A team of Italian scientists have claimed that restricting the number of calories you eat will ensure your brain keeps functioning properly for longer by activating genes linked to longer life.

Tests on mice showed those who only consumed 70% of their typical daily calorie intake lived on average a third longer than normal and demonstrated better memory and mental functions.

Dr Giovambattista Pani, who led the research, said: "This discovery has important implications to develop future therapies to keep our brain young and prevent brain degeneration and the ageing process."

Eating fewer calories triggers a protein called CREB1 which in turn activates the 'healthy' genes and Dr Pani hopes to ultimately develop a drug containing CREB1 to enable people to maintain a healthy, youthful mental state without the need for a restrictive diet as they grow older.

However, mice in trial who'd had their sirtruin molecules (which are associated with longevity) deactivated did not achieve the same benefits from dieting so further research is needed before human trials.

The findings come in the same week as MPs launched an investigation into undiagnosed dementia based on survey results that we revealed on MHT showing six in ten people with the condition are not diagnosed.

Baroness Sally Greengross, chairman of the All Party Parliamentary Group on Dementia, said: "Almost 60 per cent of people with dementia are struggling in the dark without a diagnosis.

"Because their condition has not been recognised they are being denied vital support, information and possible treatments - this can’t carry on. We need to find out why this is happening and open the door to a better life for people with dementia across the UK."