Phthalates may affect newborn brain development, study finds
Phthalates — the synthetic chemicals used in everyday products for food packaging, personal care, toys and more — have been linked to abnormal neurological development in infants.
Now, scientists may have discovered a biological pathway for how this phenomenon could occur. Researchers found that in utero exposure to phthalates is linked with altered metabolism of neurotransmitters and amino acids involved in brain maturation, according to a study published Wednesday in the journal Nature Communications.
The report is the first to use untargeted metabolomics — the study of all small molecules or metabolites in a biological system — to connect a mother's phthalate exposure to a newborn's metabolites, and those metabolites to neurological development, said senior study author Dr. Donghai Liang via email.
'This represents an important step forward in understanding how prenatal chemical exposures shape infant development at the molecular level,' added Liang, an associate professor of environmental health at Emory University's Rollins School of Public Health in Atlanta.
First introduced in the 1920s, phthalates are used to make plastics softer and more flexible, primarily in polyvinyl chloride (PVC) products such as vinyl flooring, medical devices, children's toys, food packaging or shower curtains. The chemicals also help lubricate substances and carry fragrances in various personal care products including deodorant; nail polish; perfumes; hair gels, sprays or shampoos; soaps; and body lotions.
Phthalates are also endocrine disruptors that have been linked to preterm birth, infant genital abnormalities, childhood obesity, asthma, cancer, cardiovascular issues, and low sperm count and testosterone in men.
'We conducted this study because phthalates are everywhere in our daily lives,' Liang said, hence their nickname 'everywhere chemicals.'
The findings are based on mother-newborn pairs enrolled in the Atlanta African American Maternal-Child Cohort between 2016 and 2018. In urine samples collected from 216 mothers between eight weeks and 14 weeks of gestation at visit one and 145 participants between 24 and 30 weeks' gestation at visit two, the authors measured eight phthalate metabolites. Participants were around age 24 on average, and their levels of some phthalate metabolites were higher than the average determined by the National Health and Nutrition Examination Survey.
Within a day or two of birth, the authors collected the babies' blood via a heel stick.
The team found prenatal phthalate levels were associated with lower levels of tyrosine, an amino acid and precursor to the thyroid hormone thyroxine. Thyroxine was also abnormally low in those with in utero phthalate exposure, and low thyroxine has been previously associated with greater vulnerability to illness and neurodevelopmental issues in newborns, the authors said. Tyrosine is also a precursor to the neurotransmitters dopamine, norepinephrine and epinephrine, all of which partly contribute to the body's fight-or-flight response. Low levels of these neurotransmitters can lead to various problems, including anxiety, depression and trouble focusing.
Prenatal phthalate exposure was also linked with lower levels of the essential amino acid tryptophan, which converts into 5-hydroxytryptophan (or 5-HTP), which then turns into serotonin. Both 5-HTP and serotonin were also low. Serotonin has several critical roles in the body, including mood regulation, sleep, learning, memory, digestion and the body's response to stress. Previous research has linked low serotonin with mood disorders such as depression and anxiety, sleep problems, and digestive issues.
These biological changes generally were also linked to lower scores on tests measuring attention and excitability, or the ability to respond to stimuli, in participants' newborns, according to the study.
Polyvinyl chloride plastic, a primary use for phthalates, 'continues to increase in use globally,' said Dr. Leonardo Trasande, director of the New York University Center for the Investigation of Environmental Hazards, who wasn't involved in the study. 'We know already — across not just brain development in babies, but a host of consequences that run from cradle to grave, and womb to tomb — that phthalates, in the form of (a) disease burden due to plastic, cost the US $250 billion annually.'
'This study just adds to a voluminous base of evidence that chemicals used in plastic materials harm human health,' Trasande added. 'It's not really something that we should be debating more actively. The more thoughtful approach would be to actually discuss what we need to do about the use of plastic.'
The American Chemistry Council, which represents chemical companies, said via email that its High Phthalates Panel is 'dedicated to promoting the benefits of high phthalates such as DIDP and DINP.' Phthalates with a high molecular weight have seven or more carbon atoms. The study did not measure DIDP (diisodecyl) and DINP (diisononyl phthalate), but some of phthalates identified in the study were high phthalates.
The study has a few important limitations, including the lack of information on participants' diets or whether their births were vaginal or caesarean, all of which can significantly affect both phthalate exposure and a newborn's metabolites, the authors said. Additionally, around 10% of participants reported using alcohol while pregnant, while 15% reported using tobacco and 40% reported using marijuana. There were no details collected on frequency, quantity or duration of use of those substances.
Adverse pregnancy outcomes related to environmental contaminants can also be influenced by psychological or social stressors, which the study couldn't account for.
'The sample size is small, of course, (but) it's a complicated and expensive study to conduct in the first place,' Trasande said. 'There may be multiple mechanisms by which phthalates disrupt brain development.'
