Obesity, chemical exposure speed up early puberty in children

By Bahk Eun-ji

Body changes accompanying aging is natural, but this can be a problem at times for some children who start physical development sooner than their peers.

Early puberty means a child's body begins to change into that of an adult, showing secondary sex characteristics. It is usually classified as early puberty when a child shows such characteristics before the age of eight or nine ― girls before eight and boys before nine ― which is two years earlier than average.

According to data from the National Health Insurance Corp., the number of children who reached puberty too early stood at 95,401 in 2017, up from 67,021 in 2013, with an annual growth rate of 9.2 percent.

Parents are particularly concerned about "precocious puberty," which brings rapid growth and changes in body shape and size. When puberty ends, growth in height usually slows because children's skeletons mature and bone growth decreases. So early puberty could mean an earlier-than-normal halt to growth in height.

"Children with precocious puberty usually do not reach their full adult height potential. The early growth spurt makes them tall compared to their peers, but the possibility of them having an early end to growth is higher, so they could end up shorter than they would have been," said Jung In-hyuk, a pediatrician at the National Health Insurance Service Ilsan Hospital.

Among children who visited doctors for early puberty in 2017, 85,806 or 89.9 percent were girls. However, the annual increase rate among boys has outpaced that of girls, 12.8 percent compared to 8.9 percent.

Causes of early puberty

Jung said worsening environmental pollution, the increasing rate of obesity due to rapidly changing dietary habits, and a family history of early puberty are the main causes of the steadily increasing numbers in precocious puberty.

He also pointed out that there is no clear scientific evidence showing why the number of girls reaching early puberty is higher than boys. "It is said because many endocrine disruptors are similar to female hormones and fat cells produce female hormones."

According to a recent study on 338 children from birth through adolescence, conducted by the Center for Environmental Research and Children's Health at the University of California in the United States, chemicals have been linked to early puberty including phthalates, which are often found in scent products such as perfumes, soaps and shampoos; parabens, which are used as preservatives in cosmetics; and phenols, which include triclosan. In the study, over 90 percent of the tested children's urine samples showed high concentrations of all the potentially hormone-altering chemicals.

Kim Ho-sung, a pediatrician at the Severance Children's Hospital, also said obesity might be responsible for a large portion of precocious puberty.

"When body fat increases, the level of the hormone leptin also increases. Exposure to high levels of the hormone could affect early body changes," Kim said.

According to the data from the Ministry of Education on 108,000 students at 1,023 elementary, middle and high schools nationwide in 2018, 25 percent were in the obese group.

The ministry said the children's eating and exercise habits were strongly related to the increase in obesity, as 65.9 percent of elementary students ate fast food and processed food at least once a week.

Despite the unhealthy dietary habit, only 59 percent of elementary students do strenuous exercise at least three times a week.

Kim said there is no special method to help children grow normally and healthy.

"Just let them eat healthy, sleep enough, and have enough free time to get rest. These are what children need," Kim said.

Site Map E-paper Subscribe Register LogIn
Site Map E-paper Subscribe Register LogIn