Lactose intolerance is a widely known food sensitivity that affects many. Thanks to various lactose-free alternatives available on the market, a normal lifestyle isn’t hard to achieve.
And while it is not dairy, fructose has also been known to cause problems in some people.
Fructose is a simple sugar that naturally occurs primarily in fruits but also in vegetables and honey. Fructose intolerant patients are unable to digest or absorb fructose.
“Fructose intolerance, or hereditary fructose intolerance (HFI), is a genetic condition usually diagnosed at a young age,” said Amberly Malone, a clinical dietitian at AdventHealth-Central Texas in Killeen. “Doctors can use a liver biopsy or feeding test to determine if a child has HFI, but DNA tests are the preferred method since they are less invasive and safer.”
Patients usually develop signs of the disorder in infancy when fruits, juices or other foods containing fructose are introduced into their diet. Symptoms of intolerance include bloating, abdominal pain and diarrhea but can become severe.
“Those with HFI cannot breakdown fructose correctly, so fructose will begin to accumulate in the liver and kidneys, which can cause major complications or even death if not treated,” Malone said. “It is important for those with HFI to follow a strict fructose-free diet, which means no fruit, high-fructose corn syrup or sugar alcohols like sorbitol.”
According to information from the U.S. National Library of Medicine, hereditary fructose intolerance affects 1 in 20,000 to 30,000 individuals each year worldwide.
While HFI is the most severe form of fructose intolerance, it is not the most common one.
Fructose malabsorption, a condition that is not genetically caused, affects approximately 40% of individuals in the Western hemisphere.
While its exact cause is unknown, a patient’s intestines’ cells cannot absorb fructose naturally, leading to bloating, diarrhea or constipation, flatulence and stomach pain.
“Fructose malabsorption can mimic other food intolerance symptoms, so the gold standard for diagnosis is following an elimination diet and keeping a food journal,” Malone said. “If an individual truly has fructose malabsorption, they will want to limit but not eliminate foods containing fructose in their diet.”
Since patients with fructose malabsorption are often experiencing other food sensitivities, following a so-called low FODMAP diet can be beneficial for minimizing symptoms.
The term FODMAP stands for fermentable oligo-, di-, mono-saccharides and polyol, and classify
groups of carbs that are known for triggering digestive symptoms like bloating, gas and stomach pain.
While FODMAPs are found in a wide range of foods, navigating food sensitivities can be complicated. It is beneficial for patients to follow a new diet alongside a qualified professional, like a physician or registered dietitian.