Title : Effects of a mediterranean diet on verbal fluency in patients with parkinson’s disease and healthy controls: A fNIRS study
Parkinson´s Disease (PD) is a progressive neurodegenerative disease manifesting itself in motor and nonmotor symptoms. With disease progression, cognitive deficits ranging from mild cognitive impairment (MCI) to dementia (Galtier et al., 2016) as well as deficits in word retrieval (Henry & Crawford, 2004) have been described to occur. Recent research showed that a Mediterranean diet increased or maintained cognitive functions in PD patients (Cao et al., 2016; Loughrey et al., 2017). Yet, whether this specific nutrition may have beneficial effects on verbal fluency has not been investigated so far.
To examine the effect of a Mediterranean diet in patients with PD when retrieving words within a phonemic or semantic category using functional near-infrared spectroscopy (fNIRS) recording.
Functional NIRS was measured in 20 PD patients being non-demented and having no deep brain stimulation (non-DBS) and in 19 healthy controls (HC) during phonemic and semantic word retrieval (WR) tasks. Groups were further split into PD-Mediterranean (N= 8; Age Mn 66 yrs. [54-66]; 6.3), PD-traditional (N= 12; Age Mn 66 yrs. [52-78]; 6.4), HC-Mediterranean (N=11; Age Mn 63 yrs. [52-77]; 9.4) and HC-traditional (N=8; Age Mn 66 yrs. [54-77]; 8.6) according to what their regular and daily diet type was. The term “traditional” refers to a traditional Northern European diet. The 8x8 fNIRS system integrated short channels and covered the Broca´s area, the Motor Cortex and the Wernicke´s area, as specified by the fOLD brain atlas (Zimeo Morais et al., 2018). Statistical analysis was conducted with SPSS (V.28) and results were seen as significant if p < .05 or less.
PD were outperformed by HCs (regardless of diet type) on all accounts (p < .01). For phonemic WR, the PDMediterranean group showed higher fNIRS signals bilaterally in the Motor Cortices compared to the PD-traditional group. For semantic WR, the PD-Mediterranean group had higher fNIRS signals in the left hemispheric Broca´s area and the Motor Cortex (p < .05) compared to PD following a traditional Northern European diet. For the HCs, there were no statistically significant differences between diet types.
For PD patients, a Mediterranean diet indicated better hemodynamic changes within the (left hemispheric) Broca´s area and the Motor Cortex during semantic WR and bilaterally in the Motor Cortex during phonemic WR. There were no measurable differences between diet types in the healthily aging group. Importantly, weight loss (change in the BMI) has not been considered within these statistics. Yet, weight loss is known to improve the cardiovascular condition and this may in turn, improve overall cognitive functioning.
Audience Take Away
- Results shown in this presentation are based on a pilot study. However, these are in-line with current findings and also pattern-in with findings from recent cognitive research
- Thus, professionals may be briefly introduced to the Mediterranean diet and other different diet types as specified in Medscape, 2023. Further, this presentation may help to raise awareness of possible beneficial effects of a Mediterranean diet motor-articulatory on parameters (and thus, contribute to current findings deriving from cardiovascular, psychological and cognitive research)
- Professionals working in a clinical field may provide additional information about Mediterranean diet plans directly to patients, and as thus, raise awareness in patients
- In teaching, possible effects of a Mediterranean diet may be introduced and expanded on
- In research, non-invasive approaches such as a Mediterranean diet may receive more attention for future research, in order to explain how a Mediterranean diet affects the human metabolism, for instance