Mediterranean Diet Enhanced With Olive Oil May Decrease Breast Cancer Risk, According to Research

Key Takeaways:

• Research suggests a Mediterranean diet enhanced with olive oil could possibly lower breast cancer risks.
• The study, conducted over five years with over 4,200 women, found a 68% reduction in breast cancer risk among those who included olive oil in a Mediterranean diet as compared to those on a control diet.
• Olive oil, consumed about 4 tablespoons a day, might contain elements that hinder the growth of cancer cells.
• Despite the positive findings, factors such as women’s nutrition prior to the study, exercise patterns, and individual dietary habits could have influenced the outcomes.
• Experts advise it’s never too late to adopt healthier eating habits for overall health and breast cancer prevention, even if the exact mechanisms are not entirely understood.

The well-known Mediterranean diet, abundant in plant foods, fish and the star ingredient, olive oil is not only beneficial to the heart and brain but promotes overall health. Recent research findings from Spain suggest that the intake of this diet, fortified with olive oil, may indeed lower your breast cancer risks.

A Dive into The Study

Over 4,200 women aged between 60 and 80 were randomly selected to partake in the study. They were assigned to either stick to a Mediterranean diet supplemented with extra virgin olive oil, nuts or stick to a low-fat diet.

Dr. Miguel Angel Martinez-Gonzalez, a researcher at the University of Navarra in Pamplona, Spain, stated, “We discovered a strong correlation between long-term adherence to the Mediterranean diet supplemented with extra virgin olive oil and a lowered incidence of breast cancer.”

Compared to those sticking to the control diet, participants who included olive oil in the Mediterranean diet had a 68% reduced risk of developing breast cancer, a trend observed over about five years.

Other Findings

The Mediterranean diet with nuts also showed a reduced risk, however, the results didn’t return statistically significant. Over the course of the follow-up, 35 new cases of breast cancer were diagnosed.

The women, all characterized by a high risk of heart disease, and a BMI rating of 30— which falls under obesity, a known risk factor for breast cancer, voluntarily joined the research study conducted between 2003 and 2009.

The research was done as a part of the PREDIMED study, designed to observe the diet’s effect on heart disease prevention. Despite several of the co-authors being recipients of grants from the nut industry and fees from pharmaceutical companies, it’s also important to note that the research had limitations.

One of such was the lack of clarity if whether the olive oil provided benefits on its own or within the content of the Mediterranean diet.

The Olive Oil’s Possible Role

So, how does the olive oil deliver its magic in the diet? Martinez-Gonzalez conjectured that the olive oil’s contents may hinder the growth of breast cancer cells, kill abnormal cells among other mechanisms.

The group assigned to include olive oil in their diet were instructed to consume about 4 tablespoons a day, using it as a spread, for salads, and for cooking and frying.

“Despite the research being conducted with Spanish women, there’s no reason to believe these biological mechanisms won’t be effective in women from other geographical regions,” Martinez-Gonzalez stated.

The study also suggests that it’s never too late to adopt healthier eating habits.

Expert Opinions

Connie Diekman, author of “The Everything Mediterranean Diet Book” and director of university nutrition at Washington University in St. Louis who assessed the study findings stated: “Even though the number of [breast cancer] cases was relatively small, therefore making it challenging to definitively attribute the difference to the diet, the fact that the diet with extra virgin olive oil resulted in fewer cases of breast cancer should be evaluated further.”

Questions remaining include the impact of the women’s nutrition before the study had, and how factors like exercise might have influenced the outcome of the study.
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It is of extreme value to note that the Mediterranean diet continues to support our overall health as revealed in research. Altering an eating routine to comprise more plant food and plant-based fats would certainly be rewarding for overall health, even if the mechanisms are not entirely understood,” Diekman said.

Dr. Lesley Taylor, a breast surgeon and assistant clinical professor of surgical oncology in the Breast Program at City of Hope Cancer Center, also reviewed the results and commended the large number of women who partook in the study.

Studies Hints at Positive Outcomes

She dubbed the study findings “promising news for people invested in breast cancer prevention.” However, she also tempered it by stating that the results might not translate to all groups of women and that “longer-term studies are still required,”.

She recommends other strategies for reducing breast cancer risk can include eating a diet rich in vegetables, moderate consumption of alcohol, non-smoking, and regular breast cancer screenings as advised by a doctor.

Learn More

To further understand the Mediterranean diet, you can read more about it at Oldways.