Is Plastic Making Us Fat?
BETH DALEY / Boston Globe 14jan2008
Researchers are exploring whether exposure to common
early development could set us up for a lifetime battle with the bulge
Being fat has long been seen as a personal problem, fixed only by struggling against the proliferation of fast food restaurants, unlucky genes, and a sedentary life.
Child’s Typical Day
But could something in the environment also be making Americans fat in epidemic numbers?
Animal studies in recent years raise the possibility that prenatal exposure to minuscule amounts of common chemicals — found in everything from baby bottles to toys — could predispose a body to a life of weight gain. The chemicals, known as endocrine disrupters, mimic natural hormones that help regulate, for example, how many fat cells a body makes and how much fat to store in them.
These findings have led some scientists to put forth a provocative argument: They say diet and too little exercise clearly are key reasons for the worldwide rise in obesity in the past 20 years, but they may not be the only ones. Food intake and exercise just haven't changed that much in that period, they argue. And while genetics obviously play a role — just think of someone you know who can eat three Big Macs a day and never gain an ounce — these researchers say it would be impossible to see such widespread genetic change in just two decades, giving them more reason to suspect the environment.
"This is a really new area . . . but from multiple labs on multiple levels we are getting preliminary data that all say the same thing: Chemicals can play a role," said Jerry Heindel, a program administrator for the National Institute of Environmental Health Sciences. "We know that nutrition and exercise are very, very important, but underlying that could be environmental exposures during development that alter your physiology, including how you respond to food and exercise."
Thousands of chemicals have come on the market in the past 30 years, and some of them are showing up in people's bodies in low levels. Scientists studying obesity are focusing on endocrine disrupters — which have already been linked to reproductive problems in animals and humans — because they have become so common in the environment and are known to affect fat cells.
One key researcher in the field, Bruce Blumberg of the University of California, Irvine, has even coined a new word for chemicals that can make you fat: Obesogens.
A recent US Centers for Disease Control and Prevention study found that about 93 percent of the US population had bisphenol A, a chemical that can be found in canned goods and in hard, clear plastic items such as baby bottles and hiking containers, in their body. A study at the University of Missouri-Columbia showed that mice fed bisphenol A during early development — at lower amounts than what would have resulted in the levels found in most people in the CDC study — become markedly more obese as adults than those that weren't fed the chemical. Tufts University scientists observed similar phenomenon in rats.
The chemical industry, however, disputes those studies and says dozens of others that examined bisphenol A showed no weight gain.
"The scientific evidence shows that bisphenol A . . . does not have any effect on body weight," said Steven Hentges, executive director of the polycarbonate/BPA global group of the American Chemistry Council, which represents chemical manufacturers.
Bisphenol A is only one of the chemicals scientists are studying. Blumberg's lab has also studied tributyltin, an endocrine disrupter that is used as an antifungal agent in agriculture and in marine paints to keep ship hulls free of barnacles. Female mollusks exposed to the chemical were seen to grow male sex organs. Lab mice exposed to tiny levels of tributyltin during prenatal development became fatter adults than those not given the chemical.
"It predisposed them for life," said Blumberg.
These scientists are focusing on early development because it is a critical time for determining a baby's long-term health and weight. For example, studies show that babies born underweight are likely to be fatter later in life, possibly because undernourished fetuses learn to use fat cells more efficiently — and it gets embedded in their physiology. Researchers suspect the same thing may be taking place with chemical exposures.
Exposure "can be critical on the front end of one's life where the rest of your life's physiology is being programmed," said Frederick vom Saal, a biological scientist at the University of Missouri-Columbia who studies bisphenol A.
His lab is studying genes in the fat cells of mice to better understand why the animals became fatter when exposed to the chemical.
Growing up with more fat cells isn't necessarily a problem if you are running around a lot, says Pete Myers, chief scientist for Environmental Health Sciences, which publishes the online journal Environmental Health News. But in a world where exercise is down and poor diets abound, it could exacerbate a weight problem.
Vom Saal says as people become adults, they may be able to shake off the weight with extreme diet and exercise, but it won't be easy. "It is a very intractable thing to change," he said.
