**4. Oxidative stress and Parkinson's disease**

**2. Current treatment pathways**

392 Pharmacology and Nutritional Intervention in the Treatment of Disease

resolve when the medications are no longer used.

Parkinson's disease is a degenerative disease of the nervous system. The exact cause for Parkinson's disease is not well understood. There is no definitive test for PD – diagnosis is often based on medical history and the presence of the classic symptoms and signs of PD (Samii et al. 2004; Tolosa & Katzenschlager, 2007). Sometimes people are given anti-PD drugs to see if they respond, or other tests may be performed, such as MRI and CAT scans, to rule out other disorders with similar symptoms (Gelb et al. 1999; Hughes et al. 2002). The presence of other diseases, such as dementia and general ageing can obscure PD symptoms and reduce the chance of an accurate diagnosis. Certain drugs, when taken for long periods of time or in amounts greater than recommended, can cause Parkinsonism (Di Fabio et al. 2013) and have side effects. These medications do not result in Parkinson's disease, however, and symptoms

**3. Environmental and nutritional factors in Parkinson disease**

more realistic possibility than it is today McCann & Ames, 2011).

Environmental factors and nutrients may play an important role in early life. In people who are genetically predisposed to Parkinson's disease, many experts believe that environmental exposures, such as unusual exposure to herbicides and pesticides, increase a person's risk of developing Parkinson's disease (Tanner & Langston, 1990; Van Maele-Fabry et al. 2012).

Numerous epidemiological studies and interventional trials have suggested a link, in aging, between an adequate nutritional status and health (de Lau & Breteler, 2006; Barichella et al. 2009). Nutrient deficiencies and constipation may also play a role (Dan Beth, 1992; Schelosky et al, 1995). Parkinson's patients are often deficient in vitamins, minerals and trace elements (Ames, 2011). Micronutrient sufficiency and quality of the lipid supply may play key roles in brain development. It is because of their diverse and vital roles that nutrient element imbal‐ ances are frequently found to be factors in degenerative diseases. Since the body cannot manufacture the elements-and daily losses are unavoidable-the nutrient elements are all "essential" and must regularly be taken in through the diet. Erythrocyte element levels are good indicators of body pools of essential elements such as selenium, zinc, magnesium, potassium, and calcium. Often referred to as minerals, the chemical elements are fundamental to every function in the body. It is because of their diverse and vital roles that nutrient element imbalances are frequently found to be factors in degenerative diseases. Since the body cannot manufacture the elements-and daily losses are unavoidable-the nutrient elements are all "essential" and must regularly be taken in through the diet. But they are easily lost in food processing, so it's easy to see how deficiencies can occur. It has been reported that moderate selenium and vitamin K deficiency show damage accumulates over time as a result of vitamin and mineral loss, leading to age-related diseases (Ames, 2006; McCann & Ames, 2011). Therefore, understanding how best to define and measure optimum nutrition will make the application of new technologies to allow each person to optimize their own nutrition a much

Oxidative stress could play an important role in the degenerative process leading to Parkin‐ son's disease. These considerations provide a rationale for therapeutic strategies to diminish oxidative stress in dopaminergic regions of brain. If oxidative stress is a major factor, the agents that selectively and safely chelate iron may be of value. It was reported that the mitochondrial deficiency (Shoffner et al. 1991; Jenner, 1991; Saggu et al. 1989; Perry & Yong, 1986) in electron transport, enhanced lipid peroxidation, elevated superoxide dismutase, diminished capacity to remove excess hydrogen peroxide (suggested by low glutathione and glutathione peroxi‐ dase levels) and the presence of increased iron, which catalyses formation of highly reactive hydroxyl ions from hydrogen peroxide, make attractive the suggestion that oxidative stress could play an important role in the degenerative process leading to Parkinson's disease (Ambani et al. 1975).
