A long-term study of a cohort of young people, 12,000 people now six years old, from Iceland to Greece, who have been tracked from birth and whose diets and allergies have been recorded, is evaluating maternal diet’s impact on food allergy in later life is expected to uncover causes of allergy in children.

Some pointers are already evident, they note. Compared to the UK, Israeli children typically eat nuts at an earlier age and have fewer allergies, which suggests that such dietary habits may have a protective effect against nut allergies later on. “This means that the current advice that young children should avoid nuts may make things worse,” says Clare Mills, professor of allergy in the Institute of Inflammation and Repair at the University of Manchester.

About 20 million Europeans are subject to food allergies. Now scientists are looking at these allergies in new ways. 

Child allergies linked to lack of early exposure and maternal diet. Image credit: Janice Cullivan

“Our aim is to see the allergy outcomes of their diet in early life, and even before they were born, as we have information on their mothers’ diets and on their weaning,” Mills told CommNet. A particular focus for the project is the different effects of allergenic foods in different contexts. “Someone might react very differently to nuts in a cookie or in a chocolate dessert,” says Mills.

The project aims to produce risk models, which will enable food manufacturers to look at these issues, perhaps leading them to alter cleaning protocols in their factories. In addition, project researchers are working with allergy patient groups. Mills says, “Often people don’t report allergies, but instead just cope with them. This means that we don’t get to know about them. So we are working with patient groups, and setting up an online tool to allow people to record their allergy experiences.”

While epigenetics as an explanation for everything, a sort of biological determinism, remains controversial,  Scott Sicherer, professor of paediatrics, allergy and immunology at the Icahn School of Medicine at Mount Sinai in New York believes the focus on maternal diet is the right one. “There is reason to worry about maternal diet during breast feeding and pregnancy with regard to food allergy outcomes in children. The diet may alter the nutrients and proteins in breast milk and affect the immune system. Studies thus far mostly suggest that a ‘healthy’ diet is important.” 

He adds that the food industry has a significant part to play, saying, “Proper labeling of food allergens is important for keeping persons with food allergies safe.” But he cautions that it is not the whole story. “It is also important not to label foods overly cautiously. Rampant use of cautionary labels might, if used improperly, be overly limiting,” Sicherer told youris.com.

The link between early and maternal diet and the onset of allergy is not proven and no valuable biomarkers for allergy have yet been found, cautions Karin Hoffmann-Sommergruber, associate professor in the department of pathophysiology and allergy research at Vienna Medical University, Austria.

Allergy is a global health issue, with rising incidence in newly industrializing nations, she believes. It varies in nature from place to place, with rice more of a problem in Asia, peanuts in Europe and the US, and fish and seafood everywhere.

In addition, Hoffmann-Sommergruber pinpoints allergy as a key issue that the European food industry has yet to tackle. She concludes, “[The] food industry has to set up a risk assessment and risk management plan in compliance with the current allergen labeling legislation.”