There’s no escaping it. Everywhere you turn you can see the evidence, and even if you haven’t noticed lately, the media is more than happy to remind you, we are a nation of lazy super-size me gluttons threatening to undermine the future of our health care system with the litany of health problems that will inevitably come when the overweight and obese among us start to age.
It’s estimated that roughly 60 percent of Americans are overweight or obese. People are finding it more and more difficult to shed those stubborn pounds, no matter how hard they try. But the most alarming trend, and one that might offer a clue about why the problem is so obstinate, is the rapidly rising rate of childhood obesity. For a variety of reasons, kids today are simply not getting the same amount of exercise they were getting a generation or more ago. On top of that, there’s a dearth of choices when it comes to nutritious foods kids can enjoy driving them to the nutrient-deficient junk food that typically comprises their diet. At first glance it seems that the problem can be easily explained away by the combination of these two circumstances. But if you dig beneath the surface just a bit, what you will learn might shock you.
Recent studies in the area of childhood obesity have revealed some startling findings that have forced scientific researchers to look beyond the obvious and long held beliefs about weight gain, in order to explain this alarming phenomenon. In 2006 for example, scientists at the Harvard School of Public Health reported that the prevalence of obesity in infants under 6 months rose a whopping 73 percent since 1980.
This epidemic of obesity in infants has turned conventional wisdom regarding weight gain and loss on its head. Until now everyone believed that weight gain was the direct result of consuming more calories than you burn — a perfectly good explanation except when applied to babies. Since infants pretty much only consume breast milk and formula, the logical conclusion is there must be something else going on.
Exposures Add Up
It’s no secret that when babies are exposed to harmful substances while in the womb it can have detrimental effects on their health later in life. This was the case with women in the 1950s who were given a drug called DES during pregnancy to prevent miscarriage that was later found to increase their daughters’ risk of developing cervical or vaginal cancer. Scientists are now taking a closer look at what substances may be present in pregnant women that could be impacting the later development of their children and causing them to be fat.
One explanation for the obesity puzzle that’s gaining credence is early-life exposure to traces of certain chemicals and pollutants in the environment –now commonly referred to as endocrine disruptors. These chemicals are so similar to human (and animal) hormones that they can block or disrupt the actions of regular hormones in both.
There is mounting evidence of a strong link between early exposure to some of these endocrine disruptors and the later development of obesity. Apparently these compounds act on genes in the developing fetus and newborn to turn more precursor cells into fat cells, which may pre-dispose babies and young children to becoming and staying fat. They can also alter metabolic rates, so that the body tends to hoard calories rather than burning them. The ability of these endocrine disruptors to re-program the fate of a cell and convert it to a fat cell has led to the coining of a new phrase to describe them: Obesogens.
In one study conducted by Dr. Bruce Blumberg of the University of California, Irvine, pregnant mice were fed a substance called tributyltin -a disinfectant and fungicide used in marine paints and plastics production that enters the food chain through seafood and contaminates our water supply. Their offspring were born with more fat cells and fat already stored, and became 5 to 20 percent fatter by adulthood. The genetic tests revealed that the tributyltin activated a receptor, which acts like a switch, determining whether a cell remains a fibroblast (cells that make up the body’s connective tissue) or becomes an adipocyte (a fat cell).
Not all endocrine disrupting substances are obesogens, but the biggest culprits so far are phthalates, bisphenol-A (also referred to as BPA), and some compounds used in stain repellants and non-stick cookware. Additional studies in Spain and Belgium have linked fetal exposure to pesticides and PCBs with childhood obesity.
Phthalates are often found in toys, food packaging, hoses, raincoats, shower curtains and other forms of vinyl plastic including vinyl flooring, lubricants, adhesives, detergents, nail polish, hair spray, shampoo and are often a hidden ingredient in the fragrances found in many personal care and body products.
Bisphenol-A (or BPA) is a hardener that is added to plastic to make it durable and is often found in baby bottles, food-storage containers, water coolers, dental fillings, the lining inside canned goods, sports equipment, CDs, and even sun glasses, to name a few. If it’s plastic, doesn’t bend and is durable, it’s probably BPA. It’s most often found in polycarbonate (super hard) bottles.
Polychlorinated biphenyls (PCBs) were used extensively from the late 1940s through the late 1970s as coolants and lubricants in electric equipment and have also been added to plastics, inks, adhesives, paints, and flame retardant. Although they have been banned in most forms and places since 1979, dangerous concentrations of PCBs were found as recently as 2010 in soil samples from the Great Lakes region, Northeast, Midwest, and Southern United States as well as in several European countries.
What the obesogens research has revealed so far is that prenatal exposure to certain chemicals can reprogram an infant’s metabolism so that it is predisposed to becoming fat. While much of the research on this subject is still in its infancy, its implications for the future health and well being of our children, and maybe even the adult population, are significant and shouldn’t be taken lightly.
In light of these findings, taking the necessary steps to limit or eliminate your exposure to products containing phthalates and BPA seems like a wise thing to do, especially if you’re pregnant, planning to become pregnant, or have young children.
Of course further research will likely be required to determine if adult exposure to obesogens has as much of an impact on weight gain. For now, most scientists agree that the problem seems to be isolated to fetal exposure and exposures during infancy. If you are overweight or an obese adult at the moment, it’s unlikely that it was the result of early childhood exposures or so the thinking goes. Then again, until now, we also believed that the only way you gain weight is if you consume more calories than you burn!