Scents and Sensibility: What our sense of smell tells us about our health

Olfaction, smell, is an underappreciated sense often considered an aesthetic convenience in comparison to vision or hearing. Nothing could be further from the truth. In the last half century, olfaction has been shown to be an essential component of emotion, memory, and learning. More recent research demonstrates that incremental loss of smell precedes cognitive impairment and can be used as a clinical tool to predict dementia. Remarkable new data now suggest that olfactory training may prevent or reverse such memory loss.

First, let’s settle the score on smell’s position in the pantheon of senses. Olfaction is the primal sense. It detects food, predators and mates throughout the animal kingdom. It is a fetus’ only fully developed sense in the womb. Newborn humans are attracted to a pad impregnated with their mother’s breast smell, proof of an odor memory developed during the fetal stage.

Olfaction remains the most developed sense until age 10 when sight takes over. Smell and emotion are stored as one memory. Childhood experiences define smells we will like or hate for life.

An appreciation of flavor is possible because of smell. Flavor disappears in the absence of smell. Hold your nose while eating vanilla ice cream and you will only taste sweet.