It was long-observed that decreased sense of smell (olfaction) can predict the development of certain degenerative brain diseases, such as:
- Parkinson’s disease
- Multiple sclerosis
- Alzheimer’s Disease
- Autoimmune conditions.
It was also observed that certain fragrances, such as lemon and lavender essential oils have a positive effect on stress, skin reactions, and one’s mood. One study, for example, showed that smelling lemon essential oil can really boost your mood.
But a recent study published in the medical journal Annals of Medicine reached an even more striking conclusion: they found that healthy and active seniors over the age of 70 were almost 50% more likely to pass away in the course of the next 10 years if they have a relatively worse sense of smell. The researchers cannot explain what accounts for a large percentage of the deaths, as of the 2289 participants only 22% passed away due to neurodegenerative conditions, 6% percent died as a result of weight loss and the rest are unresolved. What’s even more surprising is that a poor sense of smell was the strongest predictor of mortality in the group of participants with excellent and good health. Thus, the study concluded that a good sense of smell in your 70’s and 80’s can predict longevity, whereas bad olfaction increases the risk of mortality. In addition, other studies suggest that a bad sense of smell can be one of the first symptoms of neurodegenerative and autoimmune diseases, although the data regarding the immune effects are mainly limited to animal models.
Takeaway: Keep a close eye on your sense of smell and see your doctor if you observe that your olfaction reduced dramatically or rapidly, as it may be a warning sign of a more serious problem.