A recent study has discovered that an early warning sign of Alzheimer’s disease is losing your sense of smell, which is rather shocking. This study was published in JAMA Neurology which showed that older people with worse sense of smell were more likley to have mental difficulties which can progress to Alzheimer’s disease.
Morewover, according to the study’s findings, the sense of smell could be used in order to help screen for Alzheimer’s disease, cognitive impairment and other forms of dementia as well.
This study was conducted on 1,400 seniors with an average age of 79 and normal mental functioning. The experts conducted intermittent smell tests on the participants and they had to scratch and sniff different odors chosing the correct answer from 4 options. They were given to smell both food and non-food odors like gasoline, paint thinner, banana, onion and turpentine.
Even 250 people developed mild cognitive impairment (an early stage of mental decline which can involve problems with memory and judgement) after the follow-up period of three and a half years. Even though it doesn’t affect everyday life, it can still lead to declining mental health and dementia. 64 of the participants with mild cognitive impairment developed dementia, including Alzheimer’s disease.
Another thing that the experts discovered is that those with worse scores on the smell test were 2.2 times more likely to develop mild cognitive impairment. The experts also made a correlation between bad test scores and the development of Alzheimer’s disease and they discovered that improvement in smell test scores was connected to an improvement in the severity of dementia.
Rosebud Roberts, lead researcher on the study and a professor of neurology at Mayo Clinic, said:
“The findings suggest that doing a smell test may help identify elderly, mentally normal people who are likely to progress to develop memory problems or, if they have these problems, to progress to Alzheimer’s dementia,”.
He believes that smell tests could be a standard screening tool for elderly patients. The smell tests could give the first signs of mild cognitive impairment, but also to help predict whether those who already have cognitive decline are likely to progress to Alzheimer’s disease or other types of dementia.
The experts believe that Alzheimer’s disease as well as other forms of dementia are affecting the parts of the brain which distinguish smell. These parts of the brain may be the first to deteriorate with dementia.
The lead research of the study and a proffesor of neurology at Mayo Clinic, Dr. Rosebund Roberts, claims that some people might score low on the smell test many other different reasons like respiratory conditions or chronic sinus.
Note: it should also be mentioned that this study didn’t prove a cause – and –effect relationship. Further research needs to be done on the link between declining sense of smell and developing dementia. Latest statistics prove that one of the most common forms of dementia is Alzheimer’s disease. About 10 to 25% of seniors are estimated to have mild cognitive impairment.