I’m going to ask you to do something painful right now: think back to hitting puberty. Ouch. This is often an awkward time to look back on, as you recall adjusting to the changes in your body, developing an interest in dating and comparing yourself to friends.
For most of us, the onset of puberty happened around middle school age. But what if these changes began happening when you were just in second or first grade — or even kindergarten? What would it be like to have a talk about sex and hormones while you’re still attending playing dress-up or start growing facial hair while playing with toy cars?
Unfortunately, that’s no longer a hypothetical situation. Across the country, girls and boys alike are going through precocious puberty, and it means a whole lot more than upgrading from a training bra earlier than the previous generation. From a higher chance of being clinically depressed to an increased risk of certain types of cancers, precocious puberty is taking a toll on our nation’s youth.
Everyone Goes Through Puberty — What’s the Big Deal?
“Precocious” isn’t always a bad thing. In fact, it’s used mostly to positively describe children who are unusually mature in their mental development. When it comes to puberty, however, the word signifies premature physical development. What’s wrong with developing a little earlier? To answer that, we’re going to backtrack a bit.
Most of us are familiar with the physical signs of puberty, like hair growing in different places, menstruation in girls and voice changes in boys. But there’s a lot going on inside the body during puberty, too. (1) Puberty actually begins when the brain, in an area known as the hypothalamus, begins releasing gonadotropin-releasing hormone, or GnRH. The hormone then travels to the pituitary gland. This small gland below the brain actually produces hormones that control other glands in the body. The pituitary gland then releases two other puberty hormones, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). All these hormones traveling around the body brings about puberty, and what happens next depends on gender.
In boys, hormones travel to the testes, alerting the body that it’s time to begin producing sperm and testosterone. Boys, who have been able to have an erection since infancy, can now ejaculate.
In girls, the hormones travel to the ovaries and signal that it’s time to start maturing and producing eggs. The hormones also begin producing estrogen, which leads to a girl’s body developing into a more “woman-like” figure as her body prepares for pregnancy. The main event for girls during this time is the start of menarche, or her first period, and irregular periods in the beginning. She’s now able to become pregnant.
As you likely remember, there are also quite a few emotional changes that occur during this transitioning time. Mood swings, anxiety about bodies, sexual feelings and exploration and other “teen emotions” become prevalent during this time.
At the beginning of the 20th century, the first menstruation cycle for girls happened around ages 16 and 17. Today, the average age is younger than 13 years old. (2) But for many girls — and scientists aren’t quite sure why it seems to affect mainly girls and not boys — precocious puberty is happening at an even younger age.
What Happens When Early Puberty Hits?
When girls experience precocious puberty, their bodies are essentially becoming sexual beings at a seriously young age. This juxtaposition of being a “young woman” while still in childhood can have serious emotional repercussions. Girls who undergo puberty earlier than their peers are found to already have higher levels of depression symptoms at age 10. (3) Another study found that precocious puberty in girls raises the risk of depression for those females who have pre-existing vulnerability to the condition and that, for those who don’t, depressive symptoms might emerge. (4)
There are also the social changes that emerge. The flood of hormones coursing through a girl’s body during hormones makes her especially attentive to what others think and responsive to social pressures and rewards.
As this Newsweek article explains, during puberty, dopamine takes center stage. This neurotransmitter is responsible for experiencing pleasure, and it comes out in full force at this time. It basically remodels the pathway between the part of the brain that regulates behavior (and alerts you know that something is a bad idea) and the brain’s reward center. (5)
“The adolescent brain is one where the accelerator is pressed to the floor before there’s a good braking system in place. This gap between when the brain is easily aroused and when the braking is in place creates a period of vulnerability.”
When puberty occurs at a younger age, often girls — and their parents — aren’t prepared for the changes. In fact, although a girl’s body might be packed with hormones, her mental age is tied to her chronological age. An 8-year-old girl likely has even less control of what she does than a 13-year-old going through the same changes. That means the 8-year-old is quite likely to engage in riskier behavior as she seeks acceptance and gets attention from people who think she’s older than she is because of her body.
