You hear it said when you’re a small child, make sure you eat your vegetables. Even as we age, our doctors constantly remind us that we need more fruit and vegetables in our diet. And even when you eat more, it likely still isn’t enough. Researchers have been tracking the nutrients in our veggies and find that over the last 20 years, most have lost around 50% of their nutrient density. And it could get worse. These scientists think they know why but know that the fix is controversial…