The link between diabetes and dementia & why you should start reducing your risk now

Dementia. It’s something most of us fear as we head towards our latter years, and for a good reason.

According to Dementia Australia, there are currently an estimated 447,115 Australians living with dementia, with almost one in ten people over the age of 65 affected and 250 new cases diagnosed every day.

However, there’s increasing evidence suggesting Alzheimer’s disease and type 2 diabetes could be linked in ways we’re only beginning to understand. Some are suggesting of classifying Alzheimer’s as ‘type 3 diabetes’.

But what is the link and how can you reduce your risk? In this article I take a look at the link between the two conditions and explore how nutrition and lifestyle changes can help.

What’s the diabetes-dementia link?

In 2017, researchers from the Mayo clinic found an established link between Alzheimer’s and type 2 diabetes and a recent meta-analysis found that people with diabetes had a 56% higher risk of developing Alzheimer’s and a 127% higher risk of vascular dementia. Diabetes also appears to increase the risk of cognitive decline, particularly the longer you have the condition.
The reasons for this association are not fully understood but are most likely related to a number of different mechanisms including blood vessel damage which reduces blood flow to the brain, oxidative stress (an imbalance between free radicals and antioxidants in your body), inflammation and the formation of advanced glycation end-products (AGEs) due to high blood glucose levels.

AGEs are harmful compounds that form in the body when excess glucose attaches to proteins or fats and can play a role in ageing and the development of chronic disease. They can also be produced when cooking high fat and high protein foods.

But researchers from the Mayo clinic found another possible explanation. Some people have a gene called APOE4, which significantly increases their risk of developing Alzheimer’s. In a study in mice, the researchers found that the APOE4 gene seems to interfere with the brain’s ability to use insulin, which over time can cause brain cells to starve and die. This is where the reference to ‘type 3 diabetes’ or ‘diabetes of the brain’ comes from.

How to reduce your risk of diabetes and dementia

There is plenty you can do to reduce your risk of developing diabetes or manage your diabetes to prevent developing dementia. In fact, there’s good evidence that at least half of the risk of dementia is attributed to lifestyle factors including diet, exercise and smoking. Keeping blood glucose levels, blood fats and blood pressure well managed will also help.

Equally important, having the APOE4 gene doesn’t mean that Alzheimer’s is inevitable, and those with the genotype may benefit even more from making some lifestyle changes. Studies have shown that the following can help reduce your risk:

• Staying active – aim to exercise at least 30 minutes every day
• Eliminating alcohol and smoking
• Reducing the amount of saturated fats you eat
• Eating more foods rich in B12 vitamins
• Eating more fruits, vegetables and whole grains

Vegans and vegetarians are at greater risk of vitamin B12 deficiency, as it’s a vitamin that’s found almost exclusively in animal foods. Some plant-based milks including soy milk and almond milk are fortified with vitamin B12. Read our article on how you can get enough B12 if you’re vegan or vegetarian.

These lifestyle changes are the same healthy habits that are important for managing a lot of different chronic health conditions, including diabetes and heart disease. Apart from adopting healthy lifestyle habits, keeping your brain mentally active and addressing loneliness and depression is also just as important.

Why healthy lifestyle habits matter

A UK study which followed 2,235 men over 35 years, found that five healthy lifestyle factors were associated with a reduced risk of cognitive impairment and dementia, as well as a reduced risk of diabetes, heart disease and stroke. These were exercising regularly, not smoking, eating a healthy diet, keeping a low body weight and having a low alcohol intake.

Men who followed four or five of these healthy behaviours had a 64% lower risk of cognitive impairment and dementia. In this study, a healthy diet was considered as one that was low in fat (less than 30% of energy) with three or more servings of fruit and vegetables each day.

When it comes to fat intake, research suggests unsaturated fats may be protective while a higher intake of saturated fat can increase the risk of dementia, particularly in those with the APOE4 gene. Read more about the difference between unsaturated and saturated fats here.

Tips for a healthy brain

While usually diagnosed later in life, the disease processes contributing to dementia occurs over several decades. So rather than waiting until your memory starts to fail, it’s best to start taking action now. This is even more important if you have diabetes.

A great place to start is Dementia Australia’s Your Brain Matters program, which is based on scientific evidence that health and lifestyle factors are associated with brain function and the risk of developing dementia. The program recommends five simple steps:

1. Look after your heart
2. Be physically active
3. Mentally challenge your brain
4. Follow a healthy diet
5. Enjoy social activity

You can find out more about each of these steps and join their 21-day brain health challenge by visiting their site.

For more information on nutrition and lifestyle advice for people living with type 2 diabetes, check out our latest downloadable nutrition fact sheet.