10 aromas linked to Alzheimer’s detection

Scratching & Sniffing

Could a simple scratch & sniff reveal your true state of mind?

Scientists have known for some years that the ability to identify aromas is diminished in patients with Alzheimer’s disease (AD). Exactly why this is so may never be known. But no matter, because researchers at Columbia University recently conducted a trial that may be an important step in turning this phenomenon into a key diagnostic tool.

The sniff that fails

The Columbia researchers recruited more than 200 subjects who were asked to identify 40 different scratch-&-sniff aromas. About three quarters of the subjects had been diagnosed with mild memory impairment. The others served as control subjects. After being tested, the memory-impaired patients were followed for an average of five years to track the development of Alzheimer’s disease. Results of the study were presented last month at the annual meeting of the American College of Neuropsychopharmacology.

When the Columbia team analyzed their completed data alongside the results of other Alzheimer’s/aroma trials, the researchers narrowed the 40 aromas to a list of ten that were shown to be the most accurate in determining AD risk:

• Clove
• Leather
• Lemon
• Lilac
• Menthol
• Natural gas
• Pineapple
• Smoke
• Soap
• Strawberry

Remarkably, the Columbia test had a greater degree of accuracy in predicting AD than other tests that used genetic testing or brain imaging.

Home testing

With a caution that’s typical of most researchers, the Columbia team notes that more testing will need to be done before the reliability of an aroma test can be trusted. But in the meantime, if you or someone you know is having memory problems and can’t identify some of the aromas listed above in a blindfold test, you could certainly take that as an indication that it’s high time to talk to your doctor about further testing.

And because the aroma test signifies the potential of an early stage of AD, that means there’s still time to take steps to address the problem.

In the e-alert “Not a Stitch Too Soon” (11/11/02), I told you about a major review of 33 different trials that examined the effects of ginkgo biloba in the treatment of dementia. Conducted by the Cochrane Collaboration (an international, not-for-profit organization that oversees systematic reviews of health care interventions), the researchers found “convincing evidence” that ginkgo biloba may benefit cognition, emotional function, and activities of daily living in patients who are in the early stages of Alzheimer’s.

Furthermore, many patients experienced positive results within just three months, using a dosage of less than 200 mg per day. There were also no significant differences in adverse side effects between ginkgo and placebo groups in the various studies.

The ginkgo effect

For some time now, enthusiasts of ginkgo biloba have made the claim that the herb not only sharpens cognition for healthy people, but also helps address the symptoms of Alzheimer’s disease and other forms of dementia. Ginkgo is believed to perform two primary functions that create these positive results: dilation of blood vessels and thinning of the blood. In addition, ginkgo may also produce antioxidant effects that protect nerve cells in the brain from deterioration.

In the 2002 e-Alert I told you about preparation for a trial in which ginkgo would be tested on patients with memory loss typical of the early stages of dementia. Unfortunately the startup of this trial was delayed and only recently got underway. Researchers at the Imperial College of Science, Technology and Medicine have recruited 250 subjects over the age of 55 with early signs of dementia. For six months they’ll receive 120mg of ginkgo extract daily or a placebo. Needless to say, I’ll be keeping an eye out for the results.

Too bad this study doesn’t also include a before-and-after aroma test.

Sources:
“Simple Smelling Test Detects Alzheimer’s Risk” Alison McCook, Reuters Health, 12/13/04, reutershealth.com
“Researchers Put Ginkgo on Trial for Treatment of Dementia” AlzheimerSupport.com, 8/20/04, alzheimersupport.com