Researchers say there are around 400 types of smell (olfactory) receptors in your nose, and it's their job to detect an enormous array of scents — from stinky to soothing.

You know that wonderful aroma of fresh-brewed coffee that greets you every morning? It's the result of 800 distinct types of molecules that travel from your cup to your smell receptors.

With such complex activity going on in your olfactory nerves, it's no wonder research shows that loss of smell is associated with declining cognition and Alzheimer's.

But new research by University of California, Irvine, neuroscientists found that wafting essential oils (using a diffuser) into the bedroom of people ages 65 and over for two hours a night for six months boosted their cognition by 226%. The study used seven different oils, one each night over the course of a week.

But what is aromatherapy?

It's the use of essential oils such as lavender, Ylang Ylang, jasmine, lemongrass, and patchouli to waft a scent throughout a room. As the molecules of aroma reach your brain, they affect what is called the limbic system, which impacts memory, blood pressure, breathing, and emotions.

The aromas’ potent benefits do come with potential risks for some, including people with allergies or asthma, and those who are pregnant or have high blood pressure. And no one should ever use them at full strength on the skin or orally.

Ask your doctor about giving this memory-booster, a try using a diffuser. And check out "11 Essential Oils: Their Benefits and How to Use Them," at My.ClevelandClinic.org.