Most American Indians are lactose intolerant, which means they need to find nutrients outside of dairy. Traditional cooking methods can be key to good health.
In the 1900s, nutritionists and dairy producers helped convince Americans that cow's milk was nature's perfect food. But the science and tastes have changed.
A number of for-profit labs claim to be able to pinpoint specific food intolerances via simple but expensive blood tests. Allergy scientists are dubious.
Italian researchers found that the physical pain and symptoms a person experiences might actually be related to psychological factors.