These days, bottled water is all over the world. It's very rare that a person drinks straight from the tap any more.
As for the kinds of drinking bottles used, while some personal water bottles have a metal casing inside to keep the liquid cool or hot (think of "thermos"), most are divided into glass bottles and plastic bottles.
Most plastic products, from sippy cups to food wraps, can release chemicals that act like the sex hormone estrogen, according to a study in Environmental Health Perspectives.
The study found these chemicals even in products that didn't contain bisphenol A (BPA), a compound in certain plastics that has been widely criticized because it mimics estrogen.
Many plastic products are now marketed as BPA-free, and manufacturers have begun substituting other chemicals whose effects aren't as well known.
Between 2010 - 2013, researchers in Austin, TX bought more than 450 plastic items from stores including Walmart and Whole Foods.
They chose products designed to come in contact with food — things like baby bottles, deli packaging and flexible bags, says George Bittner, one of the study's authors and a professor of biology at the University of Texas, Austin.
The testing showed that more than 70 percent of the products released chemicals that acted like estrogen. And that was before they exposed the stuff to real-world conditions: simulated sunlight, dishwashing, and microwaving, Bittner says.
In a more recent study, researchers at Johann Wolfgang Goethe University in Frankfurt, Germany used bottles that were made from a different plastic, the type used in most single-use water bottles.
The researchers washed out used water bottles made from either polyethylene terephthalate (PET) or glass and then cultured young mud snails in them.
The species actually increased its production of embryos when exposed to elevated quantities of the hormone.
And that’s what was seen in those reared in the PET containers. Compared to snails cultivated in glass bottles, PET-housed ones produced more young — up to twice as many embryos.
The team notes that the “high activity” they witnessed “would seem in indicate we have a mixture” of hormone-mimicking pollutants.
So what does all this mean?
While it may not make men grow breasts or become "girly", in men and premenopausal women, too much estrogen — a condition called estrogen dominance — causes toxic fat gain, water retention, bloating, and a host of other health and wellness issues.
As women age, there is a natural decline in testosterone and progesterone levels, leaving a relative excess of estrogen.
If you are a premenopausal woman with estrogen dominance, you likely have PMS, too much body fat around the hips, and difficulty losing weight.
Perhaps you have a history of gallstones, varicose veins, uterine fibroids, cervical dysplasia, endometriosis, or ovarian cysts. In both sexes, estrogen dominance is thought to be responsible for many types of cancers.
This particular hormone imbalance could be one of the leading causes of breast, uterine, and prostate cancer.
Here are four ways to correct estrogen dominance:
1. Watch Your Liver
Since the liver breaks down estrogen, alcohol consumption, drug use, a fatty liver, liver disease, and any other factor that impairs healthy liver function can spur an estrogen build-up.
2. Increase Healthy Bacteria
Bacterial imbalance in the gut, and other problems that compromise digestion, interfere with the proper elimination of estrogen from the body via the digestive tract. Try including a daily probiotic to your diet.
3. Boost Your Fiber Intake
Insoluble fiber binds to excess estrogen in the digestive tract, which is then excreted by the body.
A fiber supplement can also affect the composition of intestinal bacteria and reduce the build-up and re-absorption of free-floating estrogen.
Good sources include wheat bran, corn bran, rice bran, the skins of fruits and vegetables (apples, pears, berries, tomatoes, eggplant, zucchini and carrots), nuts (especially almonds), seeds (particularly sunflower seeds), soybeans, dried beans, and whole-grain foods.
4. Go Organic
Some dairy and meat products may contain hormone additives, so choosing organic dairy and meat may reduce your exposure to excess estrogen.