Common Obesogens and Their Pathways
As discussed in part one, obesogens are environmental pollutants that may alter the body’s metabolism and predispose some individuals to weight gain. They are very widespread and research has confirmed that our exposure is quite common – and particularly damaging during fetal and infant development.
There is a growing body of evidence that provides a link between our exposure to specific environment chemicals from dietary, pharmaceutical, and industrial compounds and how they alter metabolic processes and predispose some people to gain weight.
At the top of the list is a chemical called perfluorooctanoic acid (PFOA). Commercially known as Teflon, this chemical is used as a non-stick coating in cookware, waterproofing for fabrics and clothing, and as a stain repellant for carpeting. This chemical is so prevalent, it is estimated that just about every child and adult in the United States has PFOA in their blood.
Other common obesogens include: bisphenol A (BPA) which is found in medical devices and as a lining in canned foods; tributyltin (TBT) which is used as a wood preservative; diethylhexyl phthalate (DEHP) is used in PVC and to manufacture a wide range of products including cables, flooring and roofing.
Obesogens disrupt biochemical processes (called pathways) in the body causing damage that results in weight gain. Unfortunately, obesogens are not equal opportunity disrupters. While some obesogens affect a single pathway, others disrupt multiple pathways creating havoc with a body’s metabolism. For example, PFOA acts not only as an endocrine disruptor, it also disrupts leptin and is a PPARagonist. Each of these pathways is described in more detail below.
Endocrine disruptors are chemicals which bind to hormone receptors in the body. These receptors should only respond to real hormones, to help the body balance and regulate itself. When toxins come in and mimic hormones, it can trigger unwanted reactions, or even shut down the receptor altogether. Hormone receptors can be very sensitive, so it’s possible that just a small amount of a toxin can have a significant, long-lasting effect.
Researchers have found that some obesogens spur fat-cell production by activating PPAR(peroxisome proliferator–activated receptor gamma). PPARis the master regulator for making fat cells. Not only does it create new fat cells, it has the ability to make existing fat cells even fatter.
Leptin is a hormone that fat cells secrete, which influences appetite and metabolism. Its role is a bit complex; under normal conditions, it would suppress appetite, but in obese people, leptin levels can be elevated, signaling the cells to become resistant to its effect.
In addition to disrupting cell signaling, some obesogens appear to leave specific, long-lasting epigenetic marks on cells’ DNA. This means that fetal exposure can cause damage which lasts a lifetime, and since it may damage a cell’s DNA, an obesogen’s effects may be passed to future generations.
What Can You Do?
Many medical and weight-loss experts blame poor diet and lack of exercise as the sole causes of obesity. These are contributors, however, obesogens can potentially counteract even the best diets and exercise program.
Which then begs the question- due to the adverse role environmental obesogens play in obesity, are diet and exercise hopeless attempts to lose weight? Should we just give up? Our answer – absolutely not!
There is a lot we can do to be proactive in minimizing exposure to environmental toxins and to detoxifying our bodies from the toxins that are already there. We can avoid unnecessary medications, eat organic food whenever possible, filter our water, and minimize exposure to plastics and insecticides as much as possible.
In addition, we can strive to sweat for one hour twice a week to help eliminate toxins. Increasing soluble fiber in the diet can also help pull out toxins. A good multi-vitamin and nutrient supplement can help us fortify the detoxification mechanisms in our bodies as well. Diet and exercise are always crucial for optimal health.
Hopefully, research will continue to investigate environmental toxins and their role in the obesity epidemic. If researchers could prove environmental chemicals play a major role, then the medical and weight-loss communities could work on reducing exposure and have a huge effect on reducing obesity rates.
Environ Health Perspect. 2012 Feb;120(2):a62-8. doi: 10.1289/ehp.120-a62.