What Is Lactose Intolerance?

While it is not a very serious medical condition, lactose intolerance can certainly affect patients’ quality of life. It’s estimated that between 65 and 70 percent of the world’s adult population is affected by lactose malabsorption in one way or another. Like many conditions, it causes mild distress in some patients, while others may need to avoid lactose altogether.

Lactose intolerance is the inability of the body’s digestive tract to properly digest lactose, which is a sugar found in milk and other dairy products. The body needs lactase, an enzyme produced in the small intestine, to properly digest dairy products. If the person doesn’t have enough lactase in their body, digesting lactose can be a problem. Additionally, lactose intolerance can appear suddenly at any stage of life. Most infants are born with the ability to digest breast milk (which contains lactose), but some patients may develop an intolerance to it over time. 

What Are the Symptoms of Lactose Intolerance?

Symptoms of lactose intolerance can appear quickly, sometimes within 30 to 60 minutes after eating. The severity of the symptoms depends on the individual as well as how much lactose was consumed. Some of the more common signs of lactose intolerance include:

• Bloating
• Gas
• Abdominal cramps
• Diarrhea
• Nausea

Some more severe symptoms of lactose intolerance can include:

• An immediate and urgent need to make a bowel movement
• Vomiting
• Lower stomach pain

Diarrhea is one of the most common symptoms of lactose intolerance. It occurs because undigested lactose remains in your small intestine, which pushes water into the digestive tract. This water loosens the stool and can cause diarrhea and sudden urges to use the bathroom, as well as other digestive problems. 

What Are the Risk Factors for Lactose Intolerance?

Genetics do play a role in whether you may develop lactose intolerance or not. Other risk factors include being of African American heritage, and a personal medical history of other gastrointestinal disorders (such as celiac disease or irritable bowel syndrome (IBS)). If you have a relative who has problems with lactose intolerance, this heightens your chances of developing it as well. 

What Are the Different Types of Lactose Intolerance?

Lactose is a combination of both glucose and galactose. The lactate enzymes in your body break down lactose into galactose and glucose. If there isn’t enough lactase to break lactose down, you will experience digestive problems. However, there are different types and causes of lactose intolerance.

1. Primary lactose intolerance. This type of lactose intolerance is the most common. Primary lactose tolerance is when the production of lactase decreases with age. Researchers believe this type of lactose intolerance may be linked to genetics, as some ethnicities are more prone to primary lactose intolerance than others. For example, it affects between 75-95% percent of Asian and African populations. 
2. Secondary lactose intolerance. Secondary lactose intolerance occurs when a different condition affects the small intestine so that lactase production is slowed. Some of these conditions include Crohn’s disease and ulcerative colitis (known collectively as inflammatory bowel disease (IBD), celiac disease, age, and chemotherapy. 
3. Congenital lactose intolerance. This type of lactose intolerance is very rare and only presents in infants. Both parents must have the mutated gene in order for the infant to develop lactose intolerance. 
4. Developmental lactose intolerance. This is another type of lactose intolerance that only presents in infants. It is often seen in premature infants who do not yet have a fully formed digestive system. 

How Is Lactose Intolerance Diagnosed?

If you’re experiencing digestive disturbances after you consume dairy products, you should inform your physician so that they can test for the condition. Some of the diagnostic tests your doctor may perform include:

• Hydrogen breath test. This test measures hydrogen in your breath after lactose consumption. High levels of hydrogen may indicate lactose intolerance but may be connected to other conditions as well.
• Genetic testing. Genetic testing is used to detect lactose intolerance; however, there are often false negatives associated with the test. 
• Lactose tolerance test. This is a blood test that measures blood sugar after consuming dairy. 
• Lactase activity at the jejunal brush border. This test is rarely used because of its invasiveness and expense. It requires a biopsy at the jejunal brush border, which is part of your small intestine.
• Stool acidity levels. This test is used for infants with suspected lactose intolerance. It measures the pH of the stool. 

Before you make an appointment with your doctor, you can always practice an elimination test. Eliminate all dairy from your diet for two weeks, and see if your digestive problems minimize or disappear. 

What Foods Contain Lactose?

All dairy products contain lactose, but it can also hide out in other foods that you may not be aware of. Lactose can be present in processed meats, desserts, chocolate, bread, cake, desserts, biscuits, cream sauce like alfredo, soups, sauces, and cookies. If your lactose intolerance is severe, it’s best to always read the label or ask questions when eating out before you make food choices. 

What Is the Treatment for Lactose Intolerance?

The first-line therapy for lactose intolerance is to completely eliminate dairy from the diet. Your gastroenterologist can guide you on what foods to eat to replace the nutrients in dairy. However, if you don’t want to cut out dairy completely, your physician may suggest enzyme supplements, probiotics, and prebiotics. While it may be uncomfortable, it is also possible for some to expose your body to lactose often until your body adapts and is able to digest it.