Scientists who study obesity's link to chemicals say the research is still in its infancy. Among the many unanswered questions that remain: How do the changes happen? What about the combined impact of exposure to many chemicals? Are humans affected by the chemicals the same way as animals?
For those who don't want to wait until all the evidence is in, there is another question: How to avoid these chemicals now?
"It can be difficult," said Felix Grun, assistant researcher in the department of developmental and cell biology at the University of California who works with Blumberg. To minimize exposure to bisphenol A, Grun said people can avoid buying plastics with the recycling number 7 marked on the bottom, but similar types of chemicals abound in other products, too. "These compounds are everywhere, the carpet fibers, the PVC piping, etc," he said.
Scientists say years of research into a once-popular synthetic hormone — diethylstilbestrol (DES) — also bolsters their belief that chemical exposure during early development can affect weight later in life. DES was once given to women to prevent miscarriages until it was linked to cancer in female offspring. Now, research by Retha R. Newbold at the National Institute of Environmental Health Sciences shows that mice exposed to DES in utero are fatter than those not given the chemical.
Ana Soto, a Tufts University professor who studies endocrine disrupters and development, says scientists already know that the most serious health problems of DES impact mice and humans similarly. Now that mice exposed to low levels of bisphenol A are behaving much the same way they do when exposed to DES, it makes sense to conclude that humans may be at risk too. She wants the chemicals like bisphenol A to be regulated by the federal government.
"What else are we waiting for?" Soto asked. "There is evidence these chemicals have a multitude of deleterious effects in animals. . . We should be worried."
PAUL GOETTLICH / Mindfully.org
Infants sleep in cribs made of plastic, covered with synthetic sheets that are treated with fire-retardant, and washed in harsh detergents containing toxic many synthetic chemicals. Sheets are dried at high temperature creating dioxin from the chlorine bleach residue.[40b] The mattress cover’s flexibility is from plasticizers and it’s treated with an antibacterial agent. The room’s new synthetic carpeting and freshly painted walls offgass toxins. Snugly fitting disposable diapers contain toxic ingredients such sodium polyacrylates, and ethylvinylacetate-based glues, resins, softening agents and antioxidants.[40c] The lotion their precious bottoms are covered with contains phthalates, which are known to mimic hormones. A fluoride supplement is prescribed if drinking water is from a well. The water itself could be high in nitrates and coliform.[40d]
Their food has been drenched in a variety of pesticides, herbicides, and fungicides, then wrapped in plastics, coated with sealants, or canned. It’s heated in, eaten from and eaten with plastic. Warm leftovers are saved in plastic and refrigerated.[40e] The health effects of few of the constituent chemicals of plastics are known, but their collective effect is completely unknown. The FDA interestingly calls chemicals that migrate from plastic into food “indirect food additives.” Regulations governing the use of plastic in contact with food offer only limited protection.[40f]
While being driven about town, the child sits in a car seat made of several types of plastic in a car that has that new car smell, which is off-gassing of plastics. Dry-cleaned clothes, perfume, hand cream, deodorant, hairspray, nail polish, lipstick, and cigarette smoke are also part the car’s air. Driving behind a diesel truck, fine particulate matter carrying carcinogens and endocrine disruptors are forced deep into the child’s lungs.
They drive through factory fumes to pick up the father, where he works in PVC or pesticide production. He could be smoking, wearing after-shave lotion, or his clothes carry the residue a toxic chemical that he worked with. If he’s a dentist, he just finished filling a cavity with mercury. If he does auto body repair, he just finished using paints and plastic filler.
On the way home, they stop off to fill up the car’s gas tank and the fumes flow through the open window along with the odor of the degreaser the mechanic uses. During the summer ozone levels are high and smog is thick. In the winter, oil, gas, coal, and/or wood combustion byproducts permeate the air, depending upon the locality.
A few years later, when the child goes to school carrying a plastic lunch box on a bus. Diesel fumes will fill the bus. Even a nonsmoking diesel bus could be exposing the child to dangerous levels of exhaust. A child riding a school bus may be exposed to 23 to 46 times the cancer risk considered "significant" by EPA and under federal environmental laws.[40g] The air in rural areas will be laced with pesticides, herbicides, fertilizers, dust, diesel fumes, and anything else that drifts out of the urban areas. Jets fly overhead, sometimes dumping jet fuel at high altitudes, which vaporizes before reaching the ground.
