ADVERTISEMENT
It is also interesting to note that approximately 65-75% of the total population of our planet has a reduced ability to digest lactose after infancy. (5) (6) In some countries, over 90% of the adult population is lactose intolerant, take a moment to consider this fact.
Lactose intolerance is an impaired ability to digest lactose, a sugar found in milk and other dairy products. Normally, lactose is broken down by an enzyme called lactase, which is produced by cells in the lining of the small intestine.
Keep in mind that the milk we have so much trouble digesting after infancy is cow’s milk, not breast milk, which is natural. In fact, we are the only species on Earth to consume the milk of another animal.
Since lactase’s sole function is to digest lactose in milk, most mammalian species experience a dramatic reduction in the enzyme’s activity after weaning. The persistence of lactase in humans is an adaptation to the consumption of milk and non-human dairy products beyond infancy. Our diets have changed significantly, and as a result, some of our genes have adapted, but it’s not an easy process. This is why most humans are lactose intolerant.
All other species wean and then don’t drink milk for their entire lives, and as a result, they lack the enzyme that breaks down milk sugar. But during human evolution, some humans experienced a mutation in the LTC gene, the lactase gene; these mutations allow adults to process lactose. With approximately 65 to 75% of humans on the planet unable to process it properly, it’s clear enough that we’re not respecting the natural functioning of our bodies.
Below is a video by Katherine S. Pollard, Ph.D., University of California, San Francisco, to expand on the previous paragraph.
read on the next page
ADVERTISEMENT
