Sucrose Intolerance: What You Need To Know

It was almost immediate: the scratching, the flaking, the skin irritation — whenever I’d have candy or ice cream or sometimes even bread. For a long time, I thought I was allergic to gluten. But as I paid more attention and tried different diets like the elimination diet, I discovered what I had was an intolerance to table sugar — which is in everything, even most breads, like Wonder Bread, the one I grew up eating my bologna sandwiches on as a kid.

For me, any symptoms that didn’t appear immediately would appear within 24 hours of eating candy or a product with sugar in it. My scalp would itch, then large, scaly flakes would appear, a dermatitis of sorts, and then I’d scratch, sometimes until I bled. What I discovered when I stopped eating foods like my beloved taffy, or pairing Twizzlers with my buttery popcorn at the movies, is that my skin cleared up, I itched less if at all, and my belly felt better. Sucrose intolerance is a real thing, and here’s what you need to know about it.

Sucrose intolerance is known by many names: sucrase-isomaltase (SI) deficiency, disaccharide intolerance, Congenital Sucrase-Isomaltase Deficiency (CSID), or Genetic Sucrase-Isomaltase Deficiency (GSID), and it’s a commonly misdiagnosed disorder. Sucrose intolerance is caused by the slow activity of sucrose enzymes and isomaltase, which are responsible for absorbing sugar (like table sugar, or the sugars in starchy food). Sucrose intolerance can develop in your body or you can be born with it. When the breakdown and absorption of sucrose is impacted, other nutrients have a difficult time absorbing in the body.

In the United States, 80% of people who suffer with gastrointestinal issues do so because of sucrose intolerance. Once sugar and starches make their way into the large intestine, bloating, gas, abdominal pain and watery stool are all symptoms of CSID. In kids, symptoms show up as chronic colic, gassiness, abdominal pain, vomiting, diaper rash, and more. Sucrose intolerance is a lesser-known disorder and therefore is often misdiagnosed in children by healthcare professionals.

Like other gastrointestinal disorders such as lactose intolerance, which affects 25% of people in the United States, sugar intolerance symptoms are similar to lactose intolerance symptoms. Common symptoms such as gas, bloating, loose stool, or constipation can lead to a misdiagnosis — instead of an adult being diagnosed with sucrose intolerance, they’d receive a diagnosis of IBS.

But people who suffer from lactose intolerance can buy lactose-free milk or pop an over-the-counter pill to manage their symptoms. Someone suffering with symptoms of a sugar intolerance or Congenital Sucrase-Isomaltase Deficiency (CSID) cannot manage it so easily. We often just learn to live with the symptoms, like I have for much of my life.

In an article for Forkly, Canada-based nutritionist and food writer Marjan Mogharrabi points out just how many foods in our daily diets — even ones we don’t think of as “sugary” — can cause these discomforts. “[I]n a given day, we’re eating lots and lots of these foods: bread, grains, dairy products such as milk and cheeses, chickpeas, beans and legumes, potatoes, squashes, fruit, and then actual sugar and sweeteners like white and brown sugar, maple syrup, honey…GAAHH! It’s just too much for our poor bodies to process every single day.”

If you suspect or are diagnosed with sucrose intolerance, there are a few minor changes you can make that might bring some relief. You can swap out sugary fruits like apples and grapes for fruits low in sucrose like kiwi, strawberries, and peaches. It is suggested that you try the elimination diet for at least four weeks and keep tabs on how, or if, your symptoms change. Read the labels on every food you eat and keep track of what you’re eating.

Here is a healthful meal plan to get you started on a low sucrose diet. Of course, as with all suggested diets, it’s always best to check with your healthcare provider before you make any big changes.

The best defense we have against uncomfortable symptoms is to understand our own bodies. We need to pay attention to the way our bodies feel every time we eat a food, especially a new food. We should never be comfortable with feeling uncomfortable.