Think You Have A Food Intolerance? Symptoms, Diagnosis, And Healing

Food Intolerance Vs. Food Allergy

The difference between a food intolerance and a food allergy is that allergies flare up as a reaction from your immune system. Intolerances, on the other hand, impact your gut health due to non-immune factors.

I’ll give you a little more detail on the differences.

Food Intolerances

Also known as food sensitivities, intolerances don't involve a direct immune system response but instead impact the health of the gut. Usually, this happens because your body has trouble digesting certain foods or becomes irritated by them.

Symptoms include gastrointestinal bloating, abdominal pain, and nausea. A bigger amount of the food may lead to more severe symptoms or quicker onset.

Intolerance triggers may crossover with common food allergens, such as dairy and eggs.

Intolerances can be a result of enzyme deficiencies, poor gut permeability, inflammation, and even genetics. For example, lacking the lactase enzyme is how people with lactose intolerance cannot digest lactose, which is common in cow’s milk. (1)

Related: All About Salicylate Sensitivity 

Food Allergies

True food allergies come from an immediate and severe reaction of the immune system to some aspect of a particular food. Allergies may have similar symptoms to intolerances, but there are important differences. (2)

Symptoms of an allergic reaction can include:

• Rashes
• Itching
• Hives
• Runny nose
• Swelling
• Low blood pressure
• Anaphylaxis
• Difficulty breathing

While some foods may contribute to allergies or intolerances, some allergies, such as tree nut, shellfish, or peanut allergies, don't typically overlap with food intolerances.

Allergies can cause life-threatening reactions. Seek medical attention if you are having trouble breathing. Epipens contain epinephrine for quick relief, which is why physicians prescribe them for people with true food allergies. Allergy testing can help you identify what caused your reaction to prevent severe reactions in the future.

These Symptoms Might Signal Food Intolerance

In my experience with hundreds of patients, these are the most common food intolerance symptoms:

• Anxiety
• Arthritis
• Bloating
• Brain fog
• Cramping, bloating
• Constipation
• Diarrhea
• Eczema
• Fatigue
• Headaches/migraines
• Heartburn
• Hives
• IBS (irritable bowel syndrome)
• Inflammation
• Itching
• Joint pain
• Mood swings
• Muscle pain
• Nausea
• Rashes
• Sinus infections
• Skin flushing
• Stomach pain
• Sweating
• Vomiting
• Weight changes
• Wheezing

Common Types

The most common types of food intolerance I see in my patients are dairy and gluten, followed by other dietary triggers like foods that contain caffeine or histamine.

Foods that contain the following are the most likely to cause food intolerance symptoms:

• Dairy products
• Gluten
• Gluten-free grains, such as corn and buckwheat
• Caffeine
• Histamine
• Fructose
• Nightshades
• Legumes
• Nuts and seeds
• Amines
• Sulfites
• Yeast
• Eggs
• Alcohol
• Food additives, like coloring or preservatives
• MSG (monosodium glutamate)
• Sugar
• Sugar alcohols
• Artificial sweeteners
• FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols)

LISTEN: How FODMAP Intolerance & SIBO Hurt Our Mood & Gut Health + What To Do About It

Testing And Diagnosis

To begin the healing process, it’s important to find your baseline. If you think food sensitivity is a problem for you, lab tests will help determine both the root cause and specific sensitivity. Once we know the root cause, determining treatment is more effective.

Skin, breath, and blood tests are common for testing food intolerances and sensitivities. Here are just a few of the labs that I recommend for patients at my functional medicine clinic:

• Microbiome labs: This test will show you whether or not you have a bacterial imbalance in your gut. You may need to boost the good bacteria in your GI tract. Research has shown that imbalances can dysregulate the immune system and contribute to food intolerance. (3)
• Small intestinal bacterial overgrowth: SIBO occurs when bacteria overgrows in the small intestine. These bacteria end up consuming the foods you eat and will ferment in the wrong area of your gut, leading to gas, bloating, and, if untreated, leaky gut syndrome. We generally check for SIBO with a breath test.
• Leaky gut labs: These blood tests measure antibody levels to show if there has been damage to the gut lining.
• Zonulin and occludin tests: These two proteins control gut permeability. Antibodies indicate damage to intestinal tight junctions. Testing for zonulin and occludin checks for leaky gut syndrome that can lead to food intolerance.
• Actomyosin: Testing for this protein complex shows if there has been destruction of gut lining.
• Lipopolysaccharides: Testing for antibodies to these bacterial endotoxins in your gut can indicate leaky gut syndrome.
• Histamine intolerance: During an allergic reaction, your body releases chemicals known as histamines. This is a normal part of a healthy immune system. Certain foods naturally contain histamine or trigger the release of histamine. Some people, though, can have an overload of histamine due to a deficiency or dysfunction of the enzymes that break down histamine. This is known as histamine intolerance. It can create what is called a “pseudoallergy,” — an allergic reaction without an allergen.

