The effect of these natural components on women’s health is evident in the low incidence of problems associated with hypoestrogenic states in oriental women. This is because the principal component of their diet is the isoflavones derived from soya.

The two principal isoflavones are daidzein and genistein. In healthy adults, isoflavones are absorbed rapidly. The majority reaches the intestine in a glycosylated form (99%); this is inactive, which is why it needs the intestinal flora to convert it into its free and active form by means of hydrolysis. The most active metabolite is equol, produced mainly by the intestinal metabolism of genistein.

The affinity of phytoestrogens for the estrogen receptor, and preferentially for the beta receptor, has been proved. This phenomenon explains the selectivity of their actions on specific sites of the organism, so much so that they are called the ‘natural SERM’.

Results, which were not unanimous, on diverse effects of isoflavones on women have been published. The only effect which is recognised to a greater extent is that of a decrease in LDL-cholesterol and triglycerides and an increase in HDL level variables.^1,2

Randomised controlled studies have demonstrated in general that isoflavones derived from soya reduce hot flushes (Alternative phrase is hot flashes)

slightly.^3,4

But the comparison of studies is difficult, due to the use of different products and varying quantities of each of these products. The majority of studies involving isoflavones administered quantities which varied between 30 and 80mg per day, having demonstrated that the adverse effects (Alternative phrases are menopause treatment,
phyto menopause treatment,
soya menopause treatment,
phyto soya side effects and
menopause treatment south africa)

of these preparations are practically non-existent.

The effects on bone and breast are still not clear. Phyto Soya® is a specific extract of isoflavones, containing more daidzein (5%) than genistein (2%). In a double-blind randomised study with placebo, 35mg Phyto Soya® was taken twice a day, i.e. study participants received 70mg per day. The findings showed a 61.2% reduction in hot flushes in women taking Phyto Soya® (Alternative phrases are phyto soya,
phytosoya capsules and
phyto soya capsules)

versus 20.7% in the placebo group (p < 0.0095).⁵

In another study of this same product taken at the same doses, endometrial safety was analysed. After 12 months of treatment, 99.67% of endometrial atrophy and 0.33% of proliferative endometrium found. The conclusion was that the administration of 70mg/day of Phyto Soya® for one year does not produce endometrial stimulation. Quality of life and lipid profile were also assessed.

In this same study, the mammograms confirmed that breast tolerance was good. The mammary density results according to the BIRADS classification showed that taking Phyto Soya® for one year had not changed mammary density: only 19 variations were noted (density was reduced in 13 cases and increased in six cases).⁶

CONCLUSION
Taking into account the new context in which we prescribe HRT today, other alternative treatments should be studied thoroughly and phytoestrogens should be used with regard to the type of isoflavone extract and in the doses that have demonstrated efficacy and safety.

REFERENCES

1. Anderson JW, Johnstone BM, Cook-Newell ME. Meta-analysis of the effects of soy protein intake on serum lipids. N Engl J Med 1995;333(5):276-82.
2. Zhan S, Ho SC. Meta-analysis of the effects of soy protein containing isoflavones on the lipid profile. Am J Clin Nutr 2005; 81(2): 397-408.
3. Nelson HD, Vesco KK, Haney E, Fu R, Nedrow A, Miller J, Nicolaidis C, Walker M, Humphrey L. Nonhormonal therapies for menopausal hot flashes: systematic review and meta-analysis. JAMA 2006;295(17):2057-71.
4. Howes LG, Howes JB, Knight DC. Isoflavone therapy for menopausal flushes: a systematic review and meta-analysis. Maturitas 2006;55(3):203-11.
5. Faure ED, Chantre P, Mares P. Effects of a standardized soy extract on hot flushes: a multicenter, double-blind, randomized, placebo-controlled study. Menopause 2002;9(5):329-34.
6. Palacios S, Pornel B, Bergeron C, Chantre P, Nogales F, Aubert L, Vazquez F, Eden J, Mares P. Endometrial safety assessment of a specific and standardized soy extract according to international guidelines. Menopause 2007; 14 (6).