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Early onset puberty

Early Onset Puberty in Girls – What is Happening and Why?

According to the NHS, the average age for UK girls to reach puberty is 11, yet experts say more children are entering this pivotal life stage years earlier.

It is widely recognised that puberty begins in women at the development of glandular breast tissue (aka thelarche), with menstruation usually following on a couple of years later.

For some girls, thelarche is now beginning much earlier, with new research exploring a possible link between this phenomenon and factors like stress, obesity, and the pandemic.

Let’s take a look at early onset puberty for girls and what we know about why it’s happening more frequently.

What we’ll be looking into:

  • What is early onset puberty
  • The rise in precocious puberty levels
  • Stress and the hormonal implications on the body
  • EDC chemicals as part of the puzzle
  • Obesity as a potential factor in understanding early onset puberty

What is early onset puberty?

The NHS says it’s “perfectly normal for puberty to begin at any point between the ages of 8 and 13 in girls.”

They define early onset puberty or ‘precocious puberty’ as starting before age 8.

According to research conducted in pre-pandemic times, early puberty is rare and affects one in 5,000 to 10,000 children, with girls outnumbering boys 10 to 1.

But since the pandemic, doctors have reported a sharp rise in early onset puberty cases.

Now, researchers are trying to ascertain why this is happening.

Exploring the impact of the pandemic

A study in South Korea found that the number of diagnosed cases of early onset puberty almost doubled in the years between 2016 and 2021.

In January 2021, Italian researchers found that the referral rates to paediatric endocrinology centres for girls with suspected early onset puberty had jumped.

Their study of five centres showed the number of referrals surged from 140 during the period of March to September 2019 to 328 during the same period in 2020.

The modern lifestyle and early onset puberty

Much of the research into early puberty has been focused on three lifestyle factors – stress, exposure to endocrine-disrupting chemicals, and high BMI.

These issues were likely exacerbated during the pandemic as people holed up in their houses, fearful and living more sedentary lifestyles.

According to research conducted in 2022, girls in early puberty “showed more prolonged use of electronic devices and a more sedentary lifestyle before and during the pandemic, compared to the rest of the 2020 population.”

So, how do these three factors impact early onset puberty?

Stress and early onset puberty

When a person experiences stress or anxiety, their adrenal glands release cortisol as part of the fight or flight response.

According to an article about early onset puberty in the New Yorker Magazine, “researchers hypothesized that higher cortisol levels might contribute to the premature activation of the pituitary and adrenal glands.”

During puberty, the pituitary gland secretes gonadotropins, follicle-stimulating hormones and luteal hormones. Meanwhile, the adrenal gland matures and increases the secretion of sex hormones: androgens and oestrogens.

Researchers are trying to discover if the increased level of stress and anxiety during the pandemic can be linked to early onset puberty.

Endocrine-disrupting chemicals and their impact on our bodies

Another significant area of interest for scientists is the impact of chemicals on our bodies.

In a world where our food, clothes, pharmaceuticals, and personal care products are packed full of chemicals, children are exposed to endocrine disruptors (EDCs) earlier than ever.

One study found that EDCs can act as obesogens and promote early adiposity rebound, changing metabolic or peripheral signals, and increases in adrenal androgen levels, inducing early pubertal development. 

To put it more simply, EDCs can mimic naturally occurring hormones, including sex hormones that can trigger early puberty.

Interestingly, both high levels of exposure to EDCs and high cortisol levels also contribute to the third factor of interest – obesity.

Obesity and early puberty

Rising levels of obesity in younger children worldwide are of great concern to parents and doctors alike.

Research has concluded that: “The finding that overweight children, especially girls, tend to mature earlier than lean children has led to the hypothesis that the degree of body fatness may trigger the neuroendocrine events that lead to the onset of puberty. Obese children have high leptin levels, and these may play a role in their earlier onset of puberty.”

Leptin is produced in fat cells and is instrumental in raising the sex hormone oestrogen level in the body. It’s also a key component in the process for the pituitary gland to produce gonadotropins.

Early puberty and EDCs

Talking to The Scientific American, Professor Frank Biro argued the obesity link to early puberty is very complex.

He said: “Decreased physical activity and a more calorically dense diet are probably part of the puzzle. But I think another critical piece is our ubiquitous environmental exposure to EDCs.”

Interestingly, Biro argues that the way EDCs mimic oestrogen and other hormones could influence the body’s metabolism.

He theorises that they may promote weight gain or trigger early puberty due to the metabolic impact that affects oestrogen production.

The average age of puberty continues to drop

As the research into early puberty continues, it’s interesting to look at how its occurrence has changed over the years.

Research discovered that the age of girls reaching puberty had dropped 3 months per decade between 1977 and 2013.

Did you know?

According to research in 1997, the average age of puberty in girls in 1860 was 16.6 years and in 1920, it was 14.6 years.

The statistics show that puberty is happening earlier and earlier as each generation reaches the milestone.

What can we do to support our children if this happens to them?

Advocating for a child in early puberty

For a child to start developing breast buds and/or pubic hair or to experience menstrual bleeding at a young age may be scary, upsetting and confusing.

If parents, teachers and loved ones are aware of the phenomenon of early puberty, they can take the steps to support the child in question.

It’s important to go to the GP to discuss the options available to support your child.

Talking to children about early puberty

Body changes that move faster than their emotional development can be particularly problematic for children.

Coping with the feelings and thoughts brought on by hormonal changes and body developments might be tricky to navigate.

There is also the component of embarrassment about reaching puberty earlier than their peers.

What’s vital is talking to the child in question to reassure them, listen to their worries and work through any problems together.

Lean on your extended network of family, friends and teachers to help support them through early puberty.

The new normal

As we’ve discussed in this piece, there are many things that researchers looking into early puberty consider to be significant.

We are also likely to discover things that are relevant to early onset puberty as further research gives us more data about the impact of the pandemic.

But at the centre of all of this are young people who are going through puberty at an age where they might not be emotionally ready.

The more people who are aware of early puberty, the easier it will be for these young people to find the support and understanding they deserve.

At Kari, we’re here to support you and your family in any way we can.

Evidence Based
This article has been reviewed by our Kari Health Experts and Editorial Board to ensure accuracy and reliability of the information presented. However, please note that the content provided is for informational purposes only and should not replace advice from your medical professional.

Did you find this article helpful this article? 

If so, you can read related Kari Health articles here:

Menarche – The First Occurrence of Menstruation

The Role of ‘Mum’– A Girl’s First Understanding of Femininity

Male Role Models

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    Evidence Based
    This article has been reviewed by our Kari Health Experts and Editorial Board to ensure accuracy and reliability of the information presented. However, please note that the content provided is for informational purposes only and should not replace advice from your medical professional.