LISTEN: Microbiome Masterclass: Healthy Guts, Histamine Intolerance, Candida, SIBO, FODMAPS + Food Sensitivities

How To Start Healing

The first thing I tell my patients to do is identify and eliminate the food that’s triggering the intolerance symptoms. However, an elimination diet is only the first step, and it’s not a long-term solution by itself. After identifying what’s causing the problem, there are also other ways to heal the gut in a way that may correct the problem from the inside out.

1. Try An Elimination Diet

The elimination diet is my gold standard tool for identifying food sensitivities. But it is a short-term healing tool — more for figuring out the underlying cause than for long-term treatment.

After getting tested, as I discuss above, remove the offending foods for a period of time (typically about 2-3 weeks), giving your gut a healing break. Slowly reintroduce the food, and you can gain insight into which foods cause a reaction for you.

Get access to my course on Mindbodygreen for how to do a 60-day elimination diet.

2. Eat A Variety

Eating a variety of vegetables, meats, and fruits will give your body a diverse range of nutrients. Everything in moderation is often better for your gut than an excess of anything. This variety will also keep your immune system balanced as you reintroduce certain foods. Talk to a dietitian about the best diet for your unique goals.

3. Amp Up Your Gut Healing

If you don’t work on healing your gut, it doesn’t matter how many elimination diets you do. Ultimately, you’ll be left fighting the same symptoms over and over. Let’s talk about ways I recommend healing your gut.

Once you have discovered the foods that need to be eliminated or reduced, you can begin to incorporate these next-level gut healers:

• Bone broth: This soothing food medicine will bring healing to damaged gut lining.
• Probiotics: Supplements in addition to dietary probiotics like fermented foods (think kimchi and sauerkraut) may restore imbalances in your gut microbiome by bringing good bacteria into your digestive tract. (4)
• Intermittent fasting: I often see great success with this functional medicine tool in my clinic. When you go for short periods of time without eating (12-16 hours a day), you give your digestion a much-needed rest while reducing gut inflammation.
• Cooked foods: By eating only cooked foods, you decrease the amount of work your digestive system needs to do to break the food down, decreasing intolerance symptoms. (5)

4. Reduce Inflammation

Leaky gut syndrome and other chronic conditions are just the severe end of a larger inflammation spectrum. This spectrum can be broken down into 3 stages:

1. Silent autoimmunity: There are no symptoms, but there are positive antibody labs.
2. Autoimmune reactivity: When there are some symptoms, as well as positive antibody labs.
3. Autoimmune disease: When there’s enough autoimmune damage to diagnose you with a specific condition.

Reducing inflammation is necessary for sustaining long-term gut healing. Below are some common ways to lower your inflammation levels.

• Consider anti-inflammatory supplements like curcumin, green tea, and ginger.
• Reduce stress levels. Your body’s stress response is meant for short-term danger, but chronic stress can wreak havoc on your gut and immune system.
• Eat anti-inflammatory foods, including omega-3 fatty acids, high-fiber fruits and vegetables, and leafy greens.
• Avoid inflammatory foods, such as trans fats and highly processed foods, even once your gut is healed. Some of these foods may be fine for your gut in moderation, but avoid excessive consumption of inflammation-promoting foods. Get used to reading food labels!

When To Call A Doctor

If you or a loved one experiences severe allergic reactions, such as swelling of the throat, dizziness, and vomiting, call 911. You may need immediate medical attention. Remember, allergies are different from intolerances or sensitivities.

If you have symptoms of food intolerance like bloating, bowel movement changes, or sweating, you don’t necessarily need to call the doctor right away. However, always consult your healthcare provider before implementing any new diet or supplement regimen.

As experts in gut health, my team and I provide thorough testing and labs to determine what issues may be the underlying cause of your food intolerance symptoms. We also provide expert treatment and advice on what will work best for your body's specific needs.

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe.

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