New Study Links Phthalates to Cardiovascular Disease
Phthalates are chemical compounds primarily used in plastics. Past research has identified a link between phthalates and cardiovascular disease,¹ and a recent study² has helped to identify at least one mechanism linking phthalate exposure to cardiovascular disease.
A review published in 2016³ showed that there was a significantly increased risk to cardiovascular disease and infertility with phthalate exposure. Despite phthalates having been first introduced in the 1920s and gaining popularity in 1931,4 there are few studies comparing exposure to phthalates with atherosclerosis, arrhythmias, hypertension and hypertension in pregnancy.5
One study6 of 675 individuals with Type 2 diabetes demonstrated a positive association of phthalate exposure with cardiovascular disease in the population. An animal study7 published in 2017 in the American Journal of Physiology found that exposure to phthalate compounds could decrease heart variability and exaggerate arterial pressure.
The scientists believe theirs was the first study to show an association between plastic chemicals used in medical devices with an alteration in heart rate variability, cardiovascular reactivity, and autonomic regulation. These changes, which have been found to precede hypertension, atherosclerosis and conduction abnormalities, may warrant adopting safer materials for use in medical devices.8
The current study, published by researchers from the University of California Riverside, discovered one potential mechanism that may link phthalate plasticizers with dyslipidemia and cardiovascular disease risk.9
Data Show Mechanism Linking Plastic Particle to Dyslipidemia
Plastic use is ubiquitous and has become a part of modern life. While the products have proven useful, they also contribute to an array of health damage and can increase the risk of cardiovascular disease. However, while the link has been identified, researchers have found the underlying mechanism contributing to the development of heart disease has remained elusive.
According to the Centers for Disease Control and Prevention,10 people are exposed to phthalates by eating foods and drinking beverages that had contact with plastics containing the chemical. You may also be exposed through breathing phthalates; children can be exposed to phthalate-laden dust while crawling on the floor. Their hand-to-mouth activities may raise their risk.
Using a mouse study11 biomedical scientists discovered a link between dicyclohexyl phthalate (DCHP), a chemical used to make plastics more durable, and dyslipidemia and cardiovascular disease. Changcheng Zhou, Ph.D., led the team of researchers. He explained the association in a press release, saying:12
“We found dicyclohexyl phthalate, or DCHP, strongly binds to a receptor called pregnane X receptor, or PXR. 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.”
The scientists found that the animals exposed to DCHP had higher levels of ceramides circulating in their blood.13 This is a type of lipid molecule associated with cardiovascular disease risk. The researchers found the higher levels were PXR dependent. Zhou points out that:14
“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.”
Nuclear pregnane X receptor (PXR) is part of the body’s adaptive defense mechanism against foreign chemicals.15 The receptor is activated by several chemicals, including antibiotics, steroids, bile acids and antimycotics.
Using an animal model,16 researchers found that PXR plays a role in controlling metabolism of these chemicals and influences the homeostasis of steroid hormones, such as vitamin D, and bile acids.
It also plays a role in inflammatory bowel diseases. More recent research17 finds PXR negatively regulates fibroblast growth factor 15, which plays an important role in energy metabolism. The researchers postulate that it may “represent a potential therapeutic target for the treatment for metabolic disorders such as obesity.”
Artificial Chemicals Can Increase Your Risk of Obesity
Endocrine disrupting chemicals are among the most destructive in our environment. Evidence links them to growth, neurological and learning disabilities, obesity, male and female reproductive dysfunction, cardiovascular disease, birth defects and some cancers.18
The fact that endocrine disrupting chemicals like phthalates increase your risk of obesity is not new news. Phthalates are described as obesogens, or chemicals that increase your risk of obesity by disrupting lipid metabolism and producing metabolic changes. This is the type of disruption in energy metabolism found in the 2017 study published in Biochemical Pharmacology.19
Circulating levels of phthalate metabolites are related to the prevalence of diabetes and insulin resistance in an elderly population.20 Another study published in 2017 found an association with overweight and obesity in childhood after exposure to certain phthalates in utero.21
There is a common belief that increased calorie consumption and reduction in exercise causes obesity. Yet, this does not completely explain the phenomenon society has experienced. Research in the journal Basic & Clinical Pharmacology & Toxicology showed that people may be predisposed from exposure to obesogens in the womb.22
The interaction between phthalates and PXR is one mechanism that may increase the risk for weight gain. Other studies have documented that these plasticizers and metabolites have biochemical activity and antiangiogenic effects that also contribute to obesity. One paper23 reviewed the evidence linking exposure to phthalates and the possible effects on the development of obesity.