Unfortunately, the evidence isn’t just anecdotal, but proven by research. Girls who’ve gone through puberty by 5th grade are more likely to be smoking by 9th grade. As the study notes, “boys and girls who mature earlier than their peers have developed physically before their social resources have fully developed, leaving them ill-equipped to deal with challenges that may arise when entering physical maturity.” (6)
Additionally, young people who believe they’re more advanced in puberty than their peers at age 11 — probably because of how they look physically — are more likely to have recently smoked cigarettes, drank alcohol or smoked marijuana than peers who believe they’re on time or late in puberty. (7)
Women who experienced precocious puberty are also at a higher risk for a variety of diseases in adulthood, ranging from type 2 diabetes to cardiovascular diseases. (8) In fact, one study found that early puberty was associated with 48 health conditions later in life, including irritable bowel syndrome, arthritis and psoriasis. (9)
And then there’s the increased cancer risk. One researcher found that early puberty and an earlier first menarche in girls raised her risk of breast cancer by up to 30 percent. (10) Conversely, for each year that a girl’s first period was delayed, her risk of premenopausal breast cancer was reduced by 9 percent, while her risk of post-menopausal breast cancer was reduced by 4 percent.
Estrogen can also play a role in this risk of breast and reproductive cancers. Girls who hit puberty early are producing estrogen for a longer period of time than their peers, sometimes by several years. This prolonged exposure to the hormone could have health repercussions decades later.
What’s Causing Precocious Puberty?
Why exactly are girls going through precocious puberty? One of the major factors is endocrine-disrupting chemicals.
Endocrine disruptors are chemicals that mimic the effects of estrogen in the body. So when the brain recognizes that there’s already “estrogen” in the bloodstream, it kicks puberty into gear. The most common of these disruptors are found in phthalates and BPA. (11)
Phthalates are man-made chemicals used to make plastic more flexible. And they are everywhere. Think: toys, shower curtains, vinyl flooring, shampoo, detergent, food packaging. Because our bodies can’t metabolize phthalates, and so these chemicals end up messing with our endocrine systems. Think: earlier menarche and growth spurts. (12) Additionally, this chemical can also cause weight gain and indirectly lead to precocious puberty, as obesity is another risk factor.
Bisphenol A (BPA) is another widely used chemical found in cups, water bottles, food storage containers and food cans. You might have seen that some reusable food container brands have labels that say “BPA-free.” That’s because toxic BPA was found to “leak” from inside containers into food and drinks, particularly when being heated or washed.
The age of exposure to these chemicals, in addition to how long the exposure lasts, plays a role in early puberty. (13) Unfortunately, because endocrine disruptors are ubiquitous in our society, it’s difficult not only to gauge how much exposure someone has had, but how to avoid them completely.
How do I limit exposure to endocrine disruptors and reduce the risk of precocious puberty?
While this is a lot of overwhelming information, there are steps you can take to decrease the risk of precocious puberty. If you’re thinking of having a child or are currently pregnant, consider breastfeeding if you can. (14) Though investigators aren’t quite sure why, it seems that girls who were mostly fed with breast milk show a later onset of puberty.
There are also a variety of ways you can minimize your child — and your own! — exposure to endocrine disruptors.
- Focus on eating whole, fresh foods, as processed foods and meats are pumped with chemicals.
- When possible, choose organic produce to reduce ingestion of chemicals.
- Avoid storing food or using containers with BPA in them; glass is your friend.
- Use glass to reheat food. Never reheat in plastic containers, BPA-free or not, as chemicals can still be released.
- Minimize the use of canned foods, since BPA can seep through them. Opt for glass instead.
- Limit exposure to phthalates by avoiding purchasing products with recycling #3 or “PVC” on them.
- Don’t forget to check the ingredients list of your beauty products, too! Choose all-natural products where possible, including female hygiene products.
- Can’t go totally all-natural? Try avoiding artificial fragrances instead and opt for unscented. Phthalates are often to use to give products like detergents, fabric softeners and beauty product their smell.
- Use fabric shower curtains.