Olives are fruits of the olive tree and are known as “Olea europaea” or “oil of Europe.” Though small in size, olives are packed with a variety of beneficial vitamins and minerals. Both the green and black olives contain these invaluable nutrients, only differing in degree of ripening -- black olives are simply green olives that are left on the tree for a longer period of time before harvesting.
Olives contain vitamin E, which acts as a potent lipid-soluble antioxidant to protect the cell membranes and other tissues from harmful free radicals. It also plays a role in red blood cell formation, helps the body use vitamin K and keeps the blood vessels from getting too constricted. One tbsp. of olives provides 0.14 mg of vitamin E, also known as alpha-tocopherol. The Institute of Medicine recommends 15 mg per day.
Olives also provide vitamin A, a vital nutrient that helps form and maintain healthy teeth, bones and skin. It serves as an antioxidant to protect cells against the effects of free radicals. One tbsp. of canned olives offer 34 IU of vitamin A. The recommended daily amount of vitamin A for adult males and females is 900 and 700 IU, respectively.
Lutein and Zeaxanthin
Olives also contain small amounts of lutein and zeaxanthin, antioxidant compounds that are closely related to vitamin A and that filter harmful rays in the eye, according to the American Optometric Association. One tbsp. of olives contains 43 ug of the carotenoids. While the USDA does not have a recommended daily intake for lutein and zeaxanthin, recent studies have shown a health benefit with lutein and zeaxanthin supplementation at 10 mg and 2 mg per day, respectively.
Relative to their size, olives contain a significant amount of calcium -- 7 mg per tablespoon. Calcium is vital for bone structure, blood clotting, nerve impulse transmission, muscle contraction and secretion of hormones. It also activates and stabilizes proteins and enzymes, optimizing their activities. The daily recommended amount is 1,000 to 1,200 mg per day of calcium, depending on the period in the life cycle.
Iron and Zinc
Olives are a good source of iron and zinc. They provide 3.3 mg of iron, or about 25 percent of the daily value, and 0.22 mg of zinc, or 17 percent of the daily value, in 1 cup of olives. Iron is essential for the hemoglobin in red blood cells. Zinc is required for DNA and protein synthesis, immune support, and wound healing.
Other Vitamins and Minerals
Olives also contain magnesium, potassium, phosphorus, copper and selenium in very small quantities, in addition to vitamins B-1 to B-6 and vitamin K. Vitamin K is essential for blood clotting, while the B vitamins have a variety of important physiological functions. Polyphenols and flavonoids, beneficial compounds that appear to have significant anti-inflammatory properties, are also present in olives.