It’s a marvel of food technology: ice cream that resists melting.

In a video explaining the science behind it, a seller of food chemicals shows scoops of ice cream holding their shape under hot lights. The super ingredient? Polysorbate 80.

Polysorbate 80 is an emulsifier, a chemical used to control the consistency of thousands of supermarket products. Other widely used emulsifiers or stabilizers include carboxymethyl cellulose, carrageenan, and maltodextrin.

Recently, such ingredients have been showing up in scientific studies for another reason: Researchers say they may cause a variety of health problems.

Studies have found that emulsifiers can alter the mix of bacteria in the gut, known as the microbiome or microbiota; damage the lining of the gastrointestinal tract; and trigger inflammation, potentially contributing to problems elsewhere in the body.

Emulsifiers and stabilizers are among the most common ingredients in ultraprocessed foods, a prime target of the “Make America Healthy Again” campaign by Health and Human Services Secretary Robert F. Kennedy Jr.

They are on the department’s radar: Their potentially harmful effects were flagged in a document HHS recently produced to support Kennedy’s drive to eliminate petroleum-based food dyes.

But they illustrate the complexity of the war on food additives.

They show how, when it comes to food science, regulators are chronically playing catch-up. In the meantime, for many ingredients, regulators and consumers alike are left in a gray zone between suspicion and proof of harm in humans.

Emulsifiers’ assault on the microbiome could help explain inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, metabolic disorders, and even cancer, the studies suggest.

“There is a lot of data showing that those compounds are really detrimental for the microbiota and that we should stop using them,” said Benoit Chassaing, a research director at the French National Institute of Health and Medical Research and a co-author of several related studies.

Yet much larger and more ambitious clinical trials in humans are needed, Chassaing added.

For Lewis Rands, who has suffered from gastrointestinal illness, the research fits his own experience as a consumer. Changing his diet to avoid emulsifiers has made a shocking difference, easing symptoms that were debilitating, Rands said.

“Clinically, many patients have reported an improvement in symptoms with such changes,” said Ashwin Ananthakrishnan, a gastroenterologist and researcher at Massachusetts General Hospital.

The scientific findings come with caveats. For instance, much of the research has been done in mice, or by mimicking the human gut in a tube. There are many unknowns. Not all emulsifiers have bad effects, or the same effects, and some people are thought to be much more vulnerable than others. Even some researchers who have co-authored papers say that the substances have not been proven harmful to humans and that it’s too soon to say regulators should ban them.

Still, the research poses a challenge for the FDA.

When emulsifiers began spreading through the food supply, the agency wasn’t focusing on the gut microbiome, a relatively recent scientific frontier, researchers said.

Martin Makary, appointed by President Donald Trump to head the FDA, mentioned the microbiome at his Senate confirmation hearing in March. Though he didn’t cite emulsifiers specifically or identify chemicals by name, he said substances that affect the microbiome deserve the FDA’s attention.

“There’s a body of research now that suggests concern with some of these ingredients,” he said. “We have to look at those ingredients, and you have my commitment to do so if confirmed as FDA commissioner.”

“These chemicals are creating an inflammatory response in the gastrointestinal tract, and with an altered microbiome lining that GI tract, kids feel sick,” he added.

The FDA and the Department of Health and Human Services did not respond to questions about Makary’s testimony.

However, when journalist Emily Kopp asked HHS for the science behind its recent announcement that it is phasing out petroleum-based food dyes, the agency provided a compilation of information on potentially harmful compounds commonly found in ultraprocessed foods. The document, which appeared to be a draft, included a section on emulsifiers, such as xanthan gum and carrageenan. It noted that the section needed more work.

HHS subsequently provided the document to KFF Health News.

As far back as 2020, an international organization for the study of inflammatory bowel diseases advised that, for people with those conditions, it “may be prudent to limit intake” of maltodextrin, carrageenan, carboxymethyl cellulose, and polysorbate 80.

Emulsifiers are developed from a variety of sources, including plants and bacteria.

