Tel Aviv: Israeli scientists have developed a nasal spray that zaps the brain plaque doctors believe is the cause of Alzheimer’s disease.

The spray which contains bacteriophages, a virus which scientists call “phages” has only been used to treat mice with a disease similar to Alzheimer’s. But it is hoped a version for humans will go on sale within seven years.

The spray attacks beta amyloid, a sticky protein that destroying connections between brain cells in Alzheimer’s sufferers.

In tests on mice, regular treatment for a year with the spray reduced the amount of amyloid in their brains by 80 per cent. The drug also improved the mice’s memory and learning, and restored their sense of smell, which is often lost early in the onset of Alzheimer’s.

Experts are predicting an Alzheimer’s epidemic by 2050 as life expectancies increase.