Why heating plastic is bad

Steaming and microwaving could even increase content of most flavonoids, which are compounds linked to reduced risk of heart disease. Some foods, such as peas, lose nutrients when microwaved or steamed, but others, like green beans, do not Credit: Getty Images.

It could be that microwaving makes flavonoids easier to measure — perhaps by softening the plant tissue, making them easier to extract — rather than increasing their amount. In another study, researchers compared the content of phenolics compounds associated with various health benefits of various vegetables after being boiled , steamed and microwaved. Microwaving and steaming caused a loss in phenolic content in squash, peas and leeks, but not in spinach, peppers, broccoli or green beans.

The researchers also tested for antioxidant activity. We often microwave foods in plastic containers and wrapping, but some scientists warn of the risk of ingesting phthalates. When exposed to heat, these plastic additives can break down and leach into food.

When exposed to heat, plastic additives like phthalates can break down and leach into food Credit: Getty Images. In a study, researchers purchased more than plastic containers designed to contain food, and found that the majority leaked chemical that disrupt hormones. Phthalates are one of the most commonly used plasticisers, added to make plastic more flexible and often found in takeaway containers, plastic wrap and water bottles. They have been found to disrupt hormones and our metabolic system.

In children, phthalates can increase blood pressure and insulin resistance , which can increase the risk of metabolic disorders such as diabetes and hypertension. Exposure also has been linked to fertility issues, asthma and ADHD.

Phthalates are also potential disrupters of thyroid hormones, says Leonardo Trasande, professor of environmental medicine and population health at NYU School of Medicine in New York. Bisphenol BPA is also commonly used in plastic products, and studies have suggested it may also disrupts hormones. But research is limited, compared to the amount of studies looking at phthalates.

But most experts agree that heating plastic with phthalates can increase exposure. Phthalates have been found to disrupt hormones and our metabolic system Credit: Getty Images.

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Home Cancer information Reduce your risk Myths and controversies Should I put plastic containers in the microwave. Should I put plastic containers in the microwave? The claim When you heat food in the microwave using plastic containers or wrap, chemicals may leach out of the container and into the food, increasing your risk of cancer. The truth. How to safely store and reheat food.