If you've eaten a stuffed green olive from an antipasto tray or off the toothpick in your martini, it's likely you had a Spanish Manzanilla olive. The most abundant variety of green olive in the world, Spanish Manzanillas have a sharp, salty flavor. They are commonly stuffed with minced pimentos, a type of sweet red pepper. A typical 14- to 15-gram serving of stuffed Spanish Manzanillas -- approximately four or five olives -- contains around 20 to 25 calories. They are not a good source of most nutrients, though they are rich in compounds that may help lower your risk of disease.
Low in Fat and Saturated Fat
Stuffed Manzanilla olives contain approximately 2 to 2.5 grams of total fat in every serving of four to five olives. For a healthy adult following a 2,000-calorie diet, this amount would supply around 3 percent to 4 percent of the fat she should limit herself to each day. Some commercial brands of the olives also contain a small amount of saturated fat: 0.5 gram in a serving, or 3 percent of the 15-gram recommended daily limit of saturated fat for adults.
Source of Heart-Healthy Monounsaturated Fat
A four- to five-olive serving of stuffed green olives has about 1.5 grams of monounsaturated fat. According to the American Heart Association, a diet high in monounsaturated fat can help you keep your cholesterol level under control. The cuisine of people living in the Mediterranean has traditionally included olives, and the Mediterranean Diet Pyramid -- developed, in part, by the World Health Organization and the Harvard School of Public Health -- recommends eating olives and other sources of monounsaturated fat regularly.
Rich in Polyphenol Compounds
A 2002 study published in the "Journal of Agricultural and Food Chemistry" found that Spanish-style green olives are a good source of polyphenol compounds, including tyrosol, luteolin and hydroxytyrosol. Polyphenols act as antioxidants by inhibiting the free radicals that might cause damage to DNA and cellular tissue. Eating foods rich in polyphenols might help you avoid medical problems like diabetes, osteoporosis, cancer, heart disease and neurological disorders, said a 2005 report in the "American Journal of Clinical Nutrition."
High in Sodium
Adults should have no more than 2,300 milligrams of sodium each day. A typical serving of stuffed Manzanilla olives can contain between 240 and 330 milligrams of sodium, or 10 percent to 14 percent of your daily limit. If you're on a sodium-restricted diet, eating four or five olives in one sitting is 16 percent to 22 percent of the sodium you're allowed per day. So eat stuffed green olives in moderation. Whenever possible, look for low-sodium brands of Manzanillas.