The Secrets in Our Sense of Scent
Do you smell the roses? Lilacs in spring rain? The alarming odors of things burning or rotting? The answer may be more important than you think. Scientists are discovering that an impaired sense of smell is one of the earliest signs of Alzheimer's and Parkinson's and other neurodegenerative diseases.
The Quality Standards Subcommittee of the American Academy of Neurology has endorsed smell testing as an aid to the diagnoses of these diseases, writes Richard L. Doty, though such testing is still not routinely performed in neurology clinics. In an article in The Scientist, Doty, director of the Smell and Taste Center at the University of Pennsylvania's Perelman School of Medicine, describes recent research that shows difficulty smelling - a condition called hyposmia - is often an important early warning signal. He cites a pioneering study by Amy Bornstein Graves and colleagues at the University of South Florida who administered smell tests to 1,604 senior citizens who had no symptoms of dementia. Overall, people who had no sense of smell and one genetic risk factor for dementia were five times more likely to develop cognitive decline in the next two years than people whose sense of smell was not impaired. Further, Doty notes, the smell test was more predictive than cognitive test scores.
Doty, who has developed smell and taste tests, writes that olfactory test results can help doctors with diagnosis and treatment. Alzheimer's and Parkinson's diseases (AD and PD) are often misdiagnosed in patients suffering from other afflictions, including severe depression or supranuclear palsy, which are not accompanied by loss of smell and are not helped by drugs used to treat AD and PD. In some patients with mild AD, he adds, smell tests can indicate responsiveness to a drug that does improve cognitive function in some patients.
Is olfactory dysfunction the result of damage that comes with neurodegenerative diseases, or does loss of smell precede the damage? Can damage to the olfactory system induce disease in those disposed to neurodegenerative disorders? Doty says further research is needed to answer those questions, and further an understanding of the relationship between smell and health. Watch Doty's slide presentation on the sense of smell. He begins it with a picture of a Lady and the Unicorn tapestry showing the lady weaving a garland of carnations to illustrate the sense of smell. Five of the fifteenth century tapestries depict the five senses and a sixth is believe to represent love or understanding.
Doty's article is one of several in The Scientist issue devoted to examining our sense of smell. Another by Ron Yu discusses pheromones. These elusive molecules, and the scents associated with them, are known to influence mating and other behavior in insects and some mammals. When it comes to human behavior, there's disagreement. If pheromones do exist in humans, the molecular machinery that would make them work is not clear. There is also evidence that smells can leave afterimages in the brain, even after the stimulus is no longer present, that influence memory. Marcel Proust, remembering the madeleines of his childhood, wrote that tastes and smells of the past "remain poised a long time, like souls, ..."
"Smell is a potent wizard that transports you across thousands of miles and all the years you have lived." Helen Keller
Friday, October 4, 1-2 PM ET
High Intensity Exercise
Guests: Chris Jordan, Robert Lindberg, and Elizabeth Ciemins
With a complexity-informed approach to fitness you can start improving your health in and seven minutes a day. You can do it in your home, and the most elaborate piece of equipment you need is your own body. But it's not supposed to be easy.
is the Director of Exercise Physiology for the Human Performance Institute, part of Johnson & Johnson's Wellness & Prevention business. Chris has been a specialist in the exercise physiology field for approximately twenty years. This practical body weight circuit workout (a.k.a. the "7-minute workout") was designed by Chris Jordan. He and Brett Klika co-authored the peer-reviewed article "High-Intensity Circuit Training Using Body Weight" in the American College of Sports Medicine's Health & Fitness Journal. Robert Lindberg
, MD, is an internal medicine physician with a practice in Darien, CT. He is an Instructor in Clinical Medicine at Columbia University. Among the first physicians to incorporate complexity concepts into the practice of medicine, he believes the practice of medicine is about interactions-inside the human body and outside in the environments where people live. Elizabeth Ciemins
is a Health Services Research Scientist and the Research Director of the Center for Clinical Translational Research at the Billings Clinic in Billings, Montana. She also holds part time faculty positions at the University of Montana, Missoula School of Public Health and Montana State University, Billings College of Allied Health Professionals. Read their complete bios
Nursing Network PlexusCalls
Wednesday, October 16, 1-2 PM ET
Population Health: A Growing Challenge
Guests: David Nash and Jeff Cohn
Population health is an approach to health that aims to improve the health of the whole population. This approach goes beyond the individual focus of mainstream medicine and public health to address factors like environment, social structure and resource distribution. Population health examines social determinants of health and seeks to reduce health inequities. With health reform a national priority, the need for population health management has never been more eminent.
In 2008, Thomas Jefferson University in Philadelphia established the first designated School of Population Health in the country, dedicated to the exploration of policies and forces that determine the health and quality of life of populations, locally, nationally and globally. The School offers graduate academic programming in public health, population health sciences, health policy, healthcare quality and safety, and applied health economics and outcomes research.
, Founding Dean of Jefferson School of Population Health, and Jeff Cohn
, President of Plexus Institute, will join the call to talk about the concept of population health; the need for better ways to address behavioral factors, social circumstances and environmental exposures; and how JSPH is creating a curriculum to prepare leaders to work at the level of policies and systems to secure better health for everyone. Read their complete bios
Audio from all PlexusCall series are available by searching the iTunes store for plexuscalls. Or, visit plexusinstitute.org
under Resources/Call Series.