Why Ice Cream May Be Bad for Your Gut Health

By David Hilzenrath, KFF Health News

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 ultra-processed 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,” Makary 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.”

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.

Ben & Jerry’s vs Häagen-Dazs

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.”

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.”

The 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.”

Häagen-Dazs ‘Keeps It Real’

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 artificial 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.”

But 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.

KFF Health News is a national newsroom that produces in-depth journalism about health issues.

Microplastic Particles Linked to IBD

By Pat Anson, PNN Editor

Microplastics — tiny bits of plastic so small they are invisible to the naked eye --- can be found in our food, water and even the air we breathe. But research is only beginning on the prevalence and health effects of plastic particles in humans.

A 2020 study found that babies fed formula from plastic bottles swallowed millions of microplastic particles every day. And a recent review that looked at the impact of microplastics on human cells found evidence of cell death, immune response and damage to cell walls.

“We are exposed to these particles every day: we’re eating them, we’re inhaling them. And we don’t really know how they react with our bodies once they are in,” lead author Evangelos Danopoulos, a postgraduate student at Hull York Medical School in the UK told The Guardian.

For the first time, Chinese researchers have now found evidence that people with inflammatory bowel disease (IBD) have more microplastics in their feces, suggesting that plastic particles in the digestive tract could play a role in the development of Crohn’s disease and ulcerative colitis.

Researchers obtained fecal samples from 52 people with IBD and 50 healthy people from different geographic regions of China. They found that feces from the IBD patients had significantly more microplastics than the control group – an average of 41.8 particles per gram in the IBD group vs. 28 particles in healthy people. People with more severe IBD symptoms had higher levels of microplastics. Their particles also tended to be smaller.

ENVIRONMENTAL SCIENCE AND TECHNOLOGY

Researchers surveyed both groups and found that people who consumed more bottled water and takeaway food, and were often exposed to dust had more microplastics (MPs) in their feces. The two most common types of plastic found were polyethylene terephthalate (PET; used in bottles and food containers) and polyamide (PA; found in food packaging and textiles).

Still unclear is whether exposure to microplastics causes or contributes to IBD, or whether people with IBD simply accumulate more microplastics in their digestive tracts because of their disease.

“We conclude that the plastic packaging of drinking water and food and dust exposure are important sources of human exposure to MPs. Furthermore, the positive correlation between fecal MPs and IBD status suggests that MP exposure may be related to the disease process or that IBD exacerbates the retention of MPs,” researchers reported in the journal Environmental Science & Technology.

The prevalence of IBD is rising around the world. A 2015 CDC study estimated that about 3.1 million adults in the U.S. were diagnosed with IBD, nearly double the 1.8 million Americans who reported having IBD in 1999. The researchers found an association between IBD and people with lower income and education levels, but did not look into the role of microplastics.

Experts Say IBD Patients Not at Higher Risk From Coronavirus

By Pat Anson, PNN Editor

Patients with Crohn's disease, ulcerative colitis and other inflammatory bowel diseases (IBD) are not at greater risk from the coronavirus and should continue their regular therapies, according to new guidance by the American Gastroenterological Association (AGA) published in the journal Gastroenterology.

IBD is an immune system disorder that causes abdominal pain, diarrhea and weight loss. Symptoms and progression of the disease can be controlled by medications such as prednisone that suppress the immune system, which has led to concern that patients taking the drugs may be more susceptible to coronavirus infections.

Some IBD patients also need to visit medical facilities for infusions and other procedures, which may increase their risk of exposure to the SARS-CoV-2 virus.

“Despite the potential for increased exposure to SARS-CoV-2, the limited available data and expert opinion suggest that patients with IBD do not appear to have a baseline increased risk of infection with SARS-CoV-2 or development of COVID-19,” wrote lead author David Rubin, MD, Co-Director of the Digestive Diseases Center at University of Chicago Medicine.  

“It is unclear whether inflammation of the bowel per se is a risk for infection with SARS-CoV-2, but it is sensible that patients with IBD should maintain remission in order to reduce the risk of relapse and need for more intense medical therapy or hospitalization.”

Rubin and his co-authors say there is limited information on the severity of coronavirus symptoms in IBD patients, although one study in China found they were “more likely to be hospitalized.” While COVID-19 is primarily a respiratory illness, the virus can cause digestive problems and is detected in stool samples.

The experts recommend that IBD patients who do not have coronavirus symptoms continue their current treatments to avoid relapsing.

“Aside from the obvious negative consequences of a relapse, relapsing IBD will strain available medical resources, may require steroid therapy or necessitate hospitalization, outcomes that are all much worse than the known risks of existing IBD therapies,” Rubin wrote. “Similar to the recommendations to the general population, patients with IBD should practice strict social distancing, work from home, have meticulous hand hygiene, and separate themselves from known infected individuals.”

Infusion centers should have a protocol to pre-screen IBD patients for fever and other coronavirus symptoms, and providers and patients should wear masks and gloves.

For patients who test positive for the coronavirus or develop symptoms, the experts recommend lower doses of prednisone and a temporary halt to biological therapies and immune suppressing drugs such as thiopurines, methotrexate, and tofacitinib.   

“For the patient with COVID-19, adjustment of the medical therapy for IBD is appropriate, based on the understanding of the immune activity of the therapy and whether that therapy may worsen outcomes with COVID-19,” Rubin wrote. “For hospitalized patients with severe COVID-19 and risks of poor outcomes, IBD therapy likely will take a back seat, but choice of therapies for COVID-19 should take into account the co-existing IBD, if feasible.”

