Nearly Half of All People With Food Allergies Develop Them as Adults

While the number of adults with food allergies is relatively low, almost half of them developed their allergies after childhood. In this article, we explain the basics of food allergies and discuss what you should do if you suffer an allergic reaction.

Did you know that you can develop food allergies no matter how old you are? Many of us assume that once we reach adulthood, we’re safe from new food allergies. Unfortunately, this isn’t true: studies show that almost half of adults with diagnosed food allergies developed them later in life.

However, many of us with suspected food allergies really have other conditions like food sensitivities. Keep reading to learn more about food allergies, food sensitivities, and the warning signs of an adult-onset allergy.

What’s the Difference Between a Food Allergy and a Sensitivity?

Many people think that lactose intolerance and a milk allergy are the same, but these are actually two distinct conditions. Lactose intolerance is a food sensitivity, while a milk allergy is a type of allergy. Food allergies and sensitivities involve different systems and responses in your body. They also have distinct sets of symptoms and pose different health risks.

Allergies Are an Immune System Response

When you have a food allergy, your immune system mistakenly identifies components in your food as dangerous and attacks them with histamines. Your body may respond with symptoms like hives, itchy skin, vomiting, dizziness, swelling, and difficulty breathing. In the worst cases, sufferers can go into anaphylactic shock, which can be life-threatening if not treated immediately.

Food Sensitivities and Intolerances Begin in Your Digestive System

Sometimes, your digestive system can’t properly break down certain kinds of foods. When you ingest these foods, you may experience bloating, diarrhea, constipation, stomach pain, and gas. This type of reaction is called a food intolerance or sensitivity.

Unlike a food allergy, food sensitivities are rarely life-threatening, although they can cause plenty of pain and discomfort. You may be able to manage your food intolerance symptoms using over-the-counter enzyme replacements.

Food Allergies Can Develop During Adulthood

Many of us associate food allergies with childhood, but a recent study reports that more than 48% of people with food allergies develop them as adults.  Even more worrisome is the fact that more than 51% of adults with food allergies will at some point experience a severe reaction that requires medical care.

Because food allergies can develop suddenly, you need to take symptoms like facial swelling, hives, and dizziness seriously. This is especially true if those reactions occur when you’re eating foods that commonly trigger allergies such as shellfish, milk, peanuts, and tree nuts. And if you suddenly have difficulty breathing or swallowing, don’t wait — go to the nearest emergency room and get help immediately.

Self-Diagnosing Food Allergies Is Dangerous, Expensive, and Ineffective

Some people who believe they have food allergies decide to adopt restricted diets that eliminate certain foods. By following these diets, people believe they can self-diagnose potential food allergies.

While some of these diets come via recommendation from a medical professional, many people end up on these limited and expensive diets because of information they read online or hear from friends. Unfortunately, many of the “allergies” people diagnose themselves with because of these diets are really intolerances. In fact, studies show that while almost 20% of adults self-report a food allergy, only 10% really have one.

Even if your self-diagnosis is correct, you still run serious health risks if you don’t consult an allergist or immunologist about your allergy. Your immune system will not always respond the same way to a food allergen. While you may have a history of skin rashes and itching after eating a certain food, you might suddenly go into anaphylactic shock when you consume the food on a different occasion. In that case, not having epinephrine close by could have catastrophic results.

By seeing a specialist about known or potential food allergies, you can get expert help and support. Your medical team can teach you how to read food labels, communicate about your allergies in restaurants, and find satisfying alternatives to your food allergens.

Canopy Health’s Alliance Includes Respected Allergy and Immunology Specialists and Clinics

Canopy Health’s robust alliance of Bay Area physicians and hospitals includes some of the most respected allergists and immunologists in the country. If you’re a Canopy Health member, you can choose to receive treatment from any of our doctors, including allergy and immunology specialists within Meritage Medical Network, Hill Physicians, SCCIPA, John Muir Health, and UCSF’s Allergy and Immunology Clinic. To request a referral, talk to your primary care physician about our Alliance Referral Program.


Gupta, R.S., Warren, C.M., & Smith, B.M., et al. (2019, January 4). Prevalence and severity of food allergies among U.S. adults. JAMA Network Open. 2019;2(1). Retrieved from