Kiwis are high in vitamin C, which is an important immune-boosting nutrient, as well as in vitamin E, which, helps increase your body's T-cell count, says nutritionist Ian Marber, author of Supereating: A revolutionary way to get more from the foods you eat. Try the sweet green fruit in a smoothie (it pairs well with strawberries and spinach), or in one of these recipes:

• Nutty Breakfast Parfait
• The Okarito, an antioxidant-rich cocktail