Benefits of a Mediterranean diet in breast cancer

Modern medicine has tended to recommend a pill for every ill. However, there is a growing movement within the medical profession, supported by research, that food may have the power to prevent the most serious conditions, including heart disease, diabetes and cancer.

We all know that prevention is better than cure. Our friends at Viridian Nutrition have highlighted evidence showing how diet and lifestyle modifications can positively affect an individual’s health.

Breast cancer is an increasing concern. Since the 1990s, incidence rates have risen by approximately 19% in the UK, with mortality exceeding 11,433 in 2014, 99% female (Cancer Research UK). Many risk factors are associated with breast cancer, including genetics, environmental factors, endocrine hormones and menopausal status. Whilst most of these factors are largely unchangeable, research is lately identifying a relationship between the risk of developing breast cancer and an individual’s diet, hoping to find an adjustable lifestyle component that could help reduce the risk of developing the disease.

It is thought that the Westernised diet, which is infamously rich in dairy, processed meats and refined sugars, could play a role in developing cancer risk. However, evidence for an association with breast cancer remains inconclusive. On the other hand, epidemiological studies have identified a risk-reducing effect for those following a healthy balanced diet, specifically the Mediterranean diet.

Following a Mediterranean diet

A 2014 observational study found that following a Westernised diet correlated with a higher risk of developing or progressing breast cancer. In contrast, individuals in the higher quartile of Mediterranean diet adherence had a 56% lower risk than those in the lower adherence category. This protective effect was stronger for triple-negative tumours (68%) (1).

Traditionally, the Mediterranean diet comprises high-quality fresh fruit and vegetables, fish, olive oil, legumes, nuts and seeds and garlic. With a moderate intake of alcohol (wine) and little-to-no red meat or dairy consumption. These diet choices provide a favourable balance of fatty acids, antioxidants, vitamins and minerals.

Recent control trials have put the diet to the test. In 2015, a Spanish intervention investigated the effects of women following either a Mediterranean diet supplemented with extra virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control low-fat diet (2).

This long-term randomised trial (over four years) found that:

• Women following a Mediterranean diet supplemented with additional extra virgin olive oil showed a 62% relatively lower risk of breast cancer incidence compared to the control diet.
• Women following a Mediterranean diet supplementing with additional nuts had a non-significant risk reduction.
• The two Mediterranean diet interventions had a combined relative risk of 51%.

The study observed that higher consumption of extra virgin oil (> 15% of total energy intake) could be instrumental in obtaining this significant protection. Olive oil contains high levels of polyphenols shown in other research to offer powerful antioxidant properties.

Additional research has focused on the influence the Mediterranean diet has on breast cancer reoccurrence. After a three-year follow-up, women who had previously been treated for early breast cancer and followed a Mediterranean diet compared to their standard diet were significantly less likely to relapse. Eleven patients from the standard diet group had a breast cancer recurrence during the study, whilst there were no new breast cancer cases in the Mediterranean diet group[iii].

The case for a Mediterranean diet

The European Prospective Investigation into Cancer and Nutrition (EPIC) study concluded that higher adherence to the Mediterranean diet is associated with a lower risk of breast cancer in postmenopausal women, with a greater reduction in hormone receptor-negative tumours. The diet provides abundant plant-based foods rich in flavonoids, carotenoids, vitamins C and E, which play an important role in neutralising free radicals and preventing DNA damage(4).

With evidence suggesting that our diet could be a modifiable risk factor for cancer development, it is important to change eating habits towards a healthier outlook. Some easy takeaway tips:

• Replace all fats with Extra Virgin Olive Oil.
• Include sauces made from tomatoes cooked with garlic and rosemary.
• Reduce red meat consumption and eliminate processed meats.
• Cook at lower temperatures and add liquid to stew food.
• Use small amounts of good quality meats to flavour legumes or soups (for meat-dominant eaters).
• Replace simple carbohydrates (white bread, white pasta, refined sugars, milk) with complex carbohydrates (whole grains, rolled oats, lentils, chickpeas).
• Nourish your diet with a wide variety of fresh organic vegetables and fruits. Raw is best.

Author: Katie Bell, MSc BSc, nutritionist and biochemist, is a Technical Advisor at Viridian Nutrition.

Viridian Nutrition is the leading supplier of food supplements to specialist independent health food stores, www.viridian-nutrition.com. For information about personalised solutions, visit http://www.findahealthstore.com

References:

1. Castelló, A et al. “Spanish Mediterranean Diet And Other Dietary Patterns And Breast Cancer Risk: Case–Control Epigeicam Study.” British Journal of Cancer 111.7 (2014): 1454-1462. Web.

2. Toledo, Estefanía et al. “Mediterranean Diet And Invasive Breast Cancer Risk Among Women At High Cardiovascular Risk In The PREDIMED Trial.” JAMA Internal Medicine 175.11 (2015): 1752. Web.

3. Biasini, C. et al. “A05effect Of Mediterranean Diet On The Prevalence Of Breast Cancer Relapse: Preliminary Results Of The “SETA PROJECT”.” Annals of Oncology 26. suppl 6 (2015): vi4.2-vi4. Web.

4. Buckland, G et al. “Adherence To The Mediterranean Diet And Risk Of Breast Cancer In The European Prospective Investigation Into Cancer And Nutrition Cohort Study.” International Journal of Cancer 132.12 (2012): 2918-2927. Print.