Healthy Life

Why keeping your blood sugar in check could reduce your risk of dementia

September 29, 2021

Keeping your blood sugar well controlled could help to reduce the risk of getting dementia later in life.

Studies have shown links between having lots of highs and lows in blood glucose levels and increased risk of cognitive impairment. 

Too little glucose starves the brain of the energy it needs to perform tasks, whereas frequent spikes in blood sugar can make the brain produce too much beta-amyloid, a protein which has been implicated in the development of Alzheimer’s disease.

Shannon Macauley, an assistant professor of gerontology at Wake Forest School of Medicine in the US, has studied the relationship between Alzheimer’s and type 2 diabetes. Her research suggests that the brain is vulnerable to too much glucose. 

She said: “[The brain] needs [glucose] on demand in a rapid fashion but that puts the brain at excess risk when glucose levels hit one extreme or another.”

Our brains may account for just 2% of our body weight, but the brain is extremely energy-hungry. It uses 20% – 30% of circulating blood glucose to power its vital functions. The brain cannot store excess glucose, unlike other organs, which makes it sensitive to highs and lows. 

What is a normal blue sugar level range? 

The measurement of blood glucose level in the UK is mmol/L. According to Diabetes UK, a healthy range for a non-diabetic is:

  • Between 4.0 to 5.4 mmol/L (72 to 99 mg/dL) when fasting (before a meal)
  • Up to 7.8 mmol/L (140 mg/dL) 2 hours after eating

You can use a blood glucose meter if you’d like to keep track of your sugar levels.

How to maintain a normal blood sugar level for optimum brain health

Eat well

The Mediterranean diet has consistently been shown to reduce the risk of cognitive decline as we age. This is because it includes plenty of fresh fruit, vegetables, healthy monounsaturated fats, less red meat, little alcohol and no processed foods – which all maintain blood sugar at moderate levels.

Lose excess weight

Carrying excess fat is a risk factor for type 2 diabetes, as well as many other health issues, so it is really important to keep a healthy weight. The NHS advises maintaining a MBI between 18.5 and 24.9. 

Keep active

The brain and body function better when you keep active, and moving more is proven to help moderate the level of glucose in your blood, as it helps increase insulin sensitivity. You should aim to do 150 minutes of moderate exercise every week, such as going for brisk walks, running or swimming.

Other things you can do to maintain a healthy brain

Our simple steps guide has some healthy habits you can put in place to help keep your brain healthy. You can also read our guidance on sleep, gut health and keeping an active mind.