These are very difficult links to draw, and it’s also possible that people who tend to eat ultraprocessed foods are making many other lifestyle choices that affect their health. One possible link might be, “phthalates and other food contaminants in those processed foods may inhibit testosterone function, which is known to be a major risk factor for adult cardiovascular disease and stroke,” Dr. Trasande said. But this kind of study can show only an association, it doesn’t establish cause and effect, and Dr. Trasande pointed out that the conclusions have been disputed by other experts.

Even so, environmental health experts worry about both the food and the packaging. “Eat less processed food,” said Manish Arora, professor of environmental medicine and public health at Icahn School of Medicine at Mt. Sinai. It’s good for your body, he said, and “it’s also good for the environment, less processing, less carbon footprint, less chemicals into the environment, less chemicals back into us.”

“Buy fresh food not wrapped in plastic,” Dr. Trasande said, since the contact of the food with the packaging is what you want to avoid.

“How to help our children improve their health?” Dr. Arora asked. “There’s nothing like physical activity, fruits and vegetables.”

But beyond protecting yourself and your own family as far as you can, Dr. Trasande said, “there’s so much we can do with the broader public action and social action.”

Dr. Arora said, “It’s almost as if the products are released and then there’s a slow and cumbersome process to see if they’re harmful.” Decades can go by before that process is complete, he said, and during those decades, “an entire generation has been exposed during the formative years.”

This was the story with lead, and more recently, he said, it was almost the story for many plastics. Lead was present in so many places in children’s environments, from paint to auto emissions, and was gradually understood to be more and more dangerous, even at levels of exposure which had been thought to be safe.