

1. Why is the olive tree called the gift of the gods?
The olive tree, a natural health treasure trove:
The olive tree has been present in the Mediterranean region for 6,000 years. Not just a symbol of history, the olive tree is also a rich source of nutrients Every part of this tree, from its fruit to its leaves and bark, is packed with nutrients beneficial to human health, contributing to a long and healthy life.
Gifts from the olive tree:
Olive fruit is a treasure from nature, bringing countless health benefits. Moreover, olive fruit, with its characteristic fatty taste and attractive aroma, contains a rich source of monounsaturated fat, especially oleic acid, which not only helps reduce harmful cholesterol but also protects the heart and prevents cardiovascular diseases.
In addition, olive oil, pressed from olives, also contains high levels of oleic acid, along with vitamin E and phenolic compounds. Therefore, olive oil stands out as one of the healthiest cooking oils, its powerful antioxidants protect cells from damage, helping to slow down the aging process. Regular inclusion of olives and olive oil in one’s diet can significantly reduce the risk of heart disease and stroke while also promoting healthier skin and hair.

Olive leaves also have many wonderful benefits. They contain many valuable compounds such as oleuropein, flavonoids and phenolic acids, which have antibacterial, antiviral and antioxidant effects. Olive leaves are often used to make tea or extracts, supporting the treatment of some diseases such as high blood pressure, diabetes and infections.

2. What is hydroxytyrosol? Why is it found abundantly in olive trees?
Hydroxytyrosol (HT) can be extracted from olive leaves and oil, existing in a stable, free form that is easily absorbed by cells. Specifically, its chemical formula is C8H10O3, differing from tyrosol only by an additional hydroxyl group at the meta position of the aromatic ring. Furthermore, HT is derived from the hydrolysis of oleuropein during olive ripening (Figure 1). Notably, it is lipid-soluble but also slightly water-soluble. Finally, it can exist as a simple phenol or as acetate or secoiridoid derivatives. (Monteiro et al, 2021)
The average content of HT in olives and derivatives varies, in mg/kg of product, from 3.5 in virgin olive oils, to 7.7 in extra-virgin olive oils, 659 in black olives and 556 in green olives. (Turck, D. et al, 2017)
Figure 1. Chemical structure of (a) oleuropein and (b) hydroxytyrosol.
3. What are the amazing benefits of hydroxytyrosol?
With strong anti-inflammatory and antioxidant properties, hydroxytyrosol stands out as a powerful compound whose antioxidant capacity is second only to gallic acid. As a result, hydroxytyrosol brings great health benefits. (Figure 2)
Figure 2. Principal properties of hydroxytyrosol (Arangia et al, 2023).
- Prevent cancer cells:

One of the primary mechanisms through which hydroxytyrosol exerts its anticancer effects is by inducing apoptosis in cancer cells. Specifically, studies have shown that HT can promote programmed cell death in various cancer types, including breast, colon, and melanoma cancers. For example, hydroxytyrosol treatment has been reported to reduce cell viability and proliferation in human breast cancer and colon cancer cells, thereby leading to increased apoptosis. (Brito et al. 2021;Aghaei et al., 2022;Sun et al., 2014; Imran et al., 2018). Moreover, the ability of hydroxytyrosol to trigger apoptosis is often linked to its capacity to generate reactive oxygen species (ROS), which can damage cellular components and initiate apoptotic signaling cascades (Costantini et al., 2020).
Moreover, hydroxytyrosol has been found to influence the expression of various genes involved in cell cycle regulation and apoptosis. This downregulation leads to cell cycle arrest, thereby inhibiting cancer cell proliferation (Granados-Principal et al., 2010; Zubair et al., 2017). Additionally, hydroxytyrosol has been shown to modulate the expression of pro-apoptotic and anti-apoptotic genes, enhancing the apoptotic response in cancer cells (Hadipour et al., 2020).
Hydroxytyrosol’s anticancer effects are not limited to apoptosis induction; it also exhibits anti-inflammatory properties that can contribute to its overall anticancer activity. The compound has been reported to inhibit the activation of key signaling pathways involved in inflammation and cancer progression (Ramírez-Expósito & Martínez-Martos, 2018). By suppressing these pathways, hydroxytyrosol can reduce tumor growth and metastasis, further supporting its role as a potential anticancer agent.
In addition to its effects on cell proliferation and apoptosis, hydroxytyrosol has been shown to influence angiogenesis, the process by which new blood vessels form from existing ones, which is critical for tumor growth and metastasis. Research indicates that hydroxytyrosol can inhibit angiogenesis by targeting extracellular matrix remodeling enzymes, such as MMP-2, which are essential for endothelial cell migration and invasion during the angiogenic process (García-Vilas et al., 2017). This anti-angiogenic effect adds another layer to hydroxytyrosol’s anticancer potential, as it can limit the tumor’s ability to establish a blood supply.
- Protect Cardiovascular system:

