Health and Medicine
We seem to be endlessly fascinated by our bodies and our health. In this issue of Search + Discover, University of Minnesota faculty and staff answer your questions, including:
Plus, you can explore further reading and related links.
Why is it that the heart doesn’t get cancer as often as other organs in the body?
The cells that make up the heart are different from those that form more cancer-prone organs such as the colon or the lungs, according to University oncologist Edward Greeno.
All cancers have, as a common underlying cause, the accumulation of genetic errors in individual cells, Greeno says. Occasionally, some of those errors are inherited, but more often they are acquired mutations.
“The common sites of cancer, like your colon or your lung, occur because of the cells that line the inside of your airways or the inside of your colon,” he says. “Those cells are reproducing all the time, and every time they reproduce they carry forward any errors they’ve accumulated and they have the opportunity to get more errors. Those properties make them very prone to cancer.”
In the heart, however, there is little cell turnover. “Even if the heart acquires a mutation, it’s unlikely to be reproduced and it has fewer opportunities to acquire mutations,” Greeno says. “Therefore, it’s both less likely to get a mutation and it’s less likely to reproduce that mutation. Thus, you have a much lower risk of getting cancer.”
Edward W. Greeno is director of the University of Minnesota Physicians’ Masonic Cancer Clinic and a member of the University Medical School faculty.
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Does it affect your health to live in suburbs or cities?
Where you live certainly affects your health, but is difficult to isolate as a determinant, says Ann Forsyth, professor of urban design. “In suburban areas, people may be dependent on cars and more likely to die in a car accident. In the inner city, pollution may be higher. Health is also affected, however, by people’s individual behaviors and their social and economic backgrounds. What sometimes seems to be a difference due to location may really be caused by something like income.
“Different places have different benefits. University of Minnesota research is showing that while people in the inner city have lots of opportunities to walk, those in the suburbs walk less but are active in other ways.”
Ann Forsyth is professor of urban design and director of the Metropolitan Design Center in the College of Design. Back to top
Will your lungs regenerate after quitting smoking--even if you’ve smoked for 25 years--and why can some people smoke for 50 years and never get lung cancer?
“Studies have shown that 10 years after quitting smoking, your risk of lung cancer is down to about one-tenth of the risk you had before quitting smoking. So quitting smoking significantly cuts down on the risk of lung cancer.
“However, if you have smoked for more than 10 years, you probably remain at some increased risk of lung cancer even if you quit. Your lungs do suffer some permanent damage if you smoke for 10 years or more, but the earlier you can quit, the quicker some healing can take place.
“I don’t know why some people who smoke get lung cancer while others do not, and neither does anyone else. Although smoking increases your individual risk of getting lung cancer by a factor of 20, the good news is that most heavy smokers will not come down with lung cancer. Unfortunately, as mentioned in the previous paragraph, virtually all heavy smokers will develop some permanent lung damage such as emphysema even if they do not get lung cancer.
“In research originally done at the University of Minnesota over a decade ago, it was found that some people probably are more susceptible to developing lung cancer after smoking. In particular, women are at a higher risk of developing lung cancer than men if they smoke. Unfortunately, we still do not know how to identify any given individual’s risk for lung cancer after smoking. So in my opinion, the only sensible advice is to try and quit smoking if you currently do, or even better, to never start.“
--Robert Kratzke, a lung cancer specialist at the University of Minnesota Cancer Center.
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Will there ever be enough interest, time, and resources to find a cure for ALS (Lou Gehrig’s disease)?
“ALS is rare compared to diabetes or stroke, but, unfortunately, it is not rare enough; the lifetime risk of getting ALS is thought to be about 1 in 1,000. That means that out of 4 million people living in Minnesota today, 4,000 will get ALS, not nearly as rare as we would hope for a fatal disease.
“Furthermore, the degree of research effort is not simply related to disease prevalence, but to disease severity (nothing tops ALS on that score) and specific elements of the disease process. In bygone eras research focused on infectious, inflammatory, or vascular diseases, but today neurodegenerative diseases like ALS are a primary focus of the National Institutes of Health, and of the University of Minnesota.
“Currently at the University of Minnesota, there are many basic science and clinical scientists focusing on improving our understanding and ability to control ALS. At the University of Minnesota’s ALS Clinic, we are joining with the local community, the ALS Association, the Muscular Dystrophy Association, and the National Institutes of Health to conquer this disease.
