Adverse Food Reactions

There are a lot of terms out there for abnormal reactions to food – food allergies, food intolerances, food triggers, and food sensitivities. So what’s the difference?

Food Allergy

A food allergy is probably the most well-known food reaction but is also the least common - and most dangerous. When you eat a food you’re allergic to,  your body’s mast cells (part of your immune system) sense the presence of that food by using IgE antibodies. 

The mast cells then sound an alarm that can cause hives, swelling, itchy eyes, a scratchy throat, and in severe cases anaphylaxis. This reaction is due to the release of histamine, which is why you take an antihistamine like Benadryl to get rid of allergy symptoms. 

If you are allergic to a food, you must avoid eating it to prevent adverse reactions. Food allergies likely aren’t causing your migraine symptoms, but if you suspect you have a food allergy it’s a good idea to see an allergist for further testing. 

Food Intolerance

A food intolerance does NOT involve your immune system. Instead, an intolerance is caused by difficulties breaking down food, which can cause diarrhea, gas, bloating, and other uncomfortable GI symptoms. One of the most common intolerances is lactose intolerance, caused by a deficiency in the enzyme lactase. 

Intolerances likely don’t have much to do with migraine, as the symptoms are seen only in your gut. If you suspect you have a food intolerance, avoiding that food and seeing if symptoms improve is often all the treatment that’s needed. Unlike a food allergy, you may be able to eat a small amount of the food you’re intolerant to without experiencing symptoms.

Food triggers

Food triggers that contribute to migraine pain can be foods like chocolate, red wine, and aged cheese. It is thought that they might trigger migraine symptoms because they contain natural excitotoxins, or foods that can overstimulate your nerve cells. Like intolerances, food triggers do not involve your immune system and you may be able to eat a small amount without experiencing symptoms.

Food Sensitivities

Food sensitivities, like food allergies, involve your immune system. A major difference between the two is that while allergies have an immediate and often severe effect, sensitivities can take hours to days to cause symptoms that are milder and somewhat vague. 

When you eat a food you’re sensitive to, your body’s white blood cells (part of your immune system) are triggered directly and sound the alarm, causing widespread inflammation and a range of symptoms. While food allergies involve IgE antibodies, food sensitivities involve IgG, IgM, or IgA antibodies, or even just the food particle itself!

Do I Have A Food Sensitivity?

Not everyone with migraine has food sensitivities, although it’s a lot more common than you might think. 

If food sensitivities are contributing to your migraine symptoms, you likely have other issues going on like eczema, brain fog, fatigue, fibromyalgia, IBS, achy joints, depression, diarrhea, anxiety, etc. Food sensitivities contribute widespread inflammation that can either cause these symptoms directly, or make conditions you’re genetically susceptible to (like migraine) spin out of control.

What causes food sensitivities?

While we don't have the exact answer to this question yet, it is likely due to an issue with gut health. The most widely accepted factors that are thought to contribute to food sensitivities include:

• Poor digestion of food
• Imbalanced gut bacteria
• Chronic stress
• Infections from parasites or h. pylori
• Low stomach acid
• Limited diet

What can I do about food sensitivities?

Doing testing and an elimination/reintroduction diet can be very helpful, but it's important to address the potential underlying issues of your food sensitivities to avoid developing more sensitivities in the future. Working on improving the diversity of your diet, reducing stress, correcting imbalances, and getting rid of infections can all be great steps to take to eliminate food sensitivities.

Not sure where to start with this? A registered dietitian who specializes in food reactions can help you. I do NOT recommend using the food sensitivity tests available through the internet that test IgG - these are not helpful and can lead you in the wrong direction.