Hydroxytyrosol offers cardioprotective benefits primarily through its potent antioxidant properties, which help neutralize free radicals and reduce oxidative stress—factors closely linked to cardiovascular disease (Poudyal et al., 2010; Silva et al., 2016). In addition, hydroxytyrosol supports vascular health by improving endothelial function, a critical factor in maintaining proper blood flow and vascular tone. By enhancing the bioavailability of nitric oxide, a molecule essential for vasodilation, hydroxytyrosol contributes to improved blood flow and reduced blood pressure, further solidifying its role in cardiovascular protection (Poudyal et al., 2010).
Alongside its antioxidant capabilities, hydroxytyrosol possesses strong anti-inflammatory properties essential for heart health. Specifically, chronic inflammation is a critical factor in the progression of atherosclerosis and other cardiovascular issues. Otherwise, studies show that hydroxytyrosol inhibits pro-inflammatory cytokines and chemokines, thereby reducing vascular inflammation and promoting healthier blood vessels (Sarsour et al., 2014).
Finally, hydroxytyrosol positively impacts lipid profiles by lowering total cholesterol and triglycerides, both of which are closely linked to cardiovascular risk. Furthermore, by protecting LDL particles from oxidation, it helps prevent the formation of atherosclerotic plaques. As a result, this significantly lowers the risk of coronary artery disease. (Silva et al., 2016; Romani et al., 2019; Xu et al., 2022).
- Provides Antimicrobial Properties

Hydroxytyrosol exhibits notable antimicrobial activity against a variety of pathogens, including bacteria, viruses, and fungi. Studies have demonstrated that hydroxytyrosol can inhibit the growth of several bacterial strains, including Staphylococcus aureus and Escherichia coli, by disrupting their cellular membranes and metabolic processes (Imran et al., 2018;Barbaro et al., 2014). The compound’s ability to scavenge free radicals and reduce oxidative stress also contributes to its antimicrobial effects, as oxidative stress is a key factor in microbial pathogenicity (Barbaro et al., 2014). Furthermore, hydroxytyrosol has been shown to enhance the efficacy of conventional antibiotics, suggesting its potential as an adjunctive treatment in combating antibiotic-resistant infections (Imran et al., 2018).
- Have Neuroprotective Effects

