Physicists Warn Against CT Scans for the Healthy

For most people, having a CT scan as a sort of high-tech checkup not only puts you at risk of a false alarm about your health, it unnecessarily increases your exposure to radiation. For those reasons, the American Assn. of Physicists in Medicine is cautioning healthy consumers about whole-body scans.

Other medical associations, such as the American College of Cardiology and the American College of Radiology, have issued warnings, but the AAPM, a group with special expertise in the physics of medical radiation, emphasizes the danger of radiation exposure. According to the group’s statement, posted on its Web site, www.aapm.org, the typical whole-body CT scan delivers hundreds of times the radiation of a chest X-ray.

“The risk of that causing a radiation-induced cancer is unknown,” says Robert Gould, president of the association and a professor of radiology at UC San Francisco. “The question is, is that risk--however small--worth the benefit?”

CT scans for people without symptoms “has not currently been found to be scientifically justifiable or clinically efficacious,” the association said, also citing concerns about cost and the detection of minor problems that lead to unnecessary medical examinations and expenses.

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Starchy Foods May Increase Odds of Developing Pancreatic Cancer

People who are overweight and sedentary are already bumping up their risk for developing cancer. Now a study shows that the kind of carbohydrates they eat could affect their risk of developing a particularly aggressive malignancy, cancer of the pancreas.

By examining the dietary records of 89,000 women participating in the Nurses’ Health Study, an ongoing research project at Boston’s Brigham and Women’s Hospital, scientists found that overweight women who don’t get much exercise and eat a lot of starchy foods are 2 1/2 times as likely to develop the cancer than if they ate other kinds of carbohydrates.

The researchers were prompted to look at starchy foods because previous studies had indicated that excessive amounts of insulin enhance the growth of cancer cells in the pancreas. Starchy foods such as white and rye bread, white rice, and potatoes raise glucose levels higher--and so increase insulin production more--than other types of carbohydrates, such as leafy green vegetables, whole grains and beans.

People who are overweight and sedentary often already have abnormally high glucose and insulin levels. For them, starchy foods push those levels even higher.

Lean and fit people are more sensitive to insulin, so they don’t have to produce as much as overweight, insulin-resistant people do, even when they eat starchy foods. And this study found that the lean women were far less likely to develop pancreatic cancer than their overweight, inactive counterparts.

Replacing some of the foods that send insulin levels soaring with other sources of carbohydrates like green leafy vegetables and fruit is going to improve your health, not only by reducing the risk of pancreatic cancer, but by lowering the risk of diabetes and cardiovascular disease as well, says Charles S. Fuchs, a co-author of the study and an oncologist at the Dana-Farber Cancer Institute. “At the same time, it’s clear from this research that being lean and fit is also protective,” he says.

Journal of the National Cancer Institute 94(17): 1293-1300

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Next Time You Feel Faint, Try Crossing Your Legs

People prone to fainting spells might try a leg-crossing, muscle-tightening maneuver recently put to the test at the University of Amsterdam. It’s a simple technique that--unlike lying down or putting your head between your legs--isn’t obvious to others. The trick is to do it early.

Assuming the so-called cocktail party posture keeps blood from pooling in the veins--one reason why people with a tendency to faint tend to pass out when they have to stand for a long time. As the veins dilate, the heart rate drops.

Emotional stress can cause a similar response, which is why a sudden shock can trigger fainting.

To test the intervention, Dutch researchers induced fainting in 20 people with a history of vasovagal syncope, a condition that causes blood to pool in the legs. The volunteers were placed on a table that could be tilted, causing them to become lightheaded and nauseated. All of the patients had a drop in blood pressure when this happened and half had a drop in heart rate.

With the table then tilted so they were upright, the participants crossed their legs, and tensed the muscles of the abdomen, legs and buttocks, relieving their symptoms. None of them fainted.

Circulation 2002: 106 (pages not available yet.)

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A Soy Diet Early On May Lower Risk of Breast Cancer Later in Life

Women who consume tofu, fresh soybeans, miso and soy milk when they’re young may be developing defenses against breast cancer later in life. A study of Asian Americans in Los Angeles County found that women who ate a soy food at least once a week during adolescence had a 44% reduction in their risk of breast cancer as adults. Those who ate soy at least weekly as teens but stopped as adults had a 23% reduction in risk.

While Asian Americans don’t eat as much soy as their counterparts living in Asia, they still typically consume relatively high amounts. To see if the soy in their diets had an impact on breast-cancer risk, USC Keck School of Medicine researchers interviewed some 500 Chinese, Japanese, and Filipino women with breast cancer and about an equal number of healthy Asian women. Many of the women in this study moved to the U.S. as young adults.

Unlike those who ate soy as teenagers, women who didn’t eat much soy until their adult years had little reduction in breast cancer risk. However, because there were few women who fit this pattern, much larger studies are needed to determine if there is any benefit to starting to eat soy as an adult. The greatest risk reduction was among those who ate soy as adolescents and adults, even when the researchers took into account other risk factors for breast cancer.

According to the study’s co-author, Anna H. Wu, professor of preventive medicine at the Keck School of Medicine, it’s likely that those who ate soy as teenagers also ate it as young children. So although the study didn’t look at this, Wu says these results suggest that beginning early to eat some soy on a weekly basis seems beneficial.

Carcinogenesis 23(9): 1491-1496, 2002.

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Survey Finds Married Couples Mirror Each Other’s Health

When it comes to choosing a mate, we tend to marry those who are like us in terms of education, attractiveness and economic status. Now a study of more than 4,700 middle-aged couples finds that spouses also mirror each other when it comes to sickness.

Among couples who responded to a nationwide survey, men who were in excellent health had a 43% chance of being married to a woman in excellent health, but a man in poor health had only a 17.5% chance of being married to a woman in excellent health.

One reason for these findings is that education and economic status tend to predict health--well-educated people who are not financially stressed tend to be healthier. Another reason is that once married, couples share the same air, eat the same food, and have similar health habits. They share the same emotional stresses too. For instance, when one person is sick, which is stressful, the partner caring for them is under a lot of pressure too, and their health may suffer as a result.

This awareness that one partner’s health appears to mirror the other is more than just a curiosity; it has important financial implications, says Sven Wilson, the study’s co-author and assistant professor of political science and economics at the Brigham Young University in Provo, Utah. Health insurance is one consideration. “Disability insurance and long-term care insurance for a healthy spouse becomes even more important as the health of his or her partner declines,” Wilson says.

Social Science and Medicine 55(2002): 1157-1172

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Dianne Partie Lange can be reached at Dianne Lange@cs.com.