14 February 2022

Is soy milk safe? Oestrogen, breast cancer and soy – the answers…

Do soy products affect breast cancer risks and does soy help or hinder recovery from breast cancer? And what of soy milk specifically? Is it safe?

Despite years of research and clinical evidence these questions still seem confusing to many. So this week, a research and experiential soy summary, then the soy milk specifics; plus a bonus - the role of oestrogen in COVID, but first

    Thought for the day

The person who asks a question

Is a fool for one minute.

The person who does not ask a question

Is a fool for life.



The activity of most breast cancers are influenced by hormonal levels, especially the main female sex hormone oestrogen – basically more oestrogen is bad, less is better. Oestrogen is produced within the body and also can be taken in via common foods we eat; the phyto-oestrogens. 

How oestrogen influences breast cancer is by attaching onto the breast cancer cells and stimulating their activity. 

Some compounds can block this interaction; the oestrogen blockers. 

Some phyto-oestrogens stimulate breast cancer, some act as oestrogen blockers.

So the effect oestrogen has on breast cancer is a combination of the amount produced within the body plus any oestrogen-like foods consumed, minus the mitigating effect of any oestrogen blockers.

But now, consider this - most breast cancers occur after menopause when the ovaries have stopped producing oestrogen, so where does the oestrogen come from? 

Is it only from the outside? Well, no, some still comes from the body - from fatty tissue, muscle and breast cells. But also, breast cancer cells produce their own oestrogen that then can go on to stimulate more cancer growth! 

So the question is, what can be done to block the adverse effects of oestrogen? 

There are 2 possibiities

1. Blocking the adverse effects of oestrogen

In mainstream medicine a number of drugs are used as oestrogen blockers – the oldest being Tamoxifen, while more recent ones include Arimidex, Aromasin and Femara that are only suitable for women who have completed menopause.

And what about phyto-oestrogens? 

Do they act as oestrogen stimulants or as oestrogen blockers? 

In previous posts the research evidence has been made clear. 

Soy products are effectively oestrogen blockers. 

But then the question of what type of soy is OK for you to eat?

Minimally processed soy foods like cooked soybeans, tofu, tempeh are all OK. 

Highly processed soy, not so good; in fact better to minimise or avoid foods based upon Textured Soy Proteins like veggie sausages, mock meats and so on.

2. Stopping breast cancer cells from producing oestrogen

It turns out oestrogen is produced in breast cancer cells using 2 enzyme pathways. In fact, inhibiting this oestrogen production has been shown to be more effective than just trying to block the effects of the estrogen, “suggesting that the inhibition of estrogen synthesis is clinically very important for the treatment of estrogen-dependent breast cancer.”

There are drugs that do this – the common aromatase inhibitors are letrozole, anastrozole and exemestane. But how about this? The plant world is so amazing! Turns out soy phytoestrogens not only is a oestrogen blocker, it also reduces aromatase production. 

In a 2015 paper, the authors concluded “In general, phytoestrogens act as aromatase inhibitors by (a) decreasing aromatase gene expression, (b) inhibiting the aromatase enzyme itself, or (c) in some cases acting at both levels of regulation.”

Lephart ED. Modulation of Aromatase by Phytoestrogens. Enzyme Res. 2015;2015:594656. doi:10.1155/2015/594656



What does the research offer? In a randomised study, Japanese women were asked to add 400ml per day of soy milk to their diet or not for just 2 months. 400ml is quite a lot! Oestrogen levels dropped about a quarter in the soy milk supplemented group. 

Nagata C et al. Effect of soymilk consumption on serum estrogen concentrations in premenopausal Japanese women. J Natl Cancer Inst. 1998 Dec 2;90(23):1830-5. 

Japanese women live in a culture where soy is a common food, so what about in America where it is not? 

In a small study, women aged 22 – 29 consumed 350 ml soy milk and within a month halved their circulating oestrogen levels. 

Importantly, the oestrogen levels stayed down for a month or two even after the subjects stopped drinking soy milk, which suggests you may not need to consume soy daily to gain the cancer protective benefit.

The authors concluded “These results suggest that consumption of soya diets containing phytoestrogens may reduce circulating ovarian steroids and adrenal androgens and increase menstrual cycle length. 

Such effects may account at least in part for the decreased risk of breast cancer that has been associated with legume consumption.”

Lu LJ,et al. Effects of soya consumption for one month on steroid hormones in premenopausal women: implications for breast cancer risk reduction. Cancer Epidemiol Biomarkers Prev. 1996 Jan;5(1):63-70.

