Endocrine disruptors found in everyday products can mimic or block the actions of hormones.
A study from Kumamoto University in Japan has linked prenatal exposure to chemicals classified as phenols to a significant increase in the risk of asthma later in life.
Phenols are widely used in consumer products such as makeup, lotions, cleaning agents, and plastics, and exposure in small amounts is considered safe. However, they can potentially disrupt the endocrine system, the part of the body that makes and releases hormones. This may have long-term harmful health effects, including a heightened risk of allergy-related conditions, including asthma.
An array of actionable steps can help a pregnant woman reduce exposure and protect her unborn child.
Prenatal Exposure and Asthma
The study, published in Environmental Pollution on Nov. 15, focused on 24 phenols, including parabens such as butylparaben and alkylphenols such as 4-nonylphenol. Parabens are found in many personal care products, including makeup, lotions, and shampoos, while alkylphenols are found in plastics and cleaning products.
Researchers used data from a large cohort investigation, the Japan Environment and Children’s Study (JECS). (Cohort means it follows a group of individuals over a period.) To assess exposure, they measured these phenols in the urine of about 3,500 women during their first trimester of pregnancy. The researchers then tracked the health of the women’s children for four years after birth.
Data analysis showed that high exposure to butylparaben was linked to a 1.54-fold increase in the likelihood of asthma development in children.
Additionally, exposure to 4-nonylphenol was associated with a 2.09-fold rise in the risk of asthma development in boys but not girls. This suggests a sex difference exists in children’s responsiveness to prenatal phenol exposure.
These findings are consistent with earlier reports that prenatal exposure to phenols increases the risk of respiratory disease. The authors noted that some reports suggest certain phenols may affect the immune system and raise the likelihood of developing atopic dermatitis, a skin condition that can increase the risk of asthma.
The researchers acknowledged that their study might not be enough to prove a bona fide association and that future research is required. They pointed to several limitations in the study. First, the urine samples were taken only once during the first trimester, so ongoing phenol levels were not confirmed. Second, the study did not measure phenol exposure in the children after birth, which means that environmental rather than prenatal exposure may have played a role. Third, the study was limited to individuals from Japan, so the results may not apply to other locations since phenol exposure varies among countries.
“These results emphasize the need for careful evaluation of chemical exposure during pregnancy,” said lead researcher Dr. Shohei Kuraoka in a press release. “Understanding these risks allows us to develop better guidelines to protect maternal and child health.”
‘A Perfect Storm’
To understand the effects of phenol exposure during the prenatal period, it is necessary to be familiar with the concept of endocrine disruption.
“The endocrine system is like the body’s control center for hormones, which regulates everything from growth to immune function to stress response,“ pain management physician Dr. Taher Saifullah, founder of the Spine & Pain Institute in Los Angeles, told The Epoch Times in an email. “When the endocrine system is disrupted, it throws off the body’s finely tuned balance.”
He explained that endocrine disruptors can mimic or block the actions of hormones in our bodies. Even a minor disruption in this system can lead to problems like developmental issues, immune system malfunctions, or conditions like asthma. Essentially, these disruptors confuse the body’s messaging system.
According to Saifullah, the phenols highlighted in the study trick the body into thinking it has higher or lower levels of certain hormones than are actually present. This disruption can be especially dangerous during pregnancy when the baby’s immune and respiratory systems are still developing.
To illustrate, he stated that a hormone imbalance caused by phenols could affect the developing immune system, making it more prone to conditions like asthma later in life. The immune system may become hyper-reactive, meaning it overreacts to harmless substances like dust or pollen, triggering inflammation and narrowing of the airways—the hallmark symptoms of asthma.
Additionally, he said these chemicals could influence the development of the baby’s lungs. If the lungs don’t form properly, the child is more likely to develop respiratory conditions.
“It’s a perfect storm: disrupted immune regulation, altered lung development, and heightened sensitivity to environmental factors, which can all contribute to a higher risk of asthma as the child grows,” Saifullah said.
“While it’s clear that genetics influence asthma development, environmental factors, like these endocrine-disrupting phenols, may push the body in the direction of disease,” he said. “This is why it’s so important to consider these early-life exposures when thinking about long-term health outcomes. Even before birth, the body is already being shaped by its environment in ways we’re still trying to understand.”
