What is lactose intolerance?
Lactose intolerance is a digestive disorder caused by the body's inability to properly digest lactose , the main sugar in milk and other dairy products. This problem results from a deficiency of lactase, an enzyme produced in the small intestine that is essential for breaking down lactose into digestible sugars, glucose and galactose.
What is lactose?
Lactose is a disaccharide sugar found naturally in mammalian milk. Digestion of lactose requires the enzyme lactase, which breaks down lactose into two simpler sugars: glucose and galactose, which can then be absorbed by the body.
Difference between lactose intolerance and lactose allergy
Although often confused, lactose intolerance and lactose allergy (or cow's milk allergy) are two completely different conditions. Lactose intolerance is a digestive problem, while a cow's milk allergy is an immune reaction to the proteins in milk. An allergy can cause severe reactions, while intolerance primarily causes digestive problems.
Causes of lactose intolerance
The cause of lactose intolerance is usually genetic, with lactase production naturally decreasing after childhood. Other causes can be secondary, such as reduced lactase production due to damage to the small intestine from disease, surgery, or injury.
Development of lactose intolerance later in life
In many people, lactase production decreases as they age, resulting in symptoms of lactose intolerance. This can range from mild to severe, depending on the amount of lactase the body can still produce.
Can lactose intolerance go away?
Although lactose intolerance is often considered a lifelong condition, the degree to which symptoms are experienced can vary. Some people can tolerate small amounts of lactose, while others require more severe dietary restrictions.
Lactose intolerance symptoms
There are several symptoms associated with lactose intolerance, some more severe than others. These symptoms originate in the large intestine and usually occur within a few hours of consuming lactose-containing products. The most common symptoms include:
- Intestinal cramps
- Bloated feeling
- Flatulence
- Nausea
- Stomach ache
- Diarrhea
- Constipation
Diagnosis of lactose
The diagnosis is often made through a combination of history, elimination diets, and medical tests, including the lactose breath test, the lactose intolerance test, and sometimes a bowel biopsy.
Lactose intolerance test
To determine whether someone is lactose intolerant, it's essential to undergo a specific lactose intolerance test . There are several reliable methods for assessing this:
Blood test
The lactose intolerance blood test uses a small amount of blood, often just a few drops, to test for lactose intolerance.
Hydrogen breath test
This test measures the amount of hydrogen in the breath after consuming a lactose-containing beverage. An increased hydrogen level indicates possible lactose intolerance.
Lactose tolerance test (LTT)
The Lactose Tolerance Test tests whether someone is lactose intolerant by measuring blood sugar levels at various times after consuming lactose. Changes in these levels provide evidence for or against the presence of lactose intolerance.
Elimination provocation test
This method involves following a lactose-free diet for an extended period to see if symptoms improve, followed by reintroducing lactose to determine if symptoms return. This can help confirm the diagnosis of lactose intolerance.
Nutritional advice for lactose intolerance
What to avoid?
People with lactose intolerance should limit or avoid foods high in lactose. This includes:
- Milk and dairy products: Whole milk, cream, butter, cheese, and yogurt are the most common sources of lactose. It's important to read food labels carefully, as lactose can also be hidden in less obvious products.
- Processed foods: Lactose is often found in processed foods, such as bread, cookies, soups, cereals, processed meats, and ready-made meals.
- Medicines and supplements: Some medicines and nutritional supplements use lactose as a filler.
What to eat?
It's important to maintain a balanced diet, even without lactose. Here are some lactose-free alternatives and other foods that are safe to consume:
- Lactose-free milk and dairy products: Many brands offer lactose-free versions of milk, cheese, yogurt, and cream.
- Plant-based milks: Soy, almond, coconut, oat, and rice milks are popular lactose-free alternatives.
- Calcium-rich foods: Green leafy vegetables like kale and broccoli, nuts, seeds, soft-boned fish like sardines, and fortified plant-based milks can help increase calcium intake.
- Whole grains, fruits and vegetables: These foods are naturally lactose-free and essential for a balanced diet.
