The pill makes women sniff out wrong partner

Olfaction, or the ability to smell, has repeatedly been linked to how animals, possibly including humans, find a mate. Many of our cells express proteins, called MHCs, that are a relatively unique signature for each person, like fingerprints. Many studies have shown that women seem to prefer the scent of mates who have MHCs dissimilar to their own, a behavior that may reduce the dangerous effects of in-breeding. Now, research led by S. Craig Roberts, from the University of Newcastle in the United Kingdom, reveals that taking oral contraceptives might lead women to pick "wrong" partners. More than 100 women from the university were recruited to sniff T-shirts previously worn by men with varying MHCs, before and after starting the pill. Researchers found that women who used the pill were more likely to pick men with similar MHCs, while women who didn't use oral contraception were better at sniffing out a more suitable partner. BOTTOM LINE: Oral contraception might alter a woman's sense of smell, limiting her ability to distinguish an appropriate mate. CAUTIONS: Taking the pill would only affect mate selection if odor is a significant part of how we choose mates. WHAT'S NEXT: Researchers want to figure out how women in relationships might perceive odor in men differently than single women.

WHERE TO FIND IT: The Proceedings of the Royal Society B, Aug. 25. SUSHRUT JANGI

Children with poor coordination and motor skills may be as much as four times more likely than other kids to become obese as adults, a new study finds. Researchers from Sweden and Britain studied data from nearly 8,000 people enrolled in the ongoing National Child Development Study, which has followed more than 11,000 people born in Great Britain during the same week in 1958. Teachers assessed their coordination at age 7, and when participants were 11 physicians administered another battery of tests in which children were asked to copy geometrical shapes, pick up matches, and check off boxes on a page. Children who did poorly on both sets of tests - demonstrating clumsiness - were more likely to be obese at the age of 33. "There are a number of complications that obese people face later in life, including poor coordination, and the understanding has always been that these complications are a result of the obesity," said lead scientist Scott Montgomery of Sweden's Karolinska Institute. "But this suggests that the problems may have begun during infancy or maybe even before birth." Montgomery, who conducted the study with colleagues at London's Imperial College, said the link between neurological functions that control motor control and adult obesity is poorly understood. One possibility is smoking by the mother during pregnancy; another is a lack of physical activity during childhood, which could affect motor functions.

BOTTOM LINE: Motor-skill problems in children may be related to a lack of exercise, unhealthy eating habits, or other factors that increase their risk of becoming obese as an adult.

CAUTIONS: The study does not mean that all uncoordinated children will grow up to be obese or that all obese adults were clumsy children.

WHAT'S NEXT: Researchers plan to further study the roots of obesity, hoping to identify activities or risks that may predispose a child to adult obesity.

WHERE TO FIND IT: British Medical Journal Online, Aug. 13

KELLI WHITLOCK BURTON