There's more to the obesity epidemic than eating too many hot wings and excess sitting. Certainly, poor food choices, particularly too much sugar and sweeteners, and a lack of exercise are major pieces of the obesity puzzle. But a landmark 2002 study, published in the Journal of Alternative and Complementary Medicine, found the obesity epidemic paralleled the increase of industrial chemicals in the environment.
Now researchers are finding that exposures to certain common endocrine-disrupting chemicals and other food ingredients—not just lifestyle choices—could be programming us for weight gain, diabetes, and related problems. "We have to acknowledge the fact that obesity is not just about will power, that it's not just all someone's fault," says developmental biologist Retha Newbold, MS, CT, of the National Institute of Environmental Health Sciences.
Animal studies suggest that exposure to certain substances during fetal development or early in life can disrupt the normal development of an organism's hormonal system, promoting the development of fat cells and hampering the body's ability to send and receive signals that allow it to operate in good health. This sets the stage for metabolic diseases like diabetes as well as a lifetime of weight problems.
A recent Environmental Health Perspectives study found suspected obesogens in the bodies of many pregnant women, who can pass them along to their developing fetuses. "It appears that exposure to certain chemicals during critical windows of fetal and early development could permanently program a person for obesity or diabetes, which may not show up for decades down the line," says Newbold. "We're talking about different modes of action. Chemicals could be interacting with the brain, pancreas, or liver, or the fat cells themselves. The end result is going to be obesity."
The Facts: Previous studies have found an increased rate of diabetes among farmers and pesticide applicators, but it appears that even the low doses that the general public encounters can mess with our hormones. Banned organochlorine pesticides that linger in the food chain, such as DDT, have been linked to obesity, along with organophosphate pesticides and carbamates (the popular household insecticide Sevin is a carbamate pesticide). "Pesticides are designed to interfere with a lot of hormonal processes that insects require to replace themselves," explains world-renowned researcher Theo Colborn, PhD, president of The Endocrine Disruption Exchange. "The same chemicals that affect insects affect us."
Avoid It: Eat organic! Researchers have found that it takes just five days of eating organic to rid the body of nearly all pesticide residues. If the obesity link isn't compelling enough to go organic, consider that other pesticides have been linked to certain cancers, ADHD, autism, Parkinson's disease, and other health issues. And instead of using foggers and insecticide to combat household bug issues, adopt natural pest-control measures in your home.
The Facts: Studies in the lab find that BPA has the ability to accelerate fat-cell differentiation, disrupt pancreatic functioning, and cause insulin resistance, leading to obesity problems. In addition, other studies have linked BPA exposure to neurological development problems and sexual reproductive problems, including male infertility, in humans.
Avoid It: Scientists still don't know the number one exposure source of BPA, but because the chemical is produced in such high volumes, it's been found virtually everywhere. Until more data is collected about how BPA gets into our bodies, one prudent step to take is to minimize your handling of cash-register receipts--some have a high BPA content--so tell cashiers you don't need a receipt for minor purchases. Also, choose food that's fresh, frozen, or sold in glass jars over canned food, since most metal cans contain varying levels of BPA.
The Facts: Phthalates are hormone-disrupting chemicals tied to obesity, and they are ubiquitous in the personal-care product industry, particularly due to the chemicals' use in synthetically fragranced products. A 2010 study published in Environmental Health Perspectives found that children with higher phthalate levels in their bodies experienced stunted growth.
Avoid It: Avoid personal care products that list "fragrance" or "parfum" as an ingredient, and nix air fresheners and scented candles. They are likely laced with phthalates and a host of other hazardous materials. (Choose beeswax if you need candles.)
The Facts: Chemicals in vinyl chloride plastics called organotins persist in the environment, and are strongly linked to obesity. Exposure of mice to the organotin tributyltin (used on ship exteriors to prevent the buildup of crustaceans) before birth created permanent changes that pre-disposed the animals to weight problems. PVC plastics, such as pipes, vinyl flooring, and other vinyl products, contain dibutyltin, another organotin. Adding insult to injury, vinyl is also laced with phthalates, an obesogen listed above.
Avoid It:Avoid bringing vinyl products, including flooring, shades, purses, and shower curtains, into your home, and practice effective cleaning--PVC breaks down and can lurk in household dust.
