Whether you know it or not, you’re exposed to chemicals every day that can damage your endocrine system. It’s easy to think of food in terms of healthy and unhealthy. But is nutrition really that black and white?
Close your eyes right now and picture two crisp, shining Red Delicious apples in front of you. Even if the two apples look identical from the outside, they might have opposite effects on your body.
One apple could come from an orchard that’s hundreds of miles from the nearest city and has never come in contact with pesticides or pollution. The other apple might have grown next to a highway and had been doused in pesticides and other carcinogenic chemicals for its entire life.
These everyday, man-made chemicals are known as endocrine disruptors. Endocrine disrupters interfere with the function of the endocrine system by turning on, shutting off or modifying signals that hormones carry, which can affect the normal functions of tissues and organs. Scientists have linked endocrine disrupters with reduced fertility and increased incidences or progression of disease like obesity, diabetes, endometriosis and some cancers.1
Endocrine disrupting chemicals can enter your body through the water you drink, the air you breathe and even the products you put on your skin. Unfortunately, it’s virtually impossible to avoid these chemicals completely, to no fault of your own.
One of the more well known instances of the effects of endocrine disruptors on humans was popularized in the Oscar-winning film “Erin Brockovich.” The movie tells the true story of how Pacific Gas and Electric company dumped the toxic chemical hexavalent chromium in to ponds around the town of Hinkley, California. Allegedly, the chromium contaminated the drinking water, which led to a $330 million settlement.
There are over 1000 chemicals with endocrine disrupting effects2 (and those are just the chemicals we know of).
By arming yourself with the knowledge of how endocrine disrupters enter your body, you can eliminate many of them from your life.
Keep reading to learn about how endocrine disrupters affect your body, how you can minimize contact with them and how hormone imbalances damage your health.
The Importance of Hormones
If the human brain were a computer, it would be more complicated than the most sophisticated computer ever created. However, unlike your MacBook, your brain is influenced by emotions and motivations.
Near the base of your brain is a region called the hypothalamus. Despite its small size, it acts as the central regulator for your endocrine system. The endocrine system, along with the nervous system, keeps your body in a state of balance known as homeostasis.
Your nervous system is responsible for delivering quick feedback from your environment to your brain and vice versa. If you burn your hand on a stovetop, you feel pain and reflexively pull your hand away. Pain is delivered to your brain by sensory nerves, and motor neurons control the withdrawal of your hand.
However, how does your body react to a burn hours after the initial injury? For long-term responses to your environment, your endocrine system takes control. In the case of an injury or burn, your body undergoes a series of reactions3 down what is known as the adrenal axis to release the hormone cortisol.
- Your hypothalamus releases corticotropin-releasing hormone (CRH)
- CRH acts on your anterior pituitary gland to release adrenocorticotropic hormone (ACTH)
- ACTH acts on your adrenal glands to release cortisol
What Is a Hormonal Imbalance?
Hormones regulate every aspect of your health from your how much body fat you store to how energetic you feel. A hormonal imbalance is an improper function of at least one hormone in your body. What happens when one or more of your hormones fall out of a normal range? Each hormonal imbalance has a different effect on your body.
For example, if your thyroid isn’t producing enough thyroxine (T4), your metabolism slows, and you generally develop chronic coldness and fatigue.
If your body chronically overproduces insulin, the hormone responsible for controlling your blood sugar, you can develop insulin resistance or Type 2 diabetes4.
Most hormones in your body interact with other hormones in a series of feedback loops. Let’s go back to the example of burning your hand on a stovetop. When your hypothalamus senses an increase in cortisol caused by the stress of the burn, it produces less CRH, which eventually leads to a drop in cortisol5.
The way hormones interact with each other makes it difficult to diagnose the cause of a hormonal imbalance without testing the functions of multiple organs. If your cortisol levels are abnormally high or low, the problem could be at the level of your hypothalamus, pituitary gland or adrenal gland.
Here is a list of the major endocrine glands and tissues responsible for hormone release:
- Hypothalamus: The primary link between your nervous system and endocrine system
- Anterior Pituitary Gland: Helps regulate stress and growth hormones
- Posterior Pituitary Gland: Regulates water retention and lactation
- Thyroid: Regulates energy metabolism
- Parathyroid: Controls calcium levels
- Thymus: Releases hormones to support immune function
- Pancreas: Secretes insulin to regulate blood sugar
- Stomach: Releases ghrelin to control hunger
- Fat Cells: Release leptin to control hunger
- Adrenal Glands: Release your stress hormones
- Ovaries (women): Produce the female sex hormones progesterone and estrogen
- Testes (men): Produce the male sex hormone testosterone
Common Hormone Imbalances
You will likely experience the effects of a hormonal imbalance at some point in your life no matter if you’re a man or a woman. The following hormonal imbalances are all fairly common.
