This infection is one of the most common causes of death worldwide
Dr. Topor acknowledges that the reasons for this trend remain unclear, noting, "There are more questions than answers."
Lisa Swartz Topor, an associate professor of pediatrics at The Warren Alpert Medical School of Brown University and Hasbro Children's Hospital, confirms this is a well-documented and global phenomenon.
Over the 55-year study period, the proportion of girls experiencing early menarche—starting their periods before age 11—nearly doubled, reaching 16%.
A study published in the May 2024 issue of JAMA Network Open suggests that both the age of breast development and the onset of menstruation are occurring earlier in girls.
She emphasizes that this phenomenon is likely the result of a complex mix of factors, tied to the major changes the world has undergone over the past two centuries.
In addition to potential long-term health concerns, early puberty can lead to unexpected physical and behavioral changes in children. As Dr. Natasha Chaku, a psychologist at Indiana University, explains, "Your child might start to look or act like a teenager before you expected."
Puberty is starting earlier in girls, with some showing signs of breast development as young as six or seven. Experts are concerned about the potential effects this trend may have on both their physical and mental health.
The first sign of puberty in girls is typically breast development, followed by the onset of menstruation (menarche).
Consequently, parents may need to discuss puberty with their children sooner than anticipated. As Dr. Chaku emphasizes, "Parents may need to have conversations about how their bodies are going to change earlier than they expect."
A meta-analysis of 30 studies revealed that the global average age of puberty onset in girls has declined by three months per decade from 1977 to 2013, resulting in an overall shift of more than a year earlier.
This research analyzed data from 71,341 women born in the US between 1950 and 2005 and revealed a trend towards earlier puberty onset. Girls are experiencing their first periods at a younger age, and it's taking them longer to establish regular menstrual cycles.
Puberty begins when a part of the brain called the hypothalamus releases a hormone called gonadotropin-releasing hormone (GnRH).
The GnRH hormone, crucial for the reproductive system, prompts the pituitary gland to produce luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones then trigger the start of puberty.
In girls, these two hormones signal the ovaries to start releasing estrogen and progesterone, which leads to breast development, the appearance of body hair, the onset of menstruation, and body shape changes.
According to experts, this is a multifaceted issue. One contributing factor is the increase in childhood obesity rates since the 1970s. Some studies have linked obesity to early puberty, also known as precocious puberty, in girls.
Obesity can lead to increased levels of certain hormones in the bloodstream, such as insulin, insulin-like growth factor 1, and leptin, explains Dr. Aviva Sopher, an associate professor of pediatrics at Columbia University Irving Medical Center.
These hormones play a role in regulating appetite, how full we feel after eating, and how our bodies store fat. They can also impact the hormonal system that controls reproduction, which can ultimately affect when puberty begins.
Additionally, girls with obesity have higher levels of estradiol, a form of the female hormone estrogen, which may contribute to early breast development and earlier puberty onset.
The quality of a child's diet can also play a role. Diets low in fruits and vegetables and high in animal protein and processed foods have been linked to higher levels of hormones like estrogen, explains Dr. Frank Biro, a professor of pediatrics at Cincinnati Children's Hospital Medical Center.
In a study conducted in China, researchers compared three different diets. They found that girls who consumed a diet high in unhealthy foods like snacks, desserts, fried foods, and sugary drinks were more likely to experience early puberty.
Stress, such as that caused by difficult early life experiences like poverty or abuse, may also contribute to early puberty. A 2023 study in the journal Psychoneuroendocrinology found that high levels of stress in early childhood can increase the risk of early puberty in girls.
Dr. Jane Mendle, a clinical psychologist at Cornell University who specializes in the mental health of children and adolescents, emphasizes that "the timing of puberty is stress-sensitive."
Researchers suggest that one possible explanation is that both the stress response and the onset of puberty are influenced by the hypothalamic-pituitary-adrenal (HPA) axis.
Unsurprisingly, studies have shown that the stresses of the COVID-19 pandemic—such as increased screen time, social isolation, poor diets, and reduced physical activity—may be linked to a recent rise in early puberty among girls in New York City.
A 2023 study in BMC Medicine demonstrates that exposure to perfluorinated compounds—found in everyday products like stain repellents, paints, plastic cutlery, and food packaging—may contribute to early puberty in girls.
Research also points to the role of endocrine-disrupting chemicals, such as phthalates and bisphenols, found in many everyday products. These chemicals may be interfering with the body’s hormone system and contributing to these changes.
Other environmental factors may also play a role. A 2023 study in Environmental Health Perspectives concluded that girls exposed to higher levels of air pollution in the womb and during childhood may experience earlier onset of menstruation.
Early puberty is linked to an increased risk of several health issues, notes Dr. Biro. These include breast cancer, obesity, high blood pressure, type 2 diabetes, metabolic syndrome, abnormal cholesterol levels, and heart disease.
Research shows that early puberty can also affect girls' mental health, leading to higher rates of depression, stress, anxiety, and body image issues, along with difficulty managing emotions.
In some cases, medication may be recommended to slow down early puberty. This can help prevent potential negative impacts, such as stunted growth.
Sources: (National Geographic)
See also: Study finds it's harder to be a teen now than in the past
If a girl is suspected of experiencing early puberty, consult a healthcare provider, advises Dr. Biro. Typically, they will monitor her development and provide guidance on the physical and emotional changes she may experience.
There's a growing concern about a trend affecting young girls worldwide: the onset of puberty at younger ages. While puberty typically begins around ages 10-14, studies are showing that girls are hitting puberty earlier than ever, some even as young as six or seven. But what’s behind this shift, and why is it happening?
Experts point to a range of factors, with some emerging studies suggesting that everyday chemicals in plastics and air pollution may be playing a larger role than we think. These environmental influences are potentially shaping not only the timing of puberty, but also the health risks girls may face later in life.
Curious about what’s causing this, and how it might affect girls' and women’s futures? Click through to learn more.
Why are girls going through puberty so much earlier?
Understanding the changing face of girlhood
HEALTH Child development
There's a growing concern about a trend affecting young girls worldwide: the onset of puberty at younger ages. While puberty typically begins around ages 10-14, studies are showing that girls are hitting puberty earlier than ever, some even as young as six or seven. But what’s behind this shift, and why is it happening?
Experts point to a range of factors, with some emerging studies suggesting that everyday chemicals in plastics and air pollution may be playing a larger role than we think. These environmental influences are potentially shaping not only the timing of puberty, but also the health risks girls may face later in life.
Curious about what’s causing this, and how it might affect girls' and women’s futures? Click through to learn more.