For people to be able to avoid exposure to phthalates and other chemicals, experts are calling on manufacturers and policymakers to change.
'I'm part of the Scientists' Coalition for an Effective Plastics Treaty (and we) are actually suggesting banning phthalates as a group because of their demonstrated toxicity and that they can cause effects at very low doses,' said ecotoxicologist Dr. Susanne Brander, associate professor in the department of fisheries, wildlife and conservation sciences at Oregon State University. Brander wasn't involved in the study.
Some manufacturers are creating new plastic additives they hope are safer, but it's possible they could be as problematic as what we're using now, Trasande said. 'The burden needs to be on the manufacturers to prove that materials … are proven safe before they're used.'
In the meantime, people can reduce their exposure to phthalates by using glass, stainless steel or cast iron and not using nonstick cookware or microwaving or dishwashing plastic materials, Trasande said. 'Microwave safe' means the container will be OK, not your food — since it can absorb microscopic particles, he added.
When buying personal care products, look for those labeled 'phthalate-free' and check ingredient lists, Liang said. Phthalates may be listed as DEP (diethyl phthalate), DBP (dibutyl phthalate) or BBzP (butyl benzyl phthalate). You can use the Environmental Working Group's SkinDeep database to check which chemicals a product may contain.
'Since phthalates can be found in household dust, improving air circulation and regular cleaning with a damp cloth can help,' she added.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Chicago Tribune
9 hours ago
- Chicago Tribune
Used in COVID shots, mRNA may help rid the body of HIV
The technology that powered COVID vaccines may also lead scientists to a cure for HIV. Using mRNA, Australian researchers said they were able to trick the virus to come out of hiding, a crucial step in ridding the body of it entirely. The research, published last week in Nature Communications, is still preliminary and so far has been shown to be successful only in a lab. But it suggests that mRNA has potential far beyond its use in vaccines as a means to deliver therapies against stubborn adversaries. Short for messenger RNA, mRNA is a set of instructions for a gene. In the case of COVID vaccines, the instructions were for a piece of the coronavirus. In the new study, they are for molecules key to targeting HIV. Dr. Sharon Lewin, director of the Doherty Institute at the University of Melbourne, who led the study, called mRNA a 'miraculous' tool 'to deliver things that you want into places that were not possible before.' Vaccines deploying mRNA instruct the body to produce a fragment of the virus, which then sets off the body's immune response. In the United States, the shots were initially hailed for turning back the pandemic, then viewed by some with suspicion and fear. Some officials, including Health Secretary Robert F. Kennedy Jr., have falsely said that they are highly dangerous and even deadly. Last week, the Department of Health and Human Services sought to limit the vaccine's availability to pregnant women, children and healthy younger adults. The administration also canceled a nearly $600 million contract with the drugmaker Moderna to develop an mRNA shot for humans against bird flu. 'The fear right now is not rational,' Lewin said, adding that 'mRNA vaccines have been given to millions of people around the world, so we have a very good understanding of their risks.' The new study describes the use of mRNA as a tool to flush HIV out of its hiding places. Other uses could involve providing proteins missing from those with certain diseases or correcting genetic errors. Frauke Muecksch, a virologist at Heidelberg University in Germany who was not involved in the work, called mRNA a 'promising, absolutely powerful technology.' Although most people may have only heard of mRNA's use in science during the pandemic, scientists have been working with it for more than 20 years, she said. 'I think it's not just therapeutically very powerful, but also for basic science, for research, it opens up a lot of avenues,' she added. Potent antiretroviral drugs can now control HIV, suppressing it to undetectable levels. Still, minute amounts of the virus lie dormant in so-called reservoirs, waiting for an opportunity to resurge. A cure for HIV would involve ferreting out all of this virus and destroying it, a strategy that has been called 'shock and kill.' A significant hurdle is that the virus lies dormant in a particular type of immune cell, called a resting CD4 cell. Because these cells are inactive, they tend to be unresponsive to drugs. The few drugs scientists have previously used to rouse the virus in these cells were not specific to HIV and had unwanted side effects. 'It's fair to say the field's been a little bit stuck,' said Brad Jones, a viral immunologist at Weill Cornell Medicine who was not involved in the latest research. In 2022, Jones and his colleagues found that the immune boost from the mRNA vaccines awakened latent HIV in people living with the virus. (Other research has shown that mRNA vaccines also activated dormant viruses including Epstein Barr.) 'You get just a little bit of a gentle nudge with some of these vaccines, and it's enough to coax some of these latent viruses out so they can be killed,' Jones said. Lewin and her colleagues had for years experimented with other ways to activate HIV but had no luck in resting cells. Seeing the success of the COVID vaccines, which used lipid nanoparticles — tiny spheres of fat — containing mRNA, her team tested similar particles. They used the particles to deliver two different sets of molecules: Tat, which is adept at switching HIV on, and CRISPR, a tool that can 'edit' genes. The researchers showed that in resting immune cells from people living with HIV, the approach coaxed the virus out of dormancy. 'It's very, very hard to deal with these cells, so I think this really targeting the right population of cells is what makes this paper special,' Muecksch said. It's unclear whether the new approach can successfully awaken all of the dormant HIV in the body, and what side effects it might produce. Lewin said that 'mRNA will almost certainly have some adverse effects, as every drug does, but we will investigate that systematically, as we do for any new drug.' In this case, she said, side effects may be more acceptable to people living with HIV than having to take medications for the rest of their lives. The researchers plan to test the method in HIV-infected animals next, before moving into clinical trials. This article originally appeared in The New York Times.
