Older age, male sex, and a family history of Parkinson’s disease appear to associate with a higher risk of developing Parkinson’s later in life, according to an Italian study.
The research also suggested that dietary choices and work history influenced the disease’s development, with those who consumed meat on a regular basis, and those who worked as a medical doctor or pilot being at a higher risk. Women, smokers, and people who frequently ate vegetables were at a lower disease risk.
The study, “Effect of family history, occupation and diet on the risk of Parkinson disease: A case-control study,” was published in the journal PLOS One.
Although the specific causes of Parkinson’s are still controversial, the disease is thought to arise from a combination of genetic and environmental factors.
While cigarette smoking has consistently been tied to a lower risk of Parkinson’s, having a family history of the disease, living in rural areas, or being exposed to pesticides or other industrial chemicals have all been linked to an increased risk.
Yet, findings are inconsistent in studies attempting to define the contribution of several such risk factors toward Parkinson’s development, “probably due to the mixed effect of genetic susceptibility and response to predisposing factors,” the scientists wrote.
A team of researchers in Italy aimed to explore and define the contribution of a series of genetic, environmental, and lifestyle risk factors to Parkinson’s onset.
Their study was based on data from 634 patients (365 men and 269 women) with idiopathic (of unknown cause) Parkinson’s, treated for this disease at two hospitals in Rome from 2011 to 2015.
Patients were matched to 532 individuals (261 men and 271 women) of the same sex and approximately the same age, referred to the same hospitals. These people, who had been diagnosed with conditions other than neurodegenerative disorders, served as study controls.
All were asked to complete a questionnaire that gathered information on their family history, professional occupation, lifestyle, and place of residence. Statistical analyses were then used to calculate Parkinson’s risk, based on each of these factors.
Findings indicated that women had a slightly lower risk (26% lower) of developing Parkinson’s than did men. Moreover, older people (those 65 and older) were found to have a higher risk (57–92% higher) of the disease than did people age 59 or younger.
Additionally, compared with individuals with no family history of Parkinson’s, those who had a relative with the disease were more than twice as likely to develop the disease later in life. Similar analyses showed that people with a first degree relative with Parkinson’s were 34% more likely to develop the disease themselves. This risk was even higher — 65% higher — for those living in the urban center of Rome.
Current smokers were seen to have a 52% lower risk of developing Parkinson’s.
Dietary habits were also found to influence Parkinson’s risk. For instance, people who consumed vegetables on a daily basis were found to have a 63% lower risk. In contrast, a daily intake of carbonated drinks or meat elevated a person’s disease risk to nearly two times that of those who did not consume any of these products.
Additional analyses linked certain professional activities to an increased risk. This was true for physicians and pilots, who were three to five times more likely to develop Parkinson’s compared with clerical support workers, who were used as a reference in these analyses.
“This study has confirmed some of the associations already present in literature but has also highlighted an increased risk for PD [Parkinson’s disease] in some peculiar occupational activities and an important link to diet that could open the door to new lines of research,” the researchers wrote.
Additionally, the team noted that “techniques of biomonitoring should be integrated, with the aim of … modelling a holistic strategy of [Parkinson’s] prevention, based on genomics, clinical features, personality, lifestyle, aging, and comorbidities.”