Diabetes News
Insulin protects brain from Alzheimer's damage
February 9th, 2009
The most common form of dementia may be closely related to another common disease of old-age - type 2 diabetes - say scientists. Treating Alzheimer's with insulin, or with drugs to boost its effect, may help patients, they claim.
The Journal Proceedings of the National Academy of Sciences reports insulin could protect against damage to brain cells’ key to memory. UK Alzheimer’s experts said the find could be the basis of new drug treatments. The relationship between insulin and brain disease has been under scrutiny for some time since doctors found evidence that the hormone was active there.
The latest study looked at the effects of insulin on proteins called ADDLs, which build up in the brains of Alzheimer's patients and cause damage. Large sticky plaques of amyloid beta protein are a hallmark of Alzheimer's, which causes memory loss, confusion, the inability to care for oneself and eventually death. The researchers took neurons - brain cells - from the hippocampus, a part of the brain with a pivotal role in memory formation. These were treated with insulin and a drug called rosiglitazone, given to type 2 diabetics to increase the effect of the hormone on cells. After treatment, the cells were far less susceptible to damage when exposed to ADDLs, suggesting that insulin was capable of blocking their effects. The study sheds light on how insulin interacts with toxic proteins linked to the disease.
People with diabetes are at higher risk of developing Alzheimer's. It is well known that insulin affects how the brain works, and this research adds more evidence to the possibility that Alzheimer's could be a type of brain diabetes. Alzheimer's affects 30 million people globally and in the UK, there are an estimated 450 000 sufferers. The numbers of people suffering from Alzheimer’s and those with Type 2 Diabetes are rising rapidly.
Treatment hope
Sensitivity to insulin can decline with ageing, which presents a novel risk factor for Alzheimer's disease – these results demonstrate that bolstering insulin signalling can protect neurons from harm. Recognising that Alzheimer's disease is a type of brain diabetes points the way to novel discoveries that may finally result in disease-modifying treatments for this devastating disease.
This study is in its early stages but it is interesting because it suggests that insulin, alongside drugs that help the body use insulin more effectively, may protect against the underlying biological mechanisms associated with the development of Alzheimer's disease.
In Type 1 diabetes, your pancreas is not making insulin. In Type 2 diabetes, your tissues are insensitive to insulin because of problems in the insulin receptor. This newly-named ‘Type 3’ is where that insulin receptor problem is localized in the brain.
As you get older, some individuals start to have less effective insulin signalling, including in the brain, making the brain more vulnerable to toxins that cause Alzheimer's disease.
The findings suggest that measures to protect people from diabetes -- including a healthy diet and exercise -- are also important for avoiding Alzheimer's disease.
