By Katie Kerwin McCrimmon
A UK researcher who trained at National Jewish Health in Denver has shaken up the allergy world with a study released Monday in the New England Journal of Medicine that shows that early exposure to peanuts prevents rather than causes allergies.
Dr. Gideon Lack visited Denver in March to share his theories about peanut allergies and now the results of his long-term study are likely to cause tectonic shifts for allergists, pediatricians and primary care providers. (Click here to read Reversing the allergy epidemic: ‘Let them eat dirt’ and maybe peanuts too.)
Dr. Erwin Gelfand, the chief of pediatrics at National Jewish, who many years ago trained Lack when he served for five years as a fellow in Denver, summed up the implications of Lack’s findings in four simple words.
“We clearly were wrong.”
Gelfand said allergists for many years told parents to delay giving infants potentially allergenic foods like peanuts, eggs, milk and shellfish. In the meantime, the allergy epidemic exploded.
Gelfand said it’s now obvious that that advice was not rooted in science.
“We’ve been talking for five decades about holding off (on potentially allergenic foods) until the child is 12 or 14 months (old) or later. We never had a database to suggest this was true. It was almost one of these old wives tales,” Gelfand said. “Yet every pediatrician, every mother would go online and read this.”
He called Lack’s new study “overwhelming” and said the findings will trigger dozens of new studies on what’s best for preventing allergies in infants.
For now, if Gelfand were giving advice to his own daughter about how to feed his grandchildren, he’d advise a radical departure from the go-slow approach.
“There’s no allergy in our family, so give it early,” he said of teething biscuits that contain peanut. “Of course we’re not going to give them (whole) peanuts. But we worry more about aspiration (choking) not allergies.”
Gelfand warned that it’s not time yet for parents who have older children with peanut allergies or their own history of food allergies to start feeding babies peanut products early. It will be important for parents with high-risk infants to get skin testing first to see if their infants are showing proclivities toward allergies.
Dr. David Fleischer, a food allergy expert at Children’s Hospital Colorado, said it’s time for all the leading medical associations that represent allergists, pediatricians and family physicians to prepare guidelines together so parents get consistent advice.
Fleischer said he was not surprised by Lack’s findings because he’s been keeping close track of other less comprehensive studies with similar findings: that early introduction of foods can prevent allergies later.
Nonetheless, Fleischer said he’s very excited about the new study because it marks the first randomized, controlled study of its kind.
He said the advice about infant feeding began to change in 2008 when doctors realized that delaying allergenic foods wasn’t preventing the onset of peanut allergies, which have skyrocketed in recent years.
Fleischer helped write guidelines two years ago regarding infant feeding and allergies for the American Academy of Allergy, Asthma and Immunology. Now, he’ll be working on new guidelines that he hopes to complete by year’s end. He’d like to work closely with colleagues at the American Academy of Pediatrics and the National Institutes of Health.
“We all need to get the same message out,” Fleischer said.
And what would Fleischer advise?
“When babies have had a few solid foods, there’s no reason why you can’t start giving dairy or eggs in baked goods,” he said.
“The first food is not going to be peanut butter because they’re not going to be able to swallow it. For fish, it’s good to do it later too when they can swallow.”
Fleischer said parents will probably want to start with traditional first foods like rice, applesauce and bananas.
“But there’s no reason to delay potentially allergenic foods longer. They just need to be ready to eat them in a safe form,” Fleischer said.
He gave similar advice to Gelfand’s that any high-risk patients — those with siblings who have allergies or babies with moderate to severe, uncontrolled eczema — should be skin-tested before eating high-risk foods to ensure that they don’t already have a food allergy.
But he said it’s not reasonable to think that routine skin-testing of 4-month-old babies will be recommended.
“This is going to create a bit of controversy. I think there are going to be parents that are very nervous to do this. They’ll want to come see us to get skin-tested. But talking to their (babies’) primary care providers is going to be an important thing,” Fleischer said. “If a skin test is negative, there will be an extremely low chance that they will react (to allergenic foods).
“This is groundbreaking. It’s exciting,” Fleischer said. “We need to really come together as multiple organizations to see what we want to do about this.”
While parents have been cautious about what they’ve been feeding their babies, many pregnant and breastfeeding women also have restricted their diets to reduce allergies for their babies.
Fleischer said there’s no evidence that mothers should do that.
“Moms shouldn’t avoid milk or eggs,” Fleischer said. “Right now there’s no recommendation to take anything out of the diet in order to prevent allergy — including peanuts.”
Gelfand said early introduction of foods could end up having major implications for children throughout their lives. He said preventing food allergies or getting our bodies used to foods that might cause some sensitivity is much easier than trying to treat or fix an allergy later.
“It’s much easier to create tolerance in the very young than after sensitization has occurred. The immune system is hard to turn around,” he said.
Lack, who is a professor of pediatric allergy at King’s College London and heads children’s allergy treatment at Guy’s and St. Thomas’ NHS Foundation Trust in London, first came up with his theory about early exposure almost by chance.
Like most physicians, Lack said during his Denver visit last year that he used to warn parents about early introduction and in fact avoided giving his own children peanuts.
“I bought into this. I was part of the establishment,” he said.
Then in about 2003, Lack spoke at a medical conference in Israel and happened to see a friend feeding her baby a teething snack full of peanuts.
“I was horrified. If she were living in the UK, she would probably go to jail for this,” Lack joked during a talk at National Jewish.
It turned out that parents in Israel commonly feed their babies peanuts as early as four months and peanut allergies are rare.
In contrast, rates of both eczema and peanut allergies in the United Kingdom have been soaring as they have been in the U.S.
“There’s an EpiPen in just about every classroom. This really has become an epidemic,” Lack said.
His trip to Israel triggered an idea for Lack. Could babies who have eczema be getting exposed to peanut proteins through creams that commonly contain peanut oils? If these babies are not at the same time ingesting peanuts, could their bodies wrongly see peanut proteins as attackers?
As an allergy fellow, Lack had spent five years in Denver at National Jewish. He used to work in a mouse lab here and as part of research for Gelfand, Lack painted egg proteins on mice to help make them allergic. After the Israel trip, a light went off for Lack. In mice, he remembered that topical exposure to allergens could cause allergies while mice that were fed the same proteins did not become allergic. Perhaps, when it comes to peanuts, mice and babies were similar. Maybe ingesting potentially harmful proteins can be protective.
Gelfand said he heard from Lack this week and his former student is elated about the results. Since the study was blind, researchers had no idea what the study would find.
Gelfand said it was important that the study was done in the UK because some experts in the U.S. might have sought to bar testing on infants.
But, said Gelfand, Lack has proven that if we want to understand and prevent allergies, researchers must focus on the very young.
Said Gelfand: “That’s where the action is.”