacco

Exposure to tobacco increases risk of lung cancer.  But studies suggest that exposure to tobacco may reduce the risk of Parkinson's disease.  One possible explanation is that nicotine in tobacco may promote dopaminergic neuron cell survival and may decrease the formation of other metabolic toxins.

4) Caffeine

Exposure to caffeine such as coffee drinking seems to decrease the risk for Parkinson's disease.  This effect seems to be stronger in men than women.  The possible explanation is that caffeine inhibits adenosine A2A receptors and this can in turn ameliorate any parkinsonian signs and symptoms masking underlying Parkinson's disease and lead to a false-negative diagnosis of the disease.  Inhibition of A2A receptors can also protect against dopaminergic neuron toxicity, leading to the prevention of Parkinson's disease.

5) Pesticides

Pesticides are often neuron-toxins and exposure to pesticides damage the brain.  Studies show that occupation pesticide exposure was associated with 3-fold increased risk for Parkinson's disease.

6) Occupation

Farmers and those with agricultural and or rural occupations seem to have a higher risk for Parkinson's disease.

7) Urate

High blood urate concentrations have been associated with a decreased risk for Parkinson's disease.  It remains unknown why high urate concentrations are linked to lower risk for Parkinson's disease.

8) NSAIDS

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been associated with a moderate reduction in Parkinson's disease.

9) Traumatic Brain Injury

Traumatic brain injury can not also cause Alzheimer's disease, but also Parkinson's disease.

10) Exercise

Exercise is believed to be protective against Parkinson's disease.

Dietary factors

Probiotics help constipation in Parkinson's disease patients

Curcumin fights Parkinson's disease

Antioxidants may slow or prevent Parkinson's disease

Vitamin D sufficiency may help protect against Parkinson's disease

Milk Raises Parkinson's disease risk

Green tea protects against brain cell damage.

Dairy products are linked to Parkinson's disease

Vitamin E rich diet prevents Parkinson's disease

Black tea, curry spice help prevent Parkinson's disease