Some ingredients that might affect the microbiome show up in foods because they were deemed “generally recognized as safe,” or GRAS.

“New information may at any time require reconsideration of the GRAS status of a food ingredient,” the Code of Federal Regulations says.

‘More of a Difference Than Any Drug’

Rands, a genetic scientist, took matters into his own hands to battle severe inflammatory bowel disease. The illness caused bloating, stomach pain, cramps, frequent bowel movements, and bleeding, he said. It left him in a constant state of anxiety and stress, he added, wondering where the nearest bathroom was and whether he’d reach it in time.

Even taking a walk around the block with his wife and baby near their home in Australia was problematic.

Then, on the advice of a dietitian, Rands began avoiding foods with emulsifiers: chemicals such as carboxymethyl cellulose, carrageenan, guar gum, xanthan gum, and maltodextrin — plus other additives.

For instance, instead of eating Ben & Jerry’s ice cream, he switched to Häagen-Dazs ice cream that is free of the substances at issue.

The relief was dramatic.

“It’s a huge difference,” Rands said. “To me, it’s made more of a difference than any drug.”

He has been able to scale back or stop taking several drugs, which is an added relief — not least because some can have harmful side effects, and, he said, one was taking its toll.

Rands said he used a scientific approach, isolating variables in his diet and logging the results. Avoiding artificial sweeteners helps, he said, but most of the benefit relates to avoiding the emulsifiers.

Ben & Jerry’s did not respond to a request for comment.

‘Science That Hasn’t Been Done Yet’

The Consumer Brands Association, which represents makers of processed foods, stands behind use of the chemicals.

“Food safety and protecting the integrity of the food supply is priority number one for the makers of America’s food and beverage products,” Sarah Gallo, the group’s senior vice president of product policy, said in a statement.

“Emulsifiers and thickening agents play an important role in improving food texture and consistency, and have been studied by the FDA through a rigorous scientific and risk-based process,” Gallo said.

Asked for specifics on how the FDA had analyzed potential effects on the microbiome, the group did not respond.

Chassaing said the chemicals were “never considered for the potential effect on the microbiota.”

Robert Califf, who led the FDA under Presidents Barack Obama and Joe Biden, said in an interview that scientists are just beginning to understand the microbiome. He compared it to where the field of genomics was 20 years ago, only much more complicated — “multiplied by a thousand dimensions.”

He said the substances “fell within the standards” when they were greenlighted. “But hopefully most people agree that the standards need to be upgraded,” he added.

“This is different than traditional food safety thinking about, ‘Does it cause an immediate problem?’” Califf said. “We’re talking about long-term health outcomes here.”

And has the FDA evaluated those?

“How could it? There was no way to do it,” Califf said. The answers will vary depending on the emulsifier, and “proving whether it’s bad or good is going to require rigorous science that hasn’t been done yet.”

More recent scientific capabilities expand the possibilities, he said.

‘A Lot of Confusion in the Field’

For a consumer, trying to steer clear of emulsifiers can be difficult. Without realizing it, people can consume a variety of emulsifiers from a variety of foods — and the same chemicals from multiple sources.

Polysorbate 80 was listed as an ingredient on the labels of 2,311 products as of May 12, according to an online database posted by the Environmental Working Group using information from NielsenIQ. Carrageenan was listed on 8,100 product labels; maltodextrin, 12,769; and xanthan gum, 17,153.

Some emulsifiers have multiple names, making them harder to recognize. Some names can apply to more than one emulsifier. And some chemical names that appear on product labels don’t appear in the FDA’s “Substances Added to Food” inventory.

Carboxymethyl cellulose — not to be confused with methyl cellulose — is also known as carboxymethylcellulose and cellulose gum. Maltodextrin can be derived from substances such as cornstarch, rice starch, and wheat starch — but the FDA doesn’t consider it synonymous with the term “modified food starch.”

The naming practices can frustrate efforts to track the chemicals in food, to measure how much of the stuff people are taking in, and even to figure out precisely which chemicals a scientific study evaluated, researchers said.

