A common chemical in household plastics has been linked with heart disease deaths.
In 2018, about 13.5 percent of the more than 2.6 million deaths from cardiovascular disease among people ages 55 to 64 globally could have been related to exposure to a type of chemical called a phthalate, researchers report April 28 in eBioMedicine.
Phthalates are a group of chemicals found in shampoos, lotions, food packaging and medical supplies including blood bags. The chemicals are often added to plastics to make them softer and more flexible.
Phthalates can enter the body when you consume contaminated food, breathe them in or absorb them through the skin. Once inside, they act as endocrine disruptors, which means they affect hormones. Previous research has also linked the chemicals to diabetes, obesity, pregnancy complications and heart disease.
The new study looked at the effects of one particular phthalate, known as di-2-ethylhexylphthalate, or DEHP, which is often added to PVC plastics to soften them. Sara Hyman, a research scientist at NYU Langone Health, and colleagues focused on the relationship between DEHP exposure levels and cardiovascular disease, the leading cause of death worldwide. Hyman and colleagues compared estimated DEHP exposure in 2008 with death rates from cardiovascular disease ten years later in different parts of the world. By studying how the two changed together, they determined what portion of those deaths might be attributable to phthalates.
More than 350,000 excess deaths worldwide were associated with DEHP exposure in 2018, the team found. About three-quarters of those occurred in the Middle East, South Asia, East Asia and the Pacific. This disparity might be due to the regions’ growing plastics industries, the researchers suggest. The new work does not show that DEHP exposure directly causes heart disease, though — only that there’s an association between the two.
Still, globally, the percentage of cardiovascular deaths linked with DEHP exposure is “quite alarming,” says Changcheng Zhou, a biomedical scientist at the University of California Riverside who was not involved in the study.
Further research is needed to understand the true global health effects of DEHP — and of other phthalates. Some countries, such as the United States, Canada and many in Europe collect phthalate exposure data through national health surveys. But other countries, particularly in Latin America, Africa, and Asia, lack centralized monitoring, Hyman says. The team estimated DEHP exposure in these regions from past studies using smaller groups of people. But further large-scale monitoring in these regions could improve their predictions, the scientists say.
DEHP isn’t the only phthalate people encounter on a regular basis. “Co-exposure to other phthalates and chemicals is extremely likely, and our model was not able to take this into account,” Hyman says. The analysis also didn’t account for other factors that contribute to heart disease risk, like individual lifestyle choices or other medical conditions. “More research is needed that accounts for these factors.”
To fully understand the risks of exposure, scientists are still studying how phthalates affect the body at the molecular level. Different phthalates have different chemical structures, which means they affect different processes within the body. And they might not operate in isolation. “You do need to study the effect of the mixture” of phthalates people encounter regularly, says Mahua Choudhury, an epigeneticist at Texas A&M University in College Station who was not involved in the study. Some phthalates might counteract or amplify the health effects of others, she says.
The findings offer yet another reason to decrease plastic use, researchers say. “We’re going to become the plastic planet,” Zhou says. “We need to start to really address this serious issue.”