You've heard the expression that an apple a day keeps the doctor away... but what about an orange? Citrus fruits - including lemons, limes, oranges, grapefruit and tangerines - are excellent sources of antioxidants, vitamins, and nutrients, including vitamin C, fibre, folate and potassium. “Research has shown that many of these [nutrients] can protect us against chronic conditions including cancer and heart disease and may help support brain health and reduce the risk of kidney stones,” says dietitian Vandana Sheth. Here are 10 research-backed health benefits of citrus fruits, from boosting your brain health to preventing wrinkles.