Inflammation might cause Alzheimer’s – here’s how to reduce it

There is growing evidence that ongoing inflammation in various parts of the body might trigger Alzheimer’s disease. It will take many years for the science to be settled, but what is clear is that persistent inflammation has many negative effects and the things you can do to reduce it have lots of other benefits.

Inflammation occurs when immune activity is higher than normal – for instance, when a scratch gets infected and becomes swollen and sore. Short-term inflammation is usually a good thing, but when inflammation needlessly persists for months or years, it can cause or contribute to many conditions, including cancer, heart disease, strokes and rheumatoid arthritis, as well as to mental health conditions, such as depression and anxiety.

Doing what you can to reduce long-term inflammation will almost certainly benefit your physical and mental health. Here’s how:

1. Get vaccinated

Several vaccines – including those against shingles, tuberculosis and flu – have been shown to reduce the risk of dementia. For instance, people given a shingles vaccine called Shingrix were 17 per cent less likely to develop dementia in the next six years than those given an older shingles vaccine called Zostavax, which itself already reduces the risk of dementia. Exactly why isn’t certain, but one explanation is that these vaccines reduce inflammation.

2. Brush and floss

Gum disease, a form of inflammation, increases the risk of Alzheimer’s and of heart disease too. This may be because when gums bleed, bacteria can enter the bloodstream. Maintaining good dental hygiene helps prevent gum disease – and stops your breath smelling bad.

3. Eat a Mediterranean diet

Some foods reduce levels of inflammatory immune signals in the blood, while others increase them, possibly due to their effects on our gut microbiome. Anti-inflammatory foods include fruits, beans, nuts, whole grains, fish and olive oil, while inflammatory ones include red or processed meat. In other words, the Mediterranean diet is anti-inflammatory and has, of course, long been linked to other benefits, such as a longer life.

4. Exercise regularly

One of the ill effects of spending too much time sitting at a desk or slumped on a sofa is higher levels of inflammation, but numerous studies have found that exercising reduces many signs of this. A 2021 review found that the intensity of exercise doesn’t seem to matter. Yoga works too, according to a 2024 meta-analysis, though it notes that the quality of most studies was poor. Given all the other benefits of exercise, this is a no-brainer.

5. Maintain a healthy weight

Many studies have found that obesity leads to persistent inflammation, though the precise mechanisms are unclear. So, if inflammation is, in turn, linked to dementia, will taking GLP-1 weight-loss drugs such as semaglutide (commonly sold as Ozempic) lower the risk of developing Alzheimer’s? We don’t yet have a full answer.

People taking GLP-1s to treat type 2 diabetes do have a lower risk of developing dementia, but it isn’t yet clear if this is also true for people who don’t have type 2 diabetes. What is clear is that GLP-1s don’t help treat Alzheimer’s in people already diagnosed with the condition.

6. Be happy

A little stress every now and then serves a purpose, but the downsides of being constantly stressed include inflammation. If you are happy, at least most of the time, you have probably got the balance right.