A healthy lifestyle in middle-age can help to ward off Alzheimer’s disease, experts have advised.

Keeping trim, regulating blood pressure and lowering cholesterol can all reduce the risk of developing the devastating condition.

Writing in an editorial in BMJ Clinical Evidence they say that a recent panel of experts estimated that the risk could be cut by between 15 and 20 per cent.

In the journal, Dr Tom Russ and Professor John Starr, both experts in health and ageing at the University of Edinburgh, say: “Modification of these risk factors … is everybody’s business and healthcare professionals, health promotion bodies, the voluntary sector and even employers will have to play a role for a national reduction in dementia incidence to occur.”

Rebecca Wood, chief executive of the Alzheimer’s Research Trust, said: “Diet and lifestyle almost certainly plays a part in every person’s Alzheimer’s risk.

“These factors remain a magnet for research because they could offer relatively inexpensive ways to fight a disease that ruins countless lives.

“By taking regular exercise and eating a healthy diet, especially in mid-life, we may help reduce our risk of developing dementia as well as reaping numerous other benefits from living a healthy lifestyle.”

An estimated 820,000 people n Britain are thought to suffer from dementia, of which Alzheimer’s is the most common form.