Rome [Italy]: A new study from Italy has found that higher consumption of olive oil may help lower the risk of breast cancer — offering a promising dietary strategy for prevention during Breast Cancer Awareness Month.

The study, published in 2024 in the European Journal of Cancer, examined data from 11,442 women who were part of the Moli-sani cohort. These participants were tracked for nearly 13 years, with researchers analysing their dietary habits and the incidence of breast cancer.

Olive oil and breast cancer: What the study found

The findings revealed that women who consumed more olive oil had a significantly reduced risk of breast cancer. Notably, for every additional tablespoon (about 10 grams) of olive oil consumed daily, the risk of developing breast cancer decreased proportionally.

Researchers described this as a “very linear” relationship — meaning that each incremental increase in olive oil intake led to further reductions in cancer risk, even after accounting for factors such as age, weight, physical activity, and overall diet.

The protective association appeared especially strong against estrogen-receptor–negative (ER-negative) and progesterone-receptor–negative (PR-negative) breast cancers — forms that are typically more aggressive and less influenced by hormonal pathways.

Aligning with earlier research

This latest study supports a growing body of evidence linking olive oil consumption to lower breast cancer risk. A previous meta-analysis pooling data from 14 studies found that women with the highest olive oil intake had a 33% lower risk of breast cancer compared with those who consumed the least.

The results are consistent with findings from Spain’s PREDIMED trial, which showed that older women following a Mediterranean diet enriched with extra virgin olive oil (EVOO) had a 62–68% lower risk of developing breast cancer compared to those on a low-fat diet.

However, the authors of the Italian study cautioned that most of these studies were conducted in Mediterranean populations, where olive oil consumption is higher and dietary patterns differ from those in other regions.

In contrast, studies conducted in non-Mediterranean populations, such as the Nurses’ Health Study in the United States, have shown weaker associations — likely due to lower average olive oil intake and different dietary habits.

How olive oil may help protect against cancer

Researchers propose several mechanisms through which olive oil could offer protection against breast cancer:

  • Bioactive phenolic compounds: Extra virgin olive oil is rich in polyphenols like oleocanthal, hydroxytyrosol, and oleuropein, which have been shown in laboratory studies to trigger cancer cell death while sparing healthy cells.
  • Anti-inflammatory and antioxidant action: Olive oil helps reduce chronic inflammation and oxidative stress — both known contributors to cancer development. Its compounds protect DNA from damage and curb the growth of abnormal cells.
  • Hormonal and non-hormonal pathways: The stronger effect observed in ER-negative cancers suggests that olive oil may work through non-hormonal mechanisms, such as regulating gene expression and cell signalling.
  • Reduced tumour aggressiveness: Animal studies indicate that olive oil–rich diets may lead to fewer, smaller, and less aggressive tumours compared to those high in seed oils or saturated fats.

Context and limitations

While the results are promising, scientists emphasise that olive oil is not a standalone prevention method. Its benefits are most evident when part of a balanced, plant-based Mediterranean diet, which includes fruits, vegetables, whole grains, legumes, nuts, and fish.

Moreover, the type and quality of olive oil matter. The strongest effects are seen with extra virgin olive oil (EVOO) — minimally processed and high in bioactive compounds.

Experts also note that more long-term randomised controlled trials are needed to confirm these findings and establish causality. Future studies may explore dose-response effects, differences among cancer subtypes, and interactions with other dietary factors.

Key takeaways for prevention

While olive oil may play a role in lowering breast cancer risk, traditional prevention strategies remain essential. The World Health Organization (WHO) continues to emphasise:

  • Maintaining a healthy body weight
  • Staying physically active
  • Limiting alcohol and avoiding tobacco
  • Participating in routine cancer screenings

According to WHO, around 2.3 million women were diagnosed with breast cancer in 2022, and approximately 6.7 lakh lost their lives to the disease. The agency projects that both incidence and mortality could rise by 40% by 2050, particularly in regions with limited healthcare infrastructure.

In light of these figures, lifestyle and dietary modifications — including incorporating olive oil as part of a healthy diet — could offer a simple yet meaningful step toward reducing the global burden of breast cancer.