At school, the child will sit at plastic desk, on a synthetic floor covering, within walls covered with a vinyl material, under vinyl covered ceiling tiles and fluorescent lighting. The school has air conditioning with no fresh air supply, recycling stagnant air through dusty, damp, mold ridden ducts. The teacher’s perfume mixes with the accelerants of the whiteboard markers. Pesticides are used regularly throughout the school, whether needed or not. Many surfaces will be treated with bleach and antibacterial liquids. The halls are filled with the smell of the vinyl flooring. The grounds are covered with pesticides herbicides, and synthetic fertilizers that can contain just about any kind of toxic waste.
For lunch, the child eats and drinks highly processed, pesticide-ridden, irradiated foods with synthetic preservatives, colorings, and a score of unnamed substances whose only purpose is to extend the food’s shelf life. The food is often prepared at another location miles away, transported in plastic, served on, and eaten with plates and utensils made of polystyrene. Before eating the child’s hands are washed using a soap that is antibacterial/antimicrobial, using chlorinated/fluoridated water.
Someone asked for more, so here goes. . . (10feb2008)
With iPod inserted in ears, the child is an adult now and has access to money that brings contact with all sorts of wonderful pollutants from corporations devoid of ethics, morals and accountability. The child's plastic diapers have been replaced by plastic condoms and IUDs coated with spermicides and clothing coated and impregnated with every sort of anti-this and -that. The politics of the day are of stupidity and have no link to history other than expanding on the errors of the past, with frequencies approaching instant replay. Nobody learns from the past. The house pet is treated with Bayer Advantage Flea Control, making the whole animal a pesticide-release device from the tip of its wet little nose to the end of its tail. The computer is wired with Wi-Fi. But then, the whole city is a giant Wi-Fi zone, potentiating whatever else comes around. The house stereo and a number of other devices are radio-controlled. And there are so many of them in the house that there is a general stink from off-gassing electronic components. FDA rules have become even more acceptant of food containing greater amounts of synthetic chemicals. Ambient levels of the bacterium e Coli increases while food quality is significantly lower than ever. Yet it costs more and travels significantly greater distances from farm to plate. The farms are growing in size, as are the problems with them.
Because of time constraints, less fresh, whole foods and more highly processed packaged products are eaten. After sitting on a shelf in the food store for months, the plastic-wrapped, pesticide-treated foods are microwaved. By this molecular zapping, free radicals are added to the already existing ones from the plastics, pesticides and processing agents. This pathetic, disgusting meal is shoveled into the recipient's mouth with all the care that it took to create the mess. Along with antipsychotic medications and others for ADHD, diabetes, high cholesterol, growth hormones, the food products are washed down with water from the city's aging water supply system that is rapidly being replaced with PVC piping.
Each year there are many millions more cars on the road, sending a greater load of pollutants into the air, all of which is heavily bolstered by steel foundries, paint factories and assorted incinerators burning remnants of plastic wrappings, worn-out tires and chicken parts, as well as those used condoms and worn-out IUDs. Small family-owned shops have been replaced by big-box outlets. Working or shopping in one exposes one to all of the above and more. The adult passes by the garden products area with hands over nose. But the volatile chemical off-gassing enters through every pore and sticks to synthetic clothing and hair for later delivery into our bodies. The same thing happens in the tire department or the electronics or clothing departments, as well as health and beauty aids and whatever else is in the place. It all amounts to one very large toxic waste dump that effects everyone who enters, lives nearby or has anything at all to do with the system.
The result of our constant exposure is that the human species is nearly done. Our chances of contracting cancer grow each year along with the abundantly evident health problems. Our ability to reproduce is rapidly decreasing. I for one, am certain that much of this poor health is related directly to our exposure to all the wonderful technologies that have created the world we now live in. No cures will be possible without reductions in exposures. Any dreams of cures without drastic reductions in exposures are mere fantasy. Mostly the cures are nothing more than money-making schemes.
That's all I have the stomach for at this point in time. I feel out of touch with much that goes on now. Each day is a learning experience as I walk down the street and see what others are doing. . . . Paul