As we age, we experience a form of chronic low-grade inflammation in our immune system. Experts have linked this kind of age-related inflammation to dementia and cognitive decline. Research suggests that different foods can influence rates of inflammation both acutely and chronically.
Researchers have recently investigated the link between inflammatory diets and the risk of dementia in older individuals in Greece and found that those consuming highly inflammatory diets were over three times more likely to develop dementia than those consuming antiinflammatory diets.
What is an Anti-Inflammatory Diet?
Our immune system becomes activated when it recognizes anything that is foreign, such as an invading microbe, plant pollen or chemical. This often triggers a process called inflammation. Intermittent bouts of inflammation directed at truly threatening invaders protect our health.
However, sometimes inflammation persists, day in and day out, even when we are not threatened by a foreign invader. That’s when inflammation can become our enemy. Many major diseases that plague us—including cancer, heart disease, diabetes, arthritis, depression, and Alzheimer’s—have been linked to chronic inflammation.
Many studies have shown that components of foods or beverages may have antiinflammatory effects.
Foods linked to high rates of inflammation include processed foods, sugar, excess amounts of red meat and alcohol. In comparison, foods that are known for their anti-inflammatory properties include: fish, fruits, vegetables, nuts and seeds, tea and legumes.
New Study Findings
Recently, researchers from the United States, Greece, and Ireland conducted a population based-study involving men and women to investigate the effects of inflammatory diets on cognitive decline.
The researchers selected individuals from the Hellenic Longitudinal Investigation of Aging and Diet, which is a population-based study that tracks the epidemiology of dementia and other neuropsychiatric conditions in the aging Greek population.
They evaluate the participants every 3 years and select 1,059 individuals for their analysis. None of the participants had dementia at their first evaluation, and they provided dietary information on the main food groups they had consumed within the past month.
The researchers assessed the participants’ diets using the Dietary Inflammatory Index (DII), which is a tool that can assess the inflammatory potential of a person’s diet. It includes 45 food parameters, such as macronutrients and micronutrients, bioactive compounds, and spices.
The researchers split the participants into three equal groups according to how inflammatory their diets were:
- The first group, which had the least inflammatory diets, had DII scores ranging from -5.83 to -1.76.
- The second group had DII scores of between -1.76 and 0.21.
- The third group, which had the most inflammatory diets, had scores of between 0.21 and 6.01.
Per week, those with the most anti-inflammatory diets consumed an average of:
- 20 servings of fruit.
- 19 servings of vegetables.
- 4 servings of beans and other legumes.
- 11 servings of coffee or tea.
Meanwhile, those with the most inflammatory diets consumed an average of:
- 9 fruit servings per week.
- 10 vegetable servings per week.
- 2 legume servings per week.
- 9 coffee and tea servings per week.
The researchers found that those with the most inflammatory diets were 3.43 times more likely than those with the least inflammatory diets to develop dementia.
They explain that after around 40 years of age, our immune system starts to decline, and enters what is known as “inflammaging”, a state of increased proinflammatory mediators, that could reach the central nervous system and reduce brain-derived neurotrophic factor levels, which supports growth, maturation and maintenance of neurons.
Inflammaging is also linked to oxidative stress and the induction of apoptosis, or programmed cell death. These effects, note the researchers, make up some of the main neuroinflammatory and neurodegenerative pathways involved in dementia. Although inflammaging is a common factor of aging, research suggests that food components could exacerbate it.
The researchers conclude that more inflammatory diets are positively linked to a risk of dementia in community-dwelling older adults without a history of cognitive decline.
Annie Lennon (2021, Nov 15). Anti-inflammatory diets may protect against dementia. Medical News Today. Retrieved from: