Flame retardants found to cause metabolic, liver problems

Chemicals used as synthetic flame retardants that are found in common household items such as couches, carpet padding, and electronics have been found to cause metabolic and liver problems that can lead to insulin resistance, which is a major cause of obesity, according to new research from the University of New Hampshire.

"Being obese or overweight increases one's risk of many diseases including Type 2 diabetes, high blood pressure, coronary heart disease, stroke, gall bladder disease, osteoarthritis, sleep apnea and certain cancers," said Gale Carey, professor of nutrition and the lead researcher.

Carey and her team of researchers found that laboratory rats exposed to polybrominated diphenyl ethers, or PBDEs, experienced a disruption in their metabolism that resulted in the development of metabolic obesity and enlarged livers.

"Despite the plethora of resources devoted to understanding the roles of diet and exercise in the obesity epidemic, this epidemic continues to escalate, suggesting that other environmental factors may be involved.

At the biochemical level there is a growing body of experimental evidence suggesting certain environmental chemicals, or 'obesogens', could disrupt the body's metabolism and contribute to the obesity epidemic," she said.

In Carey's research, fat cells isolated from rats dosed with high levels of flame retardants daily for one month developed a sensitivity to hormones that was similar to the sensitivity experienced by people who are overweight: the fat cells became more sensitive to epinephrine and less sensitive to insulin.

Complications of obesity include the following:

Metabolic syndrome
Diabetes mellitus
Cardiovascular disorders
Liver disorders (nonalcoholic steatohepatitis [fatty liver] and cirrhosis)
Gallbladder disease
Gastroesophageal reflux
Obstructive sleep apnea
Reproductive system disorders, including infertility
Many cancers
Osteoarthritis
Social and psychologic problems

Insulin resistance, dyslipidemias, and hypertension (metabolic syndrome) can develop, often leading to diabetes mellitus and coronary artery disease. These complications are more likely in patients with fat that is concentrated abdominally, a high serum triglyceride level, a family history of type 2 diabetes mellitus or premature cardiovascular disease, or a combination of these risk factors.

Obesity is also a risk factor for nonalcoholic steatohepatitis (which may lead to cirrhosis) and for reproductive system disorders, such as a low serum testosterone level in men and polycystic ovary syndrome in women.