Hormones Matter TM

Early Onset of Puberty

April 18, 2012  |  Elena Perez


A colleague recently informed me that her niece, Kayla, just got her first training bra – but Kayla is only six years old. A photograph of Kayla captured the smile of a chubby, young girl that towered over her peers. Though Kayla is at the same psychological level as her classmates, her body is maturing at a faster rate as she deals with the early onset of puberty.

Kayla is certainly not alone. More and more girls are beginning to show signs of puberty earlier than previously recorded. In 1997, Herman-Giddens performed a study that confirmed breast development began younger than what had been considered the norm. She found that girls began developing breasts at the age of 9, two years earlier than the previously accepted age of 11.

Developed Nations Have Earlier Ages for Puberty

Parents, doctors and researchers are now trying to determine why girls are showing signs of puberty at such a young age. In 1998, research published in The American Journal of Epidemiology by the World Health Organization showed that menarche varied globally, with women in developing countries starting their periods at a later age than women in industrialized nations.

This study seems to echo trends seen in the earliest medical records, which showed that the average age of menarche dropped from 17 to 13 in Europe after the Industrial Revolution. While experts initially believed the early onset of puberty was tied to improved nutrition and safe environments for reproducing, many are beginning to believe that precocious puberty links to environmental toxins, byproducts of developed countries.

Xenoestrogens Tied to the Early Onset of Puberty

Many researchers believe xenoestrogens, or foreign compounds that mimic the effects of estrogens on the body, are the culprit for early signs of puberty. A woman’s ovaries produce several estrogens naturally, including estradiol, but xenoestrogens are introduced into the body from an outside source, usually chemical toxins.

It is difficult for doctors to pinpoint what exactly causes the early onset of puberty, but sometimes they can determine the cause. In some cases, a benign tumor is found near the pituitary gland, which causes it to release hormones that trigger the production of estradiol, which begins the maturation of the body.

In other cases of precocious puberty, ovaries don’t contribute significantly to increased estradiol levels, so where are the additional hormones coming from?

Xenoestrogens can impact estrone production, which is usually not triggered until later in life: Postmenopausal women produce estrone in their adipose tissue, where fat is stored, but xenoestrogens can stimulate these fat tissues to produce estrone sooner.

According to The Anti Estrogenic Diet, xenoestrogens induce “activity in fatty tissue, which increases estrogen levels and activity. This extra estrogen causes an increase in the size of estrogen-sensitive fatty tissues,” which sets the feedback loop in motion.

Where Do Xenoestrogens Come From?

Today there are a number of environmental contaminants that contain xenoestrogens, and even small traces of these estrogen mimics can greatly impact a child’s hormonal balance. The following are a few examples of xenoestrogens in our environment:

Organochlorines – Organochlorines are found in a number of pesticides, some of which have been banned from use due to their damaging health effects, such as DDT. Even so, the chemical structure of organochlorines takes time to break down, and is still detected in our food. Unfortunately, these long-lasting xenoestrogens are stored in fat tissue, interestingly where estrone is produced.

Nonylphenol (NP) – NP is found in industrial laundry detergents (with limited amounts in household detergents) and is a known estrogen disruptor. Residual NP is also found in plastic food packaging. Though Nonylphenol Ethoxylates are considered less toxic, they eventually break down to form NP.

Bisphenol A (BPA) – BPA is used in a number of plastic products, and though it has been banned in baby bottles in Canada and the European Union, it is still widely available for use. BPA is also known to mimic estrogen. Other plastic additives, such as Dibutyl Phthalate (DBP), impact the onset of puberty, also.

Phytoestrogens – Phytoestrogens are xenoestrogens that are found in plants. Phytoestrogens are natural, but they still mimic estrogen, which may impact a child’s development. Phytoestrogens are found in soy, but no evidence has shown deleterious health effects associated directly with soy. Even so, doctors recommend caution when consuming large amounts of soy.

Increased estrogen levels from xenoestrogens can lead to the early onset of puberty, so parents should be aware of environmental toxins that may affect them (especially during pregnancy) and their children. Since increased estrogen levels have also been linked to higher rates of breast cancer, every woman should be concerned with their intake of xenoestrogens. Stay abreast of what products may have xenoestrogens and be conscious of what you are putting into your body, so you can limit the amount of toxins you take in. We want our daughters to focus on the simplicity of childhood when they are six, as opposed to what size bra might accommodate their bodies.