Your thyroid gland sits on the front of your neck below your voice box. This gland produces the two hormones triiodothyronine (T3) and thyroxine (T4). These two hormones affect every organ in your body by regulating energy metabolism.
Here is the hormonal pathway for regulating T3 and T4 production:
- Your hypothalamus releases thyrotropin-releasing hormone (TRH)
- TRH stimulates the release of thyroid-stimulating hormone from your anterior pituitary (TSH)
- TSH stimulates the release of T3 and T4 from your thyroid gland.
The two most common dysfunctions of the thyroid gland are hypothyroidism and hyperthyroidism.
Hyperthyroidism develops when your thyroid gland produces too many hormones. This disorder causes an increased metabolism. The autoimmune disease called Grave’s Disease is a common cause of hyperthyroidism.
Hypothyroidism occurs when your thyroid gland doesn’t produce enough hormones and leads to a depressed metabolism. Hypothyroidism can be caused by a problem at the level of the thyroid gland, hypothalamus or pituitary gland6.
Insulin is most well-known for its role in diabetes. A chronic high-processed diet can cause insulin resistance, meaning that your body stops responding to circulating insulin in your blood7.
Beta cells in your pancreas release insulin. When you eat high-processed foods, your blood sugar rises. Your body releases insulin to lower the circulating glucose and to shuttle the glucose into fat cells or muscle cells.
Insulin often gets a bad reputation for “making you fat,” but it also plays a critical role in muscle-building by stimulating muscle-protein synthesis8.
Diabetes is the most common cause of insulin dysfunction, but a tumor in your pancreas can also cause problems with your insulin levels9.
The two hormones responsible for controlling your hunger are ghrelin and leptin.
Fat cells produce leptin, which has the nickname “the satiety hormone.” When your body produces a significant amount of leptin, leptin signals to your hypothalamus to decrease your hunger10.
When you lose body fat, your body produces less leptin, which causes your hunger to increase. If you’re trying to lose fat, the presence of leptin makes sustainable weight-loss difficult. If you eat a diet high in processed food and unhealthy polyunsaturated fats that cause inflammation, you put yourself at risk of developing leptin-resistance11.
Leptin resistance causes your body to stop responding to the signals of fullness it would normally receive as body fat increases. Developing leptin resistance puts you at risk of becoming obese or developing other metabolic disorders.
Your other hunger hormone, ghrelin, has the opposite effect as leptin. Your stomach produces leptin when it’s empty, which signals hunger. When your stomach is full, it produces less ghrelin and your hunger declines. It’s often nicknamed “the hunger hormone.”
Testosterone is the primary sex hormone in men. It’s responsible for giving men masculine traits such as body hair, large amounts of muscle mass, and deep voices. When testosterone levels decline with age, men can develop symptoms such as low libido, trouble building muscle and irritability12.
Men’s testes produce the majority of testosterone, but their kidneys are also responsible for a small amount of testosterone production. Testosterone naturally declines by roughly 1 percent13 per year in men over the age of 30.
Women also need testosterone for bone, sexual and muscular health. Women produce testosterone in their ovaries, but in an amount that is about 10-20 times lower than the amount produced by men. Women are at a higher risk of developing osteoporosis than men. Maintaining a healthy range of testosterone may help women avoid this disease14.
Estrogen is the primary sex hormone that gives women traits such as breast tissue and menstrual cycles. Like testosterone, estrogen plays a critical role in bone health in both men and women15.
Many factors can influence estrogen levels in women. Two of the most common factors are the usage of birth control and the onset of menopause. High levels of estrogen can cause increased symptoms of menstruation, low sex drive, weight gain, and feelings of depression or anxiety. In men, high estrogen can cause infertility and trouble with erections among other things16.
Causes of Hormonal Imbalances
Poor lifestyles habits, exposure to chemicals in your food and environment, and a genetic predisposition to disease can cause hormonal imbalances. You can’t change your genes, but you can control what you put into your body.
Aging and Your Hormone Levels
Even after all the technologies science has given us, there’s still no cure for aging. As you get older, your body becomes less efficient at regulating itself. In fact, according to the “multiple hormone deficiency” theory17 of aging, a decline in hormone production causes many of the symptoms of getting older.
In elderly or sick individuals, hormones that are normally well-regulated can become so desynchronized that the effects are life-threatening.
