Mediterranean Diets Linked to Reduced Symptom Burden
Study evaluates the Mediterranean-style diets MEDI and MIND
Better adherence to Mediterranean-style diets is associated with lower patient-reported symptom severity in people with Parkinson’s disease, according to a study of more than 1,000 patients.
Between the two evaluated diets — the Mediterranean (MEDI) and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) — the MIND diet was linked to greater benefits in symptom reduction.
Further analyses of both diets’ components showed that the most beneficial foods were berries, vegetables, nuts, beans, and non-fried fish.
“Until a [Parkinson’s]-specific diet is described, and an adherence scale developed and validated, these data suggest adherence to the MIND diet, more than MEDI, is associated with the accumulation of fewer patient-reported symptoms over time,” the researchers wrote.
The study, “Comparison of Associations between MIND and Mediterranean Diet Scores with Patient-Reported Outcomes in Parkinson’s Disease,” was published in the journal Nutrients.
Both the MEDI and MIND diets “encourage a higher consumption rate of olive oil, fresh fruits and vegetables, fish, poultry, beans, nuts, and wine, while discouraging the consumption of foods such as red meat, butter or margarine, and pastries or sweets,” the researchers wrote.
These diets have become popular due to their proposed benefits on neurological and general health. Specifically, the anti-inflammatory and antioxidant properties of such diets are thought to lower the risk of neurodegenerative diseases like Parkinson’s, or delay its onset.
Still, it isn’t well-established whether maintaining these diets after a Parkinson’s diagnosis might influence disease progression.
Moreover, while the two diets are similar, they do have key differences that might influence their effects on Parkinson’s symptoms.
For example, while MEDI rewards consumption of all vegetables, fruits, and legumes, the MIND diet encourages specific intake of green leafy vegetables, berries, and beans. Also, “in the MIND diet but not the MEDI diet, whole grains are rewarded, and fast, fried foods are penalized, along with all pastries and sweets,” the researchers wrote.
Both diets can be monitored through established rating scales, which generally award points for consuming the most encouraged foods while penalizing for eating foods that aren’t consistent with the diet. Higher scores in both scales are associated with a generally better diet adherence.
Now, a team of researchers in the U.S. evaluated whether MEDI or MIND diet scores were associated with patient-reported Parkinson’s symptoms.
Diet study design
The analysis involved 1,205 adults (mean age 66.4) with all forms of parkinsonism who already were enrolled in the ongoing Modifiable Variables in Parkinsonism (MVP) Study (NCT02194816).
Most had Parkinson’s without a known cause (95%), were Caucasian (91%), and women (59%). They had been living with the disease for a mean of 7.19 years.
Participants completed the Patient-Reported Outcomes in Parkinson’s Disease (PRO-PD) scale, as well as the MIND and MEDI questionnaires, from January 2020 to July 1, 2022. PRO-PD is a subjective assessment of the severity of 33 common Parkinson’s symptoms over the previous week.
When adjusted for potential influencing factors such as age, gender, income, and years since diagnosis, results showed that for every one-point increase in the MEDI score, total PRO-PD scores dropped by 25.6 points, reflecting a reduction in symptom burden.
Notably, for each one-point increase in the MIND score, total PRO-PD scores decreased by 52.9 points, meaning that each MIND point was “twice as strong as a MEDI point in reducing symptom severity,” the researchers wrote.
Similar trends were observed for the non-motor and motor symptom subscores of the PRO-PD scale, with better adherence to the MIND diet being associated with about twice as low symptom severity relative to the MEDI diet.
Greater MIND diet adherence also was associated significantly with lower severity for all assessed non-motor symptoms, while several, but not all of these symptoms, showed significantly lower severity with higher MEDI scores.
Compared with MEDI, the MIND diet was linked significantly to lower severity in constipation, anxiety, fatigue, insomnia, drool, forgetfulness, urinary problems, and sexual dysfunction.
In terms of specific dietary components, data from both diets generally showed that consumption of nuts, vegetables, berries, beans, and non-fried fish was tied to lower symptom severity. In contrast, butter, red meat, and sugar were associated with greater symptom severity.
When the researchers looked at changes in PRO-PD scores with increasing disease duration, they found that MEDI and MIND diets were associated with similar rates of symptom progression.
The team noted, however, that future studies collecting data over time for each patient are needed to better understand the impact of these diets in disease progression. This type of data collection “is underway,” they wrote.
Overall, both diets — but particularly MIND — may be beneficial for easing Parkinson’s symptoms.
Since the study population consisted of mostly women, Caucasian, and wealthy patients in the U.S. who had relatively good diet adherence, it is important to evaluate whether these results “are reproducible in more diverse populations,” the researchers wrote.
If so, “dietary intervention studies should focus on increasing MIND scores as a therapeutic strategy,” they added.
Moreover, “the main differences between these diets … should serve as a point of focus in future studies,” the team concluded.
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