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

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