Compound Found in Olive Oil Fights Breast Cancer Relapse

At the Olympia Health & Nutrition Awards conference in Athens, Greece, Dr. Khalid El Sayed discussed his research group’s groundbreaking discoveries: oleocanthal, a natural phenolic compound found in extra virgin olive oil, reduced the recurrence of one type of breast cancer in mice and limited the growth of other types of recurrent tumors.

This controlled study in Professor El Sayed’s laboratory at the University of Louisiana at Monroe demonstrated for the first time that oleocanthal can prevent a relapse in one of the four major types of breast cancer, HER2 dependent breast cancer, as well as decreasing the size of other types of breast cancer tumors that appear after treatment. Another study in El Sayed’s lab showed that a therapy that combines oleocanthal with a conventional breast cancer medication may work better than the drug alone. These findings suggest exciting directions for future research into novel alternatives for cancer treatment. 

Currently, El Sayed told Greek Liquid Gold, “there is no formal absolute test to predict a relapse, nor a formal drug for recurrence prevention; chemotherapeutic cancer drugs are not really able to kill the dormant tumor cells that cause a relapse.” Since most of the world’s cancer survivors are now under medical surveillance following treatment, more than 12 million patients “are living with the nightmare of watching for their relapse,” as El Sayed puts it. For these survivors and their loved ones, this research is crucial. 

Writing in the journal Cancers about their work in El Sayed’s laboratory, Abu Bakar Siddique, Nehad Ayoub, and their group point out that breast cancer (BC) “is the most commonly diagnosed cancer and the second-leading cause of cancer-related death in women worldwide. Globally, two million new BC cases are expected to be diagnosed in 2019, with an estimated 627,000 women anticipated to die from BC complications.” Recurrence remains a problem for about 70% of survivors who have had tumors surgically removed and/or have completed radiation therapy or other treatment.

On the other hand, as El Sayed and his team noted, a “wealth of data documents the reduced risk of Mediterranean populations [for] certain chronic diseases typically emerging later in life, … including atherosclerosis, cardiovascular disease, and particular types of cancer, in addition to extended life expectancy as compared to populations of other geographical regions.” Notably, “these favorable health outcomes have been widely attributed—based on much corroborating epidemiological evidence—to the regular consumption of extra-virgin olive oil (EVOO), which is a major component of the Mediterranean diet.”

El Sayed told Greek Liquid Gold he believes “daily consumption of quality EVOO can have significant preventive impact.” High quality extra virgin olive oil often contains enough oleocanthal (as well as other helpful components) to provide health benefits, and as Siddique et al wrote in Cancers, olive oil has been used “as food and even remedy throughout human history.” In various studies, oleocanthal from EVOO has shown antioxidant, anti-bacterial, neuroprotective, anti-inflammatory, and anti-cancer activities against breast, prostate, colorectal, and skin cancer.

The type of breast cancer known as HER2-dependent, HER2-amplified, or HER2-positive is a very aggressive kind of cancer which accounts for about 20% of diagnosed breast cancer cases. It is commonly treated with the medication Lapatinib, but tumor cells quickly become resistant to this treatment, making it hard to fight the disease. So this research group embarked on a novel investigation using laboratory animals.

As Siddique and his colleagues report in the journal Nutrients, the group compared the effects of oleocanthal, Lapatinib, and a combination of oleocanthal and Lapatinib (LP), with a control group. They found that the combination therapy was most effective: it reduced cancer cell growth and “significantly inhibited” the invasion and migration of breast cancer cells that often lead to death.

Given evidence that it can reduce cancer cell resistance to treatment with LP, oleocanthal thus shows great promise as part of a combination therapy to treat HER2 breast cancer. This study suggests that such a combination therapy could work better than the current treatment, while reducing the required dose of the medication (LP) to ¼ of the original dose.

However, the required dose of oleocanthal would call for consumption of about 700 ml of the best quality EVOO per day. While many enjoy eating The Governor EVOO from Corfu in Greece that was donated by the Dafnis family as a source of the oleocanthal for this and other related studies, few can consume that much in one day. To treat patients who are ill, it would therefore be necessary to extract pure oleocanthal from EVOO for use as a dietary supplement.

El Sayed’s group developed new ways of doing that, as they explain in the journal Plos One. They believe their new technique for “simplified, environmentally friendly, and cost-effective extraction and purification of EVOO phenolics” will make future studies of olive oil phenolic compounds easier “and expand their therapeutic applications.”

Exploring one such application, the group decided to investigate the possibility that oleocanthal could prevent the recurrence of certain types of breast cancer. There have been few investigations into what might inhibit breast cancer recurrence and metastasis (spreading to distant parts of the body), since sound clinical trials would involve a great deal of time, money, and patients. Yet as breast cancer surgery has shifted to a more conservative strategy of removing less tissue than a traditional mastectomy, there have been more recurrent tumors, many of them leading to death. Successful treatment to reduce recurrence is thus essential.

After establishing a useful novel example of a manageable animal model for a laboratory study, El Sayed’s group discovered that with daily oral treatment with oleocanthal, significantly fewer mice developed recurrent tumors in comparison with the control group, and those that did develop more tumors had much smaller ones. The group also extended their exploration to include the most aggressive breast cancer type, triple negative breast cancer, after making a new oral form of oleocanthal. This prevented 60% of triple negative breast cancer relapses in the mice they studied. These findings offer fresh hope for survivors.

As Siddique et al wrote in Cancers, oleocanthal may provide a better option for longer-term prevention and cancer-free survival as resistance to some treatments increases, given oleocanthal’s “remarkable selectivity to targeting cancer cells,” but not healthy ones, without either a very high cost or evidence of other negative side effects, unlike many cancer treatments. “Natural product-based recurrence inhibitors” like oleocanthal offer another advantage: they could be developed and marketed for use as dietary supplements more quickly than medications, whose development and approval takes a long time.

As El Sayed’s group concludes, oleocanthal may have far-reaching positive effects on breast cancer relapse prevention. Once again, Greece’s liquid gold, olive oil, proves its value–this time for cancer survivors.

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