Yahoo
17 hours ago
- Yahoo
Archaeologists Uncover 3 Never-Before-Seen Mayan Cities
Archaeologists working in Guatemala's Petén jungle have discovered three ancient Mayan cities, the country's Ministry of Culture and Sports announced in a statement. The cities, arranged in a triangular pattern, rest roughly three miles apart from one another. They were incorporated during a period known as the 'middle preclassic' (1,000-400 B.C.), and remained inhabited until about 1,100 years ago. One site of particular interest to archaeologists, dubbed 'Los Abuelos' or 'the Grandparents,' contains stone sculptures of a man and woman which researchers believe depict the ancestors of the city's citizens. They posit that this site may have served as a ceremonial or religious second newly discovered city, dubbed 'Petnal,' features a 108-foot tall flat-topped pyramid which contains a separate room containing murals. Though most of the artwork has degraded, scientists were able to identify red, white, and black colors; however, further analyses will be required to determine what the murals actually depicted. The third city, Cambrayal, features an intricate series of canals which begin at a water reservoir atop the city's palace. Archaeologists believe these waterways were used for removing waste."It's especially exciting to learn about the Los Abuelos site," Megan O'Neil, an associate professor of art history at Emory University who was not part of the excavation team, told Live Science. O'Neill added that the stonework found at the sites "are especially poignant and are similar to many other examples of Maya people making offerings to vital sculptures and connecting with their ancestors by interacting with sculptures from the past." She believes these recent discoveries will "help reconnect items in private and museum collections with their places of origin and deposition, helping return memory to those ceramics, to these sites, and to Maya people living in this region and across the world."Archaeologists Uncover 3 Never-Before-Seen Mayan Cities first appeared on Men's Journal on Jun 9, 2025
Yahoo
3 days ago
- Yahoo
New coronavirus discovered in China ‘only small step' from infecting humans
A new coronavirus discovered in China is only a small step from mutating and causing another global pandemic, experts have warned. Scientists believe the variant, called HKU5-CoV-2, may infect a broader range of animals than Covid-19 – which caused millions of deaths – and may have more potential for jumping between species. US researchers fear that HKU5-CoV-2, found in China, in February, could also infect humans, leading to a widespread outbreak. The new study, published in Nature Communications, looked at a lesser-known group of coronaviruses called merbecoviruses, which includes HKU5 and MERS-CoV, which is responsible for the deadly Middle East Respiratory Syndrome. The team from Washington State University looked at how the new pathogen interacts with human cells. They found that a small change in the virus's spike protein could allow it to attach to human ACE2 cells in people's throats, mouths and noses. HKU5-CoV-2 can infect and replicate inside human cells in both the airways and gut. According to the World Health Organisation, about 35 per cent of people infected with Middle East Respiratory Syndrome die. Since 2012, some 27 countries have reported cases, leading to 858 known deaths due to the infection, which spread from camels. But when HKU5 was discovered in February, scientists warned against exaggerating the risks because it does not enter human cells as readily as Sars-CoV-2, which caused Covid-19. HKU5 was first detected in bats by scientists from the Chinese laboratory where some say Covid originated in 2019. Prof Michael Letko, a virologist who co-led the study, said: 'HKU5 viruses in particular really hadn't been looked at much, but our study shows how these viruses infect cells. 'What we also found is HKU5 viruses may be only a small step away from being able to spill over into humans.' When Covid-19 emerged it was widely blamed on markets in China where different breeds of wild animal are kept caged and often slaughtered close to other animals. Meat is sold at the open-air stalls. Critics said the markets were the perfect breeding ground for new zoonotic diseases – those that spread to humans – to emerge. The scientists, whose experiments studied how the new pathogen interacts with human cells, believe the virus would have to carry certain mutations if it were to infect humans. 'These viruses are closely related to MERS, so we have to be concerned if they ever infect humans,' Prof Letko said. 'While there's no evidence they've crossed into people yet, the potential is there and that makes them worth watching.'
