According to new research, produce in the U.S. not only tastes worse than it did in your grandparents' days, but also contains fewer nutrients. In fact, the average vegetable found in today's supermarket is anywhere from 5 percent to 40 percent lower in minerals  such as magnesium, iron, calcium and zinc than those harvested just 50 years ago.

Today's vegetables are larger, but do not contain more nutrients. Jumbo-sized produce actually contains more "dry matter" than anything else, which dilutes mineral concentrations.