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Eating an anti-inflammatory diet of whole grains, fruits and vegetables instead of a pro-inflammatory diet focused on red and processed meats and highly processed foods such as sugary cereals, sodas, chips and ice cream reduced the risk of dementia by 31%, a new study finds.
This benefit even applies to people with existing diagnoses of cardiometabolic diseases such as type 2 diabetes, heart disease or stroke, said Abigail Dove, lead author of the study published Monday in the journal JAMA Network Open.
“An anti-inflammatory diet was associated with a lower risk of dementia, even in people with cardiometabolic disease who already have an increased risk of dementia,” Dove, a doctoral student at the Center for Research on Aging at the Karolinska Institutet in Solna, Sweden, said in an email.
In fact, people with type 2 diabetes, stroke or heart disease who ate the most anti-inflammatory foods “developed dementia two years later than people with cardiometabolic disease and a pro-inflammatory diet,” she added.
Dove said brain scans of those who followed an anti-inflammatory diet also showed significantly lower levels of brain biomarkers for neurodegeneration and vascular injury.
Although this is an observational study and cannot show cause-and-effect relationships, the results reflect existing research showing a link between diet-related inflammation and brain health, Dr. David Katz, a preventive and lifestyle medicine specialist who was not involved in the study, said by email.
“It is very likely that a higher quality, less inflammatory diet over time has direct effects on several areas related to brain health and neurocognitive function,” said Katz, founder of the nonprofit True Health Initiative, a global coalition of experts committed to evidence-based lifestyle medicine.
The exact biological effects of food on inflammatory processes are not yet fully understood, but researchers believe that the consumption of sugary, highly processed foods and the high levels of saturated fat from red and processed meat that are common in the Western diet, together with pollution, cigarette smoke, radiation, plastics and pesticides, may lead to increased activation of free radicals in the body.
Free radicals are molecules with unpaired electrons. In their search for a suitable match, they steal electrons from other cells, causing cellular damage that can contribute to Alzheimer’s disease and other dementia and chronic diseases.
In addition, researchers believe that highly processed and fatty foods may also trigger higher levels of other inflammatory biomarkers such as C-reactive protein, interleukin 6, and tumor necrosis factor α.
A November 2020 study found that people who ate more red and processed meats, such as bacon and sausage, and sugary, ultra-processed foods, had a 28% higher risk of stroke and a 46% higher risk of heart disease. According to a February 2019 study, just a 10% increase in such foods was significantly associated with a 14% higher risk of death from all causes.
But there is a way to fight back: According to the Mayo Clinic, research suggests that anti-inflammatory elements such as vitamins, carotenoids and flavonoids in foods like fruits and vegetables can neutralize free radicals and other inflammatory markers and reduce stress on the body.
The new study analyzed the dietary habits of over 84,000 dementia-free adults over 60 who had been diagnosed with type 2 diabetes and/or heart disease or stroke. They were part of the UK Biobank, a longitudinal study with participants from England, Scotland and Wales.
Each person was asked five times about their consumption of 206 foods and 32 beverages, divided into pro-inflammatory and anti-inflammatory nutrients. Over the next 15 years, medical records were examined to see if there was a link between consuming the least or most inflammatory foods and being diagnosed with dementia. In addition, nearly 9,000 of the participants also had brain magnetic resonance imaging (MRI) scans.
The research found that people with cardiometabolic disease who ate the most anti-inflammatory foods had greater gray matter volume—indicating less neurodegeneration—and lower white matter intensity, indicating vascular damage in the brain, compared to people who ate a pro-inflammatory diet.
Although more research is needed, overall “the signal clearly stands out from the background noise,” said Katz.
“Even when struggling with chronic cardiometabolic disease, switching to a higher quality diet appears to provide some protection to the brain, reducing and delaying both functional and anatomical signs of deterioration.”
