Understanding Lactose Intolerance

Lactose intolerance arises from the body's inability to digest lactose, a sugar in milk. This condition stems from a deficiency in lactase, the enzyme responsible for lactose breakdown.

Prevalence of lactose intolerance significantly varies worldwide. Highest rates are seen in East Asia, affecting up to 90% of adults, while Northern European countries have rates as low as 5%.

Genetic adaptations to dairy-rich diets can influence lactose tolerance. The LP allele in the MCM6 gene, associated with lactase persistence, is more common in populations with a history of dairy farming.

Symptoms often include bloating, gas, diarrhea, and abdominal pain, appearing 30 minutes to 2 hours post-dairy consumption. Severity varies depending on lactose amounts ingested and individual tolerance levels.

Diagnosis can be confirmed through tests such as the Hydrogen Breath Test, measuring hydrogen in the breath after consuming lactose, or the Lactose Tolerance Test, assessing blood sugar levels post-lactose ingestion.

Management includes lactose-reduced diets, lactase enzyme supplements, and incorporating lactose-free dairy alternatives. Fermented dairy products like yogurt can sometimes be better tolerated due to natural bacteria breaking down lactose.

Recent studies suggest lactose intolerance may affect more than digestion, potentially influencing symptoms like headaches or fatigue. An understanding of its systemic impact is still evolving within medical research.