Health Benefits of Olive Oil

Updated February 2009 - Research published in the January 2007 journal of The Federation of American Societies for Experimental Biology (FASEB) suggested that significant differences in cancer rates between northern and southern Europeans may be explained by the anti-cancer effects of olive oil in the diet. Volunteers from Denmark, Finland, Germany, Italy, and Spain consumed 25 millilitres of olive oil every day for three weeks. Urine samples were tested for by-products of oxidative cell damage, a precursor to cancer. At the beginning of the trial, the level was much higher in northern European compared to southern European subjects. However, after three weeks, the level in northern European subjects was substantially reduced.

Henrik E. Poulsen, of Rigshospitalet, Denmark and lead investigator said:

"Determining the health benefits of any particular food is challenging because it involves relatively large numbers of people over significant periods of time. In our study, we overcame these challenges by measuring how olive oil affected the oxidation of our genes, which is closely linked to development of disease. This approach allows us to determine if olive oil or any other food makes a difference. Our findings must be confirmed, but every piece of evidence so far points to olive oil being a healthy food. By the way, it also tastes great."

The study also found that phenols in olive oil are not the only compounds that reduce oxidative damage. Phenols are present in a wide range of everyday foods, such as dark chocolate, red wine, tea, fruits, and vegetables. Despite reducing the level of phenols in the olive oil, subjects still demonstrated the same level of health benefits.

A study published more recently in BMC Cancer has confirmed the bioactivity of polyphenols present in extra virgin olive oil against breast cancer cell lines. The in Vitro study was conducted by Javier A. Menéndez, of the Catalonian Institute of Oncology (ICO), in collaboration with Professors Alberto Fernández Gutiérrez and Antonio Segura Carretero, of the University of Granada. They tested the effect of fractions of phenolic compounds directly extracted from extra virgin olive oil against both positive and negative HER2 breast cancer lines. and confirmed the potentiality of polyphenols to inhibit HER2 activity and to promote its degradation.

Other Factors in the Mediterranean Diet

A study published in the Archives of Internal Medicine concludes that eating a Mediterranean diet and following national recommendations for physical activity (see Exercise Benefits Cancer Survival are each associated with a reduced risk of death over a five-year period. The studies draw on data from the National Institutes of Health-AARP Diet and Health Study, based on initial questionnaires completed by 566 407 volunteers aged 50 to 71 from six U.S. states between 1995 and 1996.

Dr Panagiota N. Mitrou then of the National Cancer Institute, Bethesda, Maryland, and now of the University of Cambridge, England, and colleagues used a nine-point scale to assess conformity with the Mediterranean diet in 380 296 participants (214 284 men and 166 012 women) with no history of chronic disease. The diet included vegetables, legumes, fruits, nuts, whole grains, fish, ratio of monounsaturated fats, alcohol and meat. During five years of follow-up, 12 105 participants died, including 5985 from cancer and 3451 from cardiovascular disease. Those with higher Mediterranean diet scores were less likely to die of any cause (including cancer or heart disease).

Another study reported in the journal Thorax found that a "Mediterranean" diet - including fruits, vegetables, whole-grains, legumes, nuts, and olive oil - also protects against allergic rhinitis and asthma symptoms in children. The researchers looked at dietary habits, respiratory symptoms, and allergic reactions of nearly 700 young people between 7 and 18 years of age living in rural Crete, the largest of the Greek islands.

While skin allergies are fairly common on the Greek island, allergies such as asthma and allergic rhinitis are comparatively rare. The extent to which the children adhered to the mediterranean diet was evaluated from detailed parental questionnaires and compared with any allergic symptoms they had. In fact, eight out of 10 participants in the study consumed fresh fruit, and more than two thirds ate fresh vegetables, at least twice per day.

The researchers concluded that:

• The mediterranean diet had it strongest effect on allergic rhinitis, but gave protection against asthma symptoms and skin allergy.
• Participants who consumed nuts a minimum of three times a week were least likely to wheeze. Nuts are rich in vitamin E, a primary defence against the cellular damage caused by free radicals. They also contain high levels of magnesium, involved in protection against asthma and boosting lung power.
• Daily consumption of oranges, apples, and tomatoes also reduced wheezing and allergic rhinitis.
• Grapes seemed to be particularly effective against wheezing and allergic rhinitis, even after adjusting for other significant factors. The researchers said that red grape skin contains high levels of antioxidants as well as resveratrol, a potent polyphenol.
• Conversely, high consumption of margarine led to a doubling of the likelihood of asthma and allergic rhinitis.

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