Can olive leaf extract boost the immune system? All the health benefits.

The olive leaf extract can improve the immune system. It has so many health benefits.

Olive leaf extract is used for centuries. It is produced from the leaves of the olive tree. Its properties are due to the high amount of phenolic compounds. Specifically oleuropein.

Above all, olive leaf extract has heavily researched from its antimicrobial, cardioprotective, anti-oxidant and anti-inflammatory properties.

Olive leaf extract for relief of symptoms of cold & flu

The common cold is the leading cause of doctor visits in the United States. More than 1 billion cold cases happen every year.

According to 2007 data, influenza infection is still a leading cause of mortality. It causes more than 36,000 deaths per year in the United States alone.

Luckily, olive leaf extract may help us. Due to oleuropein.

That’s a powerful phenolic compound that is effective against numerous microorganisms. For instance, it can help against retroviruses, coxsackieviruses, influenza, and parainfluenza.

Seems like, it interacts with the protein of virus particles.

As a result, it may make viruses less infectious. Additionally, it may inhibit the ability of viruses to replicate.

Viruses which cause colds, influenza, and lower respiratory infection are mostly affected.

So, olive leaf extract may enhance the immune system against certain viral infections.

Additionally, it is believed that olive leaf extract can shorten the duration of a cold or the flu. It may relieve you from symptoms such as sore throat, fever, or cough. 

Although, olive leaves have antimicrobial, antioxidant, and anti-inflammatory properties, more research is needed.

Ask your physician before consuming any supplement.

Olive leaf extract for a healthy heart

Studies have shown that olive leaf extract has cardioprotective, anti-oxidant and anti-inflammatory properties (2). Due to polyphenols in olive leaf extracts.

Additionally, extra virgin olive oil and fruits are rich in polyphenols. But olive leaf extract is richer in certain phenolic compounds.

Research has shown that olive leaf extract has so powerful compounds that can treat chronic inflammatory diseases.

Moreover, they can also reduce cardiovascular risks (3).

Dosages of 25-50 mg of olive leaf extract per kg gave the best results. Especially in improving blood pressure and cardiac performances (3).

Can help get low cholesterol?

Olive leaf extract is a good source of a powerful phytochemical, called oleuropein.

Oleuropein protects the heart. It fights the low-density lipoprotein (LDL) oxidation (5). The LDL is the “bad” cholesterol.

In another 2015 study, scientists gave animals a high cholesterol diet. The observed that olive leaf extract along with cholesterol-drugs significantly decreased both total cholesterol and LDL-cholesterol levels.

So, they came to the conclusion, that olive leaf extract may have beneficial effects on atherosclerosis. Atherosclerosis refers to the buildup of fat and cholesterol on your artery walls. That’s bad for the heart, as the blood flow is restricted.

Can it help you maintain normal blood pressure?

Olive leaf extract may help you maintain a normal blood pressure.

Scientists found that a dose of 50 mg/kg greatly improved blood pressure (3).

Additionally, it boosted the immune system, improving the antioxidative defense.

If you have high blood pressure always consult your physician, before taking any additional supplement. It may interact with your medication.

Do olive leaf extract supplements have anti-cancer properties?

Most noteworthy, olive leaf extract can strengthen immune system.

It can help the anti-tumor activity of the body (2).

Many studies have shown the anti-cancer properties of polyphenols (6).

Not only is olive leaf extract, but also extra virgin olive oil is rich in these cancer-fighting compounds.

Moreover, a diet rich in these cancer-fighting compounds along with the intake of an olive leaf extract supplement would be more effective, against some types of cancer.

What diet has an anti-cancer effects?

The cancer-fighting compounds are called polyphenols. They are present in plants. Diet rich in polyphenols are good for you.

For instance, the Mediterranean diet is high polyphenols. Due to the high consumption of vegetables, fruits, and olive oil.

Many studies have shown the health benefits of the Mediterranean diet.

For instance, in a large clinical study, scientists found a decrease in cancer risk by 61%, for people following the Mediterranean diet (6). Moreover, people had a decreased risk of mortality by 56%.

The Mediterranean diet means a high consumption of vegetables, legumes, fruits, and whole grains. Foods high in fiber.

Fiber is so important for our health. It’s only present in plants. So many foods are rich in fiber. For instance, potatoessweet potatoes, oatmealricespinachbroccoli, peppers, Brussel sproutsbananasapplescarrots, or avocados are all high in fiber.

Health benefits of olive oil

Furthermore, virgin olive oil may help on certain cancers.

Indeed, olive oil has linked to a lower risk of colon, breast and skin cancer (6).

Olive oil has anti-tumor properties, as well.

