Whether as an antipasto or tapa, on pizza, with pasta or chocolate cake: gourmets appreciate the fruits of the olive tree very much. And yet many are unaware of how healthy olives actually are. Olives are high in antioxidants, good for the heart, fight cancer, and may even reduce the risk of Alzheimer’s.
The olive is an ancient and healthy food
Olives are the extremely healthy fruits of the olive tree (Olea europaea). They have been cultivated in the Mediterranean since the Bronze Age (4,000 years ago). However, archaeological finds of olive pits have shown that wild olives were eaten at least 9,000 years ago.
The ancient Greeks worshiped the olive tree as the sacred tree of the goddess Athena. When she fought with Poseidon, the god of the sea, for supremacy over Athens and Attica, Poseidon released a spring. Athena gave the olive tree to the people. People agreed that the olive tree was more useful and therefore chose Athena as the city goddess of Athens.
Healthy olives, hardwood, and healing leaves
Even today, the olive tree is used in many ways: its wood is an excellent fuel and can also be processed into a wide variety of objects due to its hardness.
Tea is made from leaves, which strengthens the immune system and can help with high blood pressure and insomnia. Olive leaf extract, on the other hand, has a strong antibacterial effect and also acts against parasites, so it can be used excellently as part of intestinal cleansing.
The fruits of the tree – the olives – are a popular and healthy food – both pure and in the form of oil. The latter is still considered a universal remedy that is externally useful for skin diseases and internally helps to prevent typical civilization diseases.
Today around 90 percent of the olives are pressed into olive oil. Only 10 percent are traded as edible olives. But while healthy olive oil is now very popular all over the world, it is often not realized that the olives themselves are extremely healthy and have healing properties.
Olives: 1,000 varieties are a pleasure
Worldwide, olive trees are cultivated on an area of more than 10 million hectares and around 16.5 million tons of olives are harvested annually. The largest olive producers include Spain, Italy, Greece, Turkey, and Morocco.
No one can say how many varieties of olives there are now. It is estimated that there are up to 1,000 varieties, some of which are even limited to individual villages.
It is true that old olive varieties often contain more secondary plant substances. This is due to the fact that they are endowed with a natural resistance and can therefore also cope with fewer pesticides.
Highly cultivated olive varieties, on the other hand, are more susceptible. Although they guarantee higher yields, they require pesticides, fertilizers, and artificial irrigation.
Trees that are “spoiled” in this way automatically produce fewer secondary plant substances, since these naturally serve to defend against insects and fungi. Pesticides and fungicides now take over these tasks so that the tree no longer has to take care of its own protection.
As a rule, a distinction is made between table and oil types. While the usually larger table olives are better suited for consumption, the types of oil have a particularly high-fat content.
Olive varieties differ in size, shape, color, and taste, but even among olives of the same variety, there are differences in taste, as the aroma is also influenced by climate and soil conditions.
We would like to introduce you to three types of olives:
The Manzanilla Olive is the most widespread table olive in the world and is mainly grown in Spain. It is plump, as its name – small apple – indicates, quite small, medium-firm, and captivates with a tart aroma. There are black and green Manzanilla olives, but the unripe fruits contain more antioxidants than the ripe ones. The latter are often filled, e.g. B. with peppers, anchovy paste, or almonds.
The most famous olive variety from Greece is called Kalamata. According to a study at the Agricultural University of Athens, it is one of those varieties that contain a lot of hydroxytyrosols (see below). The almond-shaped fruits have slightly firmer skin and are reddish-brown to black in color. Kalamata olives impress with their juiciness and the spicy-aromatic note. They are usually commercially available in brine or olive oil.
The “Throuba Thassou” is a lesser-known variety of olives as it is only cultivated on the Greek island of Thassos. The fruits ripen on olive trees, some of which are 1000 years old and do not require the use of fertilizers or pesticides.
Greek researchers have found that the fruit, which is only preserved by dry salting, contains a surprising amount of oleuropein, a whopping 1.2 milligrams per olive. (Read more about oleuropein below).
However, it does not necessarily depend on the variety of whether olives are green or black in color.
Olives: The degree of ripeness determines the color
In the beginning, each olive is green. As they ripen, the fruits then take on a violet, brown or black color.
However, there are also black olives that are actually green and are simply colored black by the food industry. This is done with the help of deep black coloring iron salts (the dyes iron(II) gluconate (E 579) and iron(II) lactate (E 585)).
