What is lactose intolerance?
Lactose intolerance results from the inability to digest lactose, a sugar contained in dairy products, including milk, cheese, butter, yogurt and cream. An enzyme called “lactase” that is expressed on the surface of the small intestine cells digests lactose molecules, which are then absorbed into the blood stream. If inadequate enzyme is present, the lactose is not absorbed and passes into the colon, where intestinal bacteria digest it, producing gas, bloating and discomfort.
It is most prevalent in infancy, when we need it most, and wanes over the course of our lifetime. Some people express sufficient lactase to permit adequate lactose digestion lifelong. Others do not, and may develop lactose intolerance in the childhood.
The inability to digest lactose properly usually results from genetics. Your ethnic background is also a factor. People prone to lactose intolerance include those of Native American, Asian, Hispanic, and African descent as well as those of Jewish heritage. If it is genetic, there is no way to restore normal function.
Lactose intolerance can also result from inflammation or infection of the small intestine. In these situations, treatment of that illness – for example treatment of small intestinal infection with antibiotics, or the treatment of celiac disease with a gluten free diet – can restore normal levels of lactase.
How do we manage lactose intolerance?
If there is an underlying non-genetic cause, we treat that cause, but in most people, there is no way to restore normal levels of the lactase enzyme. If you have received a lactose intolerance diagnosis, it’s best to adapt your diet accordingly, by limiting the amount of dairy you consume. Non-dairy products like rice milk or soy milk are reasonable substitutes. Likewise, commercial products that contain predigested lactose may be helpful. Many people can tolerate small amounts of lactose, such as a little milk in their morning coffee, since they possess adequate lactase to digest this. If you have lactose intolerance, consuming lactose will be uncomfortable but it is not dangerous – it does not cause long-term damage to the intestine.
How do we diagnose lactose intolerance?
Patients often come to US with the diagnosis. You tell us that when you have a bowl of ice cream, you feel unwell an hour or two later – experiencing, typically, gas, bloating, nausea and discomfort in the abdomen. If the diagnosis is unclear, we can do a breath test in the office that proves the disorder. During this non-invasive test, we ask you to consume a solution containing lactose, and then measure indirectly the ability of your body to breakdown the lactose by assessing the chemistry of the air you exhale during the next 90 or so minutes.
Can I be intolerant of other common sugars?
Yes. Fructose and sucrose are other common sugars that – when not digested properly – can cause bloating and gas. Fructose occurs in many natural fruits and vegetables, as well as in high-fructose corn syrup, which is ubiquitous in Western diets. Special diets containing restrictions on these sugars may resolve your symptoms.
The Lactose Diet: Minimizing Your Intolerance
While there are over-the-counter products at your local pharmacy that may help with lactose intolerance, there’s no known cure, and it’s difficult to correct the problem. Instead of “correcting” how the body reacts to lactose, it’s easier to adapt your diet to include foods that don’t act as triggers.
The first step in adjusting the diet is to find the foods that cause symptoms—dairy products and the foods that contain them. Many foods contain hidden amounts of dairy products or dairy derivatives, such as powdered milk, whey, and dairy fats. It’s important to read product labels carefully and learn to recognize ingredients that are dairy-related.
Once these foods have been identified, you’ll need to find replacements that do not include dairy products. In recent years, many such products have been developed, such as milk that’s based on almonds, oats, or soy.