Lactose Sensitivity: Symptoms, Causes, Treatment, and Foods to Avoid

Lactose sensitivity: symptoms, causes, treatments, and foods to avoid

Some people experience digestive disturbances after consuming milk and its derivatives, such as bloating, abdominal pain, gas and diarrhea, and these symptoms may be linked to a condition known as lactose sensitivity or lactose intolerance, a common problem resulting from difficulty digesting the natural sugar found in milk.

Although the term "lactose sensitivity" is widely used, this condition differs from a true milk allergy; it is most often related to a deficiency of the enzyme lactase, which is responsible for breaking down lactose in the small intestine.

What is lactose intolerance?

Lactose intolerance is a digestive disorder that occurs when the body does not produce enough of the enzyme lactase, or when its activity is insufficient to digest the lactose present in milk and dairy products.

When undigested lactose reaches the large intestine, bacteria ferment it, leading to gas formation and drawing water into the intestine, which causes a range of digestive symptoms that vary in severity from person to person.

Having this condition does not necessarily mean you must completely avoid all dairy products; many people can tolerate small amounts of lactose without troublesome symptoms.

What are the symptoms of lactose intolerance?

Symptoms usually appear within a few hours of consuming milk or a product that contains lactose and may include:

• Bloating: a sensation of fullness and pressure in the abdomen.
• Gas: increased passing of gas due to fermentation of undigested lactose.
• Abdominal pain and cramps: may be mild or severe depending on the amount of lactose ingested.
• Diarrhea: resulting from increased fluid in the intestines.
• Nausea: may occur in some people after consuming milk.
• Bowel noises: caused by movement of gas and fluids in the digestive tract.

The severity of symptoms depends on the amount of lactose consumed, the person's lactase level, and the nature of the foods eaten with the milk.

It is important to note that these symptoms are not exclusive to lactose intolerance and can also occur in other conditions, such as irritable bowel syndrome and some other digestive disorders.

What causes lactose sensitivity?

There are several causes that can lead to lactose intolerance, the most prominent of which are:

1. Decreased lactase production with age

Production of this enzyme decreases in many people after childhood, and the rate at which this occurs varies according to genetic factors and population background.

2. Genetic factors

Reduced lactase activity may be linked to genes, and the condition can appear in some people from late childhood or during adolescence or adulthood.

3. Diseases of the small intestine

Some conditions, such as celiac disease or intestinal inflammations, can affect the cells responsible for producing lactase.

4. Intestinal infection

Lactose intolerance may occur temporarily after certain cases of gastroenteritis and may gradually improve as the intestine recovers.

5. Some medical conditions and treatments

Some diseases or damage to the intestinal lining can lead to a temporary or persistent decrease in the ability to digest lactose.

Which foods contain lactose?

Lactose occurs naturally in milk and is also an ingredient in many dairy products and processed foods.

The main sources include:

• Cow's, goat's and sheep's milk.
• Dried milk, whey and their derivatives.
• Some types of ice cream.
• Some types of soft cheese.
• Cream and some ready-made sauces.
• Some sweets, chocolates and baked goods that contain milk.

Some medications and dietary supplements may contain small amounts of lactose as an excipient, so it is possible to check the drug leaflet if severe symptoms occur or there is a known sensitivity to certain products.

By contrast, some aged cheeses contain less lactose, and yogurt contains variable amounts that some people tolerate better than regular milk.

Can you drink milk if you have lactose intolerance?

Yes, many people with lactose intolerance can drink milk, but this depends on their level of tolerance and the amount of lactose it contains.

After assessing symptoms, you can try the following options:

Lactose-free milk: usually contains the essential nutrients found in regular milk, but the lactose has been broken down into simpler sugars, making it suitable for many people with intolerance.

Yogurt: may be easier to digest for some people because of the live bacteria present in certain types.

Aged cheeses: such as some cheddars, which generally contain lower amounts of lactose compared with milk.

