Table 2.

An overview of studies associated with pro-inflammatory dietary patterns

Study	Cohort details	Dietary pattern	Cognitive outcome measures	Key findings
Dietary pattern, inflammation and cognitive decline: The Whitehall II prospective cohort study [89]	N = 5083 56.0 years UK Longitudinal Study	Inflammatory dietary pattern characterised by higher intake of red meat, processed meat, peas and legumes, and fried food, and lower intake of whole grains which correlated with elevated IL-6 using reduced rank regression (RRR)	3 clinical examinations over 10 years were administered for the cognitive test battery and consisted of 4 standard tasks: Alice Heim 4-I, short-term verbal memory, phonemic fluency, and semantic fluency	A greater decline in reasoning was seen in participants in the highest tertile of adherence to the inflammatory dietary pattern compared to those in the lowest tertile after adjustment for confounding variables.
An Inflammation-related Nutrient Pattern is Associated with Both Brain and Cognitive Measures in a Multi-ethnic Elderly Population [90]	N = 330 79.0 years USA Cross Sectional Study	RRR was performed using 24 predetermined nutrients as predicting variables and two inflammatory biomarkers (CRP and IL6) as response variables. The inflammatory nutrient pattern (INP) was characterised by low intakes of calcium, vitamin D, vitamins E, A, B1, B2, B3, B5, B6, folate, omega-3 PUFA, and high intake of cholesterol	MRI imaging of global brain measures including intra-cranial volume (ICV), total brain volume (TBV), total grey matter volume (TGMV), and total white matter volume (TWMV). Cognitive ability at the time of MRI scan visit was measured with a neuropsychological battery	Each unit increase in inflammatory nutrient pattern was significantly associated with 36.8 cm3 smaller total brain volume and 0.21 lower visuospatial z-score.
Long-term association between the dietary inflammatory index and cognitive functioning: findings from the SU.VI.MAX study [91]	N = 3080 52.0 ± 4.6 years France	Dietary Inflammatory Index (DII) reflecting the overall inflammatory potential of the diet	Neuropsychological Evaluation including episodic memory, lexical–semantic memory, short-term and working memory	There was a strong inverse association observed between a higher DII (reflecting a more inflammatory diet) and overall cognitive functioning. With regard to specific cognitive domains, similar associations were observed with scores reflecting verbal memory, but not executive functioning.
Inflammatory potential of diet is associated with cognitive function in an older adult Korean population [92]	N = 239 74.0 years Korea	Energy adjusted dietary inflammatory index (E-DII) reflecting the overall inflammatory potential of the diet	Korean-adjusted version of the Mini-Mental State Examination (K-MMSE)	E-DII scores were significantly inversely associated with K-MMSE score in both unadjusted and adjusted models, after controlling for confounding variables. Participants in the highest E-DII tertile (reflecting a more inflammatory diet) had increased risk for mild or moderate cognitive impairment compared with those in the lowest E-DII tertile.
The association between an inflammatory diet and global cognitive function and incident dementia in older women: The Women’s Health Initiative Memory Study [93]	N = 7085 71.0 ± 3.9 years USA	Dietary Inflammatory Index (DII) reflecting the overall inflammatory potential of the diet	Cognitive function was evaluated annually, and MCI and all-cause dementia cases were adjudicated centrally	Higher DII scores (reflecting a more inflammatory diet) were associated with greater cognitive decline and earlier onset of cognitive impairment.
Dietary inflammatory index and memory function: population-based national sample of elderly Americans [94]	N = 1723 68.4 ± 0.2 years USA	Dietary Inflammatory Index (DII) reflecting the overall inflammatory potential of the diet	Consortium to Establish a Registry for Alzheimer’s disease (CERAD) Word Learning subset, the Animal Fluency test, and the Digit Symbol Substitution Test (DSST)	Episodic memory (CERAD), semantic-based memory (Animal Fluency Test) and executive function and working-memory (DSST) performances were lowest among those with the highest mean DII score (reflecting a more inflammatory diet).