Amongst my whole family (parents, sisters, etc), I’m the only one who isn’t lactose intolerant. I’ve been drinking about 4 glasses of milk a day since I was little. So, I want to know if my habit is the reason why I never develop lactose intolerance or if it was a genetic quirk? Could someone with gluten intolerance been “cured” through eating bread?
Lactose tolerance is purely genetic. Most people can tolerate small amounts of dairy, however. It’s not really an on/off switch. Having lactose on a regular basis causes the bacterial flora in your colon to switch to species that favor lactose as a food source, which break it down (by making the enzyme lactase) and reduce symptoms compared to the species that ferment it and create gas and fatty acids.
Whatever your level of symptoms, either your lactase-making mechanism will shut down gradually over time or it won’t. Your diet is not know to make any difference.
Gluten intolerance is totally different and is better called celiac disease, an autoimmune disease that attacks the lining of the intestines. Gluten protein creates a reaction with the immune system. Eating more gluten can never be a help in any way.
For lactose tolerance, I think exposure does make some difference. I’m of Chinese heritage, and milk has always been a part of my diet when I was growing up. I can easily handle a glass or two of milk a day without any problems. I do, however, start to get a little “gassy” if I go more than that, so I know that I probably don’t have the lactose tolerant mutation genetically, but the constant exposure has likely caused my body to adapt alternate ways of dealing with it.