The Weekly Newsmagazine of Science
April 17, 1999 
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Young and Rubenesque? The good news is . . . Young women tend to be very self-conscious about their figure, especially because so few are blessed with both the genes and willpower to achieve the svelte Uma Thurman look. Indeed, many find their shape evolving instead towards a modified Rosanne Barr physique.
Susan L. Peacock of the Fred Hutchinson Cancer Research Center in Seattle and her colleagues investigated the role that body shape plays in breast cancer risk among women 21 to 45 years old. They recruited 845 women from the Seattle metropolitan area who had been diagnosed with breast cancer and another 961 area women of the same age who were free of cancer. Peacock's team measured the height and weight of each woman. The scientists then threw these measurements into a formula—weight (in kilograms) divided by the square of height (in meters)—to determine each participant's body-mass index, or BMI. Finally, they questioned each woman about any weight changes that might have occurred since she was 18. The researches statistically accounted for other factors that might affect breast-cancer risk, such as exercise practices, smoking history, and ages at menarche, first full-term pregnancy, and first use of oral contraceptives. In the Feb. 15 American Journal of Epidemiology, they report that the heaviest 20 percent of the women that they studied had the lowest breast-cancer risk. Overall, these plumper gals were just two-thirds as likely to have breast cancer as those in the thinnest category. How heavy were the low-risk women? Each weighed at least 160 pounds at the time of her interview and had a calculated BMI of 27 or more. A large annual increase in BMI from age 18 until the time of the interview was also associated with a decreased risk of breast cancer. Though women who were plump teenagers also showed a decrease in overall risk, the strongest protective effect was linked to being heftier at the time of the interview or on average throughout the adult years. Further probing showed that any strong benefit to obesity was limited to youngest age group—women under 36. Though several other studies have found indications that obesity might reduce breast-cancer risks somewhat, this study is the first to turn up signs that age affects the benefits of size, the researchers note. In any case, Peacock points out, these findings shouldn't be taken as justification for a stout Generation-Xer to reach for a second helping of cheese cake or license to snack on a chocolate shake. Once an individual puts on weight, the body will try to keep those extra pounds. That's not good, she points out, because obesity has been linked to many other health problems in premenopausal women, including heart disease and diabetes. Moreover, once a woman hits menopause, even the weak breast-cancer advantage disappears, Peacock notes. Indeed, she says, studies by others have shown that following menopause, "obesity actually becomes a [positive] risk factor for breast cancer. So unless a person plans to be obese up until age 49, and then suddenly lose all that weight around age 50, she'll have a problem." Further Readings:
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This week's Food for Thought has been prepared by Janet Raloff, senior editor of Science News. |
As these latter women wrestle with self-esteem issues within a society
that prizes sleek over ample, they can take heart in at least one new
study. It finds that their apple shape puts them at lower risk for breast
cancer than those celery stalks gliding down fashion runways.Copyright © 1999 Science Service