Mary Flemming, 19, was diagnosed with fructose malabsorption in 2013, but struggled with the symptoms for months before she was diagnosed.
Flemming said before her diagnosis she had sharp stabbing stomach pains and felt uncomfortable eating out in public because of the pain and bloating consuming food caused her.
“It was miserable not knowing what was wrong with me. All that I knew was that food was causing me to feel ill,” Flemming said.
Before her diagnoses she said she often missed school because of the pain fructose malabsorption caused her. Flemming said she was constantly worried about eating her next meal and having to excuse herself from the table during meals because the pain would be so intense that she would have to lie down after consuming fructose. She said the pain would occur sometimes an hour after she ate or drank something with fructose.
Fructose malabsorption is a digestive disorder where people have difficulty absorbing fructose in the small intestine. Fructose malabsorption is found in up to 30 percent of the population, said gastroenterologist Judy Davis, a clinical professor with the University of California San Francisco and doctor at the California Digestive Disease Center in Fresno, Calif.
People often misdiagnose fructose malabsorption as lactose intolerance or gluten intolerance because fructose malabsorption is not widely known, Davis said.
Claudia Thompson-Felty, a registered dietician and graduate assistant at Arizona State, said symptoms of fructose malabsorption include bloating, diarrhea and/or constipation, stomach pain, nausea and gas.
Pricilla Mendoza, a physician assistant with Dr. Davis’s office in Fresno, has seen an increase of people with this condition in the past couple of years.
According to the USDA, the total amount of added sugars and caloric sweeteners in the U.S. food supply grew 19 percent in the last 35 years.
“We are seeing more people coming into the office with this condition because fructose is being used a lot more frequently in foods and drinks,” Mendoza said.
This disorder doesn’t result in liver or kidney damage but can be bothersome, Davis said.
“Fructose malabsorption is a digestive disorder where the absorption of fructose is impaired due to lack of adequate fructose carriers in the small intestine,” Thompson-Fetty said.
Flemming said this condition makes social interaction uncomfortable for her because social interaction revolves around food.
“When I go out with a group and don’t eat with people I feel like it makes people uncomfortable. But I just don’t want to get sick. People don’t understand,” Flemming said.
Flemming said she struggled with the physical symptoms and was diagnosed with depression before she was diagnosed with fructose malabsorption.
“Before I knew about fructose malabsorption and what foods to avoid I would dread eating and lost weight. It wasn’t healthy. It affects your mood. It makes you miserable and moody. I also get really lethargic and just want to do nothing,” Flemming said.
Dr. Asia Muhammad, a gastroenterologist with Arizona Digestive Health in Mesa, Ariz., said people with fructose malabsorption are at a greater risk for depression. Flemming is being treated for depression.
Her other symptoms caused by fructose malabsorption include sharp stabbing pains in her stomach, bloating and nausea.
Davis said bloating from this condition is a result of fermentation in the small and large intestine. While stomach pain is due to muscle spasms.
“The pain at times makes me double over. There is no other word to describe it other than miserable. I now avoid the pain by avoiding trigger foods.”
Foods that trigger her symptoms include products with high fructose corn syrup, such as soda and syrup. Other trigger foods that make her ill include fruit high in fructose, such as apples and pears.
“Many people don’t know about this condition. Almost every time I go to eat with a group of friends I have to explain to them that I have fructose malabsorption,” Flemming said.
Flemming said she didn’t know about the condition until she was diagnosed with it through a hydrogen breath test in 2013 after experiencing symptoms for six months.
“I had no idea that fructose malabsorption was a thing. As soon as I knew what to avoid I felt a lot better. But in our society it is difficult to avoid foods with fructose,” Flemming said.
Flemming said she also has to avoid pizza and certain pastas because some sauces, along with bread, can contain high fructose corn syrup.
Lezli Stone, registered dietician with A & B Nutrition Education in Phoenix, said fructose malabsorption is prevented with a low fructose diet.
“Completely eliminating fructose from someone’s diet would be difficult. Although you can significantly reduce your fructose intake by following a low fructose diet. This is what most people with fructose malabsorption follow,” Stone said.
Davis said foods laden with fructose include foods with a high fructose-to-glucose ratio, many wheat products and artificially flavored foods.
Davis said examples of these foods include soda, cakes, syrup and bread.
“Foods containing sorbitol, present in some diet drinks and foods and other polyols (sugar alcohols), such as erythritol, mannitol, and other ingredients that end with -tol, commonly added as artificial sweeteners in commercial foods. For people with fructose malabsorption these foods should be avoided,” Davis said.
Fructose is a sugar that is naturally found in fruits, fruit juices, some vegetables and honey. Sucrose, also known as table sugar or white sugar, contains fructose, as well as high fructose corn syrup.
“I was surprised to learn that many products have high fructose corn syrup. Many people don’t expect bread to have high fructose corn syrup but many brands use it to replace sugar. I was also shocked to learn that some ketchup brands use high fructose corn syrup,” Flemming said.
Flemming said it can be difficult to avoid foods with mass amounts of fructose because many things are sweetened with artificial sweeteners.
“I am constantly checking labels for artificial sweeteners because sometimes it can be hidden in the label under different names such as corn sugar or glucose-fructose syrup. Food companies try to be tricky,” Flemming said.
Flemming said she always tries to be aware of what she is eating.
“At first it was a lot of trial and error. I would slip up and would get the sharp pains in my stomach. Then I would know that I couldn’t eat that food comfortably. Sometimes I still do consume foods that trigger my symptoms because the foods are hard to avoid. I get sick and I just deal with it,” Flemming said.
Fructose malabsorption is tested with a hydrogen breath test, said Mendoza, who conducts the test at Dr. Davis’s office in Fresno, Calif.
The test measures the amount of hydrogen in a breath. Initially a patient breathes into a bag and that breath is measured. The patient then consumes a drink containing water and a fructose mixture. Following that the patient then has their breath tested every 30 minutes for about three hours. The patient is tested for a spike in hydrogen breath levels, Mendoza said.
“Fructose that hasn’t been adequately absorbed from the small intestine is carried into the large intestine and osmotically reduces the absorption of water from the large intestine and is metabolized by normal colonic bacteria to short chain fatty acids and the gases hydrogen, carbon dioxide and methane. This abnormal increase in hydrogen is detectable with the hydrogen breath test,” Davis said.
Gastroenterologist Muhammad said another way to test for fructose malabsorption in a patient is to abide by a low fructose diet for about a week and then eat or drink something high in fructose.
Healthy people can consume about 25-50g of fructose per sitting. People suffering with fructose malabsorption, however, absorb less than 25g of fructose per sitting, Davis said.
Having fructose malabsorption consumes her life but she is thankful that she can control her symptoms, Flemming said.
“I am grateful that I know what makes me sick and that I know how to control my symptoms. I couldn’t imagine continuing to be sick all the time. Fructose malabsorption is a horrible condition to deal with,” Flemming said.