Losing sense of smell may be linked to Alzheimer's

Published on Tuesday 12 January 2010 21:29

LOSING your sense of smell could be an early indication of Alzheimer's disease, research suggests.

Scientists found that changes linked to the most common form of dementia begin in mice in an area of the brain responsible for recognising smells.

Affected animals had to sniff odours for longer to remember them than healthy mice. They also had problems differentiating between smells.

Noticing similar changes in humans may help in the early detection of Alzheimer's, before the disease has done lasting damage to the brain, say the researchers.

Reduced smelling ability in the genetically engineered mice was linked to the appearance of amyloid plaques – sticky lumps of protein in the brain that are believed to play a key role in Alzheimer's.

The findings were reported in the Journal of Neuroscience.

Professor Ralph Nixon, of New York University Langone Medical Centre, said: "These novel results provide a two-fold benefit, not only in confirming that olfactory problems may serve as an early indicator of Alzheimer's, but that further validation in humans could facilitate testing of new therapies for the disease."

Around 700,000 people in the UK suffer from dementia, almost two-thirds of whom have Alzheimer's. The figure is expected to rise to more than a million by 2025.

Often the disease is not diagnosed and treated until it has reached an advanced stage.

Rebecca Wood, chief executive of the Alzheimer's Research Trust, said: "Amyloid is a key player in Alzheimer's and this research suggests it could interfere with the ability to smell. Although this research is on mice, we hope that further studies can help us understand and better diagnose Alzheimer's in people.

"Diagnosing Alzheimer's early is essential as this is when future treatments are likely to be most effective, before irreversible damage to brain cells has occurred."