But why olive oil has these anti-cancer properties?

There are three reasons:

  • Firstly, it has a high content of oleic acid. Oleic acid doesn’t oxidate as easily as other fatty acids. For instance, palm, soybean, or sunflower oils are rich in n-6 polyunsaturated fatty acids that oxidate easily. So, olive oil is the best vegetable oil.
  • Secondly, olive oil has many antioxidants. Hydroxytyrosol and oleuropein are most abundant.
  • Finally, olive oil may reduce the bioavailability of both environmental and food carcinogens.

Oleuropein has anti-cancer properties

However, the most powerful antioxidant is oleuropein. We mainly find it in the olive leaf extract.

Most noteworthy, oleuropein fights directly tumor cells.

Furthermore, oleuropein has a strong anti-angiogenic function. It fights cancer progression in multiple steps, restraining the growth of tumor mass (6).

Osteopenia, osteoporosis, healthy bones

Oleuropein may protect the bone mass as well.

Oleuropein is an antioxidant with powerful anti-inflammatory and anti-oxidative properties. But what’s the effect on bone mass?

In a study on animals, scientists found that oleuropein can protect bones. It fights against the mechanisms that promote bone loss (6).

Most noteworthy, oleuropein both reduced bone loss and improved inflammatory biomarkers.

Moreover, a 2015 study tried to find out the effect of olive polyphenol extract to postmenopausal women with decreased bone mass, called osteopenia.

Olive leaf extract significantly improved the biomarkers that are linked to reduced bone loss. Moreover, it helped women with osteopenia to develop bone mass.

Further research is needed to find out the effect of olive leaf extract to women with osteoporosis though. Osteoporosis means an increased risk of fracture. Luckily, the results are promising.

Another study showed a positive effect of oleuropein and hydroxytyrosol intake in bone mass. These polyphenols are abundant in olive parts. They both promote bone formation. Also, they prevent bone loss.

Scientists believe that the olive polyphenols, oleuropein and hydroxytyrosol may have critical effects on the formation and maintenance of bone.

Most noteworthy, they can be used as effective remedies in the treatment of osteoporosis symptoms.

Alzheimer’s & Parkinson’s disease

Oleuropein has a therapeutic potential against Alzheimer’s and Parkinson’s disease.

Firstly, oleuropein is one of the most important neuroprotective polyphenols (6).

Moreover, both Alzheimer’s and Parkinson’s disease are neurodegenerative diseases. It means that neurons lose progressively their function or structure.

In some extent, this is normal. The progression of degenerative diseases is part of the aging process.

So, we want to slow down the aging process. Contrary, DNA damage and oxidative stress accelerates it.

As oleuropein has potent anti-oxidant properties, it may be a key factor for Alzheimer’s and Parkinson’s disease.

Is olive leaf extract a natural antibiotic?

Olive leaf extract has preservative properties, due to anti-microbial activity (1).

Moreover, we can use it as a natural preservative of food. Oleuropein, abundant in olive leaf extract, can protect us against some foodborne pathogens. 

Oleuropein is in all parts of olive tree, but most concentrated in olive leaves.

So, why the food industry doesn’t use oleuropein as a food preservative? Because of its bitter taste…

But, on the other hand, plant antimicrobials are safe, in comparison to synthetic food preservatives. Additionally, they have great health benefits.

Furthermore, olive leaves contain many polyphenol types.

For instance, they are rich in vabascoside. Vabascoside is another strong polyphenol. Even more effective than oleuropein. Especially for inhibiting bacterial growth.

So, some compounds in olive leaf extract can fight effectively specific pathogens in food. Studies have shown that oleuropein and vabascoside can control Escherichia coli and Salmonella.

Moreover, olive leaf compounds can inhibit viruses, retroviruses, bacteria, yeasts, fungi, molds, mycoplasmas, and other parasites, particularly in the gastrointestinal and respiratory tracts (7).

Besides oleuropein, other powerful compounds of olive leaf extract are vabascoside, hydroxytyrosol and tyrosol.

In conclusion, some compounds in olive leaf extract can reduce the risk of microbial infections.

Is olive leaf extract good for inflammation?

Most noteworthy, olive leaf extract is a good supplement for inflammation (5).

Olive leaf extract has so potent anti-oxidant and anti-inflammatory activities that can help on chronic inflammatory disease (2).

Once again, oleuropein is the major component responsible for this anti-inflammatory effect.

In conclusion, the olive leaf extract is a powerful natural supplement.

Does olive leaf extract kill viruses?

As already mentioned, some compounds of olive leaf extract can inhibit viruses, retroviruses, bacteria, fungi, molds, and parasites. Especially in the gastrointestinal and respiratory tracts (7).

