How Valid is Food Intolerance Testing? A Dietitian’s Opinion.

Daniel Murphy // Dietitian, Cork // Feb 24

Food intolerance testing has gained popularity in recent years, with many people seeking answers to their digestive issues or unexplained symptoms. This saw a huge rise in the availability of intolerance testing, and home testing kits. But how valid is food intolerance testing really? As a dietitian, I’ve heard countless clients ask about these tests and whether they are worth the investment. In this article, I will provide you with my professional opinion on the matter.

While food intolerance testing may seem like a convenient way to identify problem foods, it’s important to approach these tests with caution. The truth is, the scientific community is divided on the validity of these tests. Results are often inconclusive or unreliable from these tests. They also can be quite expensive. Personally, I wouldn’t recommend buying these kits. 

As a dietitian, I believe it’s crucial to take a comprehensive approach to addressing food intolerance issues. This means conducting a thorough evaluation of an individual’s symptoms, dietary patterns, and medical history. A personalised elimination diet, under the guidance of a qualified professional, is often the best way to identify and manage food intolerances. Elimination diets can be hard to do alone, so it’s best to get the help of a dietitian with this.

Common food intolerance foods

Table of Contents

Understanding food intolerances vs. allergies

Before we delve into the validity of food intolerance testing, let’s first understand the difference between food intolerances and food allergies. While these terms are often used interchangeably, they are distinct conditions with different underlying mechanisms.

Food allergies involve the immune system and can cause severe reactions, such as anaphylaxis. Common food allergens include peanuts, shellfish, and eggs. On the other hand, food intolerances do not involve the immune system and are typically characterised by digestive symptoms, such as bloating, gas, or diarrhoea. Lactose intolerance and gluten sensitivity are examples of common food intolerances.

Food Intolerance Test Kit

The process of food intolerance Testing

Food intolerance testing typically involves either blood tests, hair samples or elimination diets. Blood tests measure the levels of specific antibodies in response to certain foods. Elimination diets involve removing suspected trigger foods from the diet for a period of time and then reintroducing them to see if symptoms reoccur.

Blood and Hair tests for food intolerances are often marketed as convenient and accurate, but their validity is a topic of debate among experts. These tests claim to identify IgG antibodies, suggesting a food intolerance, but the presence of IgG antibodies alone does not indicate an intolerance. There is currently insufficient scientific evidence to support the reliability of these tests. From my experience, these tests will highlight foods that are already in the individual’s diet, which then causes the person to cut these foods out. This leaves the diet highly restricted and creates a very negative relationship with food. Please avoid these test!

Elimination diets, on the other hand, are considered a gold standard for identifying food intolerances. Under the guidance of a qualified dietitian, individuals follow a strict elimination diet, removing all potential trigger foods for a specified period of time. Foods are then systematically reintroduced, and any symptoms that arise can help identify specific intolerances. This can normally take the span of about 6 weeks depending on intolerance. This can be trialled with intolerance like lactose and gluten. 

Gluten & Lactose Intolerance

A gluten intolerance is slightly different to coeliac disease. With Coeliac Disease it’s dangerous to eat gluten and can have longer term effects on absorption and gut health. With gluten intolerance, it’s less severe as consumption of gluten leads to just gas, bloating and diarrhoea. It does not have longer term affects on health. 

Lactose intolerance occurs due to the body’s inability to digest lactose, the sugar found in milk and dairy products, due to insufficient levels of the enzyme lactase. This can become more common as we get older. As we age, lactase production can reduce meaning you can develop a lactose intolerance later in life. This can result in symptoms like gas, bloating, diarrhoea, and stomach cramps. 

Its best to trail an elimination diet around these to see if symptoms improve and then look to reintroduce to test if symptoms return. What’s important is that if things like dairy are removed from the nutrition, that the calcium is gotten through alternate means. Nowadays, lactose free milks, and fortified plant based milks are a good alternative if lactose intolerance is an issue.

Criticisms and controversies surrounding food intolerance testing

While food intolerance testing may seem appealing, it’s important to consider the criticisms and controversies surrounding these tests. One major criticism is the lack of standardisation and regulation in the industry. There are numerous companies offering different types of tests, making it difficult to determine their accuracy and reliability.

