Drinking just one-and-a-half cans of sugar-sweetened soda a day can bring on early puberty in girls and increase their breast cancer risk.
A Harvard Medical School study of 5,583 girls age nine to 14 found those who drank more than one and a half servings of sugary drinks a day had their first period 2.7 months earlier than those who drank two or fewer drinks a week. And for each year earlier they mature, their breast cancer risk increases by 5 percent, the (UK) Telegraph reports.
Drinks with added sugar are said to increase insulin concentration in the body, which in turn results in higher concentrations of sex hormones, normally associated with menstrual periods starting earlier, the Telegraph explains. Associate Professor Karin Michels said, “Our study adds to increasing concern about the widespread consumption of sugar-sweetened drinks among children and adolescents.” While a major concern about soda consumption is its contribution to childhood obesity, the study suggests that age of first menstruation “occurred earlier, independently of body mass index, among girls with the highest consumption of drinks sweetened with added sugar.” According to Michels, “A one-year decrease in age at menarche is estimated to increase the risk of breast cancer by five percent.”
The study, published in the journal Human Reproduction, found girls who drank more than 1.5 servings of sugar-sweetened drinks a day were 24 percent more likely to start their first period a month earlier. The average age of the first period among girls consuming the most sugary drinks was 12.8 years, compared to 13 years for those drinking the least. At the time the study began, none of the girls had started their periods.
When researchers adjusted results to take account of body mass index (BMI), the effect of sugary drink consumption on the age of onset of menstruation was still significant, according to the Telegraph. Michels said the research shows the importance of switching children from sugary drinks to water.