For years, we’ve known about many of the harmful effects of plastic waste on the world around us. Plastic debris are often ingested by marine animals, contaminate natural water sources, poison wildlife, and can disrupt habitats.
But it looks like plastics could be more than an environmental concern. According to a study conducted by the University of California Riverside, exposure to plastic-associated chemicals could be damaging to human health. The study found that exposure to common, everyday plastics could increase the risk of high cholesterol that may cause cardiovascular disease.
Could a chemical used in plastic production for everyday products be a potential risk for developing these conditions?
DCHP Elicits High Cholesterol
In a study recently published in the Environmental Health Perspectives journal, researchers found that phthalate—which is a chemical used to make plastics more durable—known as DCHP can increase plasma cholesterol levels.
“We found dicyclohexyl phthalate, or DCHP, strongly binds to a receptor called pregnane X receptor, or PXR,” Changcheng Zhou, biomedical scientist and professor of UCR School of Medicine, explained in the study.
“DCHP ‘turns on’ PXR in the gut, inducing the expression of key proteins required for cholesterol absorption and transport. Our experiments show that DCHP elicits high cholesterol by targeting intestinal PXR signaling.”
What Are Phthalates?
The Centers for Disease Control and Prevention (CDC) refer to phthalates as “plasticizers” which can be used to “help dissolve other materials.” You can find phthalates in everything from vinyl flooring to personal care products like shampoos, soaps, and even makeup.
“Some phthalates are in polyvinyl chloride plastics, which are used to make products such as plastic packaging, garden hoses, and medical tubing,” the CDC says.
Humans are exposed to phthalates in a number of ways. We eat and drink foods that have been in contact with products containing phthalates. We can also breathe phthalate particles in the air.
Inside the human body, phthalates are converted into metabolites that quickly leave via the urine. But, it’s not clear what the health effects are from exposure to phthalates.
The EPA Has Concerns About DCHP
DCHP is a widely used phthalate plasticizer that has been flagged by the Environmental Protection Agency (EPA) as a high-priority substance for risk evaluation. At this point, there is very little known about the adverse effects of DCHP in humans.
“To our knowledge, our study is the first to show the effects of DCHP exposure on high cholesterol and cardiovascular disease risk in mouse models,” Zhou said. “Our results provide insights and new understandings of the impact of plastic-associated chemicals on high cholesterol—or dyslipidemia—and cardiovascular disease risk.”
What Happened To The Mice?
During their study, Zhou’s team found that mice exposed to DCHP had higher circulating “ceramides” in their blood in a way that was “PXR dependent.” Ceramides are “a class of waxy lipid molecules associated with increased cardiovascular disease risk in humans.”
“This, too, points to the potentially important role of PXR in contributing to the harmful effects of plastic-associated chemicals on cardiovascular health in humans,” Zhou said.
The Effects Of Microplastics
Plastic trash that washes into the ocean and then breaks down into tiny fragments is referred to as microplastics. Marine life then consumes these microplastics, and they’ve been shown to have numerous negative effects.
Studies have shown that microplastics can induce cognitive impairment in hermit crabs, can cause aneurysms and reproductive changes in fish, and weaken the adhesive abilities of mussels. Microplastics have also been found to travel up the food chain via seals.
When it comes to humans, studies have shown that microplastics can alter the shape of and de-cluster human lung cells. Some studies have even suggested that microplastics can infiltrate the blood-brain barrier.
The plasticizer BPA has also been found to significantly damage brain cells. And now, this latest study is sounding the alarm about DCHP. Numerous studies have shown that phthalates are endocrine disruptors. One study published in October blamed up to 100,000 premature deaths in the United States to exposure to phthalates and also found strong links to heart disease.
Still A Lot To Learn
Despite the amount of research into microplastics, phthalates, and other plastic-associated chemicals, we still have a lot more to learn about the possible dangers.
Scientists have even discovered microplastics in Antarctic sea ice and near the summit of Mt. Everest, which means they’ve infiltrated some of the most extreme environments on Earth. The World Health Organization (WHO) launched a health review after discovering that plastic particles are found in 93 percent of bottled water. Seriously, they are absolutely everywhere.
With plastic being such a common household object—and plastic waste making its way to every part of the globe—there is a push to get a deeper understanding about the risks that plastics pose to human health. Scientists warn that this will be critical for human health moving forward.