Isoflavins and breast cancer risk

Still not fully confident? Isoflavones are only one of the major phyto-oetrogens, so this research is not the same as testing soy as a whole, however, in this recent meta-analysis, the authors did conclude “Taking into account the risk of bias and methodological limitations, there is little evidence that isoflavone treatment modulates risk factors of breast cancer in pre- and postmenopausal women.” 

This is a conservative finding with no positive benefit claimed, but it does state clearly the research finds no discernible risk. 

Finkeldey L, Schmitz E, Ellinger S. Effect of the Intake of Isoflavones on Risk Factors of Breast Cancer-A Systematic Review of Randomized Controlled Intervention Studies. Nutrients. 2021 Jul 5;13(7):2309. 

Lifetime effects of phyto-oestrogenss on hormones

Need more? Another recent major study concluded “In premenopausal and postmenopausal women, the reported impacts on hormones are inconsistent, although beneficial goitrogenic effects and improved glycemic control and cardiovascular risk markers have been described in postmenopausal individuals.” 

Good for diabetes and heart disease, but again, no mention of adverse effects from soy. 

Domínguez-López et al. Effects of Dietary Phytoestrogens on Hormones throughout a Human Lifespan: A Review. Nutrients. 2020 Aug 15;12(8):2456.



In my opinion, eat minimally processed soy foods regularly. 

Soy milk is OK. Bonsoy remains the best choice. 

Rest easy. 

Stay healthy.

Heal well when needed...


AND FINALLY - Oestrogen may protect from COVID-19

It has been widely observed that adult men of all ages are at higher risk of developing serious complications from COVID-19 when compared with women. This large study investigated the association of COVID-19 positivity and severity with estrogen exposure in women. 

The findings support a protective effect of estrogen exposure on COVID-19, based on positive association between predicted COVID-19 with menopausal status, and negative association with use of the combined oral contraceptive pill. 

HRT use was positively associated with COVID-19, but the results should be considered with caution due to lack of data on HRT type, route of administration, duration of treatment, and potential unaccounted for confounders and comorbidities.

Costeira R et al. Estrogen and COVID-19 symptoms: Associations in women from the COVID Symptom Study. PLoS One. 2021 Sep 10;16(9) 


The latest on soy and breast cancer 

Is soy safe – Part 1

Is soy safe – Part 2


08 February 2022

Can you see the cloud in the water? Thich Nhat Hahn – a tribute Part 2

He gently elevated a glass of water into the air. Hundreds of eyes followed Thich Nhat Han’s hand as it rose higher. Then the gentle, assured voice : Can you see the cloud in the water? 

Well not literally, but then the point was made; without the cloud there would be no water. The cloud and the water are inter-dependent. Can you see the cloud in the water?

So this week, more stories of meeting with our sadly missed Thich Nhat Hahn at his main retreat centre in Plum Village, France, a few select teachings and recounting co-presenting a remarkable cancer retreat in Germany with one of his monks, but first

       Thought for the day

    Breathing in I calm my body

    Breathing out I smile

    Dwelling in the present moment

    I know this is a wonderful moment

                           Thich Nhat Hahn


Plum Village

In 1982 Thầy, as he if known to his followers, found an old farm in the Dordogne Valley of southwest France. There, amid rolling hills and vineyards, they established a mindfulness practice center which became known as Plum Village after the 1,250 plum trees they planted in the rich soil. 

The existing buildings were dilapidated, but soon barns became meditation halls and sheep-sheds became dorms, with beds made of wooden boards balanced on bricks.

Over the next 4 decades, Plum Village grew into the largest Buddhist retreat center in the west, attracting people from around the world, with over 4,000 retreatants every summer and more than 10,000 visitors every year.

Visiting Plum Village

What better notion of a holiday than spending time in the company of a spiritual adept? And Plum Village is both beautiful, and serene. Serene and actually quite slow in pace. A bit like Club Med meets spirituality! 

There is not much of a fixed program, although every 15 minutes a huge gong sounds out across the land and everyone stops for a mindful moment. Then there are group discussions for an hour after lunch and Thay alternates speaking in French with a translator or English with a translator.

Ruth and myself visited in 2010. 

Can you see the cloud in the water? 

We also joined Thai in walking meditation and felt the entreaty to “walk gently upon the land”.

In fact, the strength, diversity and vitality of Thầy’s international community may be his greatest legacy of all. 

His aspirations and hopes live on in a thriving community of all ages, nationalities, and backgrounds, continuing to evolve and develop his teachings and practices, making them ever more appropriate to our times. 

Teaching – a true pioneer of mindfulness in the West

Thầy came from a Zen background but preferred to say he was “presenting the teachings of Early Buddhism in a Mahayana spirit”. 

His teachings on ‘everyday mindfulness’ and his style of walking meditation have been taken up and popularised by the secular ‘mindfulness movement’ and brought healing to millions around the world. 

