4. Brazil Nuts

These South American nuts are the easiest to spot as they are the largest. They are rich in selenium which is known to help prevent prostate ailments and cancers. Selenium is also observed to help in the digestion of protein in the body. They help keep the muscles in tone and the nervous system in good conditions. Brazil nuts are in fact seeds of a tree, however, for all practical purposes, people refer to them as nuts. They also pack good amounts of magnesium and zinc minerals.