In 1974, when Mac Davis sang the song "Stop and Smell the Roses," he crooned: "There's a whole lot more to life than work and worry."

Well he was right. But half of people age 65 to 80 and 80% of those over 80 can't smell the roses or much of anything else. That stinks.

Loss of sense of smell is associated with neurogenerative conditions such as Alzheimer's and Parkinson's, even before symptoms are evident, as well as cardiovascular disease, nutritional deficiencies such as iron anemia (what you can't smell, you don't eat), and immune disorders.

Research that appeared in JAMA Otolaryngology — Head & Neck Surgery looked at 11 studies from around the globe and found that being unable to identify even two of 12 odors was a sign that a health problem such as diabetes or kidney disease may be developing or worsening.

Loss of smell is not only associated with disease risks. If you can't smell a gas leak, a fire, or spoiled food, that threatens your well-being.

If you find that smells from flowers, food, or a passing truck have faded or disappeared from your everyday experiences, tell your doctor. Get a physical and cognitive checkup to identify signs of impending health issues. Many can be slowed or reversed if you take aggressive action early.

And practice smelling four aromas daily: coffee, onions, lemons, and lavender.