What is lactose intolerance?
Lactose intolerance—that is, an intolerance to milk sugar—is caused by a lactase deficiency. Without this enzyme, lactose cannot be broken down or digested and enters the intestine in large quantities. This causes an influx of water that can lead to diarrhea. In addition, undigested lactose ferments under the action of intestinal bacteria, leading to the production of intestinal gas that causes stomachaches, bloating, and colic.
This intolerance, caused by a genetic mutation, is very common among adults in the Mediterranean region, as well as among Asian and African populations.
Intolerance or Allergy: Distinguishing Between the Two
Lactose intolerance should not be confused with a milk protein allergy, which remains rare and is primarily found in infants.
An accurate diagnosis is essential, as many patients mistakenly believe they are lactose intolerant when they are actually suffering from irritable bowel syndrome, with symptoms such as diarrhea or abdominal pain. Initially, dairy products (milk, yogurt, fresh cheese) are eliminated from the diet, with a reintroduction a few weeks later. If symptoms reappear, the diagnosis is confirmed by a test known as the hydrogen breath test.
Should dairy products be eliminated completely?
In cases of confirmed intolerance, treatment involves reducing lactose in the daily diet. Lactose is found primarily in mammalian milk (cow, sheep, and goat) and certain lightly fermented dairy products: cream, sour cream, coffee cream, kefir, fresh cheese, quark, cottage cheese, and blanc-battu. The food industry also frequently uses lactose in all kinds of products (cold cuts, rolls, braided breads, and condiments).
It is estimated that most people with lactose intolerance can tolerate 10 g of lactose spread out over the course of the day, which is equivalent to 200 ml of milk.
It is best to test your own tolerance level rather than completely eliminating dairy products, which remain an important source of calcium. By choosing lactose-free dairy products, as well as hard cheeses—such as Brie or Camembert (which contain only trace amounts of lactose)—people with lactose intolerance can maintain a high-quality calcium intake and a balanced diet. Calcium-rich mineral waters are a good complement to dairy products.
Our practical tips for better lactose tolerance
- Avoid drinking milk on an empty stomach or in excessive amounts.
- Spread out your intake of dairy products and pair them with other foods.
- Incorporate milk into dishes (mashed potatoes, rice pudding, semolina pudding, etc.).
- Opt for yogurt and aged cheeses, which naturally contain less lactose due to lactic acid bacteria and the draining/aging process.
- Choose lactose-free milk rather than plant-based milks, which are often low in calcium.
- If it’s difficult to control lactose intake (e.g., dining out, social gatherings, vacations), lactase-based pharmaceutical supplements can be used.
It is recommended to ensure optimal calcium intake throughout life to support bone growth and strength. If there is a risk of deficiency, consult your doctor, who may prescribe calcium and vitamin D supplements.
Frequently Asked Questions
What is the difference between lactose intolerance and milk protein allergy?
Lactose intolerance is a digestive disorder caused by a lack of lactase, whereas milk protein allergy is an immune reaction that is rarer and primarily seen in infants.
How can I tell if I’m actually lactose intolerant?
An accurate diagnosis requires eliminating dairy products from your diet, followed by a gradual reintroduction. If symptoms reappear, a hydrogen breath test can confirm the diagnosis.
Do I have to completely eliminate dairy products?
No, total elimination is generally not necessary. Most people with lactose intolerance can tolerate a small amount of lactose per day and may continue to eat certain aged cheeses or lactose-free products to maintain their calcium intake.
What foods contain lactose without me realizing it?
In addition to milk and dairy products, lactose is sometimes used by the food industry in deli meats, rolls, braided breads, and certain condiments.
Can I use lactase tablets?
Pharmaceutical preparations containing lactase are available and can make it easier to consume dairy products in situations where controlling lactose intake is more difficult, such as at restaurants or while traveling.