Ever wondered why a dish prepared with spinach is said to be "Florentine"? Well, it's because Catherine de Medici, who was from Florence, was a super fan of this super green.

In fact, she liked it so much that in 1533, after she had married Henry II and become queen of France, she decreed that every meal in the palace be served with spinach.

In the 1500s, anyone who survived childhood (around 40 percent did not) might live to be 50 or even 60. But clever Catherine lived to the age of 70 — and you can bet the spinach helped.

Recent research published in Neurology reveals that eating a serving of leafy greens a day is associated with a sharper memory and a slower rate of cognitive decline.

The other benefits are equally impressive: Greens like spinach are rich in fiber, which is linked to a lower risk of heart disease.

They also help fight certain cancers. In a study that tested eight common vegetables for their anti-cancer properties, a nutrient found in leafy greens was the strongest when it came to inhibiting human cancer cell proliferation.

A diet rich in collards, kale, and other greens also is associated with a reduced risk for Type 2 diabetes. Plus, those leafy powerhouses are low-cal, but keep you feeling full.

Try arugula, Swiss chard, or spicy mustard greens tossed into a salad, mixed into a smoothie, or sautee with garlic and lemon juice. You'll be royally rewarded with better health.