We’ve all been there at some point. Whether it’s the takeaway food you just ordered or leftovers from yesterday’s meal, it’s sometimes easier to eat straight from the plastic container. Convenient, cheap, and lightweight, these containers seem like a harmless part of modern life. But a recent study suggests they’re not that harmless—they could be damaging your heart.

The damage comes from harmful chemicals that leach from these containers when exposed to heat.

Plastic is already bad enough news. If you didn’t know, there’s probably plastic inside your body already, and every week, you’re eating about a credit card’s worth of microplastics. The authors of the new study looked at two things to study how plastic containers can affect the heart.

First, they conducted a survey of 3,179 individuals, assessing their plastic exposure through daily use of takeout containers. The results were significant—those who frequently used plastic food containers had a 13% higher risk of developing congestive heart failure. This association remained even after accounting for other lifestyle and health factors.

Then, the researchers looked at lab rats. They split the rats into four groups. The first one was a control group, and the other three groups were given water that had been in contact with plastic takeout containers for 1, 5, and 15 minutes at boiling temperatures. After three months, their bodies revealed major signs of distress.

Microscopic examination of their heart tissue showed inflammatory cell infiltration, swollen mitochondria, and signs of oxidative stress. The gut bacteria of exposed rats changed significantly. There were fewer beneficial microbes and more harmful strains linked to inflammation. Markers of oxidative stress, inflammation, and myocardial injury were also significantly higher in the exposed rats compared to the control group.

Curiously, there were no major differences between the three groups. In other words, it doesn’t take much for the plastic to start releasing harmful chemicals.

Why you shouldn’t eat from plastic containers

The study strongly suggests that heated plastic containers release harmful chemicals that enter the body, disrupt gut microbiota, and contribute to inflammation and oxidative stress—both of which are key factors in cardiovascular disease.

Granted, there are caveats. The hot food you’d eat from a plastic container wouldn’t be as hot as boiling water. Studies show that heating plastics from 25°C to 95°C increases the release of plastic particles by nearly 100 times. Microwaving plastic food containers is even worse as it releases millions of microplastics per square centimeter. However, the hot food would also be in contact with plastic for a longer time.

The leaching chemicals likely don’t affect the heart directly; it first damages the gut microbiome.

Your gut microbiome—the community of bacteria living in your digestive tract—plays a crucial role in overall health, including heart health. The study found that plastic exposure led to significant changes in gut microbiota, particularly an increase in Prevotella and Ruminococcus Gnavus, which are associated with inflammation. Previous research has linked disruptions in gut microbiota to various diseases, including hypertension, obesity, and diabetes.

How to reduce the risk

This study highlights the findings as a public health issue, given that millions of people eat from such containers every week. Researchers call for stronger regulations on plastic use in food packaging and public awareness campaigns. In the meantime, given the potential dangers, minimizing your exposure to heated plastics is crucial. Here are some simple steps you can take:

1. Avoid heating food in plastic containers. Use glass, ceramic, or stainless steel instead.
2. Don’t pour hot liquids into plastic cups or bottles. Even BPA-free plastics can release harmful chemicals when heated.
3. Limit your use of disposable takeout containers. Bring your own reusable containers when possible.
4. If you do use disposable containers, make sure they’re not made of plastic. Alternatives do exist.
5. Stay hydrated with glass or stainless steel water bottles. Plastic bottles, especially when left in hot cars, can leach chemicals into the water.
6. Read product labels. Look for plastics labeled “BPA-free,” but be cautious—some substitutes may also be harmful.
7. Encourage policy changes. Support regulations that reduce plastic waste and improve safety standards.

The study “Effects of leachate from disposable plastic takeout containers on the cardiovascular system after thermal contact” was published in the journal Ecotoxicology and Environmental Safety