What are the causes and risk factors of food allergy?

Joan Salge Blake, MS, RD
Nutrition & Dietetics Specialist

A food allergy is an abnormal physical reaction of the immune system in response to the consumption of a particular food allergen. Food allergens are proteins that are not broken down during cooking or by the gastric juices and enzymes in the body during digestion. Because they are not degraded, they enter the body intact, and can cause an adverse immune reaction if the allergen is perceived as a foreign invader.

No one really knows why some people have food allergies and others don’t. Having asthma or eczema increases the chance of having a food allergy. 

Like other kinds of allergies, the tendency to have an allergy to food—although not the specific allergy—is inherited. Not only that, but certain foods—including tree nuts, eggs, wheat, peanuts, fish, shellfish and milk—are frequent troublemakers. Children often have more food allergies than adults do, especially to cow's milk and to peanuts. Infants outgrow many food allergies by the age of four. Allergic reactions to shellfish, tree nuts and fish are more common in adults.

Ms. Vandana  R. Sheth
Nutrition & Dietetics Specialist

Food allergies do run in families. If a child has two parents with food allergies, it significantly increases the chances of the child developing food allergies. However, there is an increase in the number of children developing allergies without a family history of allergies.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.