Relationships between dietary nutrients intake and lipid levels with functional MRI dorsolateral prefrontal cortex activation

Abstract

BackgroundDorsolateral prefrontal cortex (DLPFC) is a key node in the cognitive control network that supports working memory. DLPFC dysfunction is related to cognitive impairment. It has been suggested that dietary components and high-density lipoprotein cholesterol (HDL-C) play a vital role in brain health and cognitive function.PurposeThis study aimed to investigate the relationships between dietary nutrient intake and lipid levels with functional MRI (fMRI) brain activation in DLPFC among older adults with mild cognitive impairment.Participants and methodsA total of 15 community-dwelling older adults with mild cognitive impairment, aged ≥60 years, participated in this cross-sectional study at selected senior citizen clubs in Klang Valley, Malaysia. The 7-day recall Diet History Questionnaire was used to assess participants’ dietary nutrient intake. Fasting blood samples were also collected for lipid profile assessment. All participants performed N-back (0- and 1-back) working memory tasks during fMRI scanning. DLPFC (Brodmann’s areas 9 and 46, and inferior, middle, and superior frontal gyrus) was identified as a region of interest for analysis.ResultsPositive associations were observed between dietary intake of energy, protein, cholesterol, vitamins B6 and B12, potassium, iron, phosphorus, magnesium, and HDL-C with DLPFC activation (P<0.05). Multivariate analysis showed that vitamin B6 intake, β=0.505, t (14)=3.29, P=0.023, and Digit Symbol score, β=0.413, t (14)=2.89, P=0.045; R2=0.748, were positively related to DLPFC activation.ConclusionIncreased vitamin B6 intake and cognitive processing speed were related to greater activation in the DLPFC region, which was responsible for working memory, executive function, attention, planning, and decision making. Further studies are needed to elucidate the mechanisms underlying the association.

Does traditional asian vegetables (ulam) consumption correlate with brain activity using fMRI? A study among aging adults from low‐income households

“…While the attention, working memory, and executive functioning are controlled by the prefrontal cortex that is located at the frontal part of the brain, the working memory, on the other hand, was reported to have been supported by the left superior frontal, right middle frontal gyrus, and the inferior frontal gyrus . The involvement of the middle frontal gyrus in the working memory tasks such as word‐reading and numerical operations has also been proven from previous studies . Since our findings had shown the significance of right DLPFC activation from performing the N‐back tasks, we can therefore surmise that the subjects with higher ulam consumption as demonstrating a greater right‐hemispheric dominance during the visual‐spatial processing stage as compared with lower ulam consumption …”

“…33 The involvement of the middle frontal gyrus in the working memory tasks such as word-reading and numerical operations has also been proven from previous studies. 6,33 Since our findings had shown the significance of right DLPFC activation from performing the N-back tasks, we can therefore surmise that the subjects with higher ulam consumption as demonstrating a greater righthemispheric dominance during the visual-spatial processing stage as compared with lower ulam consumption. 34 As the involvement of the middle frontal gyrus while performing the SCWT had been proven from a previous study, 23 our findings too had revealed that the subjects with higher ulam consumption as demonstrating better left DLPFC activation for both of the SCWT tasks, with the left hemisphere displaying more of the brain activity during the assigned word recognition task.…”

“…23 The sample size of this study was also calculated and justified sufficiently, where the investigation on the association between ulam consumption and brain activation had been successfully conducted through the use of the fMRI; hence, corresponding to several previous studies that were conducted on the nutrients intake and brain activation with a small sample (n = 15-30). 6,13,37 The neuroimaging approach that was complemented with the neuropsychological batteries for the evaluation of cognitive domains such as working memory and cognitive flexibility can thus be regarded as a strength of this investigation, since the variations in brain functions that arose from the initial signs of Alzheimer's disease could be examined by this sort of MRI.…”

“…Impaired synaptic neuroplasticity, which is caused by dorsolateral prefrontal cortex dysfunction, may lead to mild cognitive impairment . A recent study has successfully shown that higher vitamin B6 intake was closely related to better working memory using N‐back task functional magnetic resonance imaging (fMRI) in DLPFC among mild cognitive impairment older adults …”

“…5 A recent study has successfully shown that higher vitamin B6 intake was closely related to better working memory using N-back task functional magnetic resonance imaging (fMRI) in DLPFC among mild cognitive impairment older adults. 6 Many Asian countries have conducted a series of studies on the prevention of neurodegenerative diseases through food-based recommendation such as those of ulam, which is a type of traditional salad that is normally consumed in raw form by the Asian populations (Southeast Asia, Japan, Korea, and India) with rice or fermented sauces. 7,8 This traditional dish was not only found to have contained a high level of antioxidants, the polyphenol in the ulam was also reported in a review as attenuating the oxidative stress that consequently prevents cognitive decline.…”