“There’s a lot of confusion in the field,” said Christine McDonald, a researcher at the Cleveland Clinic who has studied maltodextrin. She called for more consistent naming of additives in the United States.

The very term “emulsifier” is problematic. By strict definition, emulsifiers create an emulsion — a stable blend of liquids that would not otherwise mix, such as oil and water. However, the term is used broadly, encompassing chemicals such as maltodextrin that thicken, stabilize, or alter texture.

Gummed Up

Emulsifiers can be found in foods marketed as natural or healthy as well as ones that look artificial. Some products contain multiple emulsifiers.

Products sold at Whole Foods, for instance, list a variety of emulsifiers on their labels. 365 brand Organic Vegan Ranch Dressing & Dip contained organic tapioca maltodextrin and xanthan gum. Pacific Seafood Starfish brand Cornmeal Crusted Fishsticks — marked as wild-caught and MSC-certified (sustainably sourced) — contain guar gum. Flour tortillas by 365 included monoglycerides of fatty acids and “stabilizer (guar gum, xanthan gum, carrageenan).”

At a Safeway supermarket, Healthy Choice Grilled Chicken Pesto With Vegetables listed modified potato starch, modified corn starch, carrageenan, xanthan gum, and guar gum.

The label on Newman’s Own Caesar salad dressing said the product contained no artificial preservatives or flavors, no colors from an artificial source, and was gluten-free. The ingredient label listed, “as a thickener,” xanthan gum.

In response to questions for this article, Whole Foods Market said it prohibits more than 300 ingredients commonly found in food. “Our experts evaluate ingredients for acceptability in all food products we sell based on the best available scientific research,” the company said in a statement provided by spokesperson Rachel Malish.

Safeway’s parent company, Albertsons Companies, did not respond to inquiries. Nor did Pacific Seafood, Newman’s Own, or Conagra Brands, which makes Healthy Choice.

A Growing Body of Research

Research on emulsifiers has been building in recent years.

For example, a study published in January by the Journal of Crohn’s and Colitis concluded that a diet low in emulsifiers is an effective treatment for mild or moderate Crohn’s disease. The eight-week clinical trial, which tracked 154 patients in the United Kingdom, focused on carrageenan, carboxymethyl cellulose, and polysorbate 80.

A study published in February 2024 in the journal PLOS Medicine found that higher intakes of carrageenan and mono- and diglycerides of fatty acids were associated with higher risks of cancer. The study observed 92,000 French adults for an average of 6.7 years.

A study published in September 2023 in The BMJ, formerly known as the British Medical Journal, found that intake of several types of emulsifiers was associated with the risk of cardiovascular disease. The study observed more than 95,000 French adults for a median of 7.4 years.

A series of earlier studies found that emulsifiers “can promote chronic intestinal inflammation in mice”; that two in particular, carboxymethyl cellulose and polysorbate 80, “profoundly impact intestinal microbiota in a manner that promotes gut inflammation and associated disease states”; and that, based on a laboratory study of human samples, “numerous, but not all, commonly used emulsifiers can directly alter gut microbiota in a manner expected to promote intestinal inflammation,” as recounted in a 2021 paper in the journal Microbiome.

Other findings diverge.

A study from Australia, published in February in Alimentary Pharmacology and Therapeutics, followed 24 Crohn’s patients over four weeks and concluded that, in the context of a healthy diet, the emulsifier content had “no influence over disease activity.”

Authors declared conflicts of interest, including payments from PepsiCo, drug companies, and Mindset Health Pty, which promotes hypnosis-based therapy.

One of the authors, gastroenterology professor Peter Gibson of Monash University in Australia, said the conflicts of interest “have nothing whatsoever to do with the study.”

“It is important not to overinterpret results of studies,” he said, adding that his team’s report “does not mean that emulsifiers are good for you or that there are no health benefits in avoiding emulsifiers.”

‘Keeping It Real’ (Or Not)

Häagen-Dazs touts the absence of such chemicals as a virtue.

