Food Intolerance

Food intolerance happens when your body repeatedly reacts to a certain food or ingredient. It’s very common. Unlike a food allergy, it doesn’t involve your immune system. Instead, it’s linked to your digestive system. The condition can start at any point in your life. Another name for it is food sensitivity.

Food intolerance isn’t usually life-threatening. But it can still have a big impact on your health and quality of life. It can cause ongoing symptoms like diarrhea, belly pain and bloating. Over time, this can affect your nutrition and gut health.

Food intolerance is typically a long-term condition. But you can manage it. Treatment focuses on finding and limiting trigger foods. But you still need to get enough nutrients. Work with a healthcare provider or a dietitian. They can help you find the right balance.

What are the most common types of food intolerance?

Common food intolerances include:

• Lactose intolerance: This is the most common type. It happens when your body doesn’t make enough lactase. Lactase is the enzyme that breaks down lactose (a sugar in dairy).
• Histamine intolerance: Histamine is a chemical your body naturally makes. But it’s also in foods like aged cheese, chocolate and some fruits (like bananas). If your body doesn’t make enough diamine oxidase (an enzyme) to break it down, histamine can build up.
• Gluten intolerance: Gluten is a protein in wheat, rye and barley. Gluten sensitivity isn’t the same as celiac disease (an autoimmune disease). If you’re gluten intolerant, your body has a hard time breaking down gluten.
• FODMAP intolerance: FODMAPs are a type of carb. They’re in foods like beans, onions, garlic, some fruits and dairy. They may be hard to digest.
• Fructose intolerance: Fructose is a natural sugar. It’s in fruit, honey and some sweeteners. Your small intestine may not be able to absorb it.
• Food additives and chemicals: You may be sensitive to certain ingredients like caffeine or sulfites (in wine and dried fruit).

Symptoms of food intolerance

Food intolerance symptoms usually affect your digestive tract. They often come on slowly. They may develop hours after you eat a trigger food. In many cases, symptoms depend on how much of the food you eat. Common signs of food intolerance include:

• Abdominal (belly) pain or cramping
• Diarrhea
• Gas and bloating
• Nausea
• Heartburn
• Headaches or migraines

Food intolerance causes

People develop food intolerances for a variety of reasons. Causes may include:

• Enzyme deficiencies: Your body may not be able to digest certain foods if you lack specific enzymes. If you lack the lactase you need for dairy, it could lead to lactose intolerance.
• Sensitivity to food chemicals: Some people react to natural substances in foods. You may be sensitive to caffeine or histamine. Or you could be intolerant of an ingredient in chocolate.
• Reactions to food additives: Your body may respond to ingredients added to foods. Sulfites, artificial sweeteners and preservatives can trigger symptoms.
• Digestive system conditions: Conditions that damage your digestive system, like inflammatory bowel disease, may make you more sensitive to certain foods.

Risk factors

Risk factors include:

• Changes in gut bacteria: An imbalance in your gut microbiome can affect how well you digest carbs and other nutrients.
• Age: Some intolerances become more common as you get older. Enzyme levels naturally go down over time.
• Medications or illness: Certain infections, antibiotics or treatments can affect your digestive tract. They can trigger short- or long-term intolerance.
• Eating patterns: Eating lots of hard-to-digest foods may increase symptoms.

Complications of food intolerance

Possible complications include:

• Missing nutrients: Avoiding certain foods can make it harder to get important nutrients. If you cut out dairy, it may lead to low calcium and vitamin D. Avoiding grains with gluten may reduce fiber and B vitamins.
• Ongoing digestive symptoms: If you don’t find your trigger foods, symptoms can continue and affect your daily life.
• Unintended weight loss: Strict eating plans can lead to weight changes. Unbalanced plans mean you may not get enough calories.

How doctors diagnose food intolerance

There isn’t one simple food intolerance test. Instead, a healthcare provider will look at your symptoms and medical history. They’ll also want to know what you typically eat. Common ways to diagnose food intolerance include:

• Food diary: Your provider may ask you to track what you eat and any symptoms you have. This can help find patterns and possible trigger foods.
• Elimination diet: You take away certain foods from what you normally eat for a few weeks. Then, you slowly add them back in. If symptoms go away and return after bringing back a food, it may point to a food intolerance.
• Breath tests: A hydrogen breath test can help diagnose certain intolerances, like lactose or fructose intolerance. During the test, you drink a liquid that contains the suspected trigger. Then, you breathe into a device over a few hours. This measures gas levels.
• Medical check-up: Your provider may rule out other conditions, including a food allergy or celiac disease. These can cause similar symptoms.

There aren’t any standard skin or blood tests. That’s why tracking your symptoms and working with a provider are key.

How is food intolerance treated?

Treatment for food intolerance focuses on managing your symptoms and avoiding trigger foods. Common treatment options include:

• Changes to what you eat: You can remove, avoid or limit trigger foods. Work with a dietitian to create a balanced plan.
• Over-the-counter medicines: Antacids, anti-gas or anti-diarrheal products can ease some symptoms.
• Enzyme supplements: For lactose intolerance, lactase pills or drops can help you digest dairy products. Lactose-free milk and other products are also available.
• Tracking and adjusting: Keep a food diary and track your symptoms. This can help you find sensitivities. Then, you can change what you need to eat.

To avoid nutrient deficiencies, it’s important to eat as wide a variety of foods as possible while managing your symptoms. This may mean trying new foods to replace the foods you’re avoiding.

You can usually manage food intolerance with these steps. Unlike with food allergies, you rarely need prescription medicines.

When should I see my healthcare provider?

Contact your provider if you notice severe or ongoing symptoms, like:

• Extreme belly pain
• Persistent diarrhea
• Unexplained weight loss
• Unexplained anemia or iron deficiency

These could mean you have a more serious condition.

It’s also helpful to discuss your food intolerance with a provider. They can help you manage what you can eat. You might ask about:

• The specific type of food intolerance you have
• Foods or ingredients you should avoid
• Risks of nutrient issues or other health problems
• Signs of complications to watch for

Talk openly with your provider. They can help you manage your symptoms and prevent future problems. You can maintain a balanced eating plan while living with a food intolerance.

What can I expect if I have this condition?

Sometimes, food intolerances last a lifetime. But most people can manage their symptoms. Food intolerance is often related to how much you eat. So, you may be able to tolerate small amounts of a food as long as it stays below the level that triggers symptoms.

The symptoms can be unpleasant. But food intolerance isn’t life-threatening like a food allergy.