Lettuce

Ever notice no one ever says, 'Eat Your Pizza!' or 'Eat Your Meat!' But we all grew up being told to eat our greens. It turns out those people were right to tell us to eat more greens (and fruits). 

A study done in Taiwan showed that spending only $0.50 per day on fruits and vegetables gives us a 10% drop in mortality. And as Dr. Michael Greger of NutritionFacts.org points out, "Imagine if there was a drug that - without side-effects - could lower our risk of death 10%. How much do you think drug companies would charge? Probably more than 50 cents."