Nosing around finds those at risk of Alzheimer’s

SCIENTISTS yesterday revealed a top 10 list of smells, including lemons and leather, which can be used to help predict which patients will develop Alzheimer’s disease.

The inability to smell certain odours can determine which patients with minimal or mild cognitive impairment will go on to develop Alzheimer’s, the researchers said.

The smells they believe are the best predictors of the disease are strawberry, smoke, soap, menthol, clove, pineapple, natural gas, lilac, lemon and leather.

The researchers, presenting their results at the American College of Neuropsychopharmacology annual meeting, said their odour identification test was a strong predictor of Alzheimer’s.

The team, from the New York State Psychiatric Institute, said their results were similar to tests measuring reduction in brain volumes on MRI scans and memory tests in acting as potential predictors.

Estimates suggest that 2%-5% of people over 65 and up to 20% of those over 85 suffer from Alzheimer’s, a progressive brain disorder which gradually destroys the memory.

The five-year study involved testing 150 patients with mild cognitive impairment using the 10 odours every six months, alongside 63 healthy elderly subjects.

Columbia University professor of clinical psychiatry and neurology Dr Davangere Devanand said: “Narrowing the list of odours can potentially expedite screening and help with early diagnosis.”

The researcher said studies involving the brains of Alzheimer’s patients showed that nerve pathways involved in perceiving and recognising odours were affected at a very early stage.

“Early diagnosis of Alzheimer’s disease is critical for patients and their families to receive the most beneficial treatment and medications.

“While currently there is no cure for the disease, early diagnosis and treatment can help patients and their families to better plan their lives,” Dr Devanand said.

Alzheimer’s Society head of research Dr Susanne Sorensen said: “The sense of smell is affected in dementia like the other senses, but anecdotal evidence suggests that the ability to smell and identify some odours disappears faster than the other senses.

“There is still no 100% certain way of diagnosing Alzheimer’s disease while a person is alive and the physician relies on several tests to reach a best clinical judgment.

“A test that is quick to carry out and non-evasive would, if proven to work, be a significant step forward.

“The Alzheimer’s Society is funding a study into a person’s ability to smell lavender.

“There are many types of dementia and this research is investigating whether they affect a person’s sense of smell differently.”