WHAT IS LACTOSE?
Lactose is a sugar found in milk and other dairy products. People who suffer from lactose intolerance are unable to digest lactose because they lack an enzyme called lactase. Lactase is made by the cells that line the small intestines. Its job is to break down lactose into two simpler sugars—glucose and galactose—which are then absorbed into the bloodstream for energy.
WHAT CAUSES LACTOSE INTOLERANCE?
When lactose is not digested by lactase, it passes into the lower gastrointestinal tract and is metabolized by bacteria. This fermentation process causes the uncomfortable symptoms associated with lactose intolerance.
Most people are born producing lactase because it is needed to digest breast milk. In some cases, however, infants are born lactose intolerant due to a genetic condition called primary lactase deficiency. As these infants age and their diets become less reliant on milk, lactase production declines—typically beginning around age two. Symptoms often do not appear until adolescence or adulthood.
Secondary lactase deficiency is caused by damage to the small intestines and can occur at any age. Possible causes include: chemotherapy, untreated celiac disease, Crohn’s disease, diabetic gastropathy, gastrectomy, long-term antibiotic use, intestinal resection, intestinal inflammation, tropical sprue.
Note: Lactose intolerance is not the same as a milk allergy. A milk allergy is an immune reaction to milk proteins and can be life‑threatening. A product labeled “dairy‑free” contains no lactose, but a product labeled “lactose‑free” may still contain dairy.
IS THERE A CURE?
Once lactose intolerance develops, there is no treatment that restores the body’s ability to make sufficient lactase. Undigested lactose ferments in the intestines, causing symptoms such as abdominal pain, bloating, cramps, constipation or diarrhea, gas, and nausea. Symptoms typically appear within 30 minutes to two hours after consuming lactose.
Severity varies depending on how much lactose is consumed and how much lactase the body still produces. Determining your tolerance level requires trial and error. A simple test from your doctor can confirm lactose intolerance. Although there is no cure, symptoms can be managed through diet and lifestyle adjustments.
READ LABELS – EVERY LABEL!
Removing lactose from your diet is the primary treatment, but complete avoidance is not always necessary. Lactose can be found in many foods across all sections of the grocery store. Reading labels is essential.
Ingredients that may contain lactose include: butter, cheese, dairy solids, margarine (most contain whey), milk (whole, reduced‑fat, non‑fat, dry, instant, half‑and‑half, whipping cream), sour cream, and whey (acid, dried, reduced lactose, protein, sweet, etc.). Whey is found in many packaged foods and even some medications.
Lactose‑free “lact” ingredients: lactates, lactones, lactylates, lactalbumin, lactoglobulin. The only “lact” that contains lactose is lactose.
NON‑DAIRY SOURCES FOR CALCIUM & VITAMIN D
Supplement options: Calcium and vitamin D are essential for bone health. If you reduce or eliminate dairy, supplementation may be necessary. Explore Vitamin D and Calcium options.
For more on vitamin D, read: Vitamin D Deficiency.
Non‑dairy foods rich in calcium: almonds, avocados, broccoli, calcium‑fortified products, canned salmon, milk substitutes (soy, rice), oranges, pinto beans, rhubarb, spinach.
Non‑dairy foods rich in vitamin D: egg yolks, fatty fish, liver.
PROBIOTICS to the RESCUE!
Studies show that probiotics—especially Lactobacillus acidophilus—can help digest lactose because they produce lactase. When lactose remains in the lower GI tract, symptoms persist longer. Probiotics help break down lactose more efficiently.
Yogurt is a good example: active cultures of Lactobacillus acidophilus break down lactose during fermentation, which is why many lactose‑intolerant individuals can tolerate yogurt and other fermented dairy products.
A study in the Journal of Dairy Science found that children consuming milk with Lactobacillus acidophilus experienced a “significant decrease” in symptoms (Source).
Probiotics offer additional benefits, including support for diarrhea, pathogen control, IBS, Crohn’s disease, vaginal yeast infections, and immune health. Explore our favorite probiotics for adults and children.
A 2005 report in the Journal of the American College of Nutrition states that lactase supplements can aid lactose digestion. Digestive enzyme supplementation is increasingly popular as research continues to confirm its importance. Most enzyme formulas include amylase, lipase, cellulase, proteolytic enzymes, and lactase.
You may also enjoy our article: The Link Between Digestive Enzyme Deficiency and Poor Health.
We hope this article was helpful and informative. If you have questions or suggestions, feel free to fill out our Ask the Doctor form.
Until next time, stay healthy!
Yours in health,
Dr. Gregg Gittins