It is easy to explain why this happens: black olives usually have to stay on the tree longer and are therefore more susceptible to pests and weather influences. They are also ultimately softer and more sensitive than their green sisters, which is why harvesting and processing are much more difficult and expensive. So you prefer to harvest green and color the olives artificially.
How do you recognize colored olives?
According to the European additives regulation, the addition of 150 milligrams of iron salt per kilogram of olives is permitted and is classified as harmless to health. Nonetheless, critics regard the black coloring as deceiving the consumer, and, as a rule, this is why organic producers strictly reject it.
However, there are some tips on how to easily identify black-colored fruits:
- Dyed olives are uniformly pitch black, while tree-ripened olives have varying shades of black and gray on the same fruit.
- Before you buy, study the list of ingredients for the above-mentioned iron salts or E-substances. An explicit declaration such as B. “redacted” is only mandatory for open goods.
Olives: Low carbs – healthy fats
Both green and black olives contain very few carbohydrates, which makes the oily fruits suitable for low-carb diets:
There are about 3 grams of carbohydrates in 100 grams of green olives and 5 grams in 100 grams of black olives. A large part of this amount of carbohydrates (80 percent) also consists of fiber.
The fat content, on the other hand, is around 14 percent in unripe green olives and 35 percent in ripe black ones. Their energy and calorie content vary accordingly.
The fat of the olive consists mainly of the healthy monounsaturated fatty acids – the oleic acid – at a good 75 percent.
It has been shown that oleic acid can lower bad LDL cholesterol and increase good HDL cholesterol. Numerous studies have shown that the Mediterranean diet rich in olives and olive oil can prevent arteriosclerosis, high blood pressure, and heart disease.
In addition, the delicious oil fruits can even help you lose weight: a few olives are enough to stop hunger and thus reduce the overall intake of food.
Olives: the vital substances
Rarely do you eat more than 10 olives at a time? But even these 10 have interesting properties and can help to cover the need for vital substances.
For example, 10 olives (approx. 25 grams) contain 65 µg of copper (5 percent of the recommended daily requirement).
Copper is involved in the formation of copper-containing enzymes, blood formation, bone metabolism, nerve cell structure, and much more. Also, iron could not become active without the presence of copper. Iron is also found in olives:
10 olives provide about 0.8 mg of blood-forming iron, which is not bad considering the small amount consumed and can already cover 5 to 10 percent of the recommended daily requirement. However, the iron values are very variable, so the olive does not seem to be a reliable source of iron.
Calcium is found in almost the same amount of olives as in milk. However, with 10 olives it is only about 30 mg.
Olives also contain vitamins B2, B9 (folic acid), and E as well as the eye-friendly carotenoids beta-carotene, lutein, and zeaxanthin.
However, the specialty of olives is that of secondary plant substances with an antioxidant effect, which occurs almost exclusively in olives and is so healing that in Spain the consumption of olives is even recommended by the government.
dr Carmen Gómez Candela, President of the Sociedad Española de Nutrición Básica y Aplicada (SENBA, Spanish Society of Nutritional Sciences), recommends eating an average of seven olives a day for the benefit of health. Numerous studies have shown that people who regularly enjoy olives and olive oil live healthier lives.
Olives are rich in healthy antioxidants
One of the reasons why olives are so healthy is that they contain very specific antioxidants. The most important antioxidants in olives include:
- phenolic compounds (e.g. oleuropein, tyrosol, hydroxytyrosol, oleocanthal)
- Flavonoids (e.g. apigenin, luteolin quercetin)
- Hydroxycinnamic acids (e.g. caffeic acid, cumic acid)
- Anthocyanidins (e.g. cyanidins, peonidins)
- Hydroxybenzoic acid (e.g. gallic acid, vanillic acid)
We now want to take a closer look at some of these ingredients and show their health benefits.
Oleuropein is what makes olives so healthy
Oleuropein is one of the active ingredients that make olives so healthy. The substance is one of the most effective natural antioxidants and is mainly responsible for the bitter taste of the unprocessed olive. If you have ever tasted an unripe olive straight from the tree or planned to do so, you have certainly come into contact with this intensely bitter substance. It usually leads to the olive being immediately spat out again.
In order to reduce the high bitter content and to make the green olives edible, the conventional fruits are treated with caustic soda. They are then fermented in a salt solution with added lactic acid bacteria.
Many organic suppliers only soak their olives in salt water, using the lactic acid bacteria naturally occurring on the fruit. Although this method requires more time, it is gentler and ensures a better aroma. Green olives must be in the brine for up to six months. With black olives, some of the bitter substances are broken down as they ripen on the tree.
