Study Finds Exposure to Chemical Pollutants Increases Fat

Rats exposed to high levels of chemical pollutants in fish oil could not regulate fat properly

Join Our Community of Science Lovers!

Researchers have for the first time found a connection between exposure to certain chemicals and insulin resistance, according to a study published in the online edition of Environmental Health Perspectives.

A group of European scientists examined whether exposure to persistent organic pollutants (POPs) contributed to insulin resistance, which has been increasing around the world. More than 25 percent of U.S. adults suffer from metabolic conditions stemming from insulin resistance that include fatigue, obesity and difficulty regulating blood levels of fat and sugar.

Researchers fed rats a high-fat diet of either crude or refined fish oil from farmed Atlantic salmon over 28 days. The crude fish oil contained average levels of POPs that people are exposed to through fish consumption, while the refined oil contained none. Both had equal fat levels.

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

They found that rats exposed to the crude fish oil developed belly fat and could not regulate fat properly. They had higher levels of cholesterol and several fatty acids in their livers. Those exposed to the refined fish oil experienced none of those symptoms.

Researchers said the findings provide "compelling evidence" of a causal relationship between POP exposure common in the food chain and insulin resistance, and highlight the need to understand the interactions of POPs and fat-containing foods such as fish, dairy products and meat.

How to deal with POPs is particularly challenging because they persist in the environment for long periods and can build up in animals' tissues.

The 2001 Stockholm Convention, which the United States has ratified but not signed, lists and bans numerous POPs from manufacture and use. The researchers say their evidence reinforces the need to have international agreements aimed at limiting the release of POPs into the environment in an effort to protect public health.

Reprinted from Greenwire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American