I have fielded many questions lately about obesity and chemicals, I wrote an article a few years back about obesogens that covers this topic.
What are obesogens?
By definition they are: chemical compounds foreign to the body that are hypothesized to disrupt normal development or homeostasis of metabolism of lipids ultimately resulting in obesity. In other words, Chemicals that shift the energy balance toward a weight gain and storage function. No longer is obesity just a system of too many calories in and not enough energy expended. Epidemiology has shown us over the last thirty years that the obesity epidemic is outpacing what would be expected based on the theory of calories in versus calories out. Something else has changed recently. Chemicals!
Science time. The deposition of fat is regulated by hormones that control satiety and hunger, glucose levels, neural control of baseline metabolic rate, regulation of the metabolic set point, and the function of adipocytes (fat cells). K. Spaulding states that obesity is the result of a prolonged disturbance in the homeostatic regulation of energy metabolism that favors triglyceride storage and adipocyte hypertrophy. Obese people also have more fat cells.
A scary finding is that our fat cell number is largely set by early adulthood. These cells can shrink and grow, but generally do not disappear. Therefore, it benefits us to avoid developing too many of them in the first place.
Epidemiologically, the more fat cells you have the more likely you are to develop cancer, diabetes mellitus, high blood pressure and so on. These are all diseases of the western world that are highly associated with poor nutrition namely, high saturated fat and refined sugars, as well as chemicals that are not proven to be safe.
There is now sufficient evidence to pin part of this problem on plastic chemicals, drugs and persistent organic pollutants called organotins. The body sees these chemicals as metabolic agents that signal receptors on cells to change. For example, a receptor known as PPARg can be turned on by the anti-diabetic drug rosiglitazone, which then induces fat differentiation and proliferation. A drug to treat diabetes worsens obesity, ironic.
Bisphenol A and other Xenoestrogens (foreign hormone analogues) are chemicals that are not natural and are ubiquitous in our environment. They are found in plastics, canned foods, electronics, paints and more. Google BPA and see what comes up! Infant formula used to have increased concentrations according to testing performed by the environmental working group. These chemicals turn on genes that regulate fat differentiation and also enhance glucose uptake. The end result is increased weight and disease.
Humans are most susceptible to chemicals when cells are rapidly developing. This occurs primarily during pregnancy, till age 2 years old and also during adolescence.
I often worry about the perfect storm of pregnancy. A child being developed by a mother who consumes fast food, is exposed to lots of chemicals, takes diabetic and antacid drugs because of a bad diet, delivers by caesarian section and then uses formula to nourish the child. All of these events have evidence to support their avoidance where possible. I try to counsel all parents about the importance of proper nutrition and chemical avoidance all throughout life, but especially at these critical times of rapid growth.
Although completely eliminating exposure to BPA may not be possible, there are steps you can take to reduce your family's exposure to this and other chemicals.
From the Environmental working group:
Infant formula: All U.S. manufacturers used BPA-based lining on the metal portions of the formula containers until the ban went into effect in 2013.
EWG's testing of canned foods found that BPA leaches from the liner into the food itself. Sensitive groups such as kids and pregnant women should limit canned food consumption. Beverages appear to contain less BPA residues, while canned pasta and soups contain the highest levels. Rinsing canned fruit or vegetables with water prior to heating and serving could lessen BPA ingestion.
Certain plastics called polycarbonates leach low levels of BPA into food or liquids. Leaching from plastic baby bottles and food containers appears to happen at a much lower level than found in canned foods and baby formula. Nevertheless it is good to take simple precautions.
BPA is found in polycarbonate plastic food containers often marked on the bottom with the letters "PC" recycling label #7. Not all #7 labeled products are polycarbonate but this is a reasonable guideline for a category of plastics to avoid. Polycarbonate plastics are rigid and transparent and used for sippy cups, baby bottles, food storage, and water bottles. Some polycarbonate water bottles are marketed as 'non-leaching' for minimizing plastic taste or odor, however there is still a possibility that trace amounts of BPA will migrate from these containers, particularly if used to heat liquids.
Safer products and uses: When possible it is best to avoid #3, #6 and #7 plastics, especially for children's food. Plastics with the recycling labels #1, #2, #4 and #5 on the bottom are safer choices and do not contain BPA or phthalates. Find baby bottles in glass versions, or those made from the safer plastics including polyamine, polypropylene and polyethylene. Soft or cloudy-colored plastic does not contain BPA. Bottles used to pump and store expressed breast milk by the brand Medela are also labeled BPA-free.
Some metal water bottles are lined with a plastic coating that contains BPA. Look for stainless steel bottles that do not have a plastic liner.
We recommend avoiding use of plastic containers to heat food in microwaves. Ceramic, glass, and other microwaveable dishware are good alternatives. Avoid using old and scratched plastic bottles.
Chemical safety is necessary,
Dr. M