According to various studies, oleuropein works against bacteria, viruses, and parasites, high blood pressure, and inflammation. In addition, oleuropein dilates the vessels, promotes the cardiovascular system, lowers blood sugar, strengthens the immune system, and reduces the risk of cancer.
Depending on their origin and degree of ripeness, olives provide oleuropein levels of between 4 and 350 mg/100 g. Since the oleuropein is broken down with increasing ripeness, the unripe green olives are significantly more effective.
Even higher amounts of oleuropein can be found in the leaf of the olive. Olive leaf extracts thus provide between 800 and 950 mg/100 ml.
Olives protect against free radicals
Hydroxytyrosol is also an antioxidant substance in olives. It is about 100 times stronger than vitamin C and therefore comparable to the substance resveratrol from grapes. Research has shown that hydroxytyrosol can protect passive smokers from free radicals.
The comprehensive pharmacological spectrum of action of hydroxytyrosol relates in particular to diseases affecting the heart, blood vessels, blood pressure, and lipid metabolism. Hydroxytyrosol also helps prevent inflammation and cancer.
The plant compound tyrosol is not quite as strong, but should still have the potential to protect against heart disease, as Italian researchers from the National Center for Food Quality and Risk Assessment have found.
Incidentally, according to the EU Health Claims Regulation (Regulation on nutritional and health-related information about food), every 20 grams of olive oil must contain at least 5 milligrams of hydroxytyrosol, oleuropein, and tyrosol. Only then can the manufacturer advertise that its oil has a positive effect on health.
Oleic acid in olives keeps the heart healthy
The already mentioned oleic acid in the olive is one of the omega-9 fatty acids and, according to Spanish scientists from the University of the Balearic Islands, is primarily responsible for the blood pressure-lowering and heart-protective effect of olives or olive oil.
In addition, oleic acid is said to help prevent liver damage, regulate blood lipids and reduce inflammation.
For a long time, these healing effects were attributed exclusively to the high proportion of monounsaturated fatty acids, which were considered to be so healthy. Today, however, we know that the active ingredient oleocanthal also plays a very important role.
Oleocanthal against cancer
Oleocanthal is a polyphenol that, according to current knowledge, is only found in olives or extra virgin olive oil.
It was discovered by the American scientist Dr. Gary K Beauchamp. He noticed that eating freshly pressed olive oil caused a stinging sensation in the throat.
Since this feeling reminded him of taking the painkiller ibuprofen, he got to the bottom of the phenomenon. In 2005, together with his research team, he isolated a substance from olive oil that actually has the same pharmacological properties as ibuprofen, but without the side effects.
dr Beauchamp came to the conclusion that this substance could be responsible for the fact that olives are so healthy and that the Mediterranean diet is so recommended. Oleocanthal is able to stop inflammatory processes and protect against heart disease and some types of tumors. According to the latest laboratory studies, cancer cells die after just 30 minutes of exposure to oleocanthal.
In addition, oleocanthal also has the potential to fight a disease that was previously considered incurable: Alzheimer’s
Healthy olives reduce the risk of Alzheimer’s
More and more researchers are getting to the bottom of why significantly fewer people develop Alzheimer’s in the Mediterranean countries in particular. A study at Northwestern University in Illinois has shown that olives, with their oleocanthal content, may be able to protect nerve cells from the damaging effects of Alzheimer’s disease.
According to scientists from the University of Louisiana at Monroe, oleocanthal should be able to remove deposits of the so-called beta-amyloids (senile plaques) from the brain, which occur in large concentrations in Alzheimer’s disease.
However, since it has now been proven that not every olive and every olive oil is equally healthy, i.e. not every olive oil contains oleocanthal, the question arises as to what the consumer should look for when buying.
At the University of Athens, 175 extra virgin olive oil varieties from Greece and California were examined and it turned out that the unripe the olives, the healthier they are, as they are then the richer in oleocanthal and other polyphenols.
Incidentally, you can recognize an olive oil that is particularly rich in oleocanthal by the fact that it contains more bitter substances and causes a slightly itchy throat when swallowed.
Experts have long since agreed that regular consumption of olives is very healthy – one more reason to include the delicate oleaginous fruit in your diet more often.
Buying healthy olives: Organic quality is worth it
Most olives come in jars with brine, vinegar, lemon juice, or oil to preserve them. Organic producers prefer extra virgin organic olive oil. Hot spices (e.g. chili) or tasty herbs (e.g. rosemary) are often added.
