Adolescence is a disturbing stage in our lives that we cannot deny. The alternation between voice changes, hair growth, and acne can be overwhelming for teens. This is the stage where hormonal changes produce physiological changes in the body such as the development of genitals and accelerated growth. But for many children the average age of puberty is falling for decades.

Some girls today start developing breasts at the age of 6 or 7. It’s something that baffles scientists who study whether these changes are affected by obesity, stress or chemicals.

Studies. In the last thirty years, Research from Europe and the United States has shown a trend. With a greater change in the age of breast development – ​​usually the first sign of puberty – compared to the first menstruation (menarche) towards the earlier onset of puberty in girls. Recent studies have confirmed that in dozens of countries, the age at which girls begin puberty has fallen by about three months per decade since 1970.

Also seen in children similar trend. A 2019 study by Trusted Source looked at the height and growth of more than 4,000 children in Sweden between 1947 and 1996. They used growth rate or the timing of a furry growth spurt as a clue. In each decade that has passed, children reached their maximum height velocity 1.5 months earlier.

disposition. For decades, medical textbooks have described the stages of adolescence using the so-called. Tanner scaleIt was based on observations of boys and girls in England between 1949 and 1971. The scale indicates that normal puberty begins at 8 years of age in girls and after 9 years in boys.

But Paul Kaplowitz, professor of pediatrics at the National Children’s Hospital in Washington in 1999, argued Studies show that the normal age of puberty should be lowered to 7 for white girls and 6 for black girls.

Why? Why? Nobody knows. Many complex factors affect the onset of puberty. Genetics are thought to explain 50-75% of the variation, while the remainder is attributed to lifestyle factors such as nutrition, general health, psychosocial stress, perinatal factors, body composition, body composition and environmental factors such as endocrine disruptors.

Obesity? Indeed, the trend towards earlier puberty is often seen in conjunction with the parallel obesity epidemic among adolescents. As noted This news from The New York TimesObesity has been associated with early menstruation in girls since the 1970s. many studies Overweight girls have been shown to start menstruating earlier than average-weight girls. Inside decades of researchchildhood obesity was associated with earlier menstruation: each standard deviation above the mean weight in childhood was associated with a doubling probability of the rule before age 12.

And in 2021, British researchers They discovered that leptin, a hormone secreted by fat cells that limits hunger, is effective in the part of the brain that also regulates sexual development.

Chemicals? Early studies on endocrine disruptors as a cause of early onset of puberty shed light on the subject. some new It showed that exposure to such chemicals during the fetal and neonatal period was also related to the timing of puberty.

Inside 2009 researchGirls who developed breasts at a young age had the highest levels of phthalates in their urine, substances used to make plastics and found in everything from vinyl flooring to food packaging lasted longer. They are substances that can affect the behavior of hormones and are called “endocrine disruptors”. last decades They have become ubiquitous in the environment.

Stress? Similarly, psychosocial stress before or during puberty delay in menarcheAccelerated puberty has been described in girls who experienced such stress in early postpartum life or as infants. There is less research on boys in this area, so little is known about what influences the onset of puberty.

Negative results. Premature puberty has been associated with adverse health effects in adults, particularly in girls. Observations show that early menarche is associated with increased mortality, as well as an increased risk of breast cancer, cardiovascular disease, and mental illness. In addition, precocious puberty has been shown to be associated with more frequent and prolonged adolescent risk behaviors.

Also, in girls entering puberty high risk suffers from depression, anxiety, substance abuse, and other psychological problems compared to younger puberty peers.

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