Reducing the quantity: a person may tolerate a small amount of milk consumed with food better than drinking a large glass on an empty stomach.

It is better to try products gradually and monitor symptoms rather than exclude all dairy products without cause.

How is lactose intolerance diagnosed?

Diagnosis depends on the nature of symptoms and their relationship to consumption of milk and its derivatives, and a doctor may recommend one of the following tests:

Hydrogen breath test: measures the rise of hydrogen in the breath after ingesting a specified amount of lactose and can help diagnose malabsorption.

Lactose tolerance test: measures the blood sugar response after ingesting lactose, but it is less used in some modern medical practices.

Trial lactose elimination: a doctor may recommend reducing lactose-containing foods for a limited period and then reintroducing them in a structured way to see if symptoms are related.

Relying on symptoms alone to confirm the diagnosis is not advised, especially if they are persistent or severe or occur even when avoiding dairy products.

What is the treatment for lactose sensitivity?

Most people do not need continuous medication; symptoms can be controlled by adjusting the diet according to tolerance level.

Key options include:

1. Reducing lactose-containing foods: complete avoidance is not always necessary; rather determine the amount the body can tolerate.

2. Using lactase enzyme: tablets or drops containing this enzyme are available and may help digest lactose when used according to product instructions or pharmacist and doctor guidance.

3. Choosing lactose-free products: can help maintain intake of protein and calcium without exposure to lactose-related symptoms.

4. Replacing nutrients: attention should be paid to obtaining adequate amounts of calcium, vitamin D and protein, especially when reducing milk and dairy products.

5. Treating the underlying cause when present: if lactase deficiency is due to a disease affecting the intestine, the ability to digest lactose may improve after treating the underlying condition.

It is important not to use antidiarrheal drugs or colon treatments repeatedly without knowing the true cause of the symptoms.

What is the difference between milk allergy and lactose intolerance?

Although the names sound similar, the two conditions are completely different.

Lactose intolerance is a digestive problem related to lactase deficiency and commonly causes gas, bloating, diarrhea and abdominal pain.

A milk allergy is an immune response to milk proteins and can cause hives, itching, swelling of the lips or tongue and vomiting; in severe cases it may lead to breathing difficulty or anaphylaxis, which is a medical emergency.

Therefore, lactose-free milk may be suitable for people with lactose intolerance, but it is not necessarily safe for those with a true allergy to milk proteins because it may still contain those proteins.

Does lactose intolerance affect children?

Lactose intolerance may appear in older children, or temporarily after an intestinal infection, but symptoms in infants require careful medical evaluation because causes differ by age.

Breastfeeding should not be stopped, infant formula should not be changed, nor should alternative milks be used for infants without consulting a pediatrician, especially if there is persistent diarrhea or poor weight gain.

When should you see a doctor?

See a doctor if bloating, diarrhea or abdominal pain are recurrent, or if they persist despite reducing lactose.

The following symptoms require prompt medical evaluation:

• Unexplained weight loss.
• Blood in the stool.
• Severe or recurrent prolonged diarrhea.
• Severe or increasing abdominal pain.
• Signs of dehydration, such as decreased urination and severe dizziness.

Difficulty breathing or swelling of the tongue and throat after consuming milk requires an immediate emergency call because it may indicate a serious allergic reaction, not just lactose intolerance.

Conclusion

Lactose intolerance is a common condition that can be controlled in many cases by identifying trigger foods, reducing inappropriate quantities and choosing lactose-free products when necessary.

However, correct diagnosis remains important because the symptoms of this condition can resemble other digestive disorders, and distinguishing it from a true milk allergy is essential to avoid complications and maintain a balanced diet.

Sources:

U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) — Lactose Intolerance Guide.

National Health Service (NHS) — Symptoms, diagnosis and treatment of the condition.

Mayo Clinic — Causes, symptoms and medical information.