Understanding diabetes and brain health

Our recent Dementia Attitudes Monitor survey found that only 39% of people think it’s possible to reduce their risk of developing dementia. But research shows that up to 45% of dementia cases worldwide may be linked to factors we can influence. 

One of these factors is diabetes, a condition that affects an estimated 5.8 million people in the UK. According to the Dementia Attitudes Monitor, only 4% of UK adults surveyed, named diabetes as a risk factor for dementia. To mark Diabetes Week (8 – 14 June), we thought we’d take a closer look at this link. 

But first, what is diabetes? 

The basics 

Diabetes is a health condition that causes people’s blood sugar levels to become too high. When this happens, it causes symptoms like feeling thirsty all the time, tiredness, and losing weight without trying to. There are two main types: 

Type 1 diabetes is an autoimmune disease that tends to develop early in life. It happens when the body can’t produce a hormone called insulin, which helps regulate blood sugar levels. It’s the less common form – about one in 10 people with diabetes in the UK have type 1. 

Type 2 is the most common type of diabetes and mostly affects people over 25. It happens when the body doesn’t produce enough insulin, or when the insulin it does produce isn’t working properly. The biggest risk factor is obesity or being overweight, but other factors like ethnicity and family history can also impact a person’s risk of developing it. 

How does diabetes affect brain health? 

Scientists don’t yet fully understand the link between diabetes and brain health. However, research suggests that there is a strong association between the two. 

One example of this comes from the Whitehall II cohort study, which recruited more than 10,000 British civil servants in the 1980s and has tracked their health outcomes over time. 

Results from the study, which was published in 2021 and focusses on type 2, show that people who developed type 2 diabetes earlier in life were more likely to also develop dementia later on. The younger they were when they developed type 2 diabetes, the more likely they were to develop dementia. 

Influential Lancet Commission on Dementia Intervention and Care which regularly assesses the overall evidence around dementia risk – has identified type 2 diabetes as a risk factor.  Some evidence suggests that people with type 1 could also be at an increased risk of dementia, however more research is needed to confirm this. 

What these studies don’t show is exactly how diabetes and dementia are linked. However, we know that diabetes can have a negative impact on people’s heart health, and that people with diabetes are more likely to develop high blood pressure and high cholesterol. These conditions are also linked to an increased dementia risk, even in people without diabetes. 

It’s important to point out that, while the link between diabetes and increased dementia risk is supported by a growing number of high-quality studies, there’s been less focus on whether taking steps to prevent or manage diabetes causes this risk to fall. 

But experts agree that taking steps to lessen your risk of diabetes, and actively managing the condition if you have it, could be an important way to help protect your brain health. 

What can I do? 

Although there’s currently no way to prevent type 1 diabetes, some cases of type 2 can be prevented. Many of the activities that are known to help protect your brain health – such as eating healthily and being active – can also help you avoid this type of diabetes. 

One person who knows this is Alzheimer’s Research UK supporter, Elaine. 

With a family history of diabetes and a previous diagnosis of pre-diabetes, Elaine uses her passion for long-distance running to keep herself fit, avoid developing the condition, and as a way to support her brain health. 

A parkrunner and ultra-distance runner, she has taken part in Alzheimer’s Research UK’s Guatemala Trek and Jurassic Coast hikes to raise money for dementia research in memory of her mum, Jeannette, who had Alzheimer’s disease. 

She said:

 

Given my mum had Alzheimer’s, I want to do everything in my power to reduce my risk of getting dementia. Managing pre-diabetes is an important way to do that.  

I want to be fit and healthy enough to continue my passion of long distance running because I know how much it helps not only my physical health, but my brain health too. 

For those living with a health condition such as diabetes, movement can sometimes feel intimidating. We Are Undefeatable shares hints and tips to make movement work for you. 

If you already have either type of diabetes, managing it effectively is also an important way to take care of your brain. As well as eating well and staying active to help keep your blood sugar levels in check, there may be treatments available to help. For example, people living with type 1, and some with type 2, will need to take insulin. 

If you have diabetes and would like more information about how to manage it, please speak to your GP.  

Our research

There’s still lots that scientists don’t know about the link between diabetes and dementia. However, we’re funding research projects to help improve understanding. 

For example, Dr Joyce Huang is researching whether a group of drugs currently used to treat type 2 diabetes could also prevent vascular dementia. 

“We’re going to analyse the medical records of people with type 2 diabetes who developed vascular dementia in their lifetimes,” says Dr Joyce Huang. “We’ll look at those who were taking thiazolidinediones (TZD) and those who weren’t to see if these drugs can lower the risk of developing vascular dementia.” 

With this work Dr Huang will build the evidence that will be needed to conduct larger clinical trials into this repurposed drug. 

We also funded a study by Prof Bettina Platt and Dr Zara Franklin at the University of Aberdeen.   They investigated a gene called BACE1 and its role in Alzheimer’s and diabetes. Findings from the project suggest the gene is linked to inflammation and cell stress, which occur in both diseases, providing more clues as to how Alzheimer’s and diabetes could be linked. 

Check-in with your brain

The evidence shows that preventing or managing diabetes can help protect your brain health. But there are also other steps you can take to look after your brain. 

Take the Think Brain Health Check-in today to explore your brain healthy habits and find tips on how to give back to your brain. 

If you’d like to find out more about diabetes, please speak to your GP or visit the Diabetes UK website.