Developing Food Allergies in Adulthood

When most people think about food allergies, they picture a child with peanut allergies having to navigate peanut-free environments and parents diligently reading food labels. However, food allergies are not limited to childhood and can develop at any stage of life.

For many adults, the sudden onset of food allergies can be confusing, frustrating, and can feel overwhelming. However, from an integrative and functional nutrition perspective, it offers an important opportunity to explore what is going on in the body and identify the root causes of the immune dysfunction.

Can someone really develop a food allergy as an adult?

This is a common question. Yes, while some individuals outgrow childhood allergies, others can unfortunately develop new sensitivities—or even true allergies—later in life. This can be due to many different contributing factors:

• Gut dysfunction or “leaky gut” – When the gut lining becomes compromised, larger food particles can enter the blood stream and trigger an immune response
• Microbiome imbalance – When the gut’s microbiome is out of balance the immune system can become hypersensitive to pollen and food proteins, leading to allergic reactions and increased histamine production.
• Toxin exposure – Environmental toxins contribute to inflammation and immune dysregulation.
• Hormonal changes – Hormonal shifts can act as triggers to how the body (immune system) reacts to previously harmless substances.
• Chronic stress – Stress as a factor in allergies? Yes, ongoing stress can impair a person’s gut health, weaken immune balance, and increase inflammation.
• Chronic infections – Persistent infections may overstimulate the immune system, making it more reactive over time.
• Chronic inflammation – Long-term inflammation can disrupt immune function and contribute to the development of food sensitivities or allergies.

Over time, the factors above can heighten immune reactivity and influence the development of food allergies.

Common Adult-Onset Food Allergies

The more common adult-onset food allergies include:

• Peanuts
• Fish
• Soy
• Wheat
• Tree nuts
• Shellfish (crap, lobster, and shrimp)

Recognizing The Symptoms

Symptoms can range from mild to severe and may include:

• Anaphylaxis, a life-threatening reaction requiring immediate medical attention.
• Swelling of the face, lips, or throat
• Losing your voice
• Difficulty breathing
• Gastrointestinal distress (nausea, vomiting, diarrhea, pain)

It is very important to differentiate between true allergies and food sensitivities, as each needs guided appropriate care.

What To Do If You Suspect A Food Allergy or Food Sensitivity

If someone suspects a new food allergy, evaluation by an allergist is important—especially if reactions are becoming more severe or unpredictable. In the meantime, keep a detailed food and symptom journal and avoid suspected trigger foods until you’ve been evaluated.

Once diagnosed, make sure to carry emergency medication at all times, if they have been prescribed.

Finally, make sure to follow up with a functional medical professional for treatment. A functional medicine provider will look beyond symptom reduction and address all of the underlying factors that may be contributing to immune dysregulation—to improve overall immune resilience, gut health, and long-term quality of life.

Living With A Food Allergy As An Adult

Adjusting to a new food allergy later in life can be challenging, but with the right support, it can be manageable. With education, personalized nutrition strategies, and mindful food choices, individuals can maintain a nourishing, safe, and enjoyable lifestyle.

Be Well,
Chardonèe