Problem:

It is estimated that rice is the staple food for over 3 billion people, many of whom live in poor, developing countries. Rice has many wonderful qualities, including high yield, the ability to grow in poorly drained soil and the lack of a requirement for a nitrogen fertilizer, (due to the presence of nitrogen fixing bacteria in the root nodules). Rice, especially brown rice, is a good source of carbohydrate, protein and fat. Nonetheless, diets that are almost wholly rice-based are associated with certain diseases, including beriberi and blindness.

Required:

Question 1: Suggest a possible cause for the diseases associated with rice-only diets.

Question 2: How might these diseases be avoided?

Include source of information for best answer.