Image: Lily MihalikIn 1950, your parents, grandparents, or a perhaps a younger version of you could eat a handful of string beans -- about three-and-a-half ounces -- and get about 9 percent of the calcium you needed for the day. Almost 50 years later, in 1999, the amount of calcium in string beans dropped by 43 percent, leaving you with only 5 percent of your daily calcium. You could eat more string beans -- except you might not want to, because they wouldn't be as flavorful as in the past. So you could eat more of other vegetables, but it's …