Once again, oleuropein is the most important compound.

It has potent antiviral activity. Oleuropein is particularly effective against (6):

  • hemorrhagic septicemia rhabdovirus (VHSV),
  • hepatitis B virus (HBV) and
  • human immunodeficiency virus (HIV).

In conclusion… Olive leaf extract may help against certain viruses.

Can it help against fatigue after exercise?

Severe exercise releases free radicals in the body.

After a demanding workout or a race, skeletal and cardiac muscles are flood with free radicals.

It’s important for an athlete to quickly remove these free radicals. Less free radicals mean less fatigue.

Therefore, it’s essential to increase the antioxidant capacity of the body. In order, to avoid damage from free radicals (4).

The best way to boost your immune system with antioxidants is by eating many vegetables and fruits. It’s the most effective method. Especially for athletes or active persons.

As a bonus, olive leaf extract may help on the recovering process. Especially due to its powerful antioxidant activity.

Less recovery time, means more often and demanding workouts. So better results.

Remember… Olive leaf extract can reduce fatigue.

Does olive leaf extract help you lose weight?

Certainly, olive leaf extract may help you lose weight. Due to oleuropein.

Oleuropein supplementation in animals reduced not only body weight, but also, the fat in liver (5).

Olive leaf extract supplementation can prevent obesity development. By regulating adipogenesis and thermogenesis (8).

Adipogenesis is the formation of fat cells.

Furthermore, thermogenesis is the process of heat production. Through thermogenesis, the body burns extra calories. Also, it boosts metabolism. Most noteworthy, the body burns more fat.

People buy thermogenic supplements to take advantage of these effects. Unfortunately, they may have side effects.

Contrary, olive leaf extract is a natural thermogenic supplement. Without side effects. Only extra health benefits…

Remember…Olive leaf extract supplements can help you burn more fat and lose weight.

Is olive leaf extract good for diabetes?

Moreover, olive leaf extract may be beneficial for people with diabetes.

Firstly, it can prevent people from gaining weight. Obesity greatly increases the risk of type 2 diabetes.

Secondly, studies have shown that polyphenols in olive leaf extract can prevent diabetes (8).

Also, they may prevent hypertension, atherosclerosis, cancer, and cardiovascular diseases…

Consult your physician if you have diabetes. Olive leaf extract may help you.

Is olive leaf extract high in minerals and vitamins?

Olive leaf extract has so many health benefits due to the high polyphenol content.

Unlike vitamins and minerals, polyphenols are not essential elements.

Certainly, they play a critical role in the human body.

Above all, they are found only in plants. So, a whole food plant-based diet seems the best option….

What’s the best source of oleuropein and other polyphenols?

Both olive leaves, olive seeds, and olive oil are rich in polyphenols.

Extra virgin olive oil is a polyphenol-rich vegetable oil. So, it seems the best choice, in comparison to other vegetable oils, such as sunflower, or canola oil.

Additionally, as a bonus, we absorb a large part of the ingested olive oil phenols (5).

Contrary, the amazing health benefits of olive leaf extract are due to oleuropein.

Oleuropein is a compound found mainly in olive leaves, seed, pulp and peel of unripe olives (5).

Olives have a bitter taste because of oleuropein.

Finally, several factors determine the amount of oleuropein in extra virgin olive oil (1,5):

  • kind of olive fruit,
  • ripening stage,
  • production technologies,
  • geographical location,
  • plant nutrition, or
  • period of harvesting.

So, if you buy olive leaf extract supplements always look at the nutrition facts, for the oleuropein content.


  1. A 2019 study of the University of Molise: Efficacy of olive leaf extract.
  2. A 2018 study of the University of Bari: Olive Leaf Extracts Act as Modulators of the Human Immune Response.
  3. A 2017 study of the University of Belgrade: Highly potent antioxidant Olea europaea L. leaf extract affects: The role of oleuropein
  4. A 2018 study of the University of Medical Sciences, Ahvaz: The effects of olive leaf extract and 28 days forced treadmill exercise
  5. A 2018 study of the University of Central Florida: Oleuropein Is Responsible for the Major Anti-Inflammatory Effects of Olive Leaf Extract.
  6. A 2014 study of the University of L’Aquila: Effects of the Olive-Derived Polyphenol Oleuropein on Human Health
  7. A 2015 study of the Qom University of Medical Sciences: Evaluation of the antifungal activity of olive leaf aqueous extracts
  8. A 2019 study of the Institute of Research and Development: Inhibitory Effect of Olive Leaf Extract on Obesity in High-fat Diet-induced Mice