By definition, treatment of ALS cannot come soon enough--those of us seeing patients weekly with this disease know that too well. While increased ALS research funds would speed treatment development and delivery, recent advances convince me that our ability to control the disease will occur in years, not decades.”
--John Day, professor in the Department of Neurology.
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Is it true that the common cold is more contagious before symptoms occur, or at least at the very beginning of the symptoms?
“There are over 200 viruses that can cause the 'common cold.' Most of these fall into the rhinovirus category. It is commonly believed that viruses are most easily spread before, or at the onset, of symptoms. This is likely due to rapid viral replication in a person’s mouth, nose, and respiratory system. The newly exposed individual may not yet be taking precautions, such as frequent hand washing, to limit transmission to family members and coworkers.
“Rhinovirus is presumed to be spread similarly to influenza: primarily when a person with the flu coughs or sneezes near someone else. Adults with flu typically spread it to someone else from one day before symptoms start to about five days after symptoms develop. Children can spread the infection for more than ten days after symptoms begin, and young children can transmit six days or even earlier before the onset of symptoms. People with severely compromised immune systems can transmit the virus for weeks to months.”
--Nancy Baker, physician, Boynton Health Service.
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Is it bad to clean the wax out of your ears?
"Ear wax is a normal product created by specialized glands in the ear canal, and it collects debris, dead skin cells, and other foreign materials that get into the canal.
It is impossible for someone to adequately clean the surface of the eardrum. Wax removes the cells and airborne debris from this area, forcing it out of the canal. Ear wax reduces infections and prevents bacteria from taking hold in the warm dark recesses of the ear canal.
"Everyone should have some wax in their ear. The normal path of this material is to come to the outside of the ear where it can be directly cleaned. A small amount of warm water and a washcloth is adequate for removal of this natural cleansing agent.
"The old adage that you shouldn’t put anything smaller than your elbow in your ear is true. I would strongly urge people to be careful about putting anything in the ear canal, even the commonly marketed Q-tip. Every year a small number of people create perforations of their eardrum by probing too deeply in the ear canal. This can be associated with permanent hearing loss, vertigo, and a need for urgent surgery.
"As we age, the cartilages of the ear canal ‘relax.’ This allows the ear canal to drop slightly and instead of being ovoid in shape it becomes almost slit-like. This causes ear wax to accumulate and block the canal.
"While there are procedures that can be performed to restore the anatomic orientation of the ear canal, many times the ear canal can be safely cleaned. Direct cleaning by a doctor or over-the-counter solutions can be helpful. It is absolutely critical that you know that there is no hole in the eardrum before starting, and the pressure exerted in the ear canal should be fairly minimal. Improperly performed irrigations and manipulation can be as dangerous for the patient as putting a Q-tip all the way down the canal. It would appear that collection of wax in some individuals can be a sign of more serious diseases and therefore needs to be checked by a physician."
—Samuel C. Levine, Department of OtolaryngologyBack to top
Can exposure to the elements cause illness?
U librarian Karla Block says that "according to the National Institute of Allergy and Infectious Diseases, there is no evidence you can get a cold from exposure to cold weather. Colds may be more common during colder months because people spend more time indoors around others and because seasonal changes in relative humidity allow better survival for cold-causing viruses.” She also says that childhood health experts at the Nemours Foundation state that going outside with wet hair won’t cause you to catch a cold, but dry air, allergies, lack of sleep, stress, and improper nutrition can all lower resistance to infection.
But she points to new research at Cardiff University’s Common Cold Centre, where researchers are investigating whether exposure to cold weather may cause the onset of cold symptoms. "One 2005 study found that students whose feet were chilled in cold water had twice as many colds over the next five days when compared to a control group,” says Block. “Researchers there suggest a new theory for the seasonality of colds. They propose that resistance to infection is lowered because our noses are colder during colder months. Latent viruses already present in the nose may replicate and cause cold symptoms when blood vessels in the nose constrict in cold weather.”
Karla Block is one of more than 100 librarians serving the University’s Twin Cities campuses. For this question, she consulted Web-based health resources from trusted sources. For more information on health information resources, visit the Bio-Medical Library.
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Last modified on June 13, 2008