Dementia Risk Dropped With Anti-Inflammatory Diet for Certain Patients

— Brain markers of degeneration, injury were better, too

Last Updated August 13, 2024
MedicalToday
A photo of foods associated with the anti-inflammatory diet including pineapple, salmon, blueberries, broccoli, and avocado.

Key Takeaways

  • An anti-inflammatory diet was associated with lower dementia risk in adults with cardiometabolic diseases.
  • Over 12 years, dementia risk was 31% lower for those who followed an anti-inflammatory diet.
  • The diet was also tied to larger gray matter volume and fewer white matter hyperintensities.

An anti-inflammatory diet was tied to a lower risk for dementia in people ages 60 and older with cardiometabolic diseases, U.K. Biobank data showed.

Among people with cardiometabolic diseases including type 2 diabetes, heart disease, or stroke, those who were on an anti-inflammatory diet had a 31% lower risk for dementia compared with those on a pro-inflammatory diet (HR 0.69, 95% CI 0.55-0.88, P=0.003), reported Abigail Dove, MSc, of the Aging Research Center at the Karolinska Institute in Stockholm, and co-authors.

In a joint effect analysis, the hazard ratio for dementia among people with cardiometabolic disease was 1.65 (95% CI 1.36-2.00) with an anti-inflammatory diet, 1.91 (95% CI 1.57-2.32) with a neutral diet, and 2.38 (95% CI 1.93-2.93) with a pro-inflammatory diet over 12 years of follow-up.

Those on an anti-inflammatory diet had larger gray matter volume and a lower burden of white matter hyperintensities on MRI than those who had more pro-inflammatory foods, the researchers wrote in .

As the population ages, cardiometabolic diseases are becoming more prevalent, Dove observed.

"A relevant question is how to reduce dementia risk among the growing number of older adults with cardiometabolic diseases," she told . This study draws attention to diet as a modifiable lifestyle factor that may promote brain and cognitive health, she noted.

"Chronic low-grade inflammation is a key feature of cardiometabolic diseases and has been implicated in the development of dementia," Dove pointed out.

"We hypothesize that having an anti-inflammatory diet dampens levels of systemic inflammation in the body, thereby slowing the progression of neurodegenerative damage and vascular injury in the brain and making it less likely for an individual to experience cognitive impairment and, eventually, dementia," she added.

The findings dovetail with other research about brain health and inflammatory diets. In the Framingham Heart Study Offspring cohort, for example, a pro-inflammatory diet was associated with smaller total brain volume. And a study in Greece showed that older adults with the highest inflammatory diet scores were three times more likely to develop incident dementia than those with the lowest scores.

Dove and co-authors followed 84,342 dementia-free adults ages 60 and older in the from baseline to January 2022. Of these, 8,917 participants underwent brain MRI between 2014 and 2020. Dementia diagnoses were based on information from inpatient records, self-reported medical history, and death registers.

Participants completed the , a 24-hour dietary assessment, up to five times during the study. From the participants' average intake of 31 dietary parameters, the researchers calculated (DII) scores as anti-inflammatory, neutral, or pro-inflammatory.

The parameters included macronutrients, micronutrients, bioactive components, foods, and spices. Anti-inflammatory parameters included flavones; flavanols; beta-carotene; fiber; garlic; ginger; green or black tea; magnesium; polyunsaturated fatty acids; omega-3 fatty acids; vitamins B6, A, C, D, E, and zinc; and other food components. Pro-inflammatory parameters included saturated fat, carbohydrates, cholesterol, trans fat, and more.

Mean age of participants was about 64 years; 51.2% were women, and 16.7% had at least one cardiometabolic disease at baseline. Type 2 diabetes was determined by medical records, self-report, and prescription records. Heart diseases included myocardial infarction, atrial fibrillation, and heart failure; these, plus stroke, were ascertained by medical records and self-report.

Median follow-up was 12.4 years; in that period, 1,559 participants (1.9%) developed dementia. As a continuous variable, a higher DII score was associated with a significantly increased risk of dementia.

Joint effect analyses showed that participants with cardiometabolic disease and an anti-inflammatory diet had larger gray matter volume (β = -0.15 vs β = -0.27) and smaller white matter hyperintensity volume (β=0.05 vs β=0.16) compared with those with a pro-inflammatory diet.

The presence of significant interactions between cardiometabolic disease status and dietary inflammatory potential in this study "could suggest that the potential benefits of an anti-inflammatory diet for cognitive and brain health may be more pronounced in people with cardiometabolic diseases," Dove and co-authors wrote. "This warrants deeper investigation in future studies."

The findings may be influenced by volunteer bias in the U.K. Biobank sample and may not apply to other groups, the researchers acknowledged.

"This is an observational study in which anti-inflammatory diet was associated with more favorable brain MRI markers and lower risk of dementia, but this does not necessarily imply a causal relationship," Dove said. "Interventional studies in which participants are randomized to an anti-inflammatory versus a pro-inflammatory diet would be required to conclusively test this hypothesis."

  • Judy George covers neurology and neuroscience news for , writing about brain aging, Alzheimer’s, dementia, MS, rare diseases, epilepsy, autism, headache, stroke, Parkinson’s, ALS, concussion, CTE, sleep, pain, and more.

Disclosures

This study was funded by grants from Alzheimerfonden, Demensfonden, Lindhés Advokatbyrå, the Swedish Research Council, the Swedish Council for Health Working Life and Welfare, and the Karolinska Institutet Board of Research.

Dove and co-authors reported no conflicts of interest.

Primary Source

JAMA Network Open

Dove A, et al "Anti-inflammatory diet and dementia in older adults with cardiometabolic diseases" JAMA Netw Open 2024; DOI: 10.1001/jamanetworkopen.2024.27125.