The 101 on Food Allergy vs. Intolerance vs. Sensitivity

Your stom­ach starts grum­bling just think­ing about a greasy cheese­burg­er. A carb fest leaves you feel­ing exhaust­ed for sev­er­al days. You won’t even touch a peanut but­ter cup for fear that you will end up in the hospital. 

Chances are that you already know if you can’t eat cer­tain foods, whether it’s because they just don’t sit well with you or because your reac­tion could be life-threat­en­ing. But do you know if what you have is a food aller­gy, an intol­er­ance, or a sensitivity?

The terms ​“aller­gy,” ​“intol­er­ance,” and ​“sen­si­tiv­i­ty” are often used inter­change­ably, but they are actu­al­ly very dif­fer­ent from one another. 

Food Aller­gies and Intol­er­ance in the US

• 20% have a food intolerance
• About 50 mil­lion Amer­i­cans have a food allergy
• 51% of adults and 42% of chil­dren with a food aller­gy expe­ri­ence a severe reaction

Here’s the low-down on the dif­fer­ences between the three and what they might mean for your food choices.

Food Aller­gy vs. Intol­er­ance vs. Sen­si­tiv­i­ty: The Dif­fer­ences Between…

What’s Hap­pen­ing in Your Body?

One of the biggest dif­fer­ences between aller­gies, intol­er­ances, and sen­si­tiv­i­ties is where and how they affect your body.

Food aller­gies affect your immune sys­tem. When the aller­gen (what you’re aller­gic to) enters your body, your immune sys­tem mis­takes it for a threat and begins to attack. This can cause seri­ous symp­toms, like itch­i­ness or swelling on your skin, vom­it­ing, or diarrhea. 

In severe cas­es, an aller­gy can lead to a life-threat­en­ing reac­tion called ana­phy­lax­is. Symp­toms of ana­phy­lax­is include:

• Dif­fi­cul­ty breathing
• Dizzi­ness
• Rash or hives
• Loss of consciousness
• Swelling of the throat, lips, or tongue

If you expe­ri­ence these symp­toms, call 911 immediately. 

Food intol­er­ance affects your diges­tive sys­tem and occurs when your body has trou­ble digest­ing cer­tain foods or ingre­di­ents. A food intol­er­ance can cause mild symp­toms such as:

• Nau­sea
• Heart­burn
• Bloat­ing
• Upset stom­ach and pain
• Diar­rhea
• Gas and bloating

Food sen­si­tiv­i­ties are a bit of a hybrid, and it’s not 100% clear what hap­pens in your body if you have one. Some researchers believe that cer­tain food sen­si­tiv­i­ties are immune sys­tem respons­es but that they are slow­er than aller­gic respons­es and are fre­quent­ly due to a prob­lem with your diges­tive tract. When you eat a food that you have a sen­si­tiv­i­ty to, you may notice symp­toms like joint or stom­ach pain, fatigue, rash­es, or brain fog. While these symp­toms can be dis­rup­tive, they are not life-threatening. 

What Hap­pens if You Eat a Small Amount?

Between aller­gies, intol­er­ances, and sen­si­tiv­i­ties, aller­gies are the only reac­tions ones that can be fatal. Eat­ing just the tini­est amount of the aller­gen can spark a severe reac­tion. Because of this, it’s cru­cial to com­plete­ly stay away from the aller­gen and to avoid cross-con­tact (also called cross-con­t­a­m­i­na­tion), where the aller­gen acci­den­tal­ly comes into con­tact with your food.

Also, sim­ply touch­ing an aller­gen or inhal­ing the scent can cause at the reac­tion. Depend­ing on the sever­i­ty of your aller­gy, you might be at risk just by being near the allergen.

When it comes to intol­er­ance or sen­si­tiv­i­ty, you have a bit more free­dom. Many peo­ple can eat a lit­tle bit of the food and have lit­tle to no symp­toms. If you do have symp­toms, they aren’t life-threat­en­ing, so it’s noth­ing to pan­ic about. Whether or not you choose to sac­ri­fice a stom­achache for a slice of piz­za or a choco­late bar real­ly depends on how bad you feel after eat­ing it and if you’re will­ing to do it. 

You also don’t need to wor­ry about cross-con­t­a­m­i­na­tion or acci­den­tal­ly get­ting a whiff of the food. The amount you would get into your sys­tem from that would be small, so it might not cause a reac­tion. Even if you do get a lit­tle bit into your sys­tem, you won’t have a life-threat­en­ing reac­tion if you don’t have an allergy. 

Med­ica­tions and Treatment

If you have a severe aller­gic reac­tion, no over-the-counter antacid or med­ica­tion is going to cut it (although an anti­his­t­a­mine might help relieve itch­ing or con­ges­tion). You will need life­sav­ing care, like an epi­neph­rine or adren­a­line injec­tion. If you have a severe reac­tion, call 911 immediately.

On the oth­er hand, non-aller­gic respons­es can some­times be treat­ed or pre­vent­ed with med­ica­tion. For exam­ple, if you have lac­tose intol­er­ance, over-the-counter lac­tase enzyme prod­ucts (e.g., Lac­taid®) could allow you to occa­sion­al­ly eat your favorite ice cream or chow down on mac and cheese with­out prob­lems. Bis­muth sub­sal­i­cy­late (e.g., Pep­to-Bis­mol®) could help relieve diar­rhea or stom­achaches if you do have symptoms. 

Spot­light on Gluten

One of the biggest sources of con­fu­sion when it comes to this top­ic is gluten. The term ​“gluten-free” has tak­en the world by storm, with many peo­ple say­ing that they can’t eat gluten or that they are aller­gic to it. 

There are three main con­di­tions that can make some­one unable to eat gluten: Celi­ac dis­ease. This is an immune sys­tem dis­or­der. Acci­den­tal­ly eat­ing some­thing with gluten is high­ly unlike­ly to be dan­ger­ous. How­ev­er, cross-con­t­a­m­i­na­tion is still a con­cern. Even just crumbs can cause inter­nal dam­age to the diges­tive tract or bring on uncom­fort­able symptoms.

• Gluten sen­si­tiv­i­ty. When it comes to gluten, ​“sen­si­tiv­i­ty” and ​“intol­er­ance” may be inter­change­able. The exact cause is unknown. It doesn’t cause the same type of dam­age to the diges­tive sys­tem as celi­ac dis­ease, but it can cause severe symp­toms. Cross-con­t­a­m­i­na­tion is not an issue for gluten sensitivity. 
• Wheat aller­gy. It’s impos­si­ble to be aller­gic to gluten, so peo­ple who say they have a ​“gluten aller­gy” might actu­al­ly have an aller­gy to wheat – which con­tains gluten. Like oth­er food aller­gies, a wheat aller­gy can cause symp­toms, like hives or swelling in the throat, and can become life-threat­en­ing. Because of that, it’s crit­i­cal to avoid cross-con­t­a­m­i­na­tion with wheat. 

Whether you have an aller­gy, intol­er­ance, or sen­si­tiv­i­ty, your Quin­cy Med­ical Group provider can help you under­stand what trig­gers a reac­tion and how you can man­age your con­di­tion or symptoms.