“Keeping it real, the way it should be,” it said in an online plug for its vanilla ice cream. “No emulsifiers. No stabilizers.”

However, at the company that makes Häagen-Dazs in the United States, Dreyer’s Grand Ice Cream, there are limits to that approach.

Under other brand names — such as Edy’s, Dreyer’s, and Drumstick — it markets products that contain emulsifiers or stabilizers. The company did not respond to questions. In addition, a spokesperson for Nestlé, which markets Drumstick and Häagen-Dazs brands internationally, did not respond.

Drumstick Vanilla Caramel Sundae Cones have no artificials flavors or colors, the package says — but they feature an array of other ingredients, including soy lecithin, guar gum, monogylcerides, and carob bean gum.

The cones, the company’s website says, offer “one incredibly creamy experience.”

And the creamy filling doesn’t melt.

Instead, over 24 hours on a KFF Health News reporter’s kitchen counter, it bled a caramel-tinged fluid and shrank into a sticky white foam that could be cut with a knife.

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This article first appeared on KFF Health News and is republished here under a Creative Commons license.

A year ago, a new head of Social Security set out to stop the agency from financially devastating many of the people it was meant to help.

The agency had long made it a practice to reduce or halt benefit checks to recoup billions of dollars in payments it sent recipients but later said they never should have received.

Martin O’Malley, then the Social Security Administration commissioner, announced in March 2024 the agency would no longer cut off people’s monthly old-age, survivors, and disability checks to recoup money they had allegedly been overpaid — a pattern he called “clawback cruelty.” Instead, it would default to withholding 10% of monthly benefits. The new policy allowed people who already live on little to pay their rent and keep food on the table.

Last Friday, the Trump administration reversed that policy.

Beginning March 27, to recover new overpayments, the Social Security Administration will automatically withhold 100% of recipients’ monthly benefits, the agency announced.

The agency said it was acting in the interest of fiscal responsibility and that the reversal would save the government about $7 billion over a decade.

“It is our duty to revise the overpayment repayment policy back to full withholding, as it was during the Obama administration and first Trump administration, to properly safeguard taxpayer funds,” acting Commissioner Lee Dudek said in a news release.

Advocates for Social Security beneficiaries described the action as cruel and harmful.

“The results are predictable: more unnecessary suffering,” said Kathleen Romig, who worked at the Social Security Administration under O’Malley and is now director of Social Security and disability policy at the Center on Budget and Policy Priorities.

Kate Lang of the advocacy group Justice in Aging said she was heartbroken.

“Those who are most vulnerable, with the fewest resources, are the ones who will feel the harsh impacts of this change,” she said. Many “are going to be unable to buy food or keep the roof over their head,” she said.

In 2023, after an investigation by KFF Health News and Cox Media Group cast a spotlight on overpayments and clawbacks, lawmakers from both parties called on the Social Security Administration to change its approach.

The policy change a year ago was inspired in part by the plight of people such as Denise Woods, who was sleeping in her Chevy in Savannah, Georgia, in December 2023 while contending with lupus and congestive heart failure after the government cut off her disability benefits. The government was demanding she repay almost $58,000.

Many overpayments are the result of government error. It can take the government years to figure out it has been paying someone too much, and by then, the amount the government says it is owed can grow far beyond a beneficiary’s ability to repay. And it has often demanded that recipients repay the full amount within 30 days.

As of October, the SSA was withholding at least a portion of monthly benefit payments from hundreds of thousands of people, according to data the SSA provided last fall to KFF Health News and Cox Media Group. The agency said it was withholding up to 10% from 669,903 people to recoup an overpayment. Asked whether those numbers covered all types of benefits administered by the SSA, the agency’s press office didn’t say.

“Under Trump’s leadership, Social Security has reinstated a cruel policy of clawing back Social Security overpayments with no regard for an American’s ability to pay or whether the overpayment was an error by the agency,” said Sen. Ron Wyden of Oregon, the top Democrat on the Senate Finance Committee.

