Study examines contaminants found in human breast milk, toxicants originated from personal care products

The health benefits of feeding infants breast milk, as opposed to formula or other milk substitutes, have been well studied and documented. Immunological protection and significantly decreased risk of asthma, allergy, obesity and various cancers are a few advantages that breast-fed infants have over infants fed substitute milk.

However, contaminants found in human breast milk raise question to the risks associated with breastfeeding. A study funded through the UC Davis Environmental Health Sciences Center examined human breast milk for presence of harmful chemicals, specifically toxicants that originate in personal care products such as toothpaste and liquid hand soap.

As breastfeeding rates continue to rise in America, with 81.1 percent of infants being breastfed, according to the CDC Breastfeeding Report Card, the discovery of toxic chemicals in breast milk raises significant health concerns for the environmental health research community.

“The main goal of this study was to identify the transfer of contaminants from personal care products into our bodies and to bring awareness [to] how we can avoid them,” said Candace Bever, principal investigator and assistant project scientist

The chemical triclosan, an antibacterial agent commonly found in consumer products such as toothpaste, soaps, detergents and toys, served as the study’s model research contaminant.

“We chose triclosan to observe because it passes through the body quickly, and we have good detection techniques for it,” Bever said.

Breast milk was used to measure contaminants because it is seen as a food product rather than a waste product. A waste product, like urine, has a higher accumulation of contaminants that pass out of the body; however, milk is seen as more important.

“The most dominant amount of triclosan was found in Colgate toothpaste,” Bever said.

The function of triclosan in toothpaste is to fight harmful plaque germs and reduce the risk of gingivitis, a gum disease.

“The triclosan in hand soap products was not demonstrated as more effective than products without it, so the Food and Drug Administration (FDA) banned this chemical from soap products,” Bever said. “Companies had to take their triclosan soaps off the market.”

There are personal care products that contain much lower levels of triclosan such as mascara and deodorant; however, its purpose is to prevent bacterial growth within the product —  essentially to act as a preservative.

Although triclosan was used as a model chemical for research purposes and has no documented health impact, many other environmental toxins have the potential to harm infants and children, with risks such as abnormal brain growth and development.

“Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia and other cognitive impairments affect millions of children worldwide, and some diagnoses seem to be increasing in frequency,” said Birgit Puschner, a professor and the chair of the Department of Molecular Biosciences at the UC Davis School of Veterinary Medicine.

Some of the highest levels of contaminants in breast milk are seen in women who live in agricultural areas of the world that are treated extensively with pesticides.

“Industrial chemicals that injure the developing brain are among the known causes for this rise in prevalence,” said Jennifer Smilowitz, an assistant professional researcher for the Department of Food Science and Technology at the Foods for Health Institute.

A great area of concern is the San Joaquin Valley region, just south of Sacramento and home to many UC Davis students and their families — key cities include: Modesto, Stockton, Fresno and Bakersfield.

The San Joaquin Valley is the agricultural heart of California and a crucial food production zone for the country. Yet, it is one of the most polluted areas nationwide, and does not meet the health standards for ozone and pesticide levels set by the United States Environmental Protection Agency.

Research that involves measuring harmful chemicals and how they impact human health is imperative in a society that continuously affects the environment.

“By assessing environmental contaminants in available breast milk samples, we will be able to determine inter and intra-individual variation among women and across lactation, and assess a pathway for unintended exposure to infants,” Puschner said.

Human milk contains numerous beneficial proteins, fatty acids, minerals, vitamins and disease-fighting potential that is crucial for an infant’s healthy development.

When a woman creates milk for her infant, her body utilizes its fat storage. This also happens to be where many toxic chemicals are stored. Therefore, the body transmits a portion of environmental contaminants to the newborn during breastfeeding.

“Typically pyrethroids, organophosphates, organochlorides and flame retardants (not pesticides) are found in breast milk. Concentrations are low, however. Home products that kill bugs or insects contain pyrethroids. [Pet flea] shampoo may also contain them,” said Ameer Taha, assistant professor in the Department of Food and Science Technology.

In 1951, dichlorodiphenyltrichloroethane (DDT) was the first environmental pollutant found in human milk, and today is found in breast milk in women around the world.

Additional well-studied toxic metal contaminants in breast milk include: lead, mercury, arsenic and cadmium. These are of great concern to infants because it has been well documented that contamination of these metals lead to neurodevelopmental disorders, lower IQ and mental disabilities.

Further research is required to study environmental contaminants in breast milk in order to raise awareness of the issue and to find solutions.

Note: Despite the chemicals studied above and those found as contaminants in human breast milk, the benefits of breast milk consumption still outweigh the risk. As mentioned above, breast-fed infants have immunological and metabolic advantages, and lower risk for allergies, asthma and obesity over non-breast-fed infants. Bringing awareness to potential risks of contaminants in breast milk is important to help women and their families avoid harmful toxicants and more safely breastfeed their infants. For example, avoiding seafood consumption, known to have heavy metals that can negatively affect infant brain development. In addition, avoidance of home products that kill bugs and are known to contain pyrethroids. Specific cases where breastfeeding is not recommended include use of radiation and chemotherapy.

