Common Antibacterial Agent Triclosan Linked to Muscle Damage

Researchers indicate that triclosan, which is a common antibacterial agent used in many personal care products in the United States, could be damaging to muscles. 

In a study published in the Proceedings of the National Academy of Sciences of the United states of America (PNAS) and conducted by researchers at the University of California, Davis, and the University of Colorado, triclosan (TCS) was found to hinder muscle contractions and reduce muscle strength when tested on fish and mice.

Triclosan is added to many personal care products as an antibacterial agent. It is used in hand soap, deodorants, toothpaste and is added to other products like bedding, clothing and toys to reduce the risk of bacterial contamination.

The U.S. Environmental Protection Agency estimates that more than 1 million pounds of triclosan are produced annually in the U.S.

According to the consumer watchdog group Beyond Pesticides, formerly known as the National Coalition Against the Misuse of Pesticides, many common products are known to contain triclosan including Dial Liquid Soap, Clearasil Daily Face Wash, Colgate Total Toothpaste, Revlon ColorStay LipSHINE Lip color, Old Spice High Endurance Stick Deodorant and many others.

During the experiments, scientists performed many tests using doses of triclosan that are similar to what people and animals are exposed to everyday. Anesthetized mice had a 25% reduction in heart function within only 20 minutes of triclosan exposure and 18% reduction in grip strength.

In another experiment, triclosan impaired the ability of isolated heart muscle cells and skeletal muscle fibers in mice to contract. Researchers noted that the normal communication between proteins that function as calcium channels was impaired as a result of exposure to triclosan, causing skeletal and cardiac muscle failure.

“The effects of triclosan on cardiac function were really dramatic,” said Nipavan Chiamvimonvat in a press release regarding the findings. Chiamvimonvat is a study co-author and professor of cardiovascular medicine at UC Davis. “Although triclosan is not regulated as a drug, this compound acts like a potent cardiac depressant in our models.”

Researchers also studied the effect triclosan had on fathead minnows after exposure in the water for seven days. The minnows had a significant reduction in swimming activity and muscle impairment.

Previous studies also linked Triclosan to the disruption of reproductive hormone activity and of cell signaling in the brain. These and other studies regarding bacteria have raised questions whether triclosan, and other antibacterial agents, may potentially make bacteria resistant to antibiotics with continued overuse of the products.

The EPA also notes that triclosan is commonly detectable in human urine, blood and breast milk.