Imagine a sliced apple, say the health experts at Canyon Ranch. Leave those slices sitting for a bit and before long, they'll turn brown. Oxidation is the cause. And harmful free radicals are the result. Free radicals pull apart molecules in healthy living tissue and eventually cause the apple to dry and shrivel. They can cause human skin to wrinkle and can cause cancer too.

Now don't forgo apples in your diet -- just don't slice and let them brown. But do let the visual of those brown pieces motivate you to choose a rainbow of colorful, antioxidant-rich plant foods to enrich your diet each day. Here's what you need.