Research & Your Health

Research & Your Health is a series of articles written in accessible, everyday language, focused on the latest scientific research of natural health products.

Long-term Association Between the Dietary Inflammatory Index and Cognitive Functioning

On January 2, 2017

Background: There is some evidence that systemic inflammation is associated with cognitive decline. A link has been shown between systemic inflammation in the body and neuro-inflammation in the brain. Neuro-inflammation contributes to neuronal damage, which may lead to impaired cognitive functioning. A dietary contribution to systemic inflammation is hypothesized to affect inflammation in the brain and thus impair mental processes and memory.

Objective: The purpose of this study was to determine if a pro-inflammatory diet at midlife is associated with a decline in cognitive functioning later in life.

Methods: During the years 1994-2002, a French study (titled the SU.VI.MAX) assessed the dietary intake of middle-aged men and women using four 24 hour food logs, randomly distributed throughout the year. In the current study, the cognitive functioning of 3080 of these participants was assessed approximately 13 years later. The participants’ cognitive scores were then compared to the degree of inflammatory foods in the diet at baseline 13 years ago before. Six cognitive tests were performed and associations with diet were investigated using two models: one controlling for just age and gender, the other controlling for age, gender, and 12 other variables.

Results: In terms of individual tests, significant associations were found in three of the six tests when controlling for all variables: one for cued recall (memory) and two for verbal functioning. When all six tests were combined, this gave a significant association between a pro-inflammatory diet during midlife and global cognitive functioning 13 years later.

Conclusion: A pro-inflammatory diet midlife may be associated with cognitive decline later in life.

Findings in Perspective: While systemic inflammation is a risk factor for disease, its causes are multifactorial.  This study aimed to tease out the relationship of systemic inflammation due to diet on cognitive functioning. In doing so, other factors that may affect inflammatory levels were controlled for and a strong correlation between an inflammatory diet and cognitive decline later in life was found.  Focusing on a diet rich in whole foods, fruits, vegetables, nuts, and seeds can help to lower inflammation in the body.

Kesse-Guyot, E., Assmann, K. E., Andreeva, V.A., et al. European Journal of Nutrition (2016), 1-9.