Hormonal imbalances can lead to the symptoms of diseases that onset with age such as obesity, cardiovascular disease, cancer, diabetes, osteoporosis and dementia. Improper hormonal regulation can lead to excessive free radicals, failure to repair damaged cells and a compromised immune system.
Stress and Hormonal Imbalance
People with a workaholic lifestyle often have trouble taking time to relax. However, accumulated stress can be extremely damaging to your body. Stress takes many forms including muscular damage from intense exercise, financial worry or bereavement. When your body is chronically stressed, it produces elevated amounts of cortisol, adrenaline and noradrenaline18.
Think back to our prehistoric ancestors hundreds of thousands of years ago. What do you think was the biggest threat to survival for these people? Probably avoiding large animals and food shortage. For our ancestors, the stress reaction was beneficial because these hormones break down stored carbohydrates, proteins and fat to make energy quickly available. However, in our modern lives, we don’t usually have to worry about getting chased by woolly mammoths, and most of the stress we face is mental.
When your stress hormones remain elevated chronically, it can put you at risk of developing severe complications including an impaired memory, cardiovascular disease and a compromised immune system19.
Sleep and Hormonal Imbalance
The field of research examining the link between sleep and hormone levels is still growing. Many of your hormones fluctuate throughout the day based on your sleep-wake cycles. Sleep disruption can affect the production of growth hormone, melatonin, cortisol, ghrelin and leptin20.
People who experience long-term disruptions of sleep, like shift workers, may suffer health complications such as impaired glucose metabolism and disrupted cortisol rhythms.
Human Growth Hormone and Hormone Levels
Humans naturally produce a hormone called human growth hormone. When this hormone circulates through your blood, it signals to your liver to create another hormone called insulin-like growth factor 1 (IGF-1). IGF-1 is responsible for the tissue-building effects of human growth hormone (imagine the before and after pictures of baseball players who’ve injected human growth hormone for an example of this hormone’s potential).
Many dairy cows are injected with synthetic hormones to increase their milk production. Among the hormones of concern is recombinant bovine growth hormone (rBGH), a synthetic version of the cow-equivalent of human growth hormone. Some countries including Canada and countries in the European Union have banned this hormone.
There are two primary concerns21 about drinking milk from cows injected with rBGH. First, some research shows that consuming milk from cows given this hormone can raise IGF-1 in humans. It’s speculated that elevated levels of IGF-1 may increase your risk for developing cancer. However, it’s still not known how bioavailable the rBGH in cow’s milk is for humans.
Some research performed in the 1990s suggests that drinking milk with rBGH may only cause a slight increase in IGF-1; however, research supporting the avoidance of this hormone is compelling enough to have led to several countries banning its usage.
Cows given rBGH also have a higher risk of developing udder infections than regular cows, which means they’re given more antibiotics. Milk from cows given antibiotics may also cause health complications for humans (although research is still inconclusive).
Exercise and Hormones
Many people know that exercise is good for them, but most people don’t know what exercise does to their hormone levels. Exercise itself doesn’t make you fitter. However, it signals your body to undergo a series of biological changes that make your body stronger and leaner.
When you lift weights, you break down your muscle fibers. Your body increases production of hormones such as growth hormone and testosterone to respond to this stress, which causes your body to rebuild muscle fibers stronger than they were before exercise22.
Regular aerobic exercise also reduces your risk of developing insulin resistance and other metabolic disorders23.
Can you exercise too much? Yes, but unless you’re an elite athlete, you’re probably not going to have to worry about it.
Ask any professional athlete if they’ve ever overtrained at some point in their career, and they’ll probably say yes. Because exercise is a form of stress, your body produces the hormone cortisol, which has a suppressing effect on testosterone.
Usually, after a temporary period of having elevated cortisol levels and suppressed testosterone, your hormone levels return to normal. However, if you break your body down faster than it can repair itself, you can disrupt your hormonal profile.
Athletes use hormonal profiling to measure their current state of training. Athletes coming off hard training blocks often have elevated cortisol and depressed testosterone levels for months at a time24.
It’s worth noting that both women and men benefit from increasing their testosterone levels through exercise. However, because women produce far less testosterone, they usually don’t build the same amount of muscle mass as men.
Endocrine Disrupting Chemicals
Chemicals found in your environment that closely replicate hormones in the human body are called endocrine disrupters. These chemicals can activate, inhibit or change the production of hormones in your body.
In 1958, an endocrinologist named Roy Hertz first postulated that chemicals fed to livestock could enter the human body2.
