Lactose, the primary carbohydrate in milk and dairy products, is broken down by lactase, an enzyme produced in the small intestine. This enzyme splits lactose into glucose and galactose for easier absorption.
Lactase levels peak in full-term infants but decline significantly in adulthood. In France, 20-50% of adults retain just 10% of their original lactase activity. Tolerance varies: some react to as little as 3g of lactose (less than a small glass of milk), while others handle up to 12g (about 250ml). No methods exist to boost lactase production in humans.
Lactose intolerance stems from lactase deficiency. Undigested lactose ferments in the colon, triggering symptoms like:
It may also cause indigestion or vomiting.
Temporary intolerance can follow gastroenteritis and resolves over time. Follow these digestion tips during episodes.
Distinguish it from milk protein allergy: intolerance involves enzyme shortage; allergy triggers immune response. You're "intolerant," not allergic, to lactose.
Lactose digests better when consumed gradually. Fats and fibers slow gastric emptying, enhancing digestibility. Thus:
Consume dairy with meals, including vegetables or fruit, for optimal results.
Lactose levels differ across dairy. Per Ciqual 2013 data:
Milk poses the biggest challenge. Try:
Cottage cheese and petit Suisse are low-lactose.
Cheese has minimal lactose—consume freely.
Yogurts benefit from bacteria aiding lactose breakdown.
Watch for traces in processed foods and medications.
https://www.lemangeur-ocha.com/fileadmin/images/dossiers/LeCHE-cahier-de-nutrition-marteau.pdf
https://pro.anses.fr/TableCIQUAL/index.htm
