Have you ever had a painful stomach ache or felt lethargic and icky after eating something sugary? You’re not only one. But are those symptoms of a sugar allergy or something else?
In many cases, feeling crappy post-sweets is really just a “sugar hangover” that happens if you eat a ton of sugar, thanks to how loads of it at once can make your blood sugar spike, then crash and burn. But some people are super sensitive to even a smaller amount of the sweet stuff.
Yep, you can you be intolerant to sugar—or even have a real sugar allergy, in very rare cases. It sounds extreme, but different types of sugar can definitely affect people, experts say. “Sugar as a substance has a real impact on people, psychologically and physically,” New York City-based registered dietitian Jessica Cording tells SELF.
And there are actual symptoms of a sugar allergy or intolerance, so keep reading to learn the signs to watch out for.
Symptoms of a sugar allergy will typically show up immediately.
People with a true sugar allergy would usually have immediate physical symptoms that are similar to those of other food allergies. According to certified dietitian-nutritionist Lisa Moskovitz, R.D., CEO of NY Nutrition Group, those symptoms include:
- Skin rash
- Itchy mouth
But there’s a difference between a food allergy and a food intolerance.
Everyone has certain foods that just don’t sit right with them, or that cause not-so-desirable symptoms like indigestion, bloating, or cramping. But that doesn’t necessarily mean you have a true allergy to that food or ingredient. And while some people use the terms interchangeably, a food allergy and a food intolerance are actually two different things. Here’s the difference:
Food allergy: This is a reaction that occurs when your immune system overreacts to a food protein, thinking that it’s a harmful substance, Food Allergy Research & Education (FARE) explains.
Symptoms of a food allergy can range from mild to life-threatening, FARE says, and can include:
- Abdominal pain or cramping
- Trouble breathing
Food intolerance: Having an intolerance to a food or ingredient means that you have trouble digesting whatever that food is. In general, a food intolerance causes digestive issues, and the symptoms are not as severe as those of a food allergy, the Mayo Clinic says.
There are a variety of reasons that you could be intolerant to a particular food. Sometimes, it’s a result of your body not producing an enzyme necessary to break that food down (e.g. if you’re lactose intolerant, you lack the enzyme lactase that’s needed to break down lactose, the sugar in milk). Other times, it has to do with an underlying health condition, like irritable bowel syndrome (IBS), or even stress or anxiety, the Mayo Clinic says.
According to the American Academy of Allergy, Asthma, and Immunology (AAAAI), symptoms of a food intolerance include:
- Intestinal gas
- Abdominal pain
It’s easy to confuse the two because the symptoms can overlap (e.g. diarrhea, abdominal pain). But a major difference is that food intolerances are not the result of an immune system dysfunction. What’s more, people with food intolerances may be able to have a small amount of the food without any issues (or they can take something to help aid digestion), whereas with an allergy, you generally can’t have any of the food allergen.
It’s more common to have a sugar intolerance than a sugar allergy.
People are usually intolerant to certain types of sugars, rather than all sugars, says Moskovitz. Those with a sugar intolerance may just have the gastrointestinal symptoms mentioned above, possibly in addition to fatigue, some time after eating the sugars they are sensitive to, she adds.
These are the main types of sugar that may cause intolerance or sensitivity.
Fructose is naturally found in foods like fruits, some veggies, honey, and some fruit juices, the Mayo Clinic says. It’s also in table sugar as well as high-fructose corn syrup.
This is a sugar that’s found in milk and other dairy products. If you’re lactose intolerant, you can’t properly digest lactose, so you end up with those unwanted GI issues. (Reminder: This is not the same thing as a milk allergy, which means your immune system has a response to the proteins in milk.)
Sucrose is derived from sugarcane and is the type that makes up table sugar.
You’ve probably seen ingredients like erythritol or xylitol on food labels. These are actually sugar substitutes that are used in many low-calorie or sugar-free food items. But they’re worth bringing up in this context, given that they can cause GI issues for many people. They can also, in more rare cases, cause allergic reactions for some, as SELF reported previously.
In some cases, however, it may not be sugar on its own that’s the real issue.
“If someone describes a sugar intolerance, it's most likely an underlying issue that is being exacerbated by consuming foods with sugar,” says registered dietitian nutritionist Beth Warren, founder of Beth Warren Nutrition and author of Living a Real Life With Real Food.
Instead, the problem may be a microbial imbalance in the gut with an overgrowth of yeast. Since yeast feeds on sugars, it could exacerbate the problem, causing symptoms like skin rashes and puffiness, she says.
Here’s how to relieve symptoms of a sugar allergy or intolerance.
Cases of an allergic reaction to sugar are rare, but they do happen. If you have an immediate reaction after consuming sugar—your throat feels tight, you're having trouble breathing, you break out in a skin rash, etc.—you should visit your doctor or the emergency room. In severe cases, an allergic reaction could progress to anaphylaxis if not addressed quickly and early. And if you're unsure at this point whether or not you have this type of allergy (or whether it's life-threatening or not), it's safer to err on the side of caution.
In severe cases, you may be treated with epinephrine (a medication that can reverse anaphylaxis) and then possibly a steroid (like cortisone) to reduce inflammation and get the reaction under control, FARE says. Epinephrine is generally harmless, so even if it's unclear how severe your allergy is, it's safe to use, FARE explains.
If your allergic reaction is more mild, you may just need an antihistamine, FARE says. From there, your doctor or an allergist/immunologist may want to conduct skin-prick tests to pinpoint the cause of the reaction and determine if sugar is indeed the culprit. If you are diagnosed with a severe sugar allergy, you will likely need to carry an epinephrine auto-injector (EpiPen) with you in case of emergency.
If you notice that you’re having GI symptoms after eating sugar that don't seem immediate or severe, Cording recommends cutting out added sugars, as well as white bread, white flour, energy drinks, fruit, and fruit juices. “Some people do well cutting out alcohol as well,” she says. She also encourages eating a lot of protein and making sure to have non-starchy vegetables, while avoiding potatoes and corn (the starches in them convert to sugar in your body).
Of course, you may not need to go that extreme with your diet. Registered dietitian-nutritionist Karen Ansel tells SELF that it's a good idea to try to narrow down what type of sugar you think you're allergic or intolerant to. She recommends keeping a food diary and recording what causes flare-ups. "It's entirely possible that lactose may bother you but that other types of sugars are not a problem, or that too many sweets are causing you to break out," she says. Ultimately, it’s really a matter of figuring out what your body reacts to and how badly.
If you suspect you have a sugar allergy or intolerance, see your doctor to be sure.
“Any time you’re having these kinds of symptoms, it’s really important to check in with your doctor to makes sure there’s no underlying condition,” Cording says.