Food elimination diets are a common treatment for eosinophilic esophagitis (EoE), the form of food allergy where certain foods trigger damaging inflammation in the esophagus.
However, recent research that compares an often used six-food elimination diet with a diet that eliminates only one food – milk – has found encouraging results. In adults with the chronic condition, the single food elimination diet seemed to work about equally well in controlling EoE as the more restrictive diet.
The protein in cow’s milk is the most common trigger for EoE, which occurs when eosinophils, a type of white blood cell, accumulate in the esophagus, leading to symptoms such as pain, trouble swallowing and food getting stuck on the way down. But other foods are known to trigger EoE too, and the most common other five are wheat, egg, nuts (including peanuts), soy and seafood (fish/shellfish).
Many people find relief from EoE symptoms when they stop consuming their trigger foods. However, removing all six of those food groups is a big challenge for patients, especially over the long-term, says Kara Kliewer, a registered dietitian and research associate at Cincinnati Children’s Hospital Medical Center.
In the study, Kliewer and colleagues from the Consortium of Eosinophilic Gastrointestinal Disease Researchers followed two groups. Sixty-seven adults with EoE were put on a milk-elimination diet, while 62 others with EoE adopted the six-food elimination diet and stopped consuming milk, wheat, egg, nuts, soy and seafood.
After six weeks, EoE was in remission for 34 percent of those on the milk-elimination diet, compared to 40 percent of those assigned to the six-food elimination diet. This was not a statistically significant difference.
Results Were a Surprise
Remission was defined as having fewer than 15 eosinophils per high-power field (hpf), a measurement of the density of white blood cells when the tissue is viewed under a microscope. Endoscopies for both groups showed less inflammation, and both groups also had an improvement in their symptoms, although not everyone was helped by either diet.
“We were slightly surprised by the results of this study,” Kliewer said, noting that she expected more people would achieved remission on the six-food elimination diet.
The findings suggest that adults with EoE may find relief if they stop consuming dairy, and may be able to avoid the more difficult to follow six-food elimination diet, which later involves attempts to reintroduce foods and endoscopies to check the status of inflammation.
The dietitian presented the findings at the virtual American Partnership for Eosinophilic Disorders (APFED) 2021 patient education conference. In a recent smaller study with children with EoE, led by a team at Northwestern University, over half of the participants also achieved remission with milk elimination rather than the six-food elimination diet.
Still, in the Phase 2 adult study, the six-food elimination did help some more than others. Researchers found that a higher proportion avoiding the six food groups achieved “complete” remission, or fewer than one eosinophil per hpf. About 19 percent of those on the six-food elimination achieved that compared to 6 percent who eliminated only milk.
“We concluded that starting with a one-food elimination diet is a reasonable place to start and, if that is not successful, escalating to a six-food elimination diet,” Kliewer says.
Patients who did not go into remission on the single-food elimination diet were given the option to step up to a six-food elimination diet. Of those, 43 percent achieved remission. Likewise, patients not reaching remission after six weeks on the six-food elimination diet were offered the option of high-dose, topical swallowed steroids. Of the participants who tried that, 82 percent went into remission.
“Probably equally important, we found in Phase 2 of the study, patients that failed to respond to the one-food elimination diet were rescued by a six-food elimination diet. And we found patients that failed to respond to a six-food elimination diet were rescued by topical swallowed steroids,” Kliewer says.
Elemental Diet Helps Adults with EGID
Also at the APFED conference, researchers presented the Phase 1 findings of a new study on treating adults with two other eosinophilic diseases – eosinophilic gastritis and eosinophilic gastroenteritis – with an elemental formula diet.
In eosinophilic gastritis (EG), the white blood cells called eosinophils cause inflammation and damage to the stomach, along with symptoms such as pain, diarrhea, nausea, vomiting and inflammation. With eosinophilic gastroenteritis (EGE), the white blood cells cause inflammation in both the stomach and the small intestine. Together, EoE, EG, and EGE are known as eosinophilic gastrointestinal disorders, or EGIDs. EG and EGE are rare diseases and less common than EoE.
In the study, 15 adults diagnosed with EG or EGE followed an allergen-free diet for six weeks, during which patients received all nutrients by drinking a formula containing amino acids, sugars, vitamins, minerals, and fats. At the start of the trial, patients had symptoms that included abdominal pain, trouble swallowing, diarrhea, nausea and vomiting.
After six weeks, participants had less inflammation, a “dramatic” reduction of eosinophils in the stomach and the duodenum (upper portion of the small intestine), and fewer symptoms. Participants also reported less depression and fatigue.
Not only were there improvements how the tissue looked under a microscope and in endoscopies, “our patients also felt better after the diet,” says lead study author Dr. Nirmala Gonsalves, a professor of medicine at Northwestern University’s Feinberg School of Medicine in Chicago.
Six weeks later, in the second phase of this study, researchers had the patients start adding back foods into the diet. “Similar to EoE, you want to get the gut quiet and add the foods back,” Gonsalves says.
“We don’t aim to keep people on the elemental diet indefinitely. It can be used to get people with really significant inflammation into remission, and then transition to another therapy, but this gives us evidence we can get people into remission in a short amount of time,” says the expert. The ultimate goal is to add back as many foods as possible.
Thus far, the results of food reintroduction have been mixed. “We’ve had a lot of great success in getting a lot of patients through big categories of food, but we have also had some patients who reacted early in the process,” she says. Those patients still need formula to ensure they get enough nutrients, she added.
Researchers are also continuing to study what level of eosinophils can be used as a diagnostic marker for non-EoE eosinophilic diseases, she added. While more than 15 eosinophils per hpf can be used to help diagnose EoE, the cutoff for EG and EGE in this study was higher – about 30 eosinophils per hpf.
Unlike in the esophagus, eosinophils are normally found in the gastrointestinal tract, and help to protect against pathogens. What’s normal and what’s abnormal depends on what segment of the gut you’re in, she explains. Although there isn’t a consensus yet, 30 eosinophils per hpf is often used for the stomach and upper intestine.
The elemental diet trial was the first prospective study on EG and EGE, Gonsalves says. “For a long time, people with EGID were feeling largely ignored. These are rare disorders, but we need to understand them better, develop better diagnostic criteria and ultimately better treatments. Our patients have been suffering for so long.”
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