Adherence to certain diets linked to later onset of Parkinson’s disease

Following certain diets, including the Mediterranean-DASH Intervention for Neurodegenerative Delay and the Greek Mediterranean diet, correlated with later onset of Parkinson’s disease in a cross-sectional study of patients in Canada.

The relationship between age at onset of PD and diet suggested that “nutritional strategies may be an effective tool to delay PD onset,” according to the researchers. They published the findings in Movement Disorders.

“The [Mediterranean-DASH Intervention for Neurodegenerative Delay] MIND diet has been associated with up to a 54% reduction in [Alzheimer’s disease] AD incidence and has consistently proven to be more beneficial for cognitive health than the [Mediterranean diet] MeDi. Despite this success, little research has investigated the effect of the MIND diet on other neurodegenerative diseases,” the researchers wrote. “This cross-sectional study examines the relationship between MIND diet adherence and the age of PD onset in a Canadian cohort and compares the performance of the MIND diet to both MeDi scoring methods.”

Avril Metcalfe-Roach, a PhD student in the University of British Columbia’s Michael Smith Laboratories, and colleagues enrolled 167 participants with PD and 119 controls. They scored all individuals for MIND and two versions of Mediterranean diet adherence using food frequency questionnaires. The researchers compared scores between sex and disease subgroups and correlated age at disease onset with PD diet adherence.

Patients with PD were mostly men (68.3%), with an average age of 64.9 years. These patients began experiencing motor symptoms (referred to as age of onset, according to the researchers) an average of 6.5 years previously. Fewer participants in the control group were men (39.3%) and were slightly younger (mean age, 61.8 years).

The subgroup of women abided more closely to the MIND diet than the subgroup of men, according to the study findings. In addition, Metcalfe-Roach and colleagues found that disease status did not alter diet scores.

The findings demonstrated that later age at disease onset correlated most strongly with MIND diet adherence in the subgroup of women, corresponding to differences of up to 17.4 years (P < .001) between low and high dietary tertiles. Greek Mediterranean diet adherence also significantly correlated with later PD onset in all models (P = .05-.03). However, only adherence to the Greek Mediterranean diet remained associated with later onset across all models in men, with differences of up to 8.4 years (P = .002).

“Although female participants experienced only slightly larger MeDi effect sizes compared with male participants, the average effect size of the MIND diet in women was more than [three] times that of the men and surpassed all MeDi effect sizes, suggesting that its dietary components may be better suited to delaying PD onset than MeDi in a female-specific manner,” the researchers wrote.

In addition, only the MIND diet demonstrated an interaction between sex and diet score, though neither diet normalized food intake according to sex. However, women adhered more closely to the MIND diet than men, even after researchers adjusted for age, disease status, disease duration and kilocalorie consumption, which showed that “the higher MIND score is not simply because of differences in food volume,” according to Metcalfe-Roach and colleagues.

“This tendency for women to adhere more strongly to the MIND diet may contribute to their lower rate of PD incidence,” the researchers wrote.

Overall, the findings demonstrated “a strong, female-driven correlation between MIND diet adherence and delayed PD onset in a manner similar or superior to the MeDi,” according to Metcalfe-Roach and colleagues.

“The sex specificities presented here are novel and may prove to be an important contributor to the sex differences observed in PD,” the researchers wrote. “This study should be repeated in a larger, preferably prospective cohort to confirm these findings.”