Eating away oestrogen

How dietary choices influence hormonal balance

In wine making the term "balance" refers to the degree to which all the attributes of a wine are in harmony, with none either too prominent or deficient. This definition draws great relevance to the sex hormone oestrogen and its relative harmony in the female body. While oestrogen has been considered the culprit in mediating health problems associated with elevated oestrogen levels such as oestrogen related cancers, evidence is now accumulating that shows that oestrogen metabolites, their balance and metabolism may be the real concern. Oestrogen can be metabolised (transformed) into either "good" or "bad" oestrogen, with bad oestrogen referring to certain types of oestrogen that are linked to disease development.

Oestrogen is clearly associated with the development of oestrogen related cancers such as breast cancer and it is also known that simple dietary changes can influence oestrogen metabolism potentially decreasing the risk of cancer. In support of the link between diet and cancer development The American Institute of Cancer Research estimates that if the only dietary change made was to increase the daily intake of fruits and vegetables to 5 servings per day, cancer rates in general could decline by as much as 20%.

An increased intake of fruits and vegetables is particularly relevant to oestrogen related cancers because many natural plant derived chemicals directly influence oestrogen metabolism. A family of plants of particular importance are the Brassica’s which consist of vegetables such as Broccoli, cabbage, Brussels sprouts and cauliflower. Numerous studies have shown that Brassica vegetables, and broccoli in particular, protect against cancer primarily because they are an unusually rich source of unique cancer fighting phytonutrients, as well as vitamins and minerals.

The protective effect of Brassica vegetables is in part due to their ability to promote the healthy metabolism of oestrogen. In a sense Brassica vegetables are nature’s natural oestrogen detoxifiers, they promote healthy levels of oestrogen by preventing the formation of potentially toxic types of oestrogen. In support of the protective effect of Brassica vegetables a study of women in Sweden found that those who consumed the most Brassica vegetables had a 25% reduction in breast cancer risk. The authors of this study commented that this finding supports the suggestion that "consumption of Brassica vegetables, especially 1 to 2 servings per day, lowers the risk of breast cancer by as much as 20% to 40%, possibly by shifting the pathway of oestrogen metabolism."

Another potent and natural promoter of healthy oestrogen metabolism are flax seeds. Like soy foods flax seeds are an important source of isoflavones, a group of phytonutrients that positively influence oestrogen metabolism. In a study investigating the effect of flax seeds on oestrogen metabolism a group of postmenopausal women were supplemented with either a placebo, soy (25g soy flour), or flaxseed (25g ground flaxseed) muffin for 16 weeks.

It was found that supplementation with flaxseed improved oestrogen metabolism to a greater extent than soy. A similar effect has been found with just 10 g (1 tablespoon) of ground flax seeds per day.

Flax seed is perhaps better known for its use as a source of dietary fibre improving regularity and as a remedy for constipation. What is lesser known however, is that once oestrogen is detoxified by the liver, flax seed packages oestrogen for elimination via the digestive system. Apart from its excellent nutritional value (flax is a rich source of omega-3, fibre, protein and minerals) the varied and complimentary actions of flax seed on oestrogen metabolism make it a valuable addition to a healthy diet.

Soy foods are also an important source of isoflavones and soy isoflavone consumption has been shown to favourably influence oestrogen metabolism. Specifically, soy isoflavones have been shown to lower production of potentially toxic oestrogen metabolites favouring healthy oestrogen production.

Observational studies have suggested that traditional consumption of soy foods may be linked to lower incidence of breast cancer. While soy continues to attract occasional sensationalised criticism in the popular press, it is known that when consumed at usual dietary intakes, such as those consistent with intakes in traditional Asian diets, soy isoflavones are unlikely to have negative effects in cancer free women. The Cancer Council of New South Wales recently released a statement on soy, suggesting that soy food consumption may lower risk of breast cancer but advising against soy based dietary supplements in cancer sufferers. Experts do suggest that moderate soy food consumption may be safe in women with active cancer however professional advice should be sought before considering any soy based dietary supplements.

Becoming familiar with the specific benefits of certain foods is empowering. The conscious choice of foods that may influence the risk for diseases than run in the family for example may have important ramifications later in life. For those at risk of oestrogen dependant disorders, or just wanting to maintain healthy oestrogen metabolism there are a certainly foods of particular relevance; broccoli, cauliflower, cabbage, Brussels sprouts, flax seed meal and traditional soy foods such as miso, tofu and tempeh. Introducing new foods to ones diet is not always easy; a simple way to get started is to search the local bookstore for recipe ideas. In addition an appropriately trained health professional can offer dietary counselling and advice on many other healing foods specific to your health.

Benjamin Brown N.D.
Technical Research Officer
Health World Ltd