Over 3 million people in the United States have IBD. The AGA has developed a flow chart for providers treating IBD during the COVID-19 outbreak and a reference chart for IBD patients.

Does Washing Your Hands Raise Risk of IBD?

By Pat Anson, Editor

Many of us were taught as children to always wash our hands before leaving the bathroom and before meals. But that basic sanitary practice may be contributing to an increase in inflammatory bowel diseases (IBD) such as Crohn’s disease and ulcerative colitis, according to a new study published in the journal Science.

Researchers at New York University’s Langone Medical Center tested the so-called “hygiene hypothesis” – the theory that some intestinal parasites and bacteria are beneficial because they help balance the immune system and reduce IBD rates. Sanitary practices have sharply reduced gut worm infections in developed nations, which now have some of the highest rates of Crohn’s disease and ulcerative colitis.

“Our findings are among the first to link parasites and bacteria to the origin of IBD, supporting the hygiene hypothesis,” says parasitologist P’ng Loke, PhD, an associate professor at NYU Langone.

“The prevalence of IBD is much less in regions of the world which have heavy worm infection. In fact, I got interested in the question of how worms can be beneficial when I was contacted by an individual who had deliberately infected himself with worms to treat his symptoms of IBD and was able to put his disease into remission.”

Loke and his colleagues found that laboratory mice infected with intestinal worms experienced a thousand-fold decrease in Bacteroides — a type of bacteria linked to people with higher risk of IBD. At the same time, the number of Clostridia, a bacterium known to counter inflammation, increased tenfold in the mice.

RESEARCHERS P'ng Loke and Ken Cadwell, NYU Langone Medical Center

RESEARCHERS P'ng Loke and Ken Cadwell, NYU Langone Medical Center

Researchers believe the immune response to the worms triggers the growth of Clostridia, which then either outcompete Bacteroides for nutrients or release toxins that are harmful to them.

In a second phase of the study, researchers gave mice an infusion of Clostridia – without the use of parasites – and found that it reduced the presence of Bacteroides.

“That gives us a lot of hope in terms of IBD therapy because maybe we don’t need to give people parasitic worms, which can be harmful and cause disease, and instead target the harmful bacteria by replacing them with healthy bacteria,” says microbiologist Ken Cadwell, PhD, an assistant professor at NYU Langone and the Skirball Institute of Biomolecular Medicine. “Our study could change how scientists and physicians think about treating IBD.”

Researchers say the hygiene hypothesis may also apply to other autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, and type 1 diabetes, in which processes meant to attack foreign invaders instead become oversensitive and trigger an immune response to the body’s own cells.

IBD is a chronic or recurring immune response and a painful inflammation of the gastrointestinal tract. Inflammation affects the entire digestive tract in Crohn’s disease, but only the large intestine in ulcerative colitis.

According to the Crohn's and Colitis Foundation of America, IBD affects about 1.6 million Americans and tends to run in families. Caucasians are more likely than other ethnic groups to have IBD. The diseases are especially prevalent in Jews of European descent (Ashkenazi Jews). African Americans and Hispanics in the United States are also increasingly affected.

The Importance of Awareness

By Jennifer Martin, Columnist

The other day I was made aware of a malicious Facebook post that was written about an acquaintance who was making others aware that it was World IBD Day.  She was simply educating others about inflammatory bowel disease and the difficulties that arise from having such a condition. 

The Facebook poster declared how tired he was of people posting about their diseases and trying to gain pity from others. 

The day before, another poster with a J-pouch due to ulcerative colitis mentioned that while she was leaving the bathroom a woman told her that she should use a private bathroom because what she was doing was disgusting. 

Not long before this, a chronic pain patient of mine told me she received a dirty look from someone in a grocery store parking lot because she parked in a handicap parking space, even though her handicap placard was hanging clearly from her rear-view mirror.

The same day, another patient told me that he doesn’t feel like his doctor hears him when he tells him how much pain he is in.

Unfortunately, this kind of misunderstanding and ignorance happens all of the time. People with invisible chronic pain or chronic illnesses are often the recipients of hurtful words or spiteful looks from people with have no clue what they are going through on the inside.

This is why awareness is so important. About half of all American adults -- 117 million people --have one or more chronic health conditions, yet many of us are still largely misunderstood.  We may be feeling awful, but typically we look fine from the outside. 

Many people think chronic pain patients are addicts who just want drugs.  Some who don’t understand Complex Regional Pain Syndrome (CRPS/RSD) think it’s a psychological problem.  And others believe that fibromyalgia isn’t real and that patients only want sympathy.

It is important for people to have a better understanding of what we’re going through so that the stigmas, hurtful words, and malevolent looks begin to fade.  That cannot happen if we remain silent.

May is a big awareness month for chronic pain and chronic illness:

Fibromyalgia and Chronic Pain Awareness Day was May 12.

World IBD day was May 19.

World MS day is May 27.

May is also Arthritis Awareness month.

So keep wearing those awareness t-shirts -- and keep blogging, educating, and posting.  Will it help?  I am hopeful.

Jennifer Martin, PsyD, is a licensed psychologist in Newport Beach, California who suffers from rheumatoid arthritis and ulcerative colitis. In her blog “Your Color Looks Good” Jennifer writes about the psychological aspects of dealing with chronic pain and illness. 

Jennifer is a professional member of the Crohn’s and Colitis Foundation of America and has a Facebook page dedicated to providing support and information to people with Crohn’s, Colitis and Digestive Diseases, as well as other types of chronic pain.

The information in this column should not be considered as professional medical advice, diagnosis or treatment. It is for informational purposes only and represents the author’s opinions alone. It does not inherently express or reflect the views, opinions and/or positions of Pain News Network.