He developed the practical notion of everyday mindfulness; mindful breathing, mindful walking, mindful dish-washing, teeth-brushing, cooking, or working, and the art of completely stopping and listening whenever the temple bell (or telephone) rang.

Some Excerpts

Mindfulness brings concentration. Concentration brings insight. Insight liberates you from your ignorance, your anger, your craving. When you are free from your afflictions, happiness becomes possible. How can you be happy when you are overloaded with anger, ignorance, and craving? 

Maybe intellectually people know that they should live in the present moment, but the habit energy that has been there for a long time is always pushing them to rush around, so they have lost their capacity to be in the present moment in order to lead their life deeply. That is why the practice is important, and talking is not enough. 

We can recognize happiness only against the background of suffering. It’s like when you recognize the white against the background of the black. Only if you have been hungry can you experience the joy of having something to eat. You learn from suffering, and against that background, you can recognize happiness. It is good to experience some suffering, because when you suffer you develop compassion and understanding.

Love, in Buddhism, always begins with yourself, before the manifestation of the other person in your life. The teaching of love in Buddhism is that when you go home to yourself, you recognize the suffering in you. Then the understanding of your own suffering will help you to feel better, and to love, because you feel the completeness, the fulfillment in yourself. So you don’t need another person to begin to love. You can begin with yourself.

True love does not just choose one person. When true love is there, you shine like a lamp. You don’t just shine on one person in the room. That light you emit is for everyone in the room. If you really have love in you, everyone around you will profit—not only humans, but animals, plants, and minerals. Love, true love, is that. True love is equanimity.

Our purpose is not to convert people to Buddhism. Our purpose is to live Buddhism as a path of understanding and love. You can continue to be a Jew, a Christian, or a Muslim, and you can do exactly the same thing as we do in the tradition of Buddhism. We use the Buddhist language and practice, you use the Muslim language and practice, but we arrive at the same result. That is why it can be called a global spirituality or global ethic.

Vietnam and home

Having grown up in rural Vietnam and then joining a monastery, Thay became politically active and a major spokesperson for peace during the Vietnam War. 

At the end of the war he was forced into exile and made France his new home. 

Over the years, Thầy embraced and healed the pain of not being able to return to Vietnam. 

It was, he explained, “thanks to the practice I was able to find my true home in the here and the now. 

Your true home is not an abstract idea, it is a solid reality you can touch with your feet, with your hands, with your mind. It is available in the here and the now, and nobody can take it away. They can occupy your country, yes. They can put you in prison, yes. But they cannot take away your true home and your freedom.” 

Thay described the phrase, ‘I have arrived, I am home’ as the ‘cream’ of his practice and “the shortest teaching I can give.” He guided thousands of people who attended his retreats in Plum Village, to truly arrive and feel at home in themselves in the here and now. 

Healing Retreat in Germany            

In July 2011 Ruth and I were invited to co-present a meditation based, health and healing related retreat with monks and nuns of Thich Nhat Hahn’s tradition in their German retreat Centre out of Cologne. 

Imagine this… 

You arrive at a residential cancer retreat and the Zen monk co-leading announces everyone will water fast for the duration of the 7 days. 

News to us too! 

However, the monk had such presence and conviction (albeit based upon recent reading that fasting might be helpful in response to cancer!) it seemed to work – especially after we managed to include some very watery vegetable/rice soup in the menu. 

Anyway, it was a delight to work in the environment of dedicated monks and nuns and the participants left very happy. 

The whole week was presented very simply, very clearly, very directly. 

Mind you it did take a little getting used to the head monk nodding off while I was talking with the group and he was sitting out front with me. 

No place for egos! 

The whole thing was quite memorable to say the least. 

One new technique to come from the retreat: combining deep relaxation with a contemplation: relaxing each part of the body deeply while contemplating gratitude for all that part of the body does for you and for others.

Later that same year, I co-led a meditation training and retreat with that same monk and others from Plum Village at the Foundation’s Yarra Valley Centre. That too was a wonderful few days. 

The Recommendation

Do not put it off! 

If you can, seek out spiritual leaders and spend time in their company. 

Listen to their teachings in person when you can.

If you do not have your own main teacher as yet, it makes sense to shop around, check out possibilities, take your time and then commit. It is very hard to make serious progress on the spiritual path without sticking to one main teacher.

If you do have your own main teacher, do not become distracted by dharma shopping – feeding doubts and dissatisfactions by going around checking out other teachers – but judiciously select those aligned with your own path and benefit from their experiences, realisations and insights.

What a pleasure to have spent time with Thich Nhat Hahn – one of the genuine greats of our time!