The Sex Difference
It is notable that while butylparaben affected the risk of asthma in both sexes, 4-nonylphenol only affected boys. Dr. Randall Turner, a dual board-certified physician in psychiatry and addiction medicine and medical director at Able to Change Recovery, explained this sex disparity to The Epoch Times in an email.
“The difference likely stems from how male and female hormones influence immune system development and lung function,” he said. “Boys and girls have distinct hormonal environments even before birth, and endocrine disruptors like 4-nonylphenol can interfere with these systems in ways that vary by sex.”
Turner pointed out that androgens, which are male hormones like testosterone, are crucial in shaping the immune system and lung development in boys. The chemical 4-nonylphenol, which mimics estrogen, may disrupt androgenic activity, potentially leading to an overactive or imbalanced immune response. This could increase airway inflammation or sensitivity, making boys more vulnerable to asthma.
Male immune systems are also generally more prone to pro-inflammatory responses in early childhood, which could amplify the effects of exposure to this chemical, said Turner.
“In contrast, estrogen in girls may provide some protection against inflammation, helping to mitigate the impact of endocrine disruptors like 4-nonylphenol.”
While the above provides a plausible explanation, Turner feels that more research is needed to fully understand the sex-specific mechanisms at play.
Actionable Steps for Protection
“Reducing exposure to endocrine-disrupting chemicals, such as phenols, during pregnancy is essential for protecting your baby’s health,” advised Turner. He recommended the following changes that can help anyone reduce exposure, but they are particularly important for pregnant women:
- Choose Safer Personal Care Products: Switch to personal care items labeled “paraben-free” or “fragrance-free,” as these often exclude endocrine-disrupting chemicals, such as parabens. Opt for certified natural or organic products whenever possible. These small swaps for lotions, shampoos, and makeup can make a big difference.
- Look for the EPA Safer Choice Label: For cleaning products, check for the U.S. Environmental Protection Agency (EPA) Safer Choice label, a designation that ensures the product meets rigorous safety standards for human health and the environment. Avoid antibacterial cleaners with triclosan, another phenol that is a known endocrine disruptor.
- Limit Plastic Use: Avoid using plastic containers for food storage or heating, especially if they contain bisphenol A (BPA) or similar chemicals used to make plastics that can leach into food. Opt for glass or stainless steel alternatives, which are safer and more sustainable.
- Be Mindful of Food Packaging: Choose fresh or frozen produce over canned goods when possible. Many cans are lined with BPA-containing materials, which can contaminate food. If canned foods are necessary, look for “BPA-free” labels.
- Use a Water Filter: A high-quality water filter can reduce exposure to harmful chemicals, including phenols and pesticides, often found in tap water. Look for filters certified to remove these contaminants for added peace of mind.
- Switch to Natural Household Cleaners: Ditch conventional chemical cleaners for natural alternatives like vinegar, baking soda, and essential oils. These are effective for most household cleaning needs and are safer for you and your family.
- Eat Organic Food Whenever Possible: Organic fruits and vegetables are grown without synthetic pesticides, many of which can act as endocrine disruptors. If organic isn’t available or affordable, focus on washing and peeling conventional produce to reduce pesticide residues.
- Avoid Synthetic Fragrances: Scented candles, air fresheners, and perfumes often contain phthalates, another class of chemicals that can interfere with hormones. To limit exposure, opt for unscented or naturally scented alternatives.
- Rethink Nonstick Cookware: Replace nonstick pans with stainless steel or cast-iron options. Nonstick coatings can release a harmful chemical called perfluorooctanoic acid (PFOA), a type of “forever chemical,” especially when heated. These are not phenols, but they are also linked to hormone disruption.
- Improve Indoor Air Quality: Use a HEPA air purifier to reduce airborne chemicals indoors. Good ventilation and avoiding exposure to secondhand smoke are vital to minimizing toxic exposure at home.
“No one can completely avoid exposure to endocrine-disrupting chemicals, but these small changes can make a meaningful difference,” Turner concluded. “It’s about reducing unnecessary risks wherever possible. If you’re unsure about a product or habit, consulting your health care provider or an environmental health expert can provide personalized guidance to keep you and your baby safe.”
