What Are the Symptoms of Lactose Intolerance?

Lactose is a sugar found in dairy products. Some people are unable to fully absorb lactose and digest lactose. As a result, such individuals experience gastrointestinal symptoms after they eat or drink dairy products. This condition is called lactose malabsorption or lactose intolerance. In the United States, about 1 in 3 people have lactose malabsorption. While the condition is usually harmless, its symptoms can be uncomfortable.

Please continue reading to learn more about lactose intolerance, including its causes and symptoms. We will also give you some tips on living with lactose intolerance if you cannot properly digest dairy.

What causes lactose intolerance symptoms?

Not having enough of an enzyme called lactase causes lactose intolerance. Lactase enzyme is produced by the small intestine. The body uses it to digest lactose and convert it to simple sugars (glucose and galactose), which are absorbed into the bloodstream.

Primary lactose intolerance occurs when lactase production decreases during adulthood. Secondary lactose intolerance occurs due to low lactase levels following an injury, surgery, or illness. Congenital or developmental lactose intolerance is rare and occurs in babies due to a faulty gene inherited from the parents or premature birth.

People who do not have enough lactase cannot digest milk products properly after eating dairy. The undigested lactose ferments in their intestines, interacts with bacteria, and causes symptoms of lactose intolerance like gas, bloating, and diarrhea.

What are the risk factors for long lactose intolerance symptoms?

Some of the risk factors for lactose intolerance include:

Age: Lactose intolerance usually develops in adulthood and is rare in babies.
Ethnicity: American Indians, Hispanics, Africans, and Asians are more likely to be lactose intolerant.
Intestinal Diseases: Conditions affecting the small intestines, such as intestinal infections, bacterial overgrowth, irritable bowel syndrome, Crohn’s disease, and celiac disease, can lead to reduced lactase production.
Premature Birth: Pre-term babies may have low levels of the enzyme lactase, possibly leading to lactose intolerance as an adult.
Cancer Treatments: Radiation therapy for stomach cancer or complications of chemotherapy can increase the risk of developing lactose intolerance.

How does lactose intolerance affect health?

The health of a lactose intolerant person can suffer if the condition keeps them from getting enough nutrients that are found in dairy products. This includes calcium and vitamin D, which are essential for healthy bones. However, most people who are lactose intolerant do not have to give up dairy altogether. They can consume limited amounts of dairy and get enough calcium from other sources to manage their symptoms and stay healthy.

What are the symptoms of lactose intolerance?

Common symptoms of lactose intolerance include gas, bloating, stomach pain, stomach cramps, diarrhea, nausea, vomiting, and feeling sick.

How do you know if you’re lactose intolerant?

If milk and dairy products cause uncomfortable symptoms, your doctor may order the following tests to diagnose lactose intolerance:

Hydrogen breath test: This test measures the amount of hydrogen in your breath. People who cannot properly digest lactose have higher levels of hydrogen in their breath.

Lactose tolerance test: This test measures blood sugar 2 hours after you drink a liquid with high amounts of lactose. If your blood glucose levels do not rise, it indicates you have undigested lactose.

Stool acidity test: This test measures the acidity of stool after drinking a high-lactose liquid. Normal stool is not acidic, while that of lactose intolerant individuals contains lactic acid.

These tests can also help in differentiating milk allergy from lactose intolerance.

What is the treatment for lactose intolerance?

The following measures can help people with lactose intolerance:

Treating an underlying condition that affects the body’s ability to digest lactose.
Limiting milk and dairy products in the diet.
Following low-lactose dietary guidelines by drinking milk such as lactose-reduced milk or consuming lactose-free products like soy milk or almond milk.
Eating fermented milk products like yogurt and kefir, which can improve lactose digestion by fermenting lactose.
Eating non-dairy foods to get enough calcium, such as green leafy vegetables, oranges, almonds, calcium-fortified cereals and juices, and canned sardines and salmon.
Eating small servings of foods containing lactose along with other foods at mealtimes.
Adding lactase products such as lactase tablets, liquid, or powder to milk products to help break down lactose. Lactase enzyme tablets are available over the counter under brand names like Lactaid and others.
Experimenting with low-lactose dairy products (hard cheeses) versus high-lactose foods (ice cream and milk) to see which foods cause the worst symptoms.
Keeping a food diary to better understand when to expect symptoms (how much dairy you can eat without discomfort).
Getting enough vitamin D from sun exposure and/or supplements.
Taking probiotics to help with lactose digestion.

Frequently Asked Questions

How long do lactose intolerance symptoms last?

Lactose intolerance usually begins 30 minutes to 2 hours after consuming milk products and lasts for 12-48 hours until all the lactose has passed through the digestive system.

What’s the difference between lactose intolerance, gluten intolerance, and food allergies?

Lactose intolerance is the inability to digest a sugar called lactose, which is found in milk products. It causes symptoms like abdominal pain, gas, bloating, nausea, and diarrhea. Gluten intolerance is a food intolerance or sensitivity caused by eating gluten, a protein found in foods like wheat. It causes gas, bloating, and tiredness. A food allergy or dairy allergy is an immune system reaction to a particular food that can cause life-threatening severe symptoms such as throat swelling. In general, allergies tend to trigger more serious symptoms, whereas food intolerances cause milder symptoms.

How long does it take to get dairy out of your system?

It can take up to three weeks for all traces of dairy (cow’s milk protein) to leave your system.

What does lactose intolerance poop look like?

Lactose intolerance poop tends to be loose and watery. This is because when you eat dairy foods, the undigested lactose passes through your intestines, causing loose, watery stools.

References: