Olives are small fruits that grow on olive trees (Olea europaea).

They belong to a group of fruit called drupes, or stone fruits, and are related to mangoes, cherries, peaches, almonds, and pistachios.

Olives are very high in vitamin E and other powerful antioxidants. Studies show that they are good for the heart and may protect against osteoporosis and cancer.

The healthy fats in olives are extracted to produce olive oil, one of the key components of the incredibly healthy Mediterranean diet.

Olives are often enjoyed in salads, sandwiches, and tapenades. The average olive weighs about 3–5 grams (1).

Some immature olives are green and turn black when they ripen. Others remain green even when fully ripe.

In the Mediterranean region, 90% of olives are used to make olive oil (2).

This article tells you everything you need to know about olives.

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Olives contain 115–145 calories per 3.5 ounces (100 grams), or about 59 calories for 10 olives.

The nutrition facts for 3.5 ounces (100 grams) of ripe, canned olives are (3):

  • Calories: 115
  • Water: 80%
  • Protein: 0.8 grams
  • Carbs: 6.3 grams
  • Sugar: 0 grams
  • Fiber: 3.2 grams
  • Fat: 10.7 grams

    • Saturated: 1.42 grams
    • Monounsaturated: 7.89 grams
    • Polyunsaturated: 0.91 grams

Fat

Olives contain 11–15% fat, 74% percent of which is oleic acid, a type of monounsaturated fatty acid. It is the main component of olive oil.

Oleic acid is linked to several health benefits, including decreased inflammation and a reduced risk of heart disease. It may even help fight cancer (4, 5, 6, 7).

Carbs and fiber

Carbs comprise 4–6% of olives, making them a low-carb fruit.

Most of these carbs are fiber. In fact, fiber makes up 52–86% of the total carb content.

The net digestible carb content is therefore very low. However, olives are still a relatively poor source of fiber, since 10 olives only provide about 1.5 grams.

SUMMARY Olives are an unusual fruit because of their high fat content. Their most abundant fat is oleic acid, which may have several health benefits. They also contain 4–6% carbs, most of which consists of fiber.

Olives are a good source of several vitamins and minerals, some of which are added during processing. This fruit’s beneficial compounds include:

  • Vitamin E. High-fat plant foods usually contain high amounts of this powerful antioxidant.
  • Iron. Black olives are a good source of iron, which is important for your red blood cells to transport oxygen (8).
  • Copper. This essential mineral is often lacking in the typical Western diet. Copper deficiency may increase your risk of heart disease (9, 10).
  • Calcium. The most abundant mineral in your body, calcium is essential for bone, muscle, and nerve function (11).
  • Sodium. Most olives contain high amounts of sodium since they’re packaged in brine or saltwater.
SUMMARY Olives are a good source of vitamin E, iron, copper, and calcium. They may also contain high amounts of sodium if packaged in saltwater.

Olives are rich in many plant compounds, particularly antioxidants, including (12):

  • Oleuropein. This is the most abundant antioxidant in fresh, unripe olives. It is linked to many health benefits (13).
  • Hydroxytyrosol. During olive ripening, oleuropein is broken down into hydroxytyrosol. It is also a powerful antioxidant (14, 15).
  • Tyrosol. Most prevalent in olive oil, this antioxidant is not as potent as hydroxytyrosol. However, it may help prevent heart disease (16, 17).
  • Oleanolic acid. This antioxidant may help prevent liver damage, regulate blood fats, and reduce inflammation (18, 19).
  • Quercetin. This nutrient may lower blood pressure and improve heart health.
SUMMARY Olives are particularly rich in antioxidants, including oleuropein, hydroxytyrosol, tyrosol, oleanolic acid, and quercetin.

The most common varieties of whole olives are:

  • Spanish green olives, pickled
  • Greek black olives, raw
  • California olives, ripened with oxidation, then pickled

Because olives are very bitter, they’re not usually eaten fresh. Instead, they’re cured and fermented. This process removes bitter compounds like oleuropein, which are most abundant in unripe olives.

The lowest levels of bitter compounds are found in ripe, black olives (13, 20).

However, there are some varieties that don't need processing and can be consumed when fully ripe.

Processing olives may take anywhere from a few days up to a few months depending on the method used. Processing methods often rely on local traditions, which affect the fruit’s taste, color, and texture (13).

Lactic acid is also important during fermentation. It acts as a natural preservative that protects the olives from harmful bacteria.

Currently, scientists are studying whether fermented olives have probiotic effects. This could lead to improved digestive health (21, 22).

SUMMARY Fresh olives are very bitter and usually need to be cured and fermented before eating.

Olives are a staple of the Mediterranean diet. They’re associated with many health benefits, especially for heart health and cancer prevention.

Antioxidant properties

Dietary antioxidants have been shown to reduce your risk of chronic illnesses, such as heart disease and cancer.

Olives are rich in antioxidants, with health benefits ranging from fighting inflammation to reducing microorganism growth (23).

One study showed that eating a pulpy residue from olives significantly increased blood levels of glutathione, one of the most powerful antioxidants in your body (24, 25).

Improved heart health

High blood cholesterol and blood pressure are both risk factors for heart disease.

Oleic acid, the main fatty acid in olives, is associated with improved heart health. It may regulate cholesterol levels and protect LDL (bad) cholesterol from oxidation (26, 27).

Furthermore, some studies note that olives and olive oil may reduce blood pressure (28, 29).

Improved bone health

Osteoporosis is characterized by decreased bone mass and bone quality. It can increase your risk of fractures.

The rates of osteoporosis are lower in Mediterranean countries than in the rest of Europe, leading to speculation that olives might protect against this condition (30, 31).

Some of the plant compounds found in olives and olive oil have been shown to help prevent bone loss in animal studies (30, 32, 33, 34).

While human studies are lacking, animal studies and the data linking the Mediterranean diet to decreased fracture rates are promising (31).

Cancer prevention

Olives and olive oil are commonly consumed in the Mediterranean region, where rates of cancer and other chronic diseases are lower than in other Western countries (35).

Thus, it’s possible that olives may help reduce your risk of cancer.

This may be partly due to their high antioxidant and oleic acid contents. Test-tube studies reveal that these compounds disrupt the life cycle of cancer cells in the breast, colon, and stomach (6, 7, 36, 37, 38).

However, human studies are needed to confirm these results. At this point, it’s unclear whether eating olives or olive oil has any effect on cancer.

SUMMARY Olives are very rich in antioxidants that may contribute to a variety of benefits, such as lower cholesterol and blood pressure. They may also reduce your risk of cancer and bone loss, but more research is necessary.

Olives are well tolerated by most people but may harbor high amounts of salt due to their packaging liquid.

Allergy

While allergy to olive tree pollen is common, allergy to olives is rare.

After eating olives, sensitive individuals may experience allergic reactions in the mouth or throat (39).

Heavy metals

Olives may contain heavy metals and minerals like boron, sulfur, tin, and lithium.

Consuming a high quantity of heavy metals may harm your health and increase your risk of cancer. However, the amount of these metals in olives is generally well below the legal limit. Therefore, this fruit is considered safe (40, 41).

Acrylamide

Acrylamide is linked to an increased risk of cancer in some studies, although other scientists question the connection (42, 43).

However, authorities recommend limiting your acrylamide intake as much as possible (44).

Some olive varieties — especially ripe, California black olives — may contain high amounts of acrylamide as a result of processing (45, 46, 47).

SUMMARY Olives are usually well tolerated, and allergy is rare. However, they may contain small amounts of heavy metals and high concentrations of salt. Some varieties may also contain acrylamide.

Olives are a savory and delicious addition to meals or appetizers.

They’re low in carbs but high in healthy fats. They’re also linked to several health benefits, including improved heart health.

This stone fruit is very easy to incorporate into your routine and makes a great addition to a healthy, whole-foods-based diet.