High-quality organic olives are of course preferable to industrially produced mass-produced goods. Keep in mind that cheap olives from the supermarket usually contain fewer secondary plant substances than high-quality, mostly old olive varieties.
Always check the ingredients list as well. This not only tells you whether the olives are colored but also whether flavor enhancers and preservatives have been added, which are completely unnecessary with the oil fruits and turn the originally healthy olives into a food that also contains substances that have a negative effect.
Healthy olives: all natural without salt, vinegar, oil
The fewer additives (salt, vinegar, oil) required when processing the olives, the more natural and healthier the olives are.
Although it is always said that olives are not edible without debittering, raw olives (e.g. from seedlings) show that almost untreated olives are a real delicacy. After the harvest, the olives are dried in the shade at 20 degrees and then filled into glasses – without salt, brine, water, vinegar, oil, or whatever.
Now natural gas is formed that preserves the olives. When you open the jar, the gas escapes. The olives are not ready to eat yet. You have to “mature”. To do this, spread them out on a flat plate and leave them there for two days.
Only now do they develop their aromatic and natural olive taste. They darken and become somewhat wrinkled.
The black Gemlik olives from the natural food producer Rapunzel look very similar. They also do without additives. With the help of a special, month-long fermentation process in the traditional Turkish way, they get their wonderfully aromatic taste. They are only oiled a little before bottling.
Storage: how long do olives last?
The fatty acids in olives break down over time from exposure to light and heat, as well as oxygen. For this reason, you should always store olives in a cool and dark place, i.e. in the refrigerator. Ideally, even when they are still closed.
Olives preserved in oil last the longest. While unopened jars can be kept for many years, opened jars can be stored in the refrigerator for several months. The important thing is that they are always well-covered with oil. Since even the smallest impurities can turn the olives rancid, you should always remove the precious fruit from the jar with clean cutlery.
Olives in brine are more perishable, which is why they are usually pasteurized. There are also vacuum-packed olives that have been marinated in oil with herbs. They can usually be found in the refrigerated section and should be used up as quickly as possible.
Healthy olives in the kitchen
Olives are a symbol of healthy Mediterranean cuisine. Like olive oil, tomatoes, aubergines, and garlic, they are among the basic elements of all Mediterranean cuisine.
When creating your dishes, keep in mind that the flesh of unripe green olives is firmer. They convince with an intense, a little bitter, and pungent aroma. Dark fruits, on the other hand, are riper. They are softer and taste milder.
Savory with olives
Olives should not be missing on any antipasti plate! The most diverse marinades made from olive oil and herbs ensure varied enjoyment. Good wine is usually served with it – and a beguiling Mediterranean feeling spreads, no matter how far away the nearest coast may be.
Olives not only taste great on their own, but they are also perfect for all hearty dishes. They go well with pasta sauce, with salad, on pizza, with stews, or with fried fish.
Olive bread is also a fine thing, for which the small black olives are best suited.
Herbs that go particularly well with olives are garlic, rosemary, thyme, chili, mint, sage, or basil.
But it doesn’t always have to be hearty when olives are used:
Sweets with olives
As unusual as it may sound, olives go very well with chocolate. And so there are now a wide variety of recipes for chocolate desserts, chocolate cakes, chocolate pralines, and chocolate cakes that are refined with olives.
Yes, with the naturally dried, salt-free olives mentioned above, combined with a sweetener, you can even make drinks that are strongly reminiscent of drinking cocoa.
In any case, remember: If you want to enjoy the full benefits of the valuable ingredients, you should not heat the olives – like the olive oil – too much, otherwise vital substances could be lost. A delicious raw olives recipe is the vegan olive paste tapenade:
Recipe: Vegan Tapenade
Olive paste is a very popular delicacy and there are countless variations. The so-called tapenade is an olive paste from southern France that is excellent for e.g. B. goes well with bread, pasta, and grilled food and provides the final touch in all kinds of sauces. An original tapenade normally also includes anchovies, which we have eliminated from the following vegan recipe.
- 150g pitted black olives
- 1 tsp capers
- 1 clove of garlic
- 1 small chili pepper
- 50ml olive oil
- 0.5 tsp unwaxed lemon zest
- Fleur de Sel
- Place the olives, capers, chili pepper, and garlic clove in a large mortar and grind to a fine paste, gradually adding the olive oil.
- If you don’t have a mortar at home, you can also use a hand blender.
- Add the finely grated lemon zest and the spices.