Hi
There are some very knowledgeable people here on the forum and I’d value your opinion on whether soya milk is ok as part of my diet.
In June this year I had lumpectomy, no invasive cells, and later on, rads. I’m now on tamoxifen. The cancer was er+, mixed medium and high grade, but only 11mm.
I’m veggie (no animal/fish flesh at all) and eat a pretty mixed and healthy diet, but as I don’t like cows milk much I started having soya milk on my cereal or in porridge about 2 years ago. (no more than about 1/2 a pint a day.)
Could this have contributed to the cancer in the first place and would it be wiser to stop using soya milk? What would you recommend instead?
Like us all, I want to do my best to prevent a recurrence.
Thanks,
Susie.
xx
Hi Sussex girl
There does seem to be an association between drinking large quantities of soya milk (3/4 of a pint a day) and raised levels of IGF. IGF is Insulin-like Growth Factor and is a hot button issue at the moment in cancer research generally, not just breast cancer. IGF promotes cell division and breast cancer cells have been shown to migrate to IGF, suggesting it may also promote spread of bc. It is known that those with the highest blood serum levels of IGF have a significantly raised risk of getting cancer, not just breast cancer (28% higher than those with the lowest levels), and a US study showed that in primary breast cancer patients those with the highest rates of serum IGF had a significantly raised risk of recurrence. (Got to go out now but will find the links for you later).
A small study following up on data from the EPIC research project found that comparing a small group of vegans to meat eaters and vegetarians, the vegans had 13% lower serum IGF levels, but also had much higher levels of the binding proteins that locks up IGF and prevent it getting into tissues - so the combined effect of the no meat and dairy diet was greater than the 13% IGF differential. The body is sensitive to small variations in IGF. The only vegans that didn’t have lower levels of IGF were those drinking large amounts of soya milk: their level was 28% higher than the other vegans!
My own theory about why the IGF levels are higher with soya milk - and I must stress that I haven’t seen any research, it is just my view - is that plant proteins are more easily digested than animal proteins, so will get into the bloodstream more easily.
This IGF research is separate from the phyto-oestrogen issue, which is very complicated and controversial.
So in the light of this research, I would consider changing from soya milk to coconut milk (Kara is nice), oat or rice milk. I was only drinking a small amount of soya milk, but I made the change in the light of the IGF research.
Hope this helps.
finty x
Also, forgot to mention that sugar also spikes IGF’s - so the recommendation is to minimise sugar intake, and eat any sugar (even fruit) with other foods to slow it’s absorption. So eating fruit or other sweet things with nuts is ideal, the fat from the nuts will dissipate the effect of the sugar.
finty x
I agree with Finty. The research was posted by Finty on the thread for ‘Red meat’ which is currently running - I’m going to bump that up.
I like Kara coconut milk on cereal and porridge. I prefer organic rice milk in tea. I still have the occasional soya latte or vegan cake if I’m out. I’m going to try making a lasagna using the Kara milk to make a white sauce at the weekend (and no cheese).
I thought I’d find the change over difficult but it wasn’t. My husband has done the same.
Elinda
The other thread I was referring to about ‘red meat’ is a big one, and the info on IGF 1 (including soya) is on pages 7, 8 and 9.
Also wanted to say try to think in terms of reducing risk rather than looking for causes. My husband is always saying to me don’t look back when I think should I have done this or known that. He’s right, it doesn’t help.
The diet thread as you’ll see is very controversial. I think that the current evidence on IGF-1 is enough for me to want to reduce soya, cut out dairy and meat. Others may feel differently.
take care, Elinda
Meant to say, have reduced soya milk intake, reduced meat intake and cut out dairy. What you decide may be based on what other protein you have, whether you have other dairy etc.
This paper gives an overview of the theories of how IGF’s promote cancer:
landesbioscience.com/journals/cbt/article/grimberg2-6.pdf
This paper gives a brief overview of the correlation between high IGF levels and incidence of primary breast cancer and recurrence - there are many others that come to the same conclusions.
Finty and Elinda,
Thank you both for your advice, info and links. I’ve looked at both links. Then I started looking on the web for more info and am now getting confused. It seems that some level of soy in the diet IS good for reducing recurrence of breast cancer, but not in highly processed forms such as soy based sausages etc., and not in large quantities.
Have you seen this link?
luilabas.wordpress.com/2010/04/13/settling-the-soy-controversy-by-neal-barnard-m-d/
It seems IGFs are related to high intake of essential amino acids, and that vegans have a lower intake as most essential amino acids are found in animal products. So maybe within a mainly vegan diet some soy is good rather than harmful. Most of my protein is from beans and lentils, though some from cheese and infrequent other dairy products.
I looked at this. Admittedly it is about prostate cancer though!
jnci.oxfordjournals.org/content/93/8/649.full
I am going to re-read the articles in your links Finty, and let all the info I’ve seen today sink in.
Elinda your husband gives wise advice, and I will try to look forward rather than back. Later this eveing I’ll have a look at the other thread too and see what has been said.
Thank you both again for your advice. And I think I’ll try some oat or rice milk anyway, while I’m deciding what to do about changes to my diet.
Susie.
x
Susie, it is very confusing and some of us are attempting to wade through research to make our decisions on diet. Prof Jane Plant who had breast cancer herself has written a whole programme mainly based on cutting out dairy and increasing soy.
The problem is that some of the more persuasive research on soy has been at least in part funded by the soy industry. Much the same I believe as the benefits of dairy have been funded by that industry.
It may well turn out that as well as raising IGF-1 levels that soy offers up a different protective factor. The question is what to do while we wait for the research.
My views on soy are changing. We tend to have quite a lot of processed soy e.g soya milk, soya spreads etc. I don’t think there is much evidence to support that these are particularly beneficial to us.
It sounds like your diet is quite healthy as a high amount of vegetables and pulses seem to be considered a good thing.
Be interested to make of what you read. Elinda
Susie, the whole soy debate as Elinda says is a bit of a minefield. This summary is quite a good place to start:
foodforbreastcancer.com/foods/soybeans
There does seem to be a big divide between the highly processed soy we tend to consume in the west, and the fermented soy eaten in Asia, and it is the latter that is considered to have cancer preventative properties.
Enjoy your reading. x
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