Whether you love them or hate them, you probably think you pretty much know what an olive is. But do you really? For example, did you know olives are a fruit?
Olives, which grow on the olive tree (botanical name Olea europaea), belong to the stone fruit family. That means they’re related to mangoes, peaches, and cherries, as well as two more fruits we don’t think of as fruits—almonds and pistachios.
All varieties of olives contain a wealth of antioxidants, and studies indicate they can improve the health of your heart as well as reduce your risk of osteoporosis and cancer. Olive oil, made by extracting the healthy fats from olives, is a key component of the well-researched Mediterranean diet as well as the diets of people living in the “Blue Zones,” geographic pockets where people traditionally live exceptionally long lives.
Olives are high in healthy, unsaturated fats and contain several essential vitamins and minerals. They’re also low in carbohydrates. They do tend to be high in sodium, which means you may want to exercise caution when it comes to your serving size.
What’s the Difference Between Green and Black Olives?
According to Shea Rosen, director of Product Development at Mezzetta, a company founded in 1935 that specializes in olives, “The color of the olive corresponds to how ripe they are when picked.” Rosen explained that green olives are picked before ripening, while black olives are picked at a further point in the ripening process when their color has deepened from green to black. Raw, freshly picked olives of any color are intensely bitter, so they’re always cured—meaning packed in salt, brine, or water—before being eaten.
Green olives tend to be denser, firmer, and more bitter than black olives, which makes sense. They’re less ripe, remember? But the ultimate taste and texture of any olive, Rosen said, depends primarily on how it’s cured and how long it’s cured for.
There’s a distinct combination of flavor notes found in all variety of olives that can best be summarized as sharp and briny. But there’s also a whole spectrum of olive intensity. Mild olives can have a butteriness to them, while more pungent ones can make you pucker.
“Oxidized black olives are truly the most mild,” said Rosen, “but olive aficionados don’t really categorize them with natural olives.”
Black and Green Olive Nutrition Facts
When it comes to the nutrients they contain, there are minimal differences between green and black olives. In fact, Rosen said that “There are no nutritional differences between green and black olives.”
It’s true that all kinds of olives yield abundant stores of plant compounds, most notably, antioxidants such as:
- Oleuropein: Concentrations of this antioxidant, which has been linked to numerous benefits especially in connection to heart health, are highest in young, unripe olives.
- Hydroxytyrosol: As olives ripen, oleuropein breaks down into hydroxytyrosol, a powerful antioxidant in its own right that may have potent anti-cancer properties.
- Tyrosol: Though not as powerful as hydroxytyrosol, this antioxidant (more prevalent in olive oil than in olives themselves) appears to have a strong cardioprotective effect.
- Oleanolic acid: An antioxidant jack-of-all-trades, oleanolic acid has been shown to impart a multitude of health benefits, including preventing damage to the liver, quelling inflammation, lowering blood cholesterol levels, and possibly even exhibiting anti-tumor activity.
- Quercetin: This well-known antioxidant also improves your health on a variety of levels, such as decreasing inflammation and increasing cellular energy expenditure, which could make it a helpful aid for weight-loss efforts.
Depending on the variety, olives are composed of between 11 and 15% fat, which makes them quite an unusual fruit. And 74% of that is oleic acid, a monounsaturated fatty acid that can help to lower your risk of heart attack and stroke as well as to treat cancer, among other promising applications for human health.
While Rosen insists that green and black olives are equivalent in all ways, other sources do note minor differences between the two. Black olives, for instance, tend to be lower in both calories and saturated fat. But the two varieties have equivalent amounts of protein and fiber, as well as vitamin A, a nutrient necessary for eye, skin, and bone health.
Dr. Russell H. Greenfield, Clinical Assistant Professor of Medicine at UNC Chapel HIll School of Medicine, told an interviewer that research shows black olives often have higher levels of antioxidant activity, meaning you may see a more pronounced impact on your health.
Black olives also contain approximately twice the iron found in green olives, and we need iron to circulate oxygen in the bloodstream and keep us energized.
But green olives offer more than twice the amount of vitamin E found in black olives. Your body uses vitamin E to prevent cellular damage. A 100-gram serving gets you around 4 milligrams, or 25% of the 15-milligram recommended daily intake for adults.
Black olives, however, are lower in sodium than green ones. A 100-gram serving of black olives contains roughly 50% of the maximum amount of sodium you should limit yourself to each day, per the American Heart Association’s guidelines. But the same size serving of green olives has more than twice that amount of sodium, meaning eating just that one serving would put you slightly over your daily recommended sodium limit. If you need to keep an eye on your sodium intake for health reasons, olives might be best as an occasional indulgence, and you’ll be able to indulge more if you stick to black ones.
8 Impressive Olive Health Benefits
As we touched on in the last section, the nutritional composition of olives makes them formidable allies you want by your side as you build a health-promoting eating plan. Here are eight ways that adding olives to your diet can improve your health.
1. Fight Off Infections
The powerful antioxidants found in olives can benefit your health in so many ways. As we already discussed, they can lower your risk of heart disease and cancer, as well as protect your cells from damage.
Studies have also shown that antioxidants in olives can act as antimicrobial agents in your body. Testing reveals they can reduce the growth of potentially harmful microorganisms, like those responsible for infections in your airways and stomach.
Olives also appear to boost your overall immune health, thanks to the high concentrations of polyunsaturated fatty acids (PUFAs) they contain.
2. Quell Inflammation
Olives are a valuable source of a polyphenol called oleuropein, which has remarkable anti-inflammatory properties. Studies indicate that oleuropein acts at the origin site of inflammation to calm it quickly before damage can occur. Since many chronic conditions develop as a result of ongoing inflammation, olives can have a far-reaching protective effect.
3. Enhance Brain Health
The anti-inflammatory properties of olives prevent your body from entering a dangerous state of inflammation known as oxidative stress. Studies indicate that olives increase your glutathione levels. Glutathione deficiency is known to contribute to oxidative stress, which in turn can lead to a number of diseases, including seizures, Alzheimer’s disease, and Parkinson’s disease.
Olives also provide you with vitamin E, another nutrient that protects your cells from damage associated with oxidative stress. Your brain is especially vulnerable to this damage; in fact, it’s considered to be a primary cause of all kinds of neurodegeneration. And high levels of vitamin E are linked to better cognitive performance.
4. Protect Heart Health
As we touched on earlier, the fat in olives comes primarily from oleic acid molecules, which are strongly associated with improved heart health. Oleic acid has what are known as antiatherogenic properties, meaning it helps prevent the formation of fatty, artery-clogging plaques. Findings published in the Annals of Nutrition & Metabolism reveal that one way oleic acid does this is by preventing LDL cholesterol from oxidizing.
Olives have also been used traditionally to treat high blood pressure, and research has validated their blood-pressure lowering effects.
5. Prevent Type 2 Diabetes
Oleuropein, which as you may recall is a polyphenol found in olives, can also lower your risk of type 2 diabetes. A research team from Virginia Tech discovered that oleuropein spurs insulin production and manages the production of a signaling molecule called amylin that can go haywire and form toxic aggregates that contribute to the progression of diabetes.
“Our work provides new mechanistic insights into the long-standing question of why olive products can be anti-diabetic,” said Bin Xu, lead author of the Virginia Tech study. “We believe it will not only contribute to the biochemistry of the functions of the olive component oleuropein, but also have an impact on the general public to pay more attention to olive products in light of the current diabetes epidemic.”
6. Improve Circulation
Polyphenols from olives can boost your nitric acid production, which benefits your health in a number of ways, such as expanding blood vessels, increasing blood flow, and decreasing blockages and clotting. All that results in better circulation, which in turn leads to a cascade of health benefits ranging from increased endurance to decreased risk of chronic disease.
7. Improve Bone Health
Lower rates of osteoporosis, a progressive thinning and weakening of your bones, in Mediterranean countries compared to other European countries has led researchers to hypothesize that olives might be providing valuable protective nutrients. Evidence supports this idea, indicating that phenols found in olives can prevent the loss of bone mass.
And cellular studies show that olives improve the overall health of your bones by enhancing biomechanical strength. They also balance out production of osteoblasts, the cells responsible for bone formation, and osteoclasts, the cells that break down your bones. When osteoclasts work faster than osteoblasts, your bones begin to weaken.
8. Inhibit Cancer Cell Growth
Rates of cancer and other chronic diseases are also lower in Mediterranean countries than in Europe or the United States, and again, experts think this may have to do with olive consumption.
Experiments have shown that bioactive compounds found in olives can disrupt the lifecycle of cancer cells. Oleic acid has been shown to suppress the overexpression of a gene linked to multiple kinds of cancers. Maslinic acid inhibits the proliferation and causes apoptotic death of colon cancer cells. Erythrodiol, a precursor of triterpenic acids, has similar effects on colorectal carcinoma cells.
As this research has not yet progressed to human studies, it’s too soon to say definitively whether eating olives has a protective effect against cancer. The findings so far are promising, especially given what we already known about how high-antioxidant foods impact your risk of developing cancer.
How to Add More Olives to Your Diet
You can, of course, simply enjoy olives all on their own. They make a great addition to an appetizer spread. You can also mix olives into pasta, quinoa, or rice dishes to add a piquant pop of flavor. They’re also a wonderful option for punching up the taste and texture of a soup or stew. You can also sprinkle a handful of olives on top of a pizza or flatbread, or toss them into a salad. Or add some olives to your wrap or sandwich to boost its healthy fat content and prevent flavor boredom. And don’t forget about breakfast! Add a Mediterranean twist to your omelet or scrambled eggs by folding in some olives.