Link Between Fetal Exposure to PVC Plastic Chemical and Obesity in Offspring
January 30, 2013
By Dr. Mercola
When you get out of the shower in the morning, you probably don’t pay much attention to your vinyl shower curtain, except to maybe note when it needs a cleaning.
And if your home contains soft, flexible plastic flooring, such as vinyl or those padded play-mat floors for kids (often used in day cares and kindergartens, too), you probably don’t give them much thought either...
You might know that plastic is hard and very rigid and the only way to make these flexible plastics is to use plasticizers such as phthalates, and one of the phthalates is a particularly pernicious one called tributyltin.
Tributyltin is not only a common phthalate in PVC, it’s also found in marine paints, where it acts as a biocide to discourage the growth of barnacles, bacteria, algae and other organisms on ship and boat hulls.
Although now phased out in marine paint, its former use comes at a steep price, as the chemical is known to leach into waterways and accumulate in marine life, including in the seafood you may eat. PVC piping used for drinking water and sewer systems are another reason why tributyltin is now pervasive in the environment. It’s also used as a wood preservative.
Even Low-Dose Exposure to Tributylin Might Make Future Generations Fat
If you or your children are exposed to a small amount of tributylin (TBT), you probably won’t know it. But that doesn’t mean it’s not having an effect.
New research has shown that pregnant mice exposed to low doses of the chemical (similar to amounts found widely in the environment) had children, grandchildren and great-grandchildren with increased body fat, liver fat and fat-specific gene expression.1 The researchers stated:
“Prenatal TBT exposure produced transgenerational effects on fat depots and induced a phenotype resembling nonalcoholic fatty liver disease through at least the F3 generation. These results show that early life obesogen exposure can have lasting effects.”
What makes the study results all the more concerning is that TBT is commonly detected in household dust, which is easily ingested by young children who crawl and play on the floor. This isn’t surprising considering how pervasive PVC is in most homes. Aside from plastics, shower curtains and flooring, PVC may also be found in wallpaper, vinyl window blinds, handbags and countless other “everyday” items.
According to one study, TBT and related organotin compounds were found in all of the house dust samples analyzed, and dust ingestion by children was estimated to account for, on average, up to 18 percent of the tolerable daily intake of such chemicals proposed by the World Health Organization (WHO).2 It was also found that the rate of organotin ingestion among children due to household dust was, on average, eightfold higher than the intake rates calculated for adults.
It would also be prudent to be concerned about ANY flexible plastic, as odds are there is some toxic additive to induce the flexibility that makes the plastic product more usable but more than likely has never been tested for toxicity.
Obesogens: Are We Being 'Programmed' to be Fat?
As we see rising rates of obesity around the world, among both adults and children, it’s imperative that exposures to obesogens like TBT be taken seriously. The term “obesogen” was first coined by Bruce Blumberg, a biology professor at the University of California, Irvine, who also authored the above study. It refers to a growing group of environmental chemicals linked to obesity. Among his early work on TBT, Blumberg noted that exposure to TBT caused stem cells to become predisposed to becoming fat cells.
“The insidious thing is that our animals are exposed in utero to TBT, then never again, yet TBT caused a permanent effect,” he noted ... “If you give tributyltin [TBT] to pregnant mice, their offspring are heavier than those not exposed ... We’ve altered the physiology of these offspring, so even if they eat normal food, they get slightly fatter.”3
Upwards of 20 environmental chemicals, most of them known as “endocrine-disrupting chemicals,” have been shown to cause weight gain when exposure occurs during fetal and infant development, although some are also linked to adult exposures. Along with TBT, this includes:
|Atrazine and DDE (a DDT breakdown product)
||Certain drugs, such as the diabetes drug Avandia
||The soy phytoestrogen genistein
|Monosodium glutamate (MSG)
||Phthalates (found widely in PVC plastics, laundry products, personal care products, air fresheners and more)
|Diethylstilbestrol (DES, a synthetic estrogen prescribed to pregnant women through the 1970s)
||Bisphenol-A (BPA, pervasive in certain plastics, canned foods, cash register receipts and medical devices)
||Perfluorooctanoic acid (PFOA, used in non-stick cookware, stain-resistant clothing/upholstery, mattresses, microwavable food packaging, etc.)
