You count calories, eat all of the fruit and veggies you can get your hands on, watch your sugar and fat intake, and exercise religiously. You do all of the right things, and yet the needle on your scale still keeps creeping up. What gives?
If this scenario sounds familiar, you might be surprised to learn that the one thing sabotaging your waistline may have nothing to do with how much you eat or work out. This possible culprit? Obesogens.
Put simply, an obesogen is something that makes you fat. Although obesity can be caused by too much food, too little exercise and your genes, among other factors, a new class of obesogens has recently emerged. These are called endocrine-disrupting chemicals (EDCs) —manmade chemicals that interfere with the hormone-secreting glands that make up your endocrine system. Think thyroid, thymus, pancreas, gonad, adrenal, and pituitary, for starters. Even your heart, brain, digestive system, kidneys, and adipose (fatty) tissue churn out hormones.
“These hormones maintain our health, metabolism, reproduction, growth and development and many other functions,” says Andrea C. Gore, Ph.D., a professor of pharmacology and toxicology at the University of Texas at Austin. And when EDCs “get into our bodies, that can disrupt hormone systems,” she explains. The result: Problems such as obesity, diabetes, cancer, infertility and heart disease.
The ABCs of EDCs
There are thousands of EDCs out there. Among them: organochlorinated pesticides, industrial chemicals, plastics and plasticizers, and fuels. The most widely studied is Bisphenol A (BPA) primarily because it’s everywhere, turning up in products like baby bottles and food containers. However, “BPA is the tip of the iceberg,” says Dr. Gore, who is also editor-in-chief of the journal Endocrinology.
Here’s what you need to know about BPA and four other common EDCs.
BPA. Bisphenol A is a chemical used to make polycarbonate plastics and epoxy resins. It is found in beverage containers; CDs and DVDs; plastic dinnerware; auto parts; toys; the linings of food cans; dental sealants; cash register receipts; and baby bottles, as well as other products.Researchers from the Harvard School of Public Health found that people who downed a 12-ounce serving of canned vegetable soup daily for five days had more than a 1000 percent increase in BPA in their urine than people who ate homemade vegetable soup. The study appeared in the Journal of the American Medical Association in 2011.
Using data from the 2003 to 2004 National Health and Nutrition Examination Survey, other researchers have found that people who had higher levels of BPA in their urine were more likely to be diagnosed with cardiovascular disease, diabetes, and liver enzyme abnormalities. The study, published in the Journal of the American Medical Association in 2008, included 1455 people ages 18 through 74.
Phthalates. A phthalate is a compound, or plasticizer, that is used to soften plastic. Phthalates are everywhere—including medical devices; flexible plastic toys; floor tiles; hair spray, soap, shampoo and nail polish; vinyl floors and miniblinds; and shower curtains. Phthalates don’t stay put, so you can breathe them in via dust; eat them (food that’s wrapped in plastic may contain them); or apply them to your skin. The health effects are still being studied but high levels of certain phthalates may affect reproduction or development.
PVC. Polyvinyl chloride is commonly found in shower curtains. (If yours does, you’ll smell it when you open the package.) A 2008 study from the Center for Health, Environment & Justice found that a shower curtain containing PVC release up to 108 volatile organic chemicals (VOCs). Some could still be detected in the air 28 days after the curtain had been hung. VOCs have been linked to eye, nose and throat irritation; nausea; and liver, kidney and central nervous system damage. Some may cause cancer. PVC is also used in all kinds of products including laminated aprons and tablecloths, pipes, telephone cables, imitation leather furniture, vinyl flooring, the underside of carpets, rubber boots, nylon sports and school bags, bibs, changing mats, stroller hoods and teething rings.
PFCs. Perfluorinated compounds turn up in stain- and grease-repellent-chemicals; clothing; cookware; carpets; and food containers. A recent study published in the Journal of Clinical Endocrinology & Metabolism reported that overweight 8- to 10-year-olds with higher blood levels of PFCs had higher insulin and triglyceride levels – which could lead to diabetes and obesity.
