Researchers have a new theory on why some kids get unexplained tummy aches.
In some people, the small intestine is unable to efficiently break down fructose (and sometimes other forms of sugar). This problem is sometimes referred to as fructose intolerance. The undigested fructose passes into the large intestine, where it is broken down by bacteria. A by-product of this process is the creation of carbon dioxide and hydrogen. These two gases build up in the intestine, causing bloating, gas, pain and diarrhea. In some cases, the problem can affect absorption of important nutrients, like calcium and iron.
Researchers estimate about 33 percent of Americans have some level of sensitivity to sugar, most commonly to fructose, but the symptoms are often vague. Some people with fructose intolerance can eat small amounts of the sugar and not have any problems, making diagnosis even trickier.
Daniel Lustig, M.D., Pediatric Gastroenterologist at Mary Bridge Children’s Health Center in Tacoma, WA, says patients with chronic digestive problems should have a physician’s evaluation to rule out other possible causes of the symptoms, like Celiac disease or Crohn’s disease. Once those conditions have been ruled out, he recommends a diagnostic tool called the breath hydrogen test.
A patient is given a dose of fructose. Then, periodically, he/she breathes into an air collection bag. The gases from the bag are retrieved and analyzed for the presence of hydrogen (one of the gases given off when fructose is broken down in the large intestine). Patients whose hydrogen levels exceed 20 points beyond a baseline reading are likely to be fructose intolerant.
Lustig explains the main treatment of fructose intolerance is avoidance of foods containing fructose. That includes fruits, fruit juices, sodas and processed foods and drinks with high fructose corn syrup. Since fructose is in so many foods, it can be tricky to find and hard to avoid.
Lustig recently performed a study to look at possible fructose intolerance in 245 children and adolescents (ages 2 to 18) with unexplained chronic abdominal pain, gas or bloating. The breath hydrogen test found that nearly 54 percent of the participants tested positive for fructose intolerance. Lustig says the problem appeared to be especially high among teen girls.
Those who were judged to be fructose intolerant were given advice on using a low-fructose diet. The investigators found that nearly 68 percent of those who followed the recommended diet had an improvement or resolution in their symptoms.
People with lactose intolerance do not produce enough of the enzyme lactase to break down lactose (the form of sugar naturally found in milk). Instead, when people with lactose intolerance ingest large amounts of dairy products, or foods or medicines containing lactose, lactose stays in the intestinal tract until it reaches the colon where it can cause gas, bloating, stomach cramps or diarrhea.
Last February, the National Institutes of Health (NIH) released a statement on lactose intolerance and health to provide health care providers, patients and the general public with the latest information on the topic.
“What many people fail to understand is that lactose intolerance is not an all-or-nothing situation,” says Susan Nitzke, professor of Nutritional Sciences at the University of Wisconsin-Madison and nutrition specialist with the University of Wisconsin-Extension.
Nitzke points out that many people with lactose intolerance can consume small amounts of lactose–for example, a half cup of milk or yogurt–without experiencing any symptoms. “This is especially true if the milk or other lactose-containing food is consumed with a meal,” she says.
Nitzke urges people to consult their doctor or a dietitian (like Nastaran) before making drastic dietary changes for suspected lactose intolerance. Your doctor may do a blood, breath or stool test to find out if lactose intolerance is the true cause of your digestive problems.
Milk and dairy foods provide many important nutrients. Milk is a well-known source of calcium and vitamin D. “Dairy products are also excellent sources of protein, potassium and many other vitamins and minerals,” says Mallory Koenings, a graduate student in the Department of Nutritional Sciences at UW-Madison.
Because dairy products contain so many important nutrients, even people who are lactose-intolerant are urged to consider alternatives within the milk food group, such as yogurt or lactose-free milk.
Nastaran can translate scientific nutrition information into practical advice to help your patient make decisions about what to eat in order to achieve improved clinical and health outcomes (see Case studies). She can advise patients on a range of nutrition related conditions, including:
diabetes (type 1, type 2, gestational)
gastrointestinal disorders (eg. coeliac disease, diverticulitis)
overweight and obesity
food allergy and intolerance
polycystic ovarian syndrome
- renal disease.