Kennedy Wants to Ban Some Food Dyes. Here's What the Data Shows.

New York Times

25-04-2025

The Department of Health and Human Services announced this week that it would work to remove some artificial dyes from the U.S. food supply, citing concerns about how they might affect children's health.
Among the dyes that the health secretary, Robert F. Kennedy Jr., is targeting are colorings common in ultraprocessed foods like candy, chips and some cereals. In a news conference on Tuesday announcing the effort, Dr. Marty Makary, the Food and Drug Administration commissioner, linked these dyes to obesity, diabetes, attention deficit hyperactivity disorder, cancer and other health conditions in children.
Several, mostly small studies have found a link between some artificial food dyes and behavioral issues, which medical experts have said is cause for concern and warrants further research. But some said it is unclear if removing the dyes would have a meaningful effect on rates of childhood obesity, diabetes or other problems.
'Nobody's going to be sad to see the food dyes go, but it's definitely not the panacea that it's being portrayed as,' said Lindsey Smith Taillie, an associate professor of nutrition at the University of North Carolina's Gillings School of Global Public Health.
What dyes are supposed to be phased out?
Dr. Makary named eight specific colorings that the agency would seek to phase out: Blue No. 1 and 2; Citrus Red No. 2; Green No. 3; Orange B; Red No. 40; and Yellow No. 5 and 6.
Exactly how the agency plans to do that remains unclear. Mr. Kennedy said major food manufacturers had reached an 'understanding' with him. The F.D.A. said it would begin the process of revoking the authorizations of Citrus Red No. 2 and Orange B, which are not widely used. The other six would be subject to Mr. Kennedy's nonbinding agreement with manufacturers.
Dr. Makary said in the news conference that the process would be complete by the end of 2026. But it remains to be seen whether that timeline is logistically possible or whether the government can enforce it.
In January, during the final days of the Biden administration, the F.D.A. banned another coloring, Red Dye No. 3, from food products. Research has shown that the dye, which had already been banned from cosmetics and some medications, can cause cancer in male rats.
Food manufacturers can use various natural compounds to color their products in the absence of artificial dyes, though switching a product from artificial to natural dyes requires time and testing. The F.D.A. said this week that it would 'fast-track' authorization of four alternatives: calcium phosphate, Galdieria extract blue, gardenia blue and butterfly pea flower extract.
There is limited evidence around the health effects of those alternatives, said Emily Barrett, a professor of biostatistics and epidemiology at the Rutgers School of Public Health who has studied food contaminants.
What does the research show?
While there is some research on food dyes and health risks, there are a few factors that make the subject hard to study.
It's challenging to examine any potential long-term effects, since the dyes pass relatively quickly through the body, said Dr. Sheela Sathyanarayana, a professor of pediatrics at the University of Washington. The trials that do exist in humans, Dr. Barrett noted, have largely examined the effects in the hours right after children consume artificial dyes.
Many of the studies also look at mixtures of dyes, which makes it hard to say that any one in particular is the most problematic, explained Asa Bradman, a professor of public health at the University of California at Merced who has studied food dyes.
But the evidence we do have points to a connection between certain synthetic dyes and behavioral changes in some children.
One 2007 study out of Britain involved giving young children drinks containing blends of food additives like Yellow No. 5 and Yellow No. 6. The trial showed that these additives were linked with increased hyperactivity and lowered attention span over a six-week period.
And in a 2021 report, scientists in California examined 27 studies in children, most of which were small, and concluded that common synthetic food dyes — FD&C Blue No. 1, Blue No. 2, Green No. 3, Red No. 3, Red No. 40, Yellow No. 5 and Yellow No. 6 — can interfere with normal behavior in some children. The food industry has long said that the ingredients it uses have been well-studied and shown to be safe.
Nutrition experts noted that many ultraprocessed foods that contain artificial dyes also contain a lot of sugar, sodium and saturated fat, and far fewer nutrients than fresh foods do. While ultraprocessed foods have been linked to obesity and diabetes, there is no evidence directly linking artificial dyes to either condition, said Peter G. Lurie, the president of the nonprofit consumer advocacy group Center for Science in the Public Interest, which has lobbied to remove synthetic dyes from the food supply.
When it comes to rising rates of A.D.H.D., 'it's certainly not that food dyes are the single culprit, by any means,' said Dr. Barrett, who peer-reviewed the California report. Dr. Barrett said she would welcome larger, stronger studies 'to actually answer some of these questions definitively.'
Mr. Kennedy has said that the National Institutes of Health will study these kinds of food additives in more detail.
Will removing the dyes make children healthier?
Dr. Taillie said there was no harm in getting rid of artificial food dyes. Even if they don't cause serious health effects, she said, they don't provide benefits.
But she does not expect such a switch to improve rates of obesity and chronic disease, which she said are largely driven by other ingredients in the foods that children consume, not the dyes.
'You can take the yellow dye out of mac and cheese and replace it with turmeric, but you're still giving your kid a food that's ultraprocessed and packed with sodium,' Dr. Taillie said.
It's not clear what effect removing these dyes might have on children's behavior, Dr. Barrett said. Some European countries have stricter regulations on artificial colorings than the U.S., adding warning labels to foods with certain synthetic dyes. It isn't clear whether rates of A.D.H.D., for example, have decreased as a result of these policies.
'This one thing is unlikely to reduce A.D.H.D. diagnoses,' Dr. Sathyanarayana said. But, she added, it's possible that removing synthetic dyes might reduce children's symptoms in isolated cases. For example, a child who eats copious amounts of candy on Halloween may be less likely to become hyperactive afterward.
Dr. Taillie expressed skepticism that manufacturers would comply with Mr. Kennedy's voluntary 'understanding.' She said that historically, mandates have been much more effective than voluntary measures at getting particular ingredients out of the food supply. For example, she said, there wasn't much movement on trans fat until the government required that it be listed on nutrition labels.
Calley Means, a special government employee within the Department of Health and Human Services and an adviser to Mr. Kennedy, said, 'The food industry can do this the hard way or the easy way.'
He added: 'We are confident they'll take the easy way.'
In a statement on Tuesday, Melissa Hockstad, the president and chief executive of the Consumer Brands Association — which represents packaged goods companies including PepsiCo and Nestlé — said the companies she represented intended to 'increase the use of alternative ingredients.'