Breasts at age seven? A new study has found that puberty is occurring earlier and earlier in girls.


This may not be healthy since it puts them at higher risk for social and emotional problems, and may slightly elevate their chances of developing cancer later in life.


For the study, 1,239 girls between age six and eight were recruited in three U.S. cities: New York City, San Francisco and Cincinnati. Most of the girls were either of white, black or Hispanic descent. Examiners were carefully trained to check girls’ breasts and rate their stage of development.


At age seven, 23 per cent of black girls, 15 per cent of Hispanic girls and 10 per cent of white girls had breast development. By the time they reached age eight, 43 per cent of black girls, 31 per cent of Hispanic girls and 18 per cent of white girls were considered on the cusp of puberty. These numbers were higher than when measurements were made in a 1997 study.

Why is puberty occurring earlier? Higher rates of obesity is thought to be one cause. Heavier girls are more likely to grow breasts earlier. They are also more at risk for disease later in life: diabetes, heart disease and some cancers. Another theory is that environmental chemicals may be speeding up puberty by mimicking estrogen in the body.

Budding breasts can force young girls to deal with difficult grown-up issues they aren’t ready for, such as sexual advances and hormone-related mood swings.