Low Doses May be Worse Than High Doses
It’s often assumed that because we’re only exposed to small amounts of one chemical or another that the doses are too low to cause any significant effects. On the contrary, it appears that your body may be primed to respond to low doses even more so than higher ones. For instance, studies have shown that BPA had an impact on rodent fat cells at doses 1,000 times below the dose regulatory agencies say causes no effect in humans. Yet, higher doses appeared to have no impact.
As written in Environmental Health Perspectives:4
“Receptors typically respond to very low levels of hormone, so it makes sense that they may be activated by low levels of an endocrine mimic, whereas high levels of a chemical may actually cause receptors to shut down altogether, preventing any further response. This is known as “receptor down regulation.” As a result, some endocrine disruptors have greater effects at low than at high doses; different mechanisms may be operating.”
Can You Fight Back Against Environmental Obesogens ... and Win?
Chemicals in your environment can certainly have an impact on your health, and probably your weight. Some of these exposures may even occur before you’re born, which means it’s out of your control to some extent ... but not entirely. Not even close. As Blumberg noted, exposure to obesogens doesn’t necessarily “doom you to be fat”:5
“I would not want to say that obesogen exposure takes away free will or dooms you to be fat,” he says. “However, it will change your metabolic set points for gaining weight. If you have more fat cells and propensity to make more fat cells, and if you eat the typical high-carbohydrate, high-fat diet we eat [in the United States], you probably will get fat.”
Blumberg postulates that the effects of early-life exposure are irreversible, and those people will fight a life-long battle of the bulge. However, if such people reduce their exposure to obesogens, they will also reduce health effects that may arise from ongoing adulthood exposures. Blumberg believes it’s good to reduce exposure to all kinds of endocrine-disrupting chemicals. 'Eat organic, filter water, minimize plastic in your life,' he says. 'If there’s no benefit and some degree of risk, why expose yourself and your family?'”
In other words, do a quick check of your home and work environment to determine where your greatest exposures may be coming from. Simple changes such as these that follow can significantly reduce your risks:
- Avoid flexible plastics if at all possible
- Eat organic foods as much as possible
- Rather than eating conventional or farm-raised fish, which are often heavily contaminated with PCBs and mercury, supplement with a high-quality purified krill oil, or eat fish that is wild-caught and lab tested for purity.
- Filter your home’s water
- Avoid using plastics, especially for use with food or beverages, or in children’s toys
- Choose glass jars instead of storing your food in plastic containers
- Use natural toiletries and personal care items, cleaning supplies, laundry detergents and other household products
- Look for natural, chemical-free clothing, furniture, flooring, paint and other building supplies to use in your home
- Replace your non-stick pots and pans with ceramic or glass cookware or a safe nonstick pan
- Replace your vinyl shower curtain with one made of fabric, or install a glass shower door
A Simple Weight-Loss 'Prescription'
If you need to lose weight, don’t despair. For the majority of people, severely restricting carbohydrates such as sugars, fructose, and grains in your diet will be the key to weight loss. Refined carbohydrates like breakfast cereals, bagels, waffles, pretzels, and most other processed foods quickly break down to sugar, increase your insulin levels, and cause insulin resistance, which is the number one underlying factor of nearly every chronic disease and condition known to man, including weight gain.
When you cut grains and sugar from your meals, you typically will need to radically increase the amount of vegetables you eat, as well as make sure you are also consuming high-quality protein and healthy fats regularly. This includes saturated fats like coconut oil, which research shows can help trim your waistline. I've detailed a step-by-step guide to this type of healthy eating program in my comprehensive nutrition plan, and I urge you to consult this guide if you are trying to lose weight.