Anti-inflammatory diet may help reduce dementia risk

• A large study investigated the role of diet-related inflammation in older adults with cardiometabolic diseases, such as type 2 diabetes.
• Compared to a proinflammatory diet, following an anti-inflammatory diet was associated with a reduced risk of developing dementia.
• An anti-inflammatory dietary pattern was also linked to reduced signs of damaged blood vessels in the brain and a larger volume of gray matter in the brain.

Earlier studies have linked cardiometabolic conditions, which include type 2 diabetes, heart disease, and stroke, to an increased risk of dementia.

Some experts believe that inflammation may be the mechanism that binds these conditions together. A recent study published in JAMA Network Open asks whether anti-inflammatory diets might reduce dementia risk in older adults with cardiometabolic diseases.

Over a 15-year follow-up, the scientists observed that dementia risk was 31% lower for those following an anti-inflammatory diet compared with those following a pro-inflammatory diet.

Those with an anti-inflammatory diet also had a larger volume of gray matter — a marker of cognitive functioning, or the ability to think — and fewer signs of damage to the brain’s blood vessels.

Why inflammation is in the spotlight

In recent years, scientists have found links between many chronic conditions and persistent, or chronic inflammation. These include type 2 diabetes , cardiovascular disease , autoimmune conditions , depression , and more .

Because of this, many consider all instances of inflammation to be bad, but that is not fully justified. It is the body’s first line of defense following injury or infection. Inflammation protects against invaders, plays a role in wound healing, and is vital for our survival.

However, if inflammation is not properly regulated or persists beyond its necessary function, it can cause harm. This is usually referred to as chronic inflammation , which can eventually cause damage to the body’s cells, tissues, and organs, contributing to chronic diseases.

Like many processes in the body, inflammation needs to be finely balanced. This fine balancing act can become more challenging in certain disease states and also as we grow older.

Cardiometabolic conditions are associated with an increased risk of developing dementia, and some experts believe that inflammation may underpin this relationship.

Correspondingly, the current study found that cardiometabolic diseases were associated with an 81% increased risk of developing dementia.

Because diet can influence inflammation — for better or worse — the authors of the new study decided to investigate links between pro-inflammatory and anti-inflammatory diets and dementia risk in people with cardiometabolic disease.

Diet and inflammation: Why the link?

Research has shown that the Western diet, which typically includes red meat, refined grains, full-fat dairy, eggs, and processed foods, is linked to raised levels of inflammatory markers in the blood.

On the other hand, diets that are rich in fruits, vegetables, whole grains, legumes, and fish are linked to lower levels of inflammatory markers .

In their recent study, the authors assessed participants using the Dietary Inflammatory Index (DII). This tool assigns dietary components scores:

• A negative score means the compound is anti -inflammatory.
• A positive score means it is more pro -inflammatory.

For instance, fiber scores -0.663, whereas saturated fat scores 0.373.

Medical News Today contacted one of the study’s authors, Abigail Dove, MSc . She told us that previous research has shown that “anti-inflammatory diets are associated with a lower risk of dementia.”

However, she explained that the recent study is unique, because “it considers the relationship between diet and dementia in the context of a major dementia risk factor: cardiometabolic diseases.”

Investigating pro-inflammatory diets and dementia

The researchers analyzed data from 84,342 older adults from the ongoing UK Biobank study . These individuals were aged 60 and older and did not have dementia at the start of the study. Scientists followed them for up to 15 years.

As part of the UK Biobank research, participants provided information about their diet. A subset of 8,917 participants also had magnetic resonance imaging (MRI) brain scans.

At the start of the study, 14,079 participants had at least one cardiometabolic disease, and by the end of the study, a total of 1,559 developed dementia.

31% lower dementia risk

According to the analysis, individuals with cardiometabolic disease who followed an anti-inflammatory diet had a 31% reduced risk of developing dementia compared with individuals with similar conditions who followed a pro-inflammatory diet.

As the authors write, they also had “significantly lower levels of MRI markers of neurodegenerative and vascular brain damage.”

The analysis showed that individuals following an anti-inflammatory diet developed dementia an average of 2 years later than those with a pro-inflammatory diet.

When the researchers assessed the MRI scans, they found differences between the two groups. Those who ate a more anti-inflammatory diet had a greater volume of gray matter. This part of the brain is vital for navigating the world; it processes sensory information and plays pivotal roles in movement, speech, and much more.

Compared with the pro-inflammatory diet, those following an anti-inflammatory diet also had lower levels of white matter hyperintensity. This is a sign of cerebral small vessel disease and is linked to cognitive decline and dementia.

“Together, these results highlight an anti-inflammatory diet as a modifiable factor that may support brain and cognitive health among people with [cariometabolic diseases],” the authors conclude.

How to follow an anti-inflammatory diet

Dove provided some examples of foods with anti-inflammatory properties:

• fruits (especially berries)
• green leafy vegetables
• extra virgin olive oil
• whole grains
• fish
• green tea
• some spices, like garlic, ginger, and turmeric

“In contrast,” she explained, “red meat, high-fat dairy, refined grains, and processed foods may increase systemic inflammation and are best avoided for both cardiovascular health and brain health.”

For more information about anti-inflammatory diets, MNT has an extended list of foods , and a collection of recipes .

MNT spoke with Federica Amati, PhD , a postdoctoral medical scientist and nutritionist at ZOE, who was not involved in the study.

“This study reinforces the need to advise adults to follow a diet that is anti-inflammatory consisting of regular consumption of plants, healthy fats, and polyphenol-rich foods,” she explained.

Polyphenols are plant defense compounds that nourish the gut microbiome. They are present in particularly high amounts in colorful fruits and vegetables.

Conclusions and the way forward

The study did have some limitations. As the research was observational, the study cannot prove causation. The data the researchers used from the UK Biobank is also limited in diversity, so it may not be generalizable to the broader population. The self-reported nature of the diets also makes it subject to bias.

One other important point to mention is that the DII looks at individual dietary components in isolation and does not account for which sources foods come from (such as plant vs. animal origin) or how they are prepared (as cooking methods can affect the nutrient content of foods).

“It is great to see a study analyzing a large cohort later in the life course,” Amati told MNT . “The potential for improving public health and the quality of life in our aging population is exciting and should be a priority across the lifespan, including in older adults.”

According to Dove, “diet modification is a potential strategy to reduce the likelihood of dementia in this high risk group.” Because treatments for dementia do not work for everyone, and there is no cure, investigating ways to reduce risk is vital.

As for the future, Dove plans to continue in this vein.

“We are currently examining other dietary patterns, such as a plant-based diet, in relation to dementia risk and brain MRI outcomes,” she told MNT .