Stress Leaps When the Task Lacks Bounds, Tests Find

Most of us love a challenge. At least we do when we feel the payoff is worth it and we have the ability to do the job. When researchers examined how people react to well-defined tasks compared to those that are open-ended, they found that, sure enough, the ones that didn’t have a set limit caused the greatest cardiovascular response.

In experiments reported in the journal Psychophysiology, researchers asked college students to perform various tasks while their heart rate and blood pressure were monitored. For instance, they were told to push a button on a computer mouse every 10 seconds at one-minute intervals. Then they were given what’s called an “unfixed challenge.” They were asked to press the button as many times as possible within a minute.

Blood pressure and heart rate were consistently higher when the students were attempting the unlimited task.

What does this mean to the salesman without a quota or the weightlifter with all the time in the world at the gym? Rex A. Write, professor of psychology at the University of Alabama at Birmingham, says, “It’s probably in their best interest from a health point of view to set reasonable goals rather than to work or work out as if the sky was the limit.”

Study Contests IUDs’ Bad Image

One of the most convenient and effective forms of birth control, the intrauterine device, can’t shake its bad rap. Call it guilt by association. In 1974 one IUD, the Dalkon Shield, was taken off the market because it caused serious infections, and all other types were tainted by the debacle. Before then, about one in 10 married American women relied on IUDs for birth control. Now less than 1% do. The reasons may be doctors’ fear of lawsuits and a belief that IUDs cause pelvic inflammatory disease (PID), a serious infection that can cause infertility.

The results of a survey of 400 doctors published in the February issue of Obstetrics and Gynecology found that only 17% had inserted more than 10 IUDs in the last year, despite the fact that more than 90% of the gynecologists knew that the device is safe and effective. Twenty percent of doctors had not inserted a single IUD in the last year.

According to the authors of the study, there is no evidence that the doctors’ fears about pelvic inflammatory disease are warranted. Dr. Nancy Starwood, currently an assistant professor of obstetrics and gynecology at the University of Rochester Medical Center in New York, says the risk of pelvic infection is less than 1% during the three weeks following insertion of the device, and then drops steeply to 0.14%.

Considering that nearly half of the pregnancies in the U.S. are unintended and that about half of those are because of contraceptive failure or misuse, Starwood hopes that women and their doctors will reconsider the option. “Now is the perfect time for the renaissance of IUDs,” she says. The research was performed at the University of North Carolina at Chapel Hill.

White Spots on Your Teeth

Children and adults with white spots on their teeth may have too much fluoride to blame. Although adding fluoride to water has been the subject of controversy for years, a report published in the Journal of the American Dental Assn. says other sources of fluoride contribute greatly to enamel fluorosis, or tooth mottling. Excessive fluoride consumption in early childhood when the permanent teeth are forming creates the mottling.

Researchers compared studies of enamel fluorosis in schoolchildren in the 1930s with surveys done in the 1980s. There was a significant increase in prevalence of the tooth mottling in the later decade among children in communities with varying amounts of fluoride in the drinking water, from the lowest to the highest levels. (Some of the communities had naturally fluoridated water.)

The explanation for the increase in fluorosis is that there were many sources of the cavity-fighting chemical that didn’t exist in the 1930s, such as prescribed supplemental drops and tablets. Fluoride-containing toothpaste also became very popular during those years.

Tooth spotting was especially common among children who were 8 years old or younger between 1972 and 1983, when there were so many sources of fluoride besides the water, says Dr. Eugenio D. Beltran-Aguilar, an epidemiologist at the Centers for Disease Control and Prevention and coauthor of the study.

Today many of these sources are rare, but one that remains temptingly tasty is toothpaste with fluoride. That’s one reason why the ADA advises using only a pea-sized amount of toothpaste on the toothbrush. It’s also smart to keep toothpaste out of young children’s reach.

Sadness Depresses Immunity

Another mind-body link has been made with the discovery that a person’s ability to resist infection may be diminished if he or she is even mildly depressed. Because as many as 20% of elderly adults have symptoms of mild but chronic depression, the results of a recent study in the Journal of Abnormal Psychology have serious health implications.

Researchers found that the immune cells of people with symptoms such as sadness, insomnia and difficulty concentrating did not proliferate in response to an invader as well as cells taken from people without signs of depression.

“These people may not heal as well after surgery and are more prone to complications, and they are more likely to be hospitalized,” says Dr. Lynanne McGuire, a researcher in the Behavioral Medicine Clinic at Johns Hopkins School of Medicine. She and her colleagues tested the immune responses of depressed and non-depressed people in an 18-month study.

McGuire says there is some natural decline in immunity with age, but it could be made even worse by prolonged mild to moderate depression, making a person more vulnerable to viral infections and some kinds of cancer.

Exercise Kicks In Drug Effects

Exercise is good medicine, but medicines of the pharmaceutical kind can cause problems when people work out more intensely than usual, especially if they have any cardiovascular problems or are taking several different drugs.

Physicians should alert active seniors to the side effects of anti-hypertension agents, diuretics, antidepressants, tranquilizers, diabetes drugs like insulin and sulfonylureas, and anticoagulants, says Dr. Fred H. Brennan Jr., author of a paper in the current issue of the Physician and Sportsmedicine. And if the doctor doesn’t bring up the subject, the patient should, he says.

Even the 64-year-old triathlete can run into problems with, say, beta blockers, says Brennan. “These drugs are designed to keep the heart rate down. If a person’s heart rate doesn’t increase appropriately with exercise, he may get dizzy.”

Brennan, one of the team physicians for the Ironman triathlon, explains that tricyclic antidepressants can interfere with sweating, causing a person to become overheated. Diuretics can lead to dehydration, muscle cramping and a sudden drop in blood pressure. And those beta blockers can mask jitteriness and other signs of hypoglycemia, which could cause problems for a diabetic. If side effects do occur, the prescription or the dose may need to be changed.

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Dianne Partie Lange can be reached by e-mail at DianneLange@ cs.com.