Nose In the earliest stages of Parkinson’s disease, one goes through an impaired sense of small and this could precede motor symptoms by several years. According to a study, your nose could warn you about the onset of the disease.

The study was conducted by researchers at the Pacific Health Research Institute in Hawaii. It found that smell impairment could precede the development of Parkinson’s disease in men by a minimum of four years.

The study was led by G.Webster Ross of the VA Pacific Islands Health Care System and the Pacific Health Research Institute in Honolulu, Hawaii. It included 2,267 men who received an olfactory test and were followed for up to 8 years thereafter to find out if they developed the disease.

During the follow-up period, 35 men had developed Parkinson’s Disease. The results thus showed that a smell identification deficit could predate the development of Parkinson’s disease by at least four years. However, it was not a strong predictor beyond this time period.

A decreased ability to identify odors was associated with older age, smoking, more coffee consumption, less frequent bowel movements, lower cognitive function and excessive daytime sleepiness, but even after adjusting for these factors, those with poor odor identification had a five times greater risk of developing PD.

The pathology of smell impairment in PD is not completely understood, but nerve loss and the formation of Lewy bodies, which are abnormal clumps of proteins inside nerves cells that are thought to be a marker of PD, are known to take place in the olfactory structures of patients with the disease.

The authors said that one study involving brain dissection of dead patients with neurological disease found that olfactory structures are the earliest brain regions affected by Lewy degeneration, which supports the idea that an impaired sense of smell could be one of the earliest signs of the disease.