Food Intolerance Causes and Treatment: Genetic, Lifestyle, and Dietary Factors

Understanding food intolerance causes is key to managing uncomfortable symptoms. Food intolerance occurs when your body struggles to digest certain foods, leading to symptoms that, while usually not life-threatening like allergies, can range from mild discomfort to severe issues like bloating, nausea, and vomiting. Food intolerance is usually not severe or life-threatening, unlike a food allergy reaction, but it can be mild to extremely uncomfortable.

For instance, suppose you are lactose intolerant, and if you drink milk or consume milk products, you will experience gas and stomach cramps after a few hours. It happens because your body is not able to break down the lactose. Common food intolerance symptoms include gas, bloating, stomach pain, nausea, diarrhea, headache, and tiredness, but it is also essential to learn how to manage food allergies.

On the other hand, a food allergy is when your body feels that a certain food you eat is dangerous and attacks it. Food allergy not just affects your stomach, but the whole body, and it can also be life-threatening.

For instance, suppose you are allergic to peanuts; in that case, even a tiny bite of a peanut can make you experience a severe allergic reaction and breathing issues. Common symptoms include swelling around the eyes, lips, or tongue, itchy skin, trouble breathing, dizziness, vomiting, and can lead to a medical emergency.

When you know the root cause, you know exactly what is causing the problem, and you don’t need to keep guessing to contribute to better health. In case of food allergies, some can cause severe symptoms or be life-threatening even with a tiny amount of problematic food.

So when you know the root cause, you can avoid severe reactions and carry the essential medication with you. Food intolerance can be managed with smaller portions of specific foods and enzyme pills, while those with food allergies may need to avoid multiple foods altogether. 

While food allergies can be managed by strictly avoiding the problem food, knowing the essential medications is also important.

Food intolerance can be caused by various factors, including insufficient digestive enzymes. Here are the general causes of food intolerance that you must be aware of:

Your body requires specific enzymes to break down the food properly. When you don’t have enough enzymes, your body can not digest certain foods well. For instance, lactose intolerance means low lactase enzyme in the body. If your body doesn’t have enough lactase, you can not digest the lactose and experience stomach pain, gas, and bloating.

Some individuals react to certain natural components, such as common food allergens like gluten, additives, histamine, caffeine, and salicylates. Consuming these components can trigger food allergy symptoms such as stomach upset, headaches, and rashes.

Some gut health concerns, such as leaky gut, imbalanced gut bacteria, infections, dysbiosis, and irritable bowel syndrome, make your gut more sensitive to certain foods. Your gut is not able to tolerate foods that you used to tolerate well earlier.

Some environmental factors (air, water, weather, chemicals), stress, antibiotics, and certain other medications can affect the immune system and make your body intolerant to certain foods. Lifestyle choices such as what you eat, physical activity, and alcohol or smoking can also make your body intolerant to certain foods.

Here are the different types of food intolerance, along with their triggers and symptoms, offering a thorough understanding, which can be useful for maintaining a food and symptoms diary.

Lactose intolerance is caused by inadequate lactase in your body, the enzyme that is responsible for lactose breakdown. This type of intolerance is triggered by milk and milk products. Common symptoms of lactose intolerance include gas, stomach pain and cramps, bloating, nausea, and diarrhea, which are also typical symptoms of a food allergy.

Gluten intolerance or non-celiac gluten sensitivity occurs when the body is unable to digest gluten, the protein found in wheat, rye, and barley. Common symptoms include stomach pain, bloating, joint pain, fatigue, headaches, and brain fog.

Fructose intolerance is a type of malabsorption that occurs when your body is unable to absorb fructose well. Common symptoms of fructose intolerance include bloating, gas, diarrhea, nausea, and stomach pain.

Histamine intolerance occurs when your body finds it difficult to break down histamine, a natural compound found in some food items. The common symptoms of histamine intolerance are anxiety, digestive concerns, low blood pressure, and a runny nose, which can sometimes mimic a true food allergy.

When the body is sensitive to caffeine, which is a stimulant, it's called caffeine intolerance. Common symptoms of caffeine intolerance are nausea, insomnia, anxiety, rapid heartbeat, and restlessness.

Refer to the chart mentioned below to get a clearer picture of different types of intolerances, their causes, and symptoms:

When your digestive system has difficulty digesting lactose, a natural sugar found in milk and dairy products, the condition is called lactose intolerance. The body can't digest lactose when it lacks the lactase enzyme. Lactase is produced in the small intestine and is responsible for the breakdown of lactose.

Some people are born with lactose intolerance due to inherited lactase deficiency. It is passed down by parents through genes. In case your parents or grandparents are lactose intolerant, there is a greater chance that you will be lactose intolerant.

Non-genetic lactose intolerance occurs due to certain damages in the body that reduce the body’s immune system response and ability to produce lactase, which is essential to digest lactose (milk sugar). Non-genetic causes include aging, temporary inadequacy of lactase due to illness, and intestinal damage.

Infection of Illness: Some temporary or long-term illnesses and infections, such as food poisoning and gastroenteritis, can damage the small intestine lining that produces lactase, causing temporary lactose intolerance.

Intestinal Conditions: The health issues that affect the small intestine can significantly reduce the production of lactase. For instance, parasitic infections, Celiac disease, ulcerative colitis, and Crohn’s disease can cause lactose intolerance.

