Inability to smell could expose you to Alzheimer's disease

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New Delhi: Unable to distinguish between the smell of two things could point to the risk of Alzheimer's disease, says a study.

Researchers say that the damage to brain associated with Alzheimer's disease (AD) occurs up to 20 years before symptoms start showing.

Scientists are therefore interested in finding ways to detect the presence of the disease early on.

The findings, published in the journal Neurology, suggest that simple odour identification tests may help track the progression of the disease before symptoms actually appear, particularly among those at risk.

"Despite all the research in the area, no effective treatment has yet been found for AD," said one of the study authors John Breitner of McGill University in Canada.

"But, if we can delay the onset of symptoms by just five years, we should be able to reduce the prevalence and severity of these symptoms by more than 50 per cent," Breitner said.

Close to 300 people with an average age of 63 who are at risk of developing AD because they had a parent who had suffered from the disease, were asked to take multiple choice scratch-and-sniff tests to identify scents as varied as bubble gum, gasoline or the smell of a lemon.

One hundred of them also volunteered to have regular lumbar punctures to measure the quantities of various AD-related proteins in the cerebrospinal fluid (CSF).

The researchers found that those with the most difficulty in identifying odours were those in whom other, purely biological indicators of AD, were most evident.

(With Agency inputs)