Main Nahi Maakhan Khayo

Main Nahi Maakhan Khayo — The Genetics of Lactose Intolerance

Lord Krishna’s famous line — “Main nahi maakhan khayo” (I did not eat the butter) — takes on a whole new meaning when you consider that for a significant portion of the Indian population, avoiding dairy products like butter, milk, and paneer is not a choice but a biological necessity.

What Is Lactose Intolerance?

Lactose intolerance is the inability to fully digest lactose — the sugar found in milk and dairy products. It is caused by a deficiency of lactase, the enzyme produced in the small intestine that breaks down lactose. Without sufficient lactase, lactose passes undigested into the colon, where it is fermented by bacteria, causing symptoms such as bloating, gas, diarrhoea, and abdominal cramps.

The Genetic Basis

Lactase persistence — the ability to continue producing lactase into adulthood — is determined primarily by variants in the LCT gene and its regulatory region. The most well-studied variant is rs4988235 (also known as C/T-13910), which is strongly associated with lactase persistence in European populations. In South Asian populations, different variants are associated with lactase persistence, and the prevalence of lactose intolerance is significantly higher than in European populations.

Genomepatri by MapmyGenome includes lactose intolerance as one of its nutrition traits — helping you understand whether your genes predispose you to lactose intolerance and guiding personalised dietary recommendations.

Managing Lactose Intolerance

• Choose lactose-free dairy products or plant-based alternatives (oat milk, almond milk, soy milk)

• Consume dairy in small amounts with meals to slow digestion

• Fermented dairy products like yoghurt and aged cheese are often better tolerated

• Ensure adequate calcium and vitamin D intake from non-dairy sources