Ingredient: O

Cooking oils are extracted from plant sources like nuts, olives, and seeds, each of which imparts its own flavor. Those high in monounsaturated fats (typically good sources of vitamin E) and polyunsaturated fats (like omega-3s) don’t raise and may even lower LDL (“bad”) cholesterol; choosing them is the first step in lowering your risk of heart disease.

These long and elegant pods, also known as lady’s fingers, are high in vitamins A and C, and they’re not necessarily slimy.

Olives are tiny fruits that have been cured in salt, water, or lye to offset their bitterness. They’re packed with cholesterol-lowering monounsaturated fats, vitamin E, and antioxidants.

Among the most versatile of vegetables, these relatives of the lily add flavor—and vitamin C—to nearly any savory dish. They have a sharp taste when raw but mellow when cooked.

Once found at the bottom of Christmas stockings, oranges today mostly end up in breakfast-table juice glasses. Chock-full of nutrients like vitamin C, they also lend sweet, tangy flavor to foods.

A member of the mint family, this spicy, peppery herb is commonly used in Mediterranean, South American, and Cajun cooking.

Long known as an aphrodisiac, oysters are prized for their unusual, sweet, briny taste. If that’s not enough, they’re also high in protein and calcium.