Another concern is the potential for false positives and false negatives. False positives can lead individuals to unnecessarily restrict their diet, while false negatives may fail to identify genuine intolerances. Additionally, food intolerances can be complex and vary from person to person, making it challenging to pinpoint specific trigger foods through testing alone. My personal opinion is avoid the blood and hair tests, and get the help of a registered dietitian. 

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The limitations and potential risks of food intolerance testing

In addition to the criticisms, it’s crucial to be aware of the limitations and potential risks associated with food intolerance testing. One limitation is the inability to differentiate between a true intolerance and a temporary sensitivity caused by other factors, such as stress or a recent illness. This can lead to unnecessary dietary restrictions and potential nutrient deficiencies.

Furthermore, relying solely on food intolerance test results may overlook other underlying health conditions that could be contributing to symptoms. It’s important to consider the whole picture and work with a healthcare professional, such as a dietitian, to rule out other potential causes and develop an appropriate treatment plan.

The role of a dietitian in addressing food intolerances

As a dietitian, I strongly believe in the importance of taking a comprehensive approach to addressing food intolerances. This involves conducting a thorough evaluation of an individual’s symptoms, dietary patterns, and medical history. A dietitian can help identify potential trigger foods and guide individuals through a personalised elimination diet.

Working with a dietitian provides several advantages over relying solely on food intolerance testing. A dietitian can provide education and support, help identify nutrient deficiencies, and ensure that the elimination diet is nutritionally balanced. They can also help individuals reintroduce foods in a systematic manner, minimising the risk of unnecessary dietary restrictions.

Nutritionist making salad as part of a healthy diet.

Making informed decisions about
food intolerance testing

In conclusion, while food intolerance testing may seem like a convenient way to identify problem foods, it’s important to approach these tests with caution. The scientific community is divided on the validity of these tests, and their reliability is often questioned. As a dietitian, I believe in taking a comprehensive approach to addressing food intolerances, which includes a thorough evaluation of symptoms, dietary patterns, and medical history. Working with a qualified professional, such as a dietitian, can provide personalised guidance and support for managing food intolerances. Whether you choose to undergo food intolerance testing or explore alternative approaches, the key is to make informed decisions that are best suited to your individual needs and circumstances.

Remember, managing food intolerances is not a one-size-fits-all approach. Take the time to understand your body, seek professional guidance, and be patient with the process. With the right support and knowledge, you can navigate your food intolerances and improve your overall well-being.

Frequently Asked Questions

Food intolerance refers to difficulty digesting certain foods. Unlike food allergies, which involve the immune system, food intolerance typically involves the digestive system and can cause symptoms like bloating, gas, and stomach pain.

Food allergy and food intolerance are often confused, but they differ in their underlying mechanisms and the body’s response. A food allergy involves the immune system reacting to a specific food, leading to symptoms such as hives, swelling, difficulty breathing, or even life-threatening anaphylaxis. On the other hand, food intolerance does not involve the immune system; it’s a digestive issue where the body has difficulty digesting certain foods, resulting in symptoms like bloating, gas, stomach pain, diarrhea, or headaches. Understanding this distinction is crucial for accurate diagnosis and appropriate management of these conditions. 

Identifying food intolerance can be challenging as symptoms can vary widely and may overlap with other conditions. Keeping a food diary and noting symptoms can be helpful, but it’s best to consult with a healthcare professional for accurate diagnosis.

While there are several tests available, including blood tests and elimination diets, their reliability is often questioned. Many healthcare professionals argue that these tests may yield false positives and unnecessary dietary restrictions. It’s best not to buy the tests as they can be expensive and not accurate. 

Unfortunately, the accuracy of many food intolerance tests is poor. Studies have shown that these tests often produce inconsistent results and may not correlate with clinical symptoms.

Home testing kits are not accurate for food intolerance and their reliability is often questionable. These tests may lack scientific validation and could lead to unnecessary dietary restrictions.

Managing food intolerance often involves keeping a food diary, avoiding trigger foods based on observed reactions, and maintaining a balanced diet. Consulting with a dietitian or nutritionist can also provide personalised guidance.

Relying solely on food intolerance tests without medical supervision can lead to unnecessary dietary restrictions, nutritional deficiencies, and psychological distress. It’s crucial to approach these tests with caution and seek guidance from qualified healthcare professionals.

Alternatives to formal testing include keeping a detailed food diary, undergoing an elimination diet under the supervision of a healthcare professional, and seeking advice from a registered dietitian or nutritionist. These approaches often provide more personalised and reliable results compared to standardised tests.

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