Sense of Smell May Predict Parkinson's
Study: Elderly Men With Poor Scores on Smell Test May Be More Likely to Develop Parkinson's Disease
March 21, 2008 -- A poor sense of smell may help predict
Parkinson's disease in elderly men, according to a new study.
The study included 2,267 men of Japanese ancestry living in Hawaii and
enrolled in a long-term health study.
The men took a smell test in the early to mid-1990s, when they were nearly
80 years old, on average. None had Parkinson's disease at the time.
Taking the smell test involved smelling 12 different odors, one at a time,
and correctly identifying them. The
12 odors were banana, chocolate, cinnamon, gasoline, lemon, onion, paint
thinner, pineapple, rose, soap, smoke, and turpentine. The men got one point
for every correct answer.
Over the next eight years, 35 men were diagnosed with Parkinson's disease.
Those men tended to have low scores on the smell test four years before their
Other factors -- including age and past
smoking habits -- didn't affect the results.
"We found that impaired olfaction is associated with an increased risk
of Parkinson's disease within four years," write G. Webster Ross, MD,
of Honolulu's Veterans Affairs
Pacific Islands Health Care System, and colleagues.
It's not clear how the sense of smell and Parkinson's disease are related,
or if the findings apply to women. And the findings don't mean that all older
men who have trouble identifying odors will develop Parkinson's disease.
The study appears in the February 2008 edition of the Annals of