Triclosan Linked to Higher Breast Cancer Risk

Women with higher levels of triclosan in their urine were more likely to develop breast cancer than women with lower levels, according to a study. An endocrine disruptor, triclosan is a chemical that’s found in many products, including household cleaning products and personal care products, such as mouthwash.

Endocrine disrupters, also called hormone disrupters, can affect how estrogen and other hormones act in the body, by blocking them or mimicking them. This throws off the body's hormonal balance, which can affect health. Earlier studies have suggested that certain endocrine disrupters may increase breast cancer risk.

The aim of the study was to see if there were links between higher breast cancer risk and exposure to two types of widely used endocrine disrupters: phenols and parabens. Phenols are used as a disinfectant in many products, including household cleaning products, and consumer products, such as mouthwashes. Parabens are used as a preservative in many foods, cosmetics, and pharmaceutical products by preventing the growth of bacteria and mold.

Triclosan is a type of phenol.

The researchers used information from 4,455 women who were part of the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2014. As part of NHANES, the women provided urine samples that were analyzed for levels of various compounds, including seven endocrine disrupters: bisphenol A, triclosan, benzophenone-3, methyl paraben, ethyl paraben, propyl paraben, and butyl paraben. The women reported if they were diagnosed with breast cancer.

The women in the study had an average age of 47.5. About 68% were non-Hispanic white, 13% were Hispanic white, and 12% were Black. Overall, 134 women were diagnosed with breast cancer.

The results showed that women with higher levels of triclosan in their urine were about twice as likely to be diagnosed with breast cancer. The link between breast cancer risk and triclosan was stronger in women with excess weight (defined by the researchers as having a BMI of 25 or higher), women younger than 60, and white women.

Still, it’s important to know that overall, only 3% of the women were diagnosed with breast cancer during the study. So the increase in absolute risk was small.

There were no overall links between the other chemicals and breast cancer risk.

More than 76% of the women in the study had triclosan in their urine. This echoes results from an earlier study by the U.S. Centers for Disease Control and Prevention that found triclosan is in about 75% of the U.S. population aged 6 and older in 2003-2004.

Triclosan is in many consumer products, including personal care products, such as fluoride toothpaste, mouthwash, and facial cleansers; cosmetics; and household cleaning products. In addition, some clothing, shoes, carpeting, furniture, toys and kitchenware all contain triclosan.

In 2016 the U.S. Food and Drug Administration (FDA) issued a rule banning triclosan and triclocarban (another antimicrobial chemical) from over-the-counter antibacterial hand and body washes. The FDA said the ban was because the manufacturers didn’t demonstrate that the ingredients were both safe for long-term daily use and more effective than plain soap and water in preventing illness and the spread of infection.

Still, the ban is only for consumer soap and body wash, it doesn’t apply to hand sanitizers, mouthwash, toothpaste, or other products. It also doesn’t apply to soaps used in healthcare settings.

A 2019 study estimated that 132 million liters of triclosan-containing products are used in the United States each year. Because the estimate was calculated before the COVID-19 pandemic, that amount is likely higher these days.

If you’d like to avoid triclosan, you have to read labels, especially on personal care products. In the ingredient listing look for triclosan or 5-chloro-2-(2,4-dichlorophenoxy)phenol. If you see either of those names, the product contains triclosan.

You can also opt out of using any type of antibacterial product, including cutting boards, insoles, shower curtains, dishwashing liquid, fabric, carpeting, and sponges because they may contain triclosan.