By the way, doctor: Isn't quinoa a supplier of complete proteins?

Q. I read in your June 2010 issue that soybeans are the only plant food that could serve as a person's sole source of protein because they contain all eight essential amino acids. I thought quinoa does too.

A. Quinoa (KEEN-wah) is native to the Andes in South America. It's caught on lately in the United States as a healthful whole grain. Experts sometimes refer to quinoa as a "pseudocereal" because the Chenopodium quinoa plant it comes from is in the same botanical family as sugar beets and spinach, and not the grass family like wheat, rice, and the other grains we typically think of as being cereals.