CLEMSON, South Carolina -- Clemson University scientist William "Bill" Baldwin recently received a three-year, $362,000 grant from the National Institutes of Health to continue studies on how exposure to chemicals is likely to inhibit our bodies' internal mechanisms, which could increase the risk and severity of obesity in millions of people in the United States and billions worldwide.
More than one third of Americans are considered obese and more than two thirds are either obese or overweight. Baldwin and members of his laboratory will study whether insecticides, herbicides, industrial pollutants and even chemicals found in plastics and hand soaps are overtaxing our bodies' abilities to metabolize fatty and high-sugar foods. As a result, the unhealthy diets many people regularly consume could be packing on even more pounds than they would if the toxicants were not further debilitating our natural digestive processes.
"Our work is to look at the likelihood that toxicants are enhancing obesity and causing other illnesses in human populations," said Baldwin, a professor of biological sciences in the College of Science. "We're looking at new mechanisms that might be inhibiting the body's stably expressed cytochrome P450 enzymes from metabolizing toxicants, bile acids, steroids and fatty acids. And because these enzymes are being inhibited, we're worried that things aren't turning out so well for our waistlines."
Baldwin and his associates, including graduate students Ramiya Kumar and Melissa Heintz and master's student Allison Schmidt, are studying a subfamily of p450 genes called CYP2b and CYP3a. "CYP" is an abbreviation for "cytochrome p450."
Baldwin's hypothesis is that excessive chemical exposure is causing these two members of the p450 family of enzymes to become overwhelmed and ineffective, which in turn plays a surprisingly extensive role in the explosive expansion of obesity across the nation and globe. Baldwin's team uses mouse models to study how their health and physiques are affected by diet-based alterations.
"Our research focuses on answering a big question: Does the repression or inhibition of cytochrome P450 of the families 3a and 2b alter the metabolism of fatty acids?" said Kumar, a fourth-year Ph.D student in Baldwin's lab. "The outcome of this research will help us to understand more about how toxicants might contribute to fatty liver disease and obesity."
Baldwin's grant is titled "Does the inhibition of key xenobiotic-metabolizing CYPs cause obesity?" The purpose of the project is to test whether alterations in CYP2b and CYP3a cause the allocation of fatty acids to be misdirected.
A rise in chemical usage and the emergence of modern plastics has coincided with the obesity epidemic in the U.S., which is now three decades old and showing few signs of slowing down. In some cases, obesity can be mostly genetic. In others, it can be tied more directly to high-fat diets. But Baldwin believes most cases are probably a combination of genetics, diet and chemical exposure.
"People rarely become obese without some kind of dietary influence," Baldwin said. "It's unlikely that you could just be exposed to toxicants and become obese while otherwise eating a low-fat diet. But if you're eating French fries with all the unsaturated fatty acids and then you're exposed to toxicants, the two combined are significantly worse than just one alone. You'd probably already be overweight, but the toxicants worsen the problem."
In some regards, many toxicants are almost unavoidable. They exist in abundance in the air, water and soil. They are in the meats and vegetables people consume, as well as in pharmaceuticals. And as already mentioned, they are abundant in a variety of products, such as plastic containers and hand soaps. But people still have options that can help offset much of the potential damage.
"What we really need to do is eat a healthier, more vegetable-based diet. If I could eat local, I would, as much as possible. And if the food we purchase happens to be organic, then that's an extra bonus," said Baldwin, whose research might eventually help provide new targets for pharmaceutical companies to explore in the treatment of obesity.
"Plus, if you're exercising, you're doing your body wonders of good. And I would definitely avoid bottled water because it's got plasticizers in it. Why not have a filter attached to the tap of your kitchen sink? Pour the filtered water into a glass or stainless steel container and drink out of that. If you eat well, exercise and do just a couple of those extra things, I think you could avoid a lot of chemicals that you don't want in your system."
Research reported in this publication was supported by the National Institutes of Environmental Health Sciences under Award Number 2R15ES017321-03. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.