Four years later, the marine biologist Rachel Carson published her book “Silent Spring”, which alerted the scientific community about the potentially damaging effects of chemicals in our environment.
During the 1970s, biologists began to notice strange patterns in animal reproduction. In the Great Lakes, mink stopped having babies, and herring gull chicks were dying in their eggs. Similar reproductive issues were found in alligators in Florida and fish in England2.
Scientists became worried that certain chemicals might have similar effects in humans.
Unfortunately, up until the 1970s, doctors prescribed pregnant women a chemical called diethylstilbestrol25 (DES) to prevent pregnancy problems like miscarriages.
DES is a synthetic form of estrogen first released in 1938. Between the year 1938-1971, an estimated 5-10 million women and children were exposed to this chemical. However, in 1971 a study came out that linked prenatal DES contact with the future development of vaginal cancer in young women.
Scientists continued to study endocrine disputing chemicals throughout the 1970s and 1980s. In 1991, researchers from a variety of scientific disciplines came together at a conference in Wisconsin to release the following announcement26:
“We are certain of the following: A large number of man-made chemicals that have been released into the environment, as well as a few natural ones, have the potential to disrupt the endocrine system of animals, including humans.”
Perhaps the most famous case of endocrine disrupters affecting humans was in the dumping of hexavalent chromium into the ponds in Hinkley, California (as seen in the movie starring Julia Roberts, “Erin Brockovich”).
Throughout the 1950s and 1960s, the Pacific Gas and Electric Company dumped 370 million gallons of wastewater containing hexavalent chromium around the town. The company was using hexavalent chromium to prevent rust in machinery, but the chemical is also used in tanning, pigment manufacturing, and nuclear weapon production27.
In humans, this chemical is a known carcinogenic and may contribute to oral, lung and intestinal cancer. In the case of Hinkley, the dumping of his toxic chemical led to a $333 million settlement in a class-action lawsuit.
Endocrine disrupters can be found in the following sources:
- Hygienic Products
- Pharmaceuticals and Drugs
Endocrine disrupters found in food like soy products that mimic estrogen are called phytoestrogens. These chemicals can have harmful effects on both men and women.
In women, overconsumption of phytoestrogen can disrupt regular menstruation cycles. In men, overconsumption may cause infertility28.
The following foods (among others) may contain phytoestrogen:
- Brown Rice
- Wheat Germ
Bisphenol A (BPA)
Bisphenol A, more commonly referred to as BPA, can cause health issue in humans. Epidemiological evidence suggests that using products made from BPA can cause fertility problems because BPA replicates estrogen in the body29.
BPA30 is commonly found in polycarbonate plastics such as water bottles and food packaging. BPA can leak from these products into food and water.
You can reduce your exposure to BPA by using BPA-free baby bottles. When cooking hot foods, use glass, stainless steel, or porcelain containers. If the bottom of a container contains a recycling code of three or seven, it may contain BPA.
Flame Retardants and Pesticides.
Many products are coated with flame retardants that can have potentially dangerous effects on your endocrine system. Flame retardants can enter your body through contact with electronics, furnishings and building materials.
Research has linked the use of flame retardants with thyroid cancer 28937689. However, recently, many companies have stopped using these chemicals in their products.
Several pesticides have been identified as endocrine disrupters as well. They can get into your body through your food, the air or your water31.
Taking Back Your Endocrine Health
You’re never going to be able to eliminate endocrine disrupters from your life completely, but by being smart about the chemicals you expose yourself to you can improve your overall health.
The first step is to take a close look at your diet and look for foods that you can eliminate with known endocrine disrupting effects. As we already found out, foods like soy, beans and lentils have phytoestrogen effects that can affect your sex hormones.
You also need to examine the source of your food. Steak is an excellent source of protein. However, even if two cuts of meats have the same ratio of macronutrients, they can affect your body differently.
When buying products from animals, look for products from animals that were raised without hormones. If you have access to game meat like deer or rabbit, you can include it in your diet as another hormone-free meat source.
When it comes to fruit and vegetables, consider growing your own if you have space. When you buy from the grocery store, stick to organic fruits and vegetables.
Always wash your produce to reduce chemicals that may reside on the surface.
It’s time to rethink the meaning of “healthy.” There’s no one food that can drastically change your health, but by avoiding endocrine disrupters, you can maintain your health and prevent chronic diseases like cancer.
Whenever possible, look for ways to eliminate chemicals in your food or your environment. Remember, toxins can also get into your body through the air you breathe and the water you drink. Stick to BPA-free plastics and don’t let your food come into contact with furniture or electronics.