A study by the Glenn Biggs Institute for Alzheimer’s & Neurodegenerative Diseases at UT Health San Antonio, Boston University School of Medicine, and the Framingham Heart Study has found that higher scores on the Dietary Inflammatory Index (DII) are associated with an increased risk of developing all-cause dementia and Alzheimer’s disease (AD) dementia. As dementia rates are projected to reach 152 million by 2050, the findings underscore the growing strain on caregivers and healthcare systems. Despite advancements in drug therapies, there remains a lack of effective preventive measures for dementia.
Diet has been identified as a potential factor in reducing dementia risk, with anti-inflammatory diets such as the Mediterranean and MIND diets previously linked to slower cognitive decline and lower dementia risk. The DII is a standardized tool that assesses the inflammatory potential of diets by analyzing nutrients, bioactive compounds, and food components. Higher DII scores, indicating more pro-inflammatory diets, have been associated with systemic inflammation, which contributes to neurodegenerative diseases like Alzheimer’s.
The study, published in Alzheimer’s & Dementia, utilized data from the Framingham Heart Study Offspring cohort, which included 1,487 participants aged 60 or older who were dementia-free at the start of the study. Researchers analyzed dietary data collected from food frequency questionnaires (FFQs) over three periods between 1991 and 2001 and calculated DII scores for 36 dietary components. The study followed participants for an average of 13 years, tracking dementia diagnoses through neurological tests, neuropsychological evaluations, and medical records.
Results showed that participants with higher DII scores, indicating pro-inflammatory diets, had significantly increased risks of developing both all-cause dementia and Alzheimer’s disease. Specifically, for every unit increase in the DII score, the risk of all-cause dementia rose by 21%, and the risk of AD dementia increased by 20%. Participants with the most pro-inflammatory diets were 84% more likely to develop dementia compared to those with the most anti-inflammatory diets. These associations persisted after adjusting for factors like age, sex, physical activity, and smoking.
The findings suggest that dietary inflammation may contribute to neurodegenerative processes through pathways involving systemic inflammation. Diets high in pro-inflammatory components, such as saturated fats and processed carbohydrates, may exacerbate brain inflammation and promote the formation of amyloid-beta plaques, a hallmark of Alzheimer’s. Conversely, anti-inflammatory nutrients like omega-3 fatty acids and flavonoids could help counteract these effects, supporting brain health and reducing dementia risk. Although the study’s observational nature limits the ability to establish causality, the results suggest that dietary interventions focusing on anti-inflammatory foods could serve as a long-term strategy for reducing dementia risk and improving public health outcomes.
