Food to Fight Breast Cancer
Breast cancer is the most common cancer in UK women, with over 50,000 women being diagnosed with the disease every year. One in eight women in the UK will develop breast cancer at some point in their lifetime1.
Breast cancer can be caused by several different factors, including genetics and increased age. It is thought that approximately 27% of breast cancer cases could have been prevented, had the patient made healthier lifestyle choices – such not smoking or drinking, maintaining a healthy weight and exercising regularly2.
If you have received a breast cancer diagnosis, the amount of information available on preventing recurrence can be overwhelming and often contradictory. In this article, we will look at the findings of some of the most current scientific research into breast cancer and diet, because the right anticancer diet can help to support medical treatment, and prevent disease progression.
Dairy and breast cancer
Probably one of the most contentious topics regarding breast cancer and diet relates to the consumption of dairy products. Eating dairy products such as milk, butter and yoghurt, has been shown to be a possible risk factor in breast cancer3,4. This is thought to be either due to dairy sourced hormones5, high levels of fat, pesticide residue in the milk, or high levels of calcium, however the exact mechanism of action appears to be unclear.
The presence of hormones and growth factors in milk, is one of the most commonly cited hypotheses amongst nutritionists. Insulin-like growth factor I (IGF-1) is a growth factor that has been shown to promote breast cancer growth6,5. Milk naturally contains IGF-1, however dairy farmers often give dairy cows bovine growth hormone (BGH), which further increases the concentration of IFG-1 in the cow’s milk7.
The saturated fat content of dairy products is also of concern to nutritionists, as high saturated fat intake has been (not-conclusively) associated with increased breast cancer risk. It has been suggested that high levels of saturated fat in the diet, increases circulating oestrogen concentrations and raises the breast cancer risk8.
Given the above concerns, if you have breast cancer or are at high risk of developing breast cancer, you should avoid dairy products.
Soy and breast cancer
Soy consumption is another topic that causes confusion and concern with regards to breast cancer. Soy contains isoflavones, compounds that exert oestrogen-like actions in the body. These properties have led soy consumption to be linked to an increased risk of breast cancer.
Some studies have shown that if you give concentrated isoflavones to rats, it can promote the growth of breast cancer cells, however this isn’t directly comparable to human consumption of soy – because the amount of flavone intake through diet is significantly lower, and the human body processes dietary soy differently to rats.
In fact, scientific studies now increasingly show that eating moderate amounts of soy can have a beneficial and protective effect against breast cancer and its consumption has been linked to increased survival in some breast cancer patients.
If you have breast cancer, current research suggests that soy products are not only safe to consume, but may also protect against disease relapse.
Mediterranean diet and breast cancer
The Mediterranean diet is generally considered to be one of the most beneficial diets for women with breast cancer. The diet is naturally rich in fruits, vegetables, nuts, legumes and extra virgin olive oil, and has been associated with a significantly reduced risk of breast cancer9. The reason for this reduced risk may be due in part to the diet being rich in complex carbohydrates – found in fruits, vegetables, whole grains and legumes – which have been shown to lower the risk of developing breast cancer by 32%10.
Other compounds, such as phytonutrients, found in fresh fruits and vegetables, are known to exert an active anticancer effect. Some of these natural compounds are being further investigated for their anti-breast cancer properties. For example, the naturally occurring compound luteolin, found in celery, broccoli, thyme and parsley, has been recently shown to reduce the risk of metastasis originating from triple-negative breast cancer in women11.
Very recently published research has shown that adherence to the Mediterranean diet is particularly effective at reducing the risk of developing oestrogen-receptor-negative (ER-negative) breast cancer12.
While a diet rich in vegetables and legumes helps to lower risk of breast cancer, a recent study has linked the consumption of grilled, barbequed or smoked meats, to a higher risk of mortality in breast cancer survivors13. This risk may be due to the increased amount of saturated fats present in meat, as well as the production of heterocyclic amines (HCA) and polycyclic aromatic hydrocarbons (PAH) produced during the cooking process14.
Finally, high levels of vitamin D have been linked to higher survival rates amongst breast cancer patients. The active compound in vitamin D, calcitriol, has been shown in mice to prevent the proliferation and growth of cancer cells, prevent angiogenesis (blood vessel formation around the tumour) and trigger tumour cell suicide. Research has shown that women with low levels of vitamin D receptor expression were associated with more aggressive forms of breast cancer15. This research is in its infancy, but women with breast cancer can naturally boost the vitamin D levels in their diet by eating fortified plant-based milks, oily fish and eggs.
Breast cancer and diet summary
Huge amounts of research into breast cancer and diet gives us plenty of information to shape an appropriate anticancer diet for breast cancer patients. This guidance should be used as a complement to the treatment advised by your oncologist.
Current research suggests that the diet should contain plenty of fresh fruits, legumes and vegetables, in particular broccoli, celery, soy and fresh herbs. The diet should include plenty of extra virgin olive oil, oily fish and eggs, but be low in saturated fats and red animal meats. Dairy products should be avoided by breast cancer patients.
For more information on how to complement chemotherapy, radiotherapy and surgery with diet, the book ‘Food to Fight Cancer: What Your Doctors Aren’t Ready to Tell You’ is available to purchase from The Green Apple Club, or Amazon Kindle. This book summarizes over 100 recent studies into food and diet, using science to design the ultimate anticancer diet.
You can also purchase a unique Anticancer Snack Hamper from The Green Apple Club or Amazon UK to discover new, delicious and portable snacks that contain anticancer compounds. Treat yourself to a hamper, or gift a hamper to a loved one with cancer – hampers are currently available for UK shipping only.
Medical disclaimer – the studies in this article are provided for information only and the article is not intended to be used as medical advice. The natural compounds in food are not a treatment for cancer, but are recommended as a way of supporting the medical treatment pathway recommended by your oncologist. Always discuss significant dietary changes with a medical professional.