The health benefits of feeding infants breast milk, as opposed to formula or other milk substitutes, have been well studied and documented. Immunological protection and significantly decreased risk of asthma, allergy, obesity and various cancers are a few advantages that breast-fed infants have over infants fed substitute milk.

However, contaminants found in human breast milk raise question to the risks associated with breastfeeding. A study funded through the UC Davis Environmental Health Sciences Center examined human breast milk for presence of harmful chemicals, specifically toxicants that originate in personal care products such as toothpaste and liquid hand soap.

As breastfeeding rates continue to rise in America, with 81.1 percent of infants being breastfed, according to the CDC Breastfeeding Report Card, the discovery of toxic chemicals in breast milk raises significant health concerns for the environmental health research community.

“The main goal of this study was to identify the transfer of contaminants from personal care products into our bodies and to bring awareness [to] how we can avoid them,” said Candace Bever, principal investigator and assistant project scientist

The chemical triclosan, an antibacterial agent commonly found in consumer products such as toothpaste, soaps, detergents and toys, served as the study’s model research contaminant.

“We chose triclosan to observe because it passes through the body quickly, and we have good detection techniques for it,” Bever said.

Breast milk was used to measure contaminants because it is seen as a food product rather than a waste product. A waste product, like urine, has a higher accumulation of contaminants that pass out of the body; however, milk is seen as more important.

“The most dominant amount of triclosan was found in Colgate toothpaste,” Bever said.

The function of triclosan in toothpaste is to fight harmful plaque germs and reduce the risk of gingivitis, a gum disease.

“The triclosan in hand soap products was not demonstrated as more effective than products without it, so the Food and Drug Administration (FDA) banned this chemical from soap products,” Bever said. “Companies had to take their triclosan soaps off the market.”

There are personal care products that contain much lower levels of triclosan such as mascara and deodorant; however, its purpose is to prevent bacterial growth within the product —  essentially to act as a preservative.

Although triclosan was used as a model chemical for research purposes and has no documented health impact, many other environmental toxins have the potential to harm infants and children, with risks such as abnormal brain growth and development.

“Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia and other cognitive impairments affect millions of children worldwide, and some diagnoses seem to be increasing in frequency,” said Birgit Puschner, a professor and the chair of the Department of Molecular Biosciences at the UC Davis School of Veterinary Medicine.

Some of the highest levels of contaminants in breast milk are seen in women who live in agricultural areas of the world that are treated extensively with pesticides.

“Industrial chemicals that injure the developing brain are among the known causes for this rise in prevalence,” said Jennifer Smilowitz, an assistant professional researcher for the Department of Food Science and Technology at the Foods for Health Institute.

A great area of concern is the San Joaquin Valley region, just south of Sacramento and home to many UC Davis students and their families — key cities include: Modesto, Stockton, Fresno and Bakersfield.

The San Joaquin Valley is the agricultural heart of California and a crucial food production zone for the country. Yet, it is one of the most polluted areas nationwide, and does not meet the health standards for ozone and pesticide levels set by the United States Environmental Protection Agency.

Research that involves measuring harmful chemicals and how they impact human health is imperative in a society that continuously affects the environment.

“By assessing environmental contaminants in available breast milk samples, we will be able to determine inter and intra-individual variation among women and across lactation, and assess a pathway for unintended exposure to infants,” Puschner said.

Human milk contains numerous beneficial proteins, fatty acids, minerals, vitamins and disease-fighting potential that is crucial for an infant’s healthy development.

When a woman creates milk for her infant, her body utilizes its fat storage. This also happens to be where many toxic chemicals are stored. Therefore, the body transmits a portion of environmental contaminants to the newborn during breastfeeding.

“Typically pyrethroids, organophosphates, organochlorides and flame retardants (not pesticides) are found in breast milk. Concentrations are low, however. Home products that kill bugs or insects contain pyrethroids. [Pet flea] shampoo may also contain them,” said Ameer Taha, assistant professor in the Department of Food and Science Technology.

In 1951, dichlorodiphenyltrichloroethane (DDT) was the first environmental pollutant found in human milk, and today is found in breast milk in women around the world.

Additional well-studied toxic metal contaminants in breast milk include: lead, mercury, arsenic and cadmium. These are of great concern to infants because it has been well documented that contamination of these metals lead to neurodevelopmental disorders, lower IQ and mental disabilities.

Further research is required to study environmental contaminants in breast milk in order to raise awareness of the issue and to find solutions.

Note: Despite the chemicals studied above and those found as contaminants in human breast milk, the benefits of breast milk consumption still outweigh the risk. As mentioned above, breast-fed infants have immunological and metabolic advantages, and lower risk for allergies, asthma and obesity over non-breast-fed infants. Bringing awareness to potential risks of contaminants in breast milk is important to help women and their families avoid harmful toxicants and more safely breastfeed their infants. For example, avoiding seafood consumption, known to have heavy metals that can negatively affect infant brain development. In addition, avoidance of home products that kill bugs and are known to contain pyrethroids. Specific cases where breastfeeding is not recommended include use of radiation and chemotherapy.

Written by: Shivani Kamal — science@theaggie.org