The researchers found emerging evidence to suggest childhood exposure can increase the risk. However, the effects appear dependent on several factors, including the level of exposure, the type of chemical and the time of exposure during childhood development.
Reviewing the chemicals as a class would also prevent manufacturers from simply swapping one phthalate with another. While industry groups have pushed back due to the “costs” associated with removing the chemicals, some retailers and manufacturers have taken voluntary action to replace them.
For example, Home Depot introduced a policy to restrict phthalates in vinyl flooring and wall-to-wall carpeting and Apple removed the class of chemicals from nearly all its products.25 There are several steps you can take each day to reduce your exposure to phthalates and other plasticizers.
- Avoid plastic containers and plastic wrap for food and personal care products. Store food and drinks in glass containers instead.
- Avoid plastic children’s toys. Use toys made of natural substances, such as wood and organic materials.
- Read labels on your cosmetics and avoid those containing phthalates.
- Avoid products labeled with “fragrance,” including air fresheners, as this catch-all term may include phthalates commonly used to stabilize the scent and extend the life of the product.
- Do not microwave food in plastic containers or covered in plastic wrap.
- Frequently vacuum and dust rooms with vinyl blinds, wallpaper, flooring and furniture that may contain phthalates, as the chemical collects in dust and is easily ingested by children.
- Eat mostly fresh, raw whole foods. Food packaging is often a source of phthalates.
- Use glass baby bottles instead of plastic. Breastfeed exclusively for the first year, if you can, to avoid plastic nipples and bottles altogether.
- Remove your fruit and vegetables from plastic bags immediately after coming home from the grocery store and wash before storing them; alternatively, use cloth bags to bring home your produce.
- Avoid fabric softeners and dryer sheets; make your own to reduce static cling.
- Bring your own mug for coffee and bring drinking water from home in glass water bottles instead of buying bottled water.
Sources and References
- 1, 7, 8 American Journal of Physiology, 20217; doi.org/10.1152/ajpheart.00364.2017
- 2 Environmental Health Perspectives, 2021; 129(12)
- 3, 5 Environment International, 2016;94
- 4 Cambridge Isotope Laboratories, Phthalates
- 6 Environmental Science and Pollution Research International, 2021;28(41)
- 9 Science Daily, December 1, 2021
- 10 Centers for Disease Control and Prevention, Phthalates Factsheet
- 11, 12, 13, 14 UC Riverside News, November 30, 2021
- 15 Endocrine Review, 2002;23(5) Abstract top lines
- 16 Expert Opinions in Drug Metabolism and Toxicology, 2008;4(7)
- 17 Biochemical Pharmacology, 2017;142
- 18 Hormone Health Network, Endocrine Disrupting Chemicals
- 19 Biochemical Pharmacology, 2017;142 Abstract, top lines and last line
- 20 American Diabetes Association; 2012; 35 (7)
- 21 Pediatric Research, 2017; 82(3)
- 22 Basic & Clinical Pharmacology & Toxicology 2019; doi.org/10.1111/bcpt.13214
- 23 Annals of Pediatric Endocrinology and Metabolism, 2014;19(2)
- 24 PLOS|One, 2014; doi.org/10.1371/journal.pone.0114003
- 25 American Journal of Public Health, 2021;111(4)