Why are people lactose intolerant

Why Are People Lactose Intolerant? Understanding the Causes, Symptoms, and Management

Lactose intolerance is a common digestive concern, marked by difficulty digesting lactose, the sugar found in milk and dairy products. This primarily stems from the insufficient activity of the enzyme lactase. Lactase is produced in the small intestine and helps break down lactose into its component sugars—glucose and galactose—for absorption into the bloodstream. When there is not enough lactase, undigested lactose is fermented in the intestines, which may lead to symptoms such as bloating, cramps, excess gas, diarrhea, and sometimes nausea.

What Causes Lactose Intolerance?

The main reason people develop lactose intolerance is reduced production or activity of lactase in the small intestine. The specific causes for this decrease can vary, and understanding them is essential for both recognition and management:

1. Primary (Genetic) Lactase Deficiency

Most often, genetically programmed decline in lactase production occurs gradually with age. In many populations, especially outside of Northern Europe, lactase activity lessens after childhood, which is why a significant number of adults experience lactose intolerance symptoms. This reduction is considered a normal genetic variant, not a disease process.

2. Secondary Lactase Deficiency

Sometimes, people become lactose intolerant due to injury or illness affecting the small intestine, such as gastrointestinal infections, coeliac disease, Crohn’s disease, or after certain medical treatments. This type, called secondary lactase deficiency, can affect individuals of any age and may improve if the underlying cause is addressed and the intestine recovers. Learn more about the different types of lactose intolerance in our Knowledge Bank.

3. Developmental and Congenital Types

Rarely, some individuals are born with very low or no lactase activity due to congenital lactase deficiency. This variant appears from birth and is uncommon.

Can Someone Develop Lactose Intolerance Later in Life?

Yes, it is possible for someone who previously had no issues with dairy to start asking, “Why am I becoming lactose intolerant?” With age or after certain gastrointestinal conditions, lactase production can decrease, producing new or worsened symptoms after consuming lactose-containing foods. The change can be gradual or sudden. If these symptoms arise, consider taking an intolerance test and consulting a registered dietitian for a professional evaluation.

Recognizing the Symptoms of Lactose Intolerance

Symptoms usually appear within a few hours after consuming lactose-containing foods and can vary depending on the level of lactase available and the amount of dairy eaten. Common symptoms include:

• Cramps
• Increased flatulence
• Abdominal bloating
• Diarrhea
• Occasionally, nausea

These symptoms are similar to those of other digestive conditions; therefore, proper diagnosis is important for effective management. It’s important to distinguish lactose intolerance from a milk allergy, which involves the immune system and is not related to lactase deficiency.

For more about digestive responses, visit our article on lactose intolerance and diarrhea.

Nutritional Considerations and Dietary Adjustments

Dairy products are notable sources of nutrients like calcium, vitamin B2, and vitamin B12. Avoiding dairy because of lactose intolerance may lower the intake of these nutrients, which could affect bone health and well-being.

What Are the Alternatives?

• Lactase Enzyme Supplements: Using lactase supplements may help support the digestion of lactose and reduce bothersome symptoms. These are offered in different forms and are often used just before eating dairy. Explore products for lactose intolerance for more options.
  
  These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure, or prevent any disease.
  
• Lactose-Free or Low-Lactose Foods: Choosing lactose-free milks, cheeses, and yogurts can help maintain variety and minimize discomfort.
• Lactase Drops: Adding lactase drops to regular milk can lower the lactose content, allowing for more dietary flexibility.
• Nutrient Substitutes: Non-dairy foods rich in calcium (such as leafy greens or fortified plant-based milks), vitamin B2, and B12 are good alternatives to help meet nutritional needs.

If you are considering significant changes to your diet, contact one of our dieticians for personalized guidance.

Managing Lactose Intolerance

Managing lactose intolerance usually involves tailored dietary changes to help reduce the intake of foods high in lactose. Complete avoidance is rarely required; with the right approach, many people can manage their symptoms while still getting essential nutrients.

At Intoleran, we provide reliable digestive insights in our knowledge bank and offer products designed to help you manage discomfort associated with intolerances.

If you suspect you may be developing lactose intolerance or have persistent symptoms after dairy consumption, consult a registered dietitian. Accurate diagnosis and professional support are important for digestive comfort and overall health.