Food Allergy vs Food Intolerance

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

The terms “allergy” and “intolerance” are often used interchangeably, but they refer to very different conditions that require different management strategies.

Food Allergy

A food allergy involves the immune system and is classified as an “Allergic Hypersensitivity.” Even a tiny amount of the allergen can trigger a reaction.

Immediate Symptoms May Include:

• Swelling of the eyes, lips, tongue, or roof of the mouth

• Itchiness in the mouth, ears, or throat

• Raised, red, itchy skin rash

Delayed Symptoms (up to 72 hours after consumption) May Include:

• Eczema

• Reflux

• Loose stools

• Mucus and/or blood in the stools

• Constipation

In the case of cow’s milk allergy, the reaction is to the proteins in the milk, hence the term “cow’s milk protein allergy.” Managing this condition typically requires the complete removal of all forms of cow’s milk from the diet.

Lactose Intolerance

Lactose intolerance does not involve the immune system and is therefore classified as a “Non-Allergic Hypersensitivity.” It results from the absence or deficiency of lactase, the enzyme needed to digest lactose, the sugar found in milk.

Symptoms May Include:

• Bloating

• Nausea

• Wind

• Abdominal pain

• Constipation

• Diarrhoea

Management often involves reducing the amount of cow’s milk in the diet rather than eliminating it entirely. Many individuals with lactose intolerance can tolerate some lactose, though the amount varies between individuals. Yoghurt and hard cheese may be acceptable, as they contain lower levels of lactose than regular milk. Lactose-free milks are a good alternative, providing the same key nutrients such as calcium but with low lactose content.

Important: Lactose-free milks are not suitable for managing cow’s milk allergy, as they still contain cow’s milk proteins, which could cause an allergic reaction.

Getting the Right Diagnosis

If you suspect you may have a food allergy or intolerance, please book an appointment with your GP. Avoid self-diagnosis and unreliable high street tests.

Not recommended tests include:

• Hair analysis

• Vega tests

• Applied kinesiology

• Serum-specific IgG tests

These tests are unreliable and may be very expensive.

Regardless of the condition, it is always advisable to get a referral to see a dietitian to ensure your diet is balanced and that you're receiving all the nutrients needed for good health.