By Edwina Green, Corporate Nutritionist

Wear it Pink is the charity Breast Cancer Care annual October campaign to raise Breast Cancer Awareness. Thanks to the work of researchers, charities and oncologists the survival rates for breast cancer are some of the best for cancer in the country, with 2/3 of women surviving for 20 years or more [1]. Nevertheless, in 2013 there were 150 new cases of breast cancer diagnosed every day and Cancer Research UK cites oestrogen exposure as the main potentially avoidable risk factor for breast cancer [1].   The good news is that there are a number of nutritional and lifestyle steps we can take to reduce our exposure to excess oestrogen.

There are three sources of oestrogen:

  • Endogenous oestrogen: oestrogen naturally produced by our body that plays a vital role in reproduction, bone growth and blood clotting,
  • Phytoestrogens: compounds, produced by plants, which are molecularly similar to oestrogen and have the ability to bind to oestrogen receptor sites in human cells, but are less potent than endogenous estrogen.
  • Xenoestrogens: are man-made molecules which also mimic the action of oestrogen, but are categorised as endocrine disruptors because our bodies are unable to excrete them efficiently.

Our bodies will work to try and keep the overall pool of oestrogen at healthy levels, but when it can no longer achieve this, we (male and female) can experience ill health and in some cases this can lead to hormonal cancers, including breast cancer. So here are four measures you can take on a daily basis to help your body to maintain a healthy balance of oestrogen:

Include a portion of cruciferous vegetables:

Epidemiological studies have drawn associations between consumption of cruciferous vegetables and the reduced risk of breast cancer [2]. Cruciferous vegetables or brassicas include cabbage, cauliflower, broccoli, Brussel sprouts, kohlrabi, bok choy, kale and watercress. They are rich in zinc, vitamins A, B, C, D and E and contain a compound called Indole-3-Carbinol (I3C) which the body breaks down to 3,3-Diindolylmethane, or DIM. DIM has been shown in animal and in vitro studies to enable the body to detoxify oestrogen through pathways which lead to the formation of molecules which are less likely to be carcinogenic [3].

Cruciferous vegetables are coming into season so make them at least one of your five a day.

Drink a cup of green tea

Green tea contains a polyphenol compound called Epigallocatechin gallate (EGCG) which is undergoing extensive research to understand and harness its anti-cancer effects.  However, a small scale intervention study of Japanese American women found that intake of green tea may modify estrogen metabolism and as a consequence could reduce the risk of breast cancer [4]. The benefit was seen most strongly in post-menopausal women who consumed at least one cup of green tea a day.

Include a tablespoon of flaxseed

Flaxseed is rich in lignans, a type of phytoestrogen, and alpha-linolenic acid, a precursor to the anti-inflammatory omega 3 essential fatty acids: DHA and EPA. A control study of nearly 6,369 Canadian women found a significant association between the consumption of flaxseed and a reduction in the risk of breast cancer [5].
Flaxseeds are high in fibre so if you are not used to them introduce them slowly and build up to a tablespoon a day. Milled flaxseed is a good way to start and can be stirred into porridge in the morning or add them to overnight oats or Bircher muesli. Alternatively, whole flaxseeds can be sprinkled on salads for added crunch or look out for flaxseed crackers.

Follow your natural sleep / wake cycle

There are a number of studies looking at the possible link between disrupted circadian cycle and increased risk of breast cancer. A meta-analysis of female flight attendants found an increased risk of cancer compared with the general population [6]. There appears to be a connection between melatonin, our sleep hormone, and estrogen regulation, particularly how our body generates endogenous estrogen, as well as being a potent tumour suppressor [7].

Two simple changes will allow you to support your natural sleep/wake cycle and the production of melatonin you need to sleep but also switch off melatonin production when you no longer need it:

  • The blue light emitted by LED back lit computers, iPads, mobile phones and plasma TVs has been shown to significantly inhibit melatonin production [8] Therefore, switching off these electronics at least half an hour before going to bed can enable our sleep cycle.
  • Conversely, by greeting the day and taking in the sunlight in the morning, we engage our waking cycle and switch off melatonin production, initiating our wake cycle.

Edwina Green, Associate and Registered Nutritional Therapist

Edwina is a firm believer in natural health and the transformative benefits that good nutrition can bring. Before making the career move to naturopathic nutrition, she ran her own company working in the City of London. She is fully aware of the challenges of trying to follow a healthy diet and lifestyle, while juggling full time work and ensuring quality time with family and friends.  She is passionate about helping people take practical steps to manage their own health and teaching them to dissect the varied and often conflicting information that we receive via the media.

Edwina is currently studying for an MSc in Personal Nutrition and is specifically interested in the connection between our genes and our health.  In particular, the field of nutrigenomics where the food we eat can positively influence our genes, reducing the risk of disease.

[1] Cancer Research UK. (2016). Breast cancer statistics. Available: http://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/breast-cancer. Last accessed 4th October 2016.

[2] Liu X, Lv K. (2013). Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis. Breast. 22 (3), p.309-13.

[3] Szaefer, H. et al., 2012. Modulation of CYP1A1, CYP1A2 and CYP1B1 expression by cabbage juices and indoles in human breast cell lines. Nutrition and cancer, 64(6), pp.879–88.

Parkin, D.R. et al., 2008. Inhibitory effects of a dietary phytochemical 3,3’-diindolylmethane on the phenobarbital-induced hepatic CYP mRNA expression and CYP-catalyzed reactions in female rats. Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association, 46(7), pp.2451–8.

[4] Fuhrman BJ, Pfeiffer RM, Wu AH, Xu X, Keefer LK, Veenstra TD, Ziegler RG.. (2013). Green tea intake is associated with urinary estrogen profiles in Japanese-American women. Nutrition Journal. 12 (25), Published online 2013 Feb 15.

[5] Lowcock EC, Cotterchio M, Boucher BA. (2013). Consumption of flaxseed, a rich source of lignans, is associated with reduced breast cancer risk. Cancer Causes Control. 24 (4), p.813-6.

[6] Liu, T, Zhang, C, Liu, C (2016). The incidence of breast cancer among female flight attendants: an updated meta-analysis. Breast Cancer Research. 23 (6)

[7] Hill, S. M., Belancio, V. P., Dauchy, R. T., Xiang, S., Brimer, S., Mao, L., Blask, D. E. (2015). Melatonin: an Inhibitor of Breast Cancer. Endocrine-Related Cancer22(3)

[8] W. Sroykham and Y. Wongsawat, “Effects of LED-backlit computer screen and emotional selfregulation on human melatonin production,” 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Osaka, 2013, pp. 1704-1707.

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