Scientists uncover Alzheimer's clues

Alzeimer's disease affects the brain

Taking exercise and eating a healthy diet to ward off heart disease may also help to prevent Alzheimer's disease, researchers say.

Meanwhile, a separate study has found that Alzheimer's may be caused by brain cells beginning to divide in an unregulated way.

A team from Newcastle University has discovered that elderly people who suffer from heart disease may also be at risk of Alzheimer's disease.

They found that almost 80% of the patients with Alzheimer's disease in their study had a form of cardiovascular disease known as arteriosclerosis.

This is damage to the blood vessels exiting the heart caused either by a build up of a fatty material or degeneration of the wall of the blood vessel.

The researchers also discovered that patients with both diseases were more likely to carry a particular version of a gene called the apolipoprotein E-epsilon 4 allele.

They concluded that arteriosclerosis and Alzheimer's could be closely linked.

It may be that Alzheimer's is partly caused by a poor blood supply starving the brain of key nutrients and leading to cell damage.

Lead researcher Professor Raj Kalaria said: "Measures taken to change lifestyle or eating habits that improve cardiovascular function, may be protective against Alzheimer's disease."

Nerve cell division

In separate research, a team from Oxford University have found evidence that Alzheimer's disease develops after nerve cells start dividing in an unregulated way.

In healthy elderly people control mechanisms stop the division process, and the affected nerve cells re-establish their connections within the brain without any further consequence.

However, in Alzheimer's disease the regulatory mechanisms that control cell division are faulty and the cell division process goes too far.

The nerve cells start to produce Alzheimer-type deposits and form tangles, which lead to the confusion of messages in the brain.

Lead researcher Dr Zsuzsanna Nagy said: "Our results show that cell division starts due to high levels of a molecule that builds up during folic acid deficiency, called homocystein.

"We also found that loss of connections between nerve cells may play a role too."

It is estimated that 15 % of the population over 65 years old will develop Alzheimer's disease.

This percentage is set to double with every decade.