PBDEs. Polybrominated diphenyl ethers are used as flame-retardants in furniture, electrical equipment, TVs and computers. These EDCs have been detected in water, soil, air, household dust, animals and human tissue, according to a 2008 review in the journal Acta Bio Medica. Research has found that newborn mice and rats exposed to PBDEs experienced changes in behavior, such as hyperactivity. Their learning and memory were affected, too. Adult rodents exposed to the substances had reduced sperm counts and altered ovarian cells and lower levels of a thyroid hormone that plays a role in brain development.
The list of EDCs goes on. But it’s best not to panic. “Not every endocrine disease we are seeing today is directly linked to chemicals,” says Dr. Gore. “They’re only part of the story.”
When it comes to obesity, for instance, diet and exercise also matter. “Your lifestyle and food choices push you in one direction or another along the obesity spectrum,” says Dr. Gore. “But we think EDCs are adding to these factors to increase obesity predisposition.” Your genetic make-up plays a role, too. As a result, not everyone exposed to EDCs will gain weight, explains Dr. Gore.
While adults need to limit EDC exposure, fetuses and infants are at greatest risk for harm. “The fetal and infant periods are particularly sensitive,” says Dr. Gore. “EDCs interfere with the hormonal systems that are involved in how the body develops.” Ill effects may not be seen for years. Case in point: Fertility problems among adult males and females may be partly due to chemical exposures that began in utero and during infancy. “Those early life exposures change how the body’s hormone systems work as people mature,” says Dr. Gore. The rise in diabetes and obesity may also be partly due to early and lifetime exposures.
The good news is that scientists are working to find alternatives to EDCs, says Dr. Gore.In the meantime, err on the side of caution and minimize your exposure—and your family’s—to EDCs. Reality check: It’ll be hard to avoid every EDC out there. Just do your best. “While we can’t control contact with all of the chemicals around us, we can be more attentive to what we eat and drink,” says Dr. Gore. “Since food and beverages are a major route of exposure, making careful and healthy choices can really help.”
Some strategies to try:
Don’t microwave plastic containers. Heat can cause EDCs to leach out of the plastic containers and into food. If your frozen leftovers are in a plastic container, put them in a lead-free ceramic or glass dish before nuking them.
Eat fresh. Since cans contain BPA and other chemicals, opt for fresh fruit and vegetables rather than canned, says Dr. Gore.If you can afford it, buy organic food. Wash produce to remove residual pesticides.
Watch the animal fat. Many animals contain toxins, so the less you eat, the better. If you must eat animal fat, buy cuts that are antibiotic- and hormone-free.
Use glass, porcelain or stainless steel containers, especially for hot food and beverages, advises the National Institute for Environmental Sciences. If you use plastic, check the recycle code: Products marked with a 3 or 7 may contain BPA.
Don’t drink from plastic water bottles. Instead, fill a glass or environmentally-friendly bottle with tap water. Not only does this minimize your chemical intake, it reduces the amount of plastic in landfills.
Be label savvy. Don’t buy products that have the word vinyl or PVC on the label. Look for shower curtains and liners made of natural fibers like cotton.
Buy BPA-free bottles. Use baby bottles, pacifiers and other products that are clearly marked BPA-free. The FDA recently banned BPA from most of these items, but older items on the shelves may not be BPA-free.
Go natural. Use natural, nontoxic cleaning and personal care products whenever possible and avoid using aerosol products.
Avoid or minimize the use of nonstick cookware.
Sanitize. Wash your hands before preparing food and eating and after touching cash register receipts.
Be wary of furniture and clothing treated with flame-retardants. Don’t buy furniture labeled California Technical Bulletin 117 (TB 117), as it may contain toxic flame-retardants, according to the National Resources Defense Council.