Injury and Surgery: In case your small intestine is damaged due to injury or surgery, it may become unable to produce enough lactase. Usually, it happens after bowel surgery and cancer treatments.

When certain things that induce lactose intolerance or make it worse are called trigger causes. Triggered causes of lactose intolerance include medication or antibiotic-induced intolerance, which can lead to allergic reactions. Some antibiotics may destroy the good bacteria in the gut, reducing the lactose breakdown.

Some infections, such as gastroenteritis, a type of stomach flu, can negatively impact the intestinal cells that are responsible for lactase production. These infections can trigger lactose intolerance, causing short-term lactose intolerance.

Here are the most common foods and triggers that cause intolerance in most people:

Milk and other dairy products, such as curd, cheese, buttermilk, and ice cream, that contain lactose cause lactose intolerance in many people.

Gluten-containing foods such as bread, pasta, cereal, baked goods, and crackers are linked with most food allergies and cause gluten intolerance in many people. Gluten causes problems in individuals suffering from Celiac disease and non-celiac gluten sensitivity.

FODMAPs are carbohydrates that might be difficult to digest by the body. These types of carbohydrates are found in onions, beans, garlic, lentils, milk, yogurt, sweeteners, apples, awtermelona nd pear. These foods cause intolerance because they are fermented in the gut and lead to gas.

Some preservatives, artificial colors, MSG, wine, dried fruits, packed foods, and bottled lemon or lime juice can cause intolerance in some people. These foods and ingredients cause sensitivity in certain people.

Caffeine is a stimulant found in coffee, tea, energy drinks, and chocolates etc, which causes intolerance in some people as they are sensitive to stimulants.

The small intestine produces an enzyme called lactase that is essential for the breakdown of the milk sugar called lactose. Certain medical conditions and illnesses can affect the intestines, reducing the lactase production that leads to lactose intolerance. Similarly, certain diseases can cause food intolerance in people.

Let's understand bout the disease and medical conditions associated with food intolerance:

It's an autoimmune disease where your immune system detects certain foods as harmful and attacks them. If patients with celiac disease eat gluten-containing foods, it causes symptoms of intolerance.

It's an inflammatory bowel disease that influences the digestive tract. The inflammation in your small intestine reduces the production of the lactase enzyme, leading to long-term lactose intolerance.

It’s a kind of stomach flu that is caused by a bacteria or virus that inflames the lining of the gut. The infection causes temporary damage to the intestinal part that produces lactase, leading to temporary lactose intolerance.

It’s a common digestive disorder that causes symptoms such as bloating, cramps, and diarrhea. Patients suffering from irritable bowel syndrome are extremely sensitive to lactose, even when they are not actually intolerant. Lactose can trigger severe symptoms in these people.

Most types of food intolerance are manageable but not completely curable. Some food intolerances that are caused by gut damage or illnesses may improve with time or go away. 

Food intolerance can be easily managed by avoiding the trigger foods to reduce allergic reactions, taking enzyme supplements (on a doctor’s recommendation), healing your gut, and following your doctor’s or dietician’s meal plan and other recommendations.

Here is the reference table for a better understanding of what type of food intolerances can be cured and what can not:

Usually, food intolerance can not be cured completely, but it can be managed well, reducing the symptoms. The treatment involves avoiding or limiting the problematic or trigger foods, healing your gut, supporting digestion, and replacing the nutrients your body might be lacking.

Here’s the step-by-step guide to managing food intolerance efficiently, easing the associated symptoms:

• The first step is to identify the trigger food. For that, you can maintain a diary and note down the food you consume and the associated symptoms. If you find any trigger foods, avoid those foods and watch out for symptoms.
• Once you know the trigger foods or the foods that are causing the problem, limit that food or completely avoid it, depending on the extent of the symptoms.
• Some types of intolerances can be managed with over-the-counter enzyme medications. For example, lactose intolerance can be managed with lactase tablets or drops, histamine intolerance can be managed with DAO enzyme supplements, and fructose intolerance can be managed with Xylose isomerase.
• Pick the safe alternatives for problem food. For instance, if you are lactose intolerant, you can consider lactose-free milk or oat milk; if you are gluten intolerant, you can pick gluten-free bread; instead of FODMAPs, you can consider low-FODMAP fruits and vegetables.
• Consult your healthcare provider or an expert dietitian and get tested for food intolerance or other related diseases. They can help you create a safe and balanced diet and monitor possible deficiencies.

Food intolerance is a common problem that can be caused by genetic and lifestyle factors, certain health conditions, or other reasons. Some common types of food intolerances are lactose intolerance, gluten intolerance, and fructose intolerance. 

Food intolerances can not be cured but can be easily managed by avoiding the trigger foods, supporting healthy digestion, using supplements, and adopting healthy lifestyle habits.

Food intolerances may mimic gut issues or allergies such as celiac disease; thus, a healthcare professional can help figure out the causes and possible serious conditions. Professional guidance can help you manage your symptoms, diet, and nutrient deficiencies safely and efficiently.  

***Medical Disclaimer - The following information is for educational purposes only. No information provided on this website, including text, graphics, and images, is intended as a substitute for professional medical advice. Please consult with your doctor about specific medical advice about your condition(s).