`Mediterranean Diet with Extra Virgin Olive Oil Lowers Risk of Breast Cancer - Olive Oil Times

Mediterranean Diet with Extra Virgin Olive Oil Lowers Risk of Breast Cancer

By Sukhsatej Batra
Sep. 17, 2015 13:08 UTC

The Mediterranean diet with extra vir­gin olive oil is ben­e­fi­cial in low­er­ing risk of breast can­cer, accord­ing to find­ings of a new study pub­lished in the JAMA Internal Medicine.

The results, based on the long-term fol­low-up of 4,282 women, aged 60 to 80 years enrolled in the PREDIMED trail, add to the ben­e­fits of con­sum­ing extra vir­gin olive oil and the Mediterranean diet. The PREDIMED trial, con­ducted in Spain from 2003 to 2009, was designed to test the ben­e­fit of sup­ple­ment­ing Mediterranean diet with extra vir­gin olive oil or mixed nuts in pre­vent­ing car­dio­vas­cu­lar dis­ease.

In the present study, inves­ti­ga­tors eval­u­ated the effects of sup­ple­ment­ing the Mediterranean diet with either EVOO or mixed nuts on risk of breast can­cer.

The sub­jects enrolled in the study were ran­domly assigned to one of the three inter­ven­tion groups: the Mediterranean diet sup­ple­mented with extra vir­gin olive oil; the Mediterranean diet sup­ple­mented with mixed nuts; or the con­trol Mediterranean diet.

To ensure adher­ence to the inter­ven­tion diets, sub­jects on the Mediterranean diet with extra vir­gin olive oil were pro­vided with 1 liter of EVOO/week, while those in the mixed nut group were pro­vided with 30 grams of wal­nuts, hazel­nuts and almonds per day. Participants in the con­trol diet group were pro­vided dietary train­ing to reduce dietary fat intake.

Results of the study showed that sub­jects on the EVOO sup­ple­mented Mediterranean diet had a 62 per­cent lower risk of devel­op­ing malig­nant breast can­cer than sub­jects on the con­trol diet. Subjects who con­sumed higher amounts of EVOO low­ered their risk of malig­nant breast can­cer even more.

The pos­i­tive effect of extra vir­gin olive oil could be due to the pres­ence of polyphe­nols such as oleu­ropein, oleo­can­thal, hydrox­y­ty­rosol and lig­nans in EVOO that have been iden­ti­fied as anti­car­cino­genic agents. These polyphe­nols exhibit anti- pro­lif­er­a­tive action on the expres­sion of human onco­genes, pre­vent oxida­tive dam­age to DNA in mam­mary epithe­lial cells, inhibit tumor growth and cause apop­to­sis of breast can­cer cells in lab­o­ra­tory exper­i­ments.

Although sta­tis­ti­cally non­signif­i­cant, sub­jects on the Mediterranean diet sup­ple­mented with nuts also had a lower risk of malig­nant breast can­cer com­pared to the con­trol group. However, when results of both inter­ven­tion diet groups were com­bined, risk of malig­nant breast can­cer was reduced by 51 per­cent. Only 35 cases of malig­nant breast can­cer were iden­ti­fied dur­ing the course of the ran­dom­ized trial.

While these results are encour­ag­ing, the authors acknowl­edge that the study has lim­i­ta­tions, one of which is that these results are a sec­ondary analy­sis of the PREDIMED trial that was designed to study effect of EVOO and mixed nuts inter­ven­tion of the Mediterranean diet on pre­ven­tion of car­dio­vas­cu­lar risk.

Another lim­i­ta­tion is that the study was con­ducted on women who habit­u­ally con­sumed the Mediterranean diet, which is known to be pro­tec­tive against breast can­cer due to the high intake of fruits, veg­eta­bles, whole grains, fish and olive oil. Researchers of the paper rec­om­mend more stud­ies to con­firm these find­ings.

  • JAMA Internal Medicine


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