For about 75% of the world’s population, drinking milk means stomach discomfort.
Under normal conditions, lactose, which is the sugar in milk, is broken down in the intestine to simple sugars, glucose and galactose. This process is helped on by an enzyme called lactase.
In certain individuals, the body cannot make sufficient lactase. As a result, the lactose in consumed milk products remains undigested and gets passed into the large intestine. Bacteria then break it down into other chemicals that cause stomach bloating, pain and sometimes diarrhea.
Interestingly, the ability of our body to produce lactase also reduces with age, which is why older adults find milk consumption to be an unpleasant experience.
Though most milk products might be off limits for lactose intolerant individuals, yogurt is still a good way to consume dairy. The bacteria in yogurt contain their own lactase which gets activated in the small intestine and helps break down the lactose in yogurt.
The next time you feel your stomach rumble after drinking milk, you know your lactase is acting up!