The new plan to completely withhold monthly benefits from recipients who were allegedly overpaid does not extend to the Supplemental Security Income program, one of two Social Security programs for people with disabilities. SSI, as the agency explains, covers “people with disabilities and older adults who have little or no income or resources.”

The government’s estimate that cutting people off completely will save $7 billion over a decade implies it expects many more overpayments in the years ahead.

The SSA’s March 7 announcement was part of a broader dismantling of Biden-era policies under President Donald Trump. It was also part of a broader upheaval at the Social Security Administration, which announced In February that it would cut its staff from about 57,000 to 50,000.

In an interview Monday, O’Malley predicted that the public will experience much longer wait times trying to get through to the agency by phone and longer waits for disability determinations.

Social Security runs on a very old computer system, he said, and driving people out of the agency who understand it “can only result in system collapse.”

“The risk of totally shutting down the agency is greatly increased by people mucking around that don’t know what they’re doing,” O’Malley said.

On the PBS NewsHour last week, he advised recipients to save money to prepare for an interruption of benefits.

Trump deputy Elon Musk has boasted of taking a chainsaw to the federal government and has called Social Security a Ponzi scheme. In a signed declaration filed in federal court last week, a recently retired SSA official, Tiffany Flick, said she “witnessed a disregard for critical processes” as members of DOGE — the Department of Government Efficiency, which Trump established by executive order — demanded access to sensitive Social Security systems, including files that contain beneficiaries’ banking information.

New management at the SSA called its workforce “bloated.” But, under the previous administration, the agency was telling a starkly different story.

A year ago, O’Malley told lawmakers that, as the number of people receiving benefits increased, “historic underfunding and understaffing” at the agency had created a “service delivery crisis.”

Late last year, the agency provided data to KFF Health News showing that in September its workforce was near a 50-year low. As of last month, applicants for disability benefits were waiting an average of more than seven months for a decision, according to the SSA website.

The staffing cuts will lead to more overpayments than ever and will make it harder for the people affected to clear up mistakes, said Jen Burdick, an attorney at Community Legal Services of Philadelphia.

As KFF Health News and Cox Media Group revealed in 2023, about 2 million people a year were receiving notices from the SSA that they were overpaid and owed money back.

People can appeal overpayment notices, request a lower withholding rate, or ask the SSA to waive collection altogether, the agency said. The SSA does not pursue recoveries while an initial appeal or waiver request is pending, it said.

Shortly before O’Malley left the SSA in November, the agency implemented changes that made it easier for beneficiaries to get overpayments waived. The agency spelled out grounds for determining the beneficiary was not at fault — for instance, if the agency continued to issue overpayments after the beneficiary reported a change in their financial circumstances that should have led to a reduction in benefits. Those policy changes remain intact.

Several Republicans who expressed concern about clawbacks in the aftermath of 2023 news coverage did not respond to inquiries for this article or declined to comment. One of them was Sen. Rick Scott (R-Fla.), who is now chair of the Senate’s Special Committee on Aging.

“Hardworking American taxpayers pay into Social Security all of their lives so that they can depend on it in the time they need it most,” Scott said in a 2023 letter to the agency. “The fact that the SSA’s actions are leaving some of them worse off, through no fault of their own, is absolutely unacceptable.”

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Top U.S. officials in the Washington area have received preferential treatment from a little-known health care program run by the military, potentially jeopardizing care for other patients including active-duty service members, according to Pentagon investigators.

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White House officials, senior military and other national security leaders, retired military officers, and family members have all benefited. The Washington elite could jump the line when filling prescriptions, book appointments through special call centers, and receive choice parking spots and escorts at military hospitals and other facilities, including Walter Reed National Military Medical Center in Bethesda, Maryland, according to the Pentagon’s inspector general.

Through a unit at the White House, government personnel were routinely allowed to receive treatment under aliases, providing no home address or insurance information. For some of them, the care was free, as Walter Reed had no way to bill for it or waived charges.

