Fermented soya foods or non-fermented soya foods?

If there is food to include in our daily diet as women entering peri-menopause, fermented soy foods are the one. At this point in our lives, women ask or ponder, “Can you please help me with these hot flushes? I’m desperate?’ Then the research is confusing around soy products and the risks of breast cancer. So I want to clear up some of the mythology around soy foods, their benefits to health and why some work and some don’t.  

I see women who have had treatment for breast cancer in clinics looking for support with improving nutrition and implementing lifestyle features to help reduce cancer risks. We can make plenty of powerful daily choices with diet and lifestyle to support a healthy body, reduce the symptoms of hot flashes and increase performance.


Some nutrients in soy can have a therapeutic effect on reducing hot flashes, increasing concentration and supporting mood. Fermented soy foods contain phytoestrogens which have a weaker oestrogenic impact on our cells than our endogenous oestrogen. However, there are varying amounts of isoflavones (the phytoestrogens) in different foods, how foods are processed and what type of soy food you enjoy.

Do phytoestrogens help menopausal symptoms?

The action of soy in helping to relieve menopausal symptoms comes down to soy Isoflavones. Phytoestrogens are plant compounds called isoflavones. Isoflavones compete for oestrogen receptors or the exact landing site on the cell wall.

Isoflavones have a weaker oestrogen and an anti-oestrogen effect. Plants high in phytoestrogens are Lima beans, broad beans, lentils, legumes, kidney beans, chickpeas and soya beans. Soya beans contain 2-4 mg isoflavones / 1g protein.

As we discussed earlier, it is the type of soy food that influences the number of phytoestrogens. Fermented soy products tend to have a higher isoflavone content than tempeh, edamame beans, and fermented Soy milk. GenisteDaidzeindzin and glycitein are the 3 main Isoflavones that affect oestrogen receptors.

Isoflavones interfere with steroid metabolism by altering the rate of active estradiol metabolites; they help reduce the activity of active oestrogen. What is also essential to consider, and we often forget, is that plant-based nutrients act together and can simultaneously affect different organs and systems.

The health effects of soy and its bioactivity are more significant with the whole bean/food, not the chemical.

Isoflavones also have antioxidant potential; they influence the liver to function well, including a potent antioxidant glutathione, which is critical for healthy detoxification. Communities that have traditionally consumed Soy products, like East Asia, tend to experience fewer rates of breast cancer, prostate cancer, and heart disease and fewer bone fractures. Women of these cultures experience less incidence of age-related brain disease and menopausal symptoms. So not all soy foods have adverse effects on our health.

Does it matter what soy foods I eat?

There are some exciting features of soya digestion and the activity of Isoflavones in helping to reduce menopausal symptoms. Animal studies looking at the effect of Daidzin found that monkeys break this incredible compound, Isoflavone, down to Equol. Equol is considered to have higher oestrogenic activity than Daidzin.

This explains why soy products tend to work for some women in improving the symptoms of menopause and others do not. People have significant variability in

  • Their ability to produce Equol
  • Microbiota/gut bacteria
  • Intestinal transit time
  • Current use of medication and antibiotics

In a six-month study, women with higher urinary Equal had significantly less hot flushes, sweating and heart palpitations. 20% of Western population women produce S(-) Equal, compared to 50-60% of Asian women, which may explain the differences in menopausal symptoms across these populations.

Is soya food consumption associated with cancer?

The other active Isoflavone that has received a fair amount of research is Genistein. The study shows that Genistein is not very bio-available, and the activity of Genistein is also dependent on those previously mentioned 4 points. Once we consume a soy product, the Genistein is converted to free Genistein and broken down to surfaces or glucuronidase; only 1% or less is active or has bioavailability. So they are weak oestrogenic compounds.

More complex processes are involved in the absorption and effect of soy foods on our metabolism and long-term health. Hopefully, this blog will give some understanding that we must be critical in reading any information where one food is considered harmful for you.

https://lighthousenaturopath.com.au/Calcium and prebiotic nutritious foods


In a population-based prospective study, soy food intake was inversely associated with mortality and recurrence of breast cancer. This inverse relationship didn’t appear to vary its effect on menopausal women with ER +ve and ER -ve breast cancer in early and late-stage cancer.

Further research needs to be done on the actions of isoflavones in soya products to reduce menopausal symptoms. As you can see, we can’t look at this fantastic food and its constituents as chemicals. The population-based study looked at 5042 women and found lower risks of mortality and reoccurrence and breast cancer patients with soy consumption daily.

Other nutrients such as Omega 3 fatty acids in fish and algal oil help reduce inflammation. Lower female sex hormones are associated with an increase in inflammation. We must put out the fire and support decreased inflammation, hormone metabolism and nerve health.

Supplementing with fish oil helps to reduce inflammation and risks of heart disease. Food is medicine and can be the best place to change your health positively, reduce symptoms and get your life back. Look out for my blog next month, a favourite Corn Fritter recipe with a difference. If you are suffering from menopausal symptoms, book a consultation, by phone, in person or online. Keep it healthy.

https://lighthousenaturopath.com.au/ Fermented soy smoothie with strawberries. Alison Millican initially wrote this at Lighthouse Naturopathy. Would you like more information on this topic or help with hot flushes? Book a discovery chat today here.
original post by Alison Millican Life Soup Blog @LighthouseNaturopathy