The neuroprotective properties of hydroxytyrosol are increasingly recognized, particularly in the context of neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Therefore, hydroxytyrosol has been shown to protect neuronal cells from oxidative stress-induced damage, which is a significant contributor to neurodegeneration. Research indicates that hydroxytyrosol can modulate neuroinflammatory responses by inhibiting the production of pro-inflammatory cytokines and promoting the expression of neuroprotective factors. Additionally, hydroxytyrosol has been found to improve cognitive function and memory in animal models, further supporting its potential as a therapeutic agent for neurodegenerative conditions (Ristagno et al., 2012; Vilaplana-Pérez et al., 2014).
- Prevent osteoporosis
Hydroxytyrosol has demonstrated significant anti-osteoporotic effects, particularly in the context of postmenopausal osteoporosis. Studies have shown that hydroxytyrosol can enhance osteoblast activity and promote bone formation by increasing alkaline phosphatase (ALP) activity, a marker of bone mineralization (Chen et al., 2012; Badary et al., 2022). Furthermore, hydroxytyrosol has been reported to inhibit osteoclast differentiation and activity, thereby reducing bone resorption (Niwano et al., 2022). In vivo, studies have indicated that hydroxytyrosol supplementation can prevent bone loss in ovariectomized rats, a common model for studying osteoporosis (Chen et al., 2012; Badary et al., 2022). These findings suggest that hydroxytyrosol may serve as a beneficial dietary component for maintaining bone health and preventing osteoporosis.
- Promotes Skin Health
Hydroxytyrosol also offers protective benefits for the skin, particularly against oxidative stress and UV-induced damage. Research has shown that hydroxytyrosol can mitigate the harmful effects of UV radiation by reducing oxidative stress and inflammation in skin cells (Zwane et al., 2012; Bulotta et al., 2014). Its antioxidant properties help protect keratinocytes from UV-induced apoptosis, thereby promoting skin health and potentially reducing the risk of skin cancer (Zwane et al., 2012). Additionally, hydroxytyrosol has been found to enhance skin hydration and elasticity, making it a valuable ingredient in cosmetic formulations aimed at improving skin appearance and health (Bulotta et al., 2014).
4. What are the applications of hydroxytyrosol in life?
Functional Foods and Beverages: Hydroxytyrosol is used in foods to enhance their antioxidant content and provide health benefits associated with its bioactive properties. For instance, it is incorporated into edible oils, dairy products, and beverages to create functional foods that support cardiovascular health, reduce inflammation, and improve cellular health (Silva et al., 2020).
Dietary Supplements: Hydroxytyrosol supplements, often sold as capsules or liquid extracts, are marketed for their antioxidant and anti-inflammatory benefits. These supplements aim to support overall health, improve skin vitality, and protect against oxidative stress. They are particularly popular among those looking to benefit from the positive effects of the Mediterranean diet without consuming large amounts of olive oil.
Antioxidant Fortification in Processed Foods: Adding hydroxytyrosol to processed foods, especially those prone to oxidation (such as fish oils and other high-fat foods), helps prevent spoilage and prolongs shelf life. By inhibiting lipid oxidation, hydroxytyrosol preserves the quality of these foods and reduces the formation of harmful oxidation products (Pazos et al., 2008).
Anti-Aging Creams and Serums: The inclusion of hydroxytyrosol in skincare formulations enhances the skin’s resistance to oxidative stress, promoting a more youthful appearance by reducing fine lines and wrinkles.
Moisturizers and Sunscreens: Hydroxytyrosol can enhance the protective effects of sunscreens by neutralizing free radicals produced by UV exposure, thus preventing skin damage and promoting a radiant complexion.
5. Are there any side effects of using Hydroxytyrosol?
- Safety Profile of Hydroxytyrosol
Hydroxytyrosol has been shown to have a favorable safety profile in various studies. Research indicates that it does not exhibit significant toxicity even at high doses. For instance, a study evaluating the acute and sub-chronic oral toxicity of hydroxytyrosol-rich virgin olive oil extracts found no significant adverse effects at doses up to 2000 mg/kg body weight. Additionally, another study reported no toxic effects after a 90-day sub-chronic toxicity test of an extract containing 35% hydroxytyrosol at doses of 125, 250, and 500 mg/kg/day (Rodríguez-Lara et al., 2019). These findings suggest that hydroxytyrosol can be safely consumed without significant risk of toxicity.
Moreover, the European Food Safety Authority (EFSA) has recognized hydroxytyrosol as safe for consumption, emphasizing that it does not cause allergies or interactions with dietary components (Groff et al., 2020). The safety of hydroxytyrosol is further supported by studies that have shown no genotoxicity or mutagenicity in vitro, reinforcing its potential as a safe nutraceutical (Renzo et al., 2023).
- Recommended Daily Dose
The recommended daily intake of hydroxytyrosol varies based on its intended health benefits. The EFSA has established that a daily intake of at least 5 mg of hydroxytyrosol and its derivatives (such as oleuropein and tyrosol) is sufficient to confer health benefits, particularly in protecting low-density lipoproteins (LDL) from oxidative damage (Zhan et al., 2022; Johnson & Mitchell, 2019). This dosage is typically achieved through the consumption of olive oil, where approximately 20 g of high-quality extra virgin olive oil can provide this amount of hydroxytyrosol (Johnson & Mitchell, 2019; Boss et al., 2016)..
- Conclusion
With its diverse and excellent biological properties, Hydroxytyrosol has become one of the most extensively studied natural compounds today and opens up wide prospects for application in the pharmaceutical and healthcare fields.
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