The so-called executive medicine program was described in a report the Pentagon’s inspector general released in January. The investigation drew extensive media attention for spotlighting a history of loose prescribing practices and poor controls of powerful drugs including opioids in the White House Medical Unit, a military outfit that attends to the president, vice president, and others in the White House compound.

But the White House Medical Unit is just the tip of the broader executive medicine program, intended to provide VIP treatment to senior government and military officials. Though the program is meant largely to accommodate top officials’ busy schedules, the privileges have followed many patients into retirement. According to data from late 2019 and early 2020, the IG’s report said, 80% of the executive medicine population in the national capital region were military retirees and members of their families.

Some facilities “provided access to care for executive medicine patients over active-duty military patients that had acute needs,” according to the report, which added that prioritizing medical care by seniority rather than medical need “increased the risk to the health and safety of non‑executive general patient population.”

Much of the report was written in past tense, leaving unclear whether all the practices it described continue. Before the report was made public, a draft was under review by the White House Medical Unit for more than three years — from May 2020, when Donald Trump was in office, to last July. The delay isn’t explained in the report, and White House spokespeople didn’t respond to questions for this article.

A spokesperson for the inspector general’s office, Deputy Assistant Inspector General Reishia Kelsey, declined to elaborate on the report. A spokesperson for the Pentagon, James P. Adams, also declined to comment.

In a response included in the inspector general’s report, a Pentagon official said there were “new procedures already put in place by the White House Medical Unit.” The report didn’t detail those changes.

At Walter Reed, the program is available to Cabinet members; members of Congress; Supreme Court justices; active-duty and retired generals and flag officers and their beneficiaries; members of the Senior Executive Service who retired from the military; secretaries, deputy secretaries, and assistant secretaries of the Department of Defense and military departments; certain foreign military officers; and Medal of Honor recipients.

Walter Reed’s executive medicine program caters to the “time, privacy, and security demands” of leaders’ jobs, the hospital says on its website. The IG report makes clear that the program has, at times, provided extraordinary privileges to the government’s most elite officials.

For example, one unnamed executive medicine patient asked to have a prescription for an unspecified “controlled medication” refilled two weeks early — and complained when pharmacy staff at Fort Belvoir Community Hospital said that wasn’t allowed.

Hospital leaders told hospital staff to fill the prescription as requested. According to the report, the staff said the task required an estimated 30 hours of extra work.

Controlled medications are subject to abuse, and some, such as opioids, can be addictive. Defense Department health policy calls for minimizing the use of opioids and prescribing them only when indicated.

A spokesperson for the Fort Belvoir hospital, now known as Alexander T. Augusta Military Medical Center, said every patient is seen through the same lens and treated with the care they deserve.

The spokesperson, Reese Brown, said the facility shows military deference to top officers on account of their rank. For example, they don’t have to sit with the general population of patients.

The facility’s website mentions an “Executive Medicine Health & Wellness Clinic” for authorized patients, including eligible family members.

Brown said he was unaware of the inspector general’s account of the prescription refill and had no information about it.

The report said that at one unidentified pharmacy site, “all pharmacy staff members expressed frustration about the prioritization and filling of executive medicine prescriptions. This prioritization of executive medicine prescriptions diverted the pharmacist from filling prescriptions for patients diagnosed with conditions that are more urgent.”

Executive medicine services are also provided at the DiLorenzo Tricare Health Clinic at the Pentagon, Fort McNair Army Health Clinic, and Andrew Rader U.S. Army Health Clinic, the report said.

The inspector general recommended the Department of Defense take steps such as establishing controls for billing nonmilitary senior officials for outpatient services. The assistant secretary of defense for health affairs agreed but said the department would consider “the historical practices of the White House Medical Unit, the DoD’s health care support for non‑military U.S. Government senior officials, and the need for strict security protocols to protect the health and safety of White House principals.”

Chaseedaw Giles, KFF Health News’ digital strategy & audience engagement editor, contributed to this report.

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