Got a sweet tooth? It could lead to Alzheimer’s disease

Got a sweet tooth? It could lead to Alzheimer’s disease

Image: Andrew Crowley

New research has revealed that those with high blood sugars levels could be prone to contracting Alzheimer’s disease.

Scientists from the Washington University School of Medicine in St Louis found that high levels of blood sugar could increase the amount of rogue proteins that form plaques in the brain.

This confirms previous studies that diabetes could also be a cause of Alzheimer’s disease.

Why does increased blood sugar lead to Alzheimer’s Disease?

The research showed that higher levels of glucose in the blood rapidly increases the levels of the protein amyloid beta. This protein is known to form sticky plaques in the brain, which prevent neurons from firing and communicating effectively.

These plaques then start to kill off the nerves, causing memory loss in the first instance, and then, as the disease progresses, loss of bodily functions.

The study used mice and found that increased blood sugar led to higher amounts of amyloid beta.

People who have high blood sugar levels tend to eat sweeter, sugary foods than those who don’t. High blood sugar levels are also found in diabetes sufferers. People with diabetes cannot control the glucose in their blood. In this study, mice were bred with a condition similar to Alzheimer’s, and then injected with glucose.

The study showed that in the younger mice that did not have amyloid plaques, by doubling the amount of glucose in the bloodstream, these proteins increased in the brain by 20 per cent.

In the older mice however, where plaques were already present, it was shown that by increasing the glucose the mice received, the amount of amyloid beta rose by 40 per cent.

Shannon Macauley headed up the study and said: “Our results suggest that diabetes, or other conditions that make it hard to control blood sugar levels, can have harmful effects on brain function and exacerbate neurological conditions such as Alzheimer’s disease.

“This observation opens up a new avenue of exploration for how Alzheimer’s disease develops in the brain as well as offers a new therapeutic target for the treatment of this devastating neurologic disorder.”

Dr Laura Phipps, of Alzheimer’s Research UK, said: “There is a large body of evidence linking diabetes to an increased risk of dementia but the biological mechanisms underlying this link are not yet fully understood. Further investment in research is crucial.”

Alzheimer’s disease is said to affect around 5.2 million Americans, according to data from 2013. And the older you get, the more at risk you become. In people over the age of 65 years, it is estimated that one in nine people has Alzheimer’s. It is also believed to be the third leading cause of death in US citizens, only falling behind cancer and heart disease.

What is the similarity between Alzheimer’s Disease and diabetes?

Previous studies have pointed towards increased blood sugar as having a major effect on the risk of developing Alzheimer’s disease. It is thought that the problem lies by the body having to constantly burn glucose for fuel by the brain.

The similarity between Alzheimer’s disease and diabetes has even led to some experts calling Alzheimer’s ‘type 3 diabetes’.

Back in 2005, studies showed that the brain also produces insulin, and this insulin is vital for the brain cells to survive. The brain insulin assists with the neuron glucose-uptake and helps to regulate neurotransmitters, such as acetylcholine. Acetylcholine is important for memory and learning.

Research has shown that people with type 2 diabetes tend to have less brain volume, in particular grey matter, than those of a similar age without diabetes. Loss of grey matter is also a contributing factor for increased risk of dementia.

There have been other studies that suggest people with lower than normal levels of insulin and insulin receptors in their brain tend to suffer from Alzheimer’s disease. However, recent research has also shown that consuming too much sugar and other carbohydrates can also lead to brain disruption, whether you are diabetic or not.

The original study was published in the Journal of Clinical Investigation

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