Oestrogen

The menopause is a natural phase in a woman’s life when fertility draws to a close. The last period usually occurs between the ages of 45 and 55, but the whole process starts several years before when the ovaries start running out of eggs. As egg follicles produce female hormones, oestrogen levels start to fall from around our mid-30s.

  

Some women quickly adjust to lower oestrogen levels and notice few (if any) problems. Others find it harder to lose their hormones and experience a variety of physical and emotional symptoms, including hot flushes, night sweats, mood swings, difficulty concentrating, vaginal dryness, plus widespread aches and pains.

 

Human oestrogen is made up of three different hormones: oestriol, oestrone and oestradiol. These oestrogens have effects throughout the body. In the skin, they boost production of collagen protein and promote skin thickness, elasticity and hydration. As oestrogen levels fall, skin becomes thinner with dryness, itching, slackness and wrinkling. These effects are hastened by the damaging effects of sunlight. Although ageing skin may seem trivial in the scheme of things, it can have a profound effect on our confidence and self-esteem.

 

Hormone replacement therapy can improve collagen production, skin thickness, hydration and elasticity. Many women are unwilling, or unable, to take HRT however, preferring the more natural approach provided by phytoestrogens. These plant hormones include isoflavones such as genistein and daidzein which are found in soy and red clover. Isoflavones are able to interact with human oestrogen receptors to provide a useful oestrogen boost. As their effects are around 1000 times weaker than human oestrogens, they can improve menopausal symptoms and skin health with much less risk of side effects.

 

In cultures such as Japan, intakes of isoflavones are 50 - 100mg per day, t0 to 20 times higher than in the West. As a result, Japanese women rarely experience menopausal symptoms. The incidence of breast cancer in Japan is also around three times lower than in the UK.  

 

In fact, isoflavones may protect against breast cancer by blocking the effects of stronger human oestrogens on breast tissue. Some studies[i],[ii],[iii] have found that women with the highest soy intake are least likely to show mammography changes associated with high breast cancer risk, although the results are not conclusive. Research involving over 21,000 Japanese women and 35,000 Singapore Chinese women, however, suggests that postmenopausal women with the highest intake of isoflavones are significantly less likely to develop breast cancer than those with the lowest intake - even after adjusting for factors such as reproductive history, family history, smoking, other dietary factors and weight[iv], [v].

 

Not surprisingly, there has been concern about the possible effects of isoflavones in women with pre-existing breast cancer, especially those containing oestrogen receptors. New research suggests that isoflavones protect against all types of breast cancer, however, whether or not they are oestrogen or progesterone receptor positive[vi].

 

An important recent study followed almost 2000 breast cancer survivors for 6 years[vii]. Researchers found that “Soy isoflavones consumed at levels comparable to those in Asian populations may reduce the risk of cancer recurrence in women receiving tamoxifen therapy and moreover, appears not to interfere with tamoxifen efficacy”. Although ‘Further confirmation is needed before recommendations regarding soy intake can be issued to breast cancer survivors’ a recent analysis of all the evidence suggests that, ‘Overall, there is little clinical evidence to suggest that isoflavones will increase breast cancer risk in healthy women or worsen the prognosis of breast cancer patients. ….. the existing data should provide some degree of assurance that isoflavone exposure at levels consistent with historical Asian soyfood intake does not result in adverse stimulatory effects on breast tissue[viii].

 

Different doctors have different opinions so, if you have experienced breast cancer, it is important to seek advice from your doctor before taking an oral isoflavone supplement. Skin creams containing plant phytoestrogens are unlikely to cause concern, however.

 

 

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