Title: Understanding Genetics
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Conditions
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Content: I am not sure how big an impact something like this might have on someone's ability to drink milk. But it is a possibility...  Finally, it may be that it is a coincidence, the timing of the vegan diet and lactose intolerance. As I said before, people lose their ability to digest milk at different times of their lives. It may just be that some of your vegan friends happened to become lactose intolerant over the course of the time they were vegan. Or, it could be a combination of all three. As you can see, lactose persistence is not a simple thing. Genes, bacteria, the lining of our intestines can all contribute to becoming lactose intolerant. Or maybe I should say they all combine to make someone lactase persistent. * By the way, this wasn't some hare-brained idea. In some bacteria, a lactase gene is shut off until lactose is around.