Recent Study Indicates Lost Sense of Smell May Signal Alzheimer's

Posted Jul 2, 2007 by Pamela Jean

A recent study, conducted over a five year period asked participants to identify a dozen different scents. Of those that scored lowest, 50 per cent were likely to develop cognitive impairment leading to Alzheimer's Disease.
Excuse me - 50 per cent? That sounds less than definitive to me.
OK. So we're going to study 600 people between the ages of 54 to 100 over the next 5 years. We ask them to identify 12 scents ranging from cinnamon to bananas. Based upon their ability to smell, we are going to determine whether they will develop Alzheimer's Disease.
Sure. Well, let's first look at the choice of scents.
In the study, 600 people between the ages of 54 and 100 were asked to identify a dozen familiar smells: onion, lemon, cinnamon, black pepper, chocolate, rose, banana, pineapple, soap, paint thinner, gasoline and smoke. I'm feeling pretty confident at this point. They might be able to throw me off between soap and lemon - could be a lemon scented soap, but for the most part these seem pretty obvious to me.
Next, we'll look at statistics.A quarter of the people correctly identified all the odors or missed only one. Half of them knew at least nine of the 12. The lowest-scoring quarter of the people correctly identified eight or fewer of the odors.
The subjects took 21 cognitive tests annually over the next five years. About one-third of the people developed at least mild trouble with memory and thinking.
The people who made at least four errors on the odor test were 50 percent more likely to develop problems than people who made no more than one error. Difficulty identifying odors also was associated with a higher risk of progressing from mild cognitive impairment to Alzheimer's.
Alright, is it just me, or is anyone else looking at this statistics and thinking, um, so what? The brilliant deduction on behalf of the scientific analysts is that 50% of old people might develop Alzheimer's. And this is based upon the fact that as they grew older they couldn't remember what paint thinner versus gasoline smelled like?
You know what I smell? A rat. Who ever is funding research like this is not getting their monies worth, in my opinion.
A result that shows a 50/50 chance of developing anything is just that - a 50/50 chance.
Flip a coin. It would be a lot cheaper. But don't tell that to the researchers. They need jobs too, right?