Can Diet Reduce Risk of Parkinson Disease?

A healthy diet consisting of fruit, vegetables, and whole grains in middle age may be associated with fewer non-motor symptoms known to precede the diagnosis of Parkinson disease (PD), according to study findings published in Neurology.

In managing risk of PD, there are several symptoms that are known to occur 10 or more years before movement issues begin. These non-motor symptoms, which include constipation, daytime sleepiness, and depression, could have vital implications in the pathogenesis of the condition as a previous study spotlighted the role of various gastrointestinal and sensory deficits, which are more prominent in those with PD, in exacerbating adverse effects linked with PD.

As indicated in that prior study, dietary management can help relieve symptoms such as constipation, as well as address insufficiencies in nutrient intake. Researchers of the current study sought to assess the relationship between diet pattern and prodromal features of PD, particularly how closely people's diets followed either the alternate Mediterranean diet (aMED), similar to the Mediterranean diet but with only whole grains and no dairy, or the Alternative Healthy Eating Index (AHEI).

The study recruited 47,679 people from the Nurses’ Health Study and the Health Professionals Follow-up study, who were asked about their diet every 4 years since 1986 when they were middle-aged. In 2012, the study cohort was polled on if they had 2 conditions that are common in people later diagnosed with PD, which are constipation and rapid eye movement sleep behavior disorder. Later in 2014 and 2015, 17,400 of the participants were asked about 5 more symptoms that can precede PD: loss of sense of smell, impaired color vision, excessive daytime sleepiness, body pain, and depression.

Multinomial logistic regression was utilized to estimate the association between baseline (1986) diet pattern score quintiles and number of prodromal features (0, 1, 2, or ≥3) in 2012-2015. “Additional analyses investigated the association between long-term adherence to these dietary patterns over 20 years and prodromal features suggestive of PD,” expanded the study authors.

In the study findings, people with the highest adherence to aMED were less likely to have 3 or more symptoms that precede PD than the people with the lowest adherence at baseline (odds ratio [OR] = 0.82; 95% CI, 0.68-1.00; false discovery rate (FDR) adjusted P_trend = .03) and after long-term diet (OR = 0.67, 95% CI, 0.54-0.83; FDR-P_trend < .001). Results were found to be equally strong for the association with AHEI scores, with higher adherence to these diets also inversely associated with individual features, including constipation, excessive daytime sleepiness, and depression.

"While this study does not show cause and effect, it certainly provides yet another reason for getting more vegetables, nuts and legumes in your diet," said lead study author Samantha Molsberry, PhD, of Harvard University. "More research is needed to determine whether eating a healthy diet could delay or even prevent the development of Parkinson's disease among people who have these preceding symptoms already."

Reference

Molsberry S, Bjornevik K, Hughes KC, et al. Diet pattern and prodromal features of Parkinson disease. Neurology. Published online August 19, 2020. doi:10.1212/WNL.0000000000010523