Patients with Alzheimer's disease show rapid shrinkage of the brain - 15 per cent a year - which is 10 times faster than occurs in normal ageing, and this might be exacerbated by poor blood flow to the brain.
Professor David Smith, the head of the department of pharmacology at Oxford University, said that people might be able to cut the chances of developing Alzheimer's in later life if they took up regular exercise and a healthy diet. "Several established risk factors for vascular diseases, such as heart disease and stroke, might also be possible risk factors for Alzheimer's disease.
"The risk factors include atherosclerosis, smoking, high cholesterol, previous heart attacks and atrial fibrillation [heart flutter]," Professor Smith said.
"These epidemiological associations need to be confirmed in larger studies but, if they are confirmed, then they raise the hope that preventative medicine can be applied to Alzheimer's disease."
In Britain there are between 600,000 and 800,000 people who suffer from Alzheimer's, and this is expected to double within the next 30 years because of the ageing population, Professor Smith told the British Association.
If a poor blood flow to the brain is linked with an increase in the risk of brain shrinkage, it may be possible to concentrate on preventive strategies that can lower the incidence of Alzheimer's.
"People should be aware that Alzheimer's disease is not an inevitable part of ageing and that it might be modified by environmental factors.
"The striking success of preventative medicine, such as the cessation of smoking, lowering blood cholesterol and by diet or changes in lifestyle in lowering the incidence of heart disease and stroke is one of the major achievements of modern medicine.
"If a proportion of those who develop Alzheimer's disease do so because of exposure to the same risk factors, then similar measures could be tested to see if they also reduce the incidence of Alzheimer's disease," Professor Smith said.
"Before any steps can be taken, it will be necessary to carry out long and expensive clinical trials in several thousand subjects to see whether modification of one or more of these risk factors can influence the development of dementia."Reuse content