The Facts: In a 2010 review article of published literature on the subject, Newbold links IDs perfluoroctanoic acid (PFOA) to obesity. PFOA (sometimes called Teflon) is used in many nonstick cookwareand kitchenware lines, along with stain-proof coatings on furniture, greaseproof food wrappers, microwavable popcorn bags, and waterproof materials.
Avoid It: If you already own nonstick kitchenware, don't freak out. But when you start to see scratches and chips, replace it with American-made cast iron or untreated stainless steel cookware.
The Facts: Polybrominated biphenyls (PCBs) were used widely as flame retardants in the electricity industry, but they're no longer made because of the compound's environmental and health effects. Newbold says the obesity-inducing mechanism of PCBs could be similar to that of BPA and some pesticides, working through estrogen receptor pathways. (The same company that made the bulk of PCBs is now behind the push for a chemical farming system and genetically engineered food.)
Avoid It: Since people are exposed to PCBs by eating contaminated fish, meat, and dairy products, eating lower on the food chain more often can help reduce your exposure. That doesn't mean you necessarily have to go completely vegan, but you could ease into a more plant-based diet by giving Meatless Mondays a try.
The Facts: Soy is low in fat, but it's also a phytoestrogen, meaning it has plant-based estrogenic properties. Doses comparable to those eaten in the Western diet have been shown to promote fat-cell growth. Newbold says parents should be especially wary of feeding soy to babies or children. "Studies have shown that kids on soy formula have a tendency to gain weight," explains Newbold, who notes that soy affects developing children differently than adults. Babies born small for their gestational age who are put on high-calorie "catch-up diets" also face an increased risk of obesity later in life.
Avoid It: Since developing babies and young children seem to be most sensitive to soy, Newbold suggests that women breastfeed, if possible, and parent avoid giving young kids soy products.
The Facts: Not only do babies born to mothers who smoked throughout pregnancy face an increased risk of being born prematurely and underweight, but strong research also suggests that those same babies face an increased risk of being obese as they grow older. Nicotine (or nicotine plus some other component of cigarette smoke) could tinker with the child's metabolic system; researchers just aren't sure yet of the mechanism. Perhaps compounding the problem, low-birth-weight babies born to smokers could also be put on a "catch-up diet" referenced above, further increasing their risk of obesity later in life.
Avoid It: Don't smoke if you're pregnant, and do your best to eliminate second- and even third-hand smoke.
For more specific ways to detox your life, check out 12 Household Toxins You Should Banish from Your Home.
The Facts: Emulsifiers added to many processed foods to improve texture and extend shelf life impact your gut in a way that promotes metabolic syndrome, according to a 2015 study published in Nature.
Mice fed at levels present in our food triggered the obesity and even gut diseases like colitis. The Georgia State University team that uncovered the connection is now looking at other common emulsifiers to see if they affect humans. They said if they find similar results, it could suggest that emulsifiers are a class of food additive driving the epidemic of obesity.
Avoid It: Emulsifiers high out in most processed foods, so eat whole foods whenever possible. Scientists plan to test out emulsifiers used in organic foods, too, including soy lecithin, to see if other emulsifiers have similar obesity-promoting and gut-harming effects.
The Facts: It's a known fact that industrial farms give livestock antibiotics, in part, to make them fatten up faster. But when people ingest too many antibiotics, it could make them gain weight, too.
In one study, microbiologist Martin Blaser, of New York University, fed mice short courses of antibiotics similar to those that children receive. Compared to the non-drugged mice, the antibiotic-fed mice had lower levels of T-cells, which regulate the body's immune response. Obesity has been associated with low levels of these T-cells.
In a separate observational study, published in the April 2011 issue of the International Journal of Obesity, researchers from Denmark followed the development of 28,000 babies, and for seven years, monitored the children's weight and development. Babies who were given antibiotics within six months of birth were more likely to be overweight by age 7 than children who hadn't received such early doses of the drugs, regardless of how trim or obese their mothers were.
Avoid It:Antibiotics can be lifesavers, but avoid taking them unless you need them. Talk to you doctor and for background, check out Do You Really Need That Antibiotic and Don't Take Antibiotics for This Common Condition.