How sweet it is to smell. The nose is a hardworking organ, with powers much greater than most people realize. A keen sense of smell offers more flavors, more safety, even more happiness.

But be warned—human olfactory powers degrade as the years go by, resulting in a detectable loss by the time many people reach their 30s. Gradually, it can deteriorate to the point where people are unable to notice the odor of rancid food or a household gas leak.

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