GARLIC

The active ingredient, and the one responsible for garlic’s powerful odour, is allicin, which fights infection and bacteria. In one study, researchers gave 146 people either a placebo or a garlic supplement for 12 weeks; the garlic takers were two-thirds less likely to catch a cold. Consider a clove or capsule as a daily dose. Want to avoid garlic breath? — consume with fennel, parsley, raw apples or green tea.

Eat it: Enliven salsa or guacamole with crushed garlic, or fry with onions as a base for stews, soups and curries. Don’t cook over a high heat longer than 30 seconds, otherwise you’ll lose the beneficial compounds. Cook only until it turns fragrant.