There is a lot of debate within the whole food plant based community on whether or not
it’s safe to consume soy.
This is because a study found that just 40 grams of soy protein added to our diet can
significantly increase levels of a powerful cancer-promoting growth hormone, called Insulin-like
Growth Factor 1 – IGF-1.This growth promoter has been strongly linked to the development
of cancer of the breast, prostate, lung, and colon.
Excess IGF-1 stimulates cell proliferation and inhibits cell death – two activities
you definitely don’t want when cancer cells are involved.
But what does 40 grams equal?
Well, one soy “chicken” patty and two soy burgers add up to that 40 grams,
Let’s hear Dr Caldwell Esselstyn’s answer to the question is soy safe to consume…
Again now we are talking about soy, I eat soy, I maybe eat soy, tofu about 3 to 4 times
a month, when my wife makes a wonderful dessert with it.
But I’m a little cautious about soy once it has been highly processed, I think edamame
is fine but even then it’s 40% fat and my good friend Colin Campbell who wrote The China
Study has pretty well convinced me that an excess of so protein can increase your IGF-1
which is a tumour promoter.
Dr T Colin Campbell states “Soybeans in their whole form (in soups, or as edamame)
are fine occasionally, but I’d not recommend anyone drink glasses of soy milk, especially
kids.
Dr John McDougall has said this about soy…“There is a dark side to the soy story that warns
that these foods may increase your risk for cancer, impair your thyroid, immune, and brain
function, and cause you bone loss and reproductive problems.
Fortunately, these worries are relevant mostly for people lured into consuming “fake foods”
synthesized from man-made components of soy and other foods, and high potency soy supplements
– not for those who consume traditional soy foods as a small portion of their diet.”
So it looks like there are two issues here the first is that soy products may not be
healthy when consumed in large amounts and secondly that heavily processed soy and isolated
soy protein products may behave very differently in the body when compared to whole soy foods
like edamame beans or even tofu.
So now lets hear form Dr Michael Greger as shares from the research how many servings
of soy, if any are safe for us to eat….
So is there some magic number of soy food servings we should shoot for?
So far we know that somewhere between 7 and 18 may not be so good, so more than 18 definitely
gets the axe.
This two year study found no effect on IGF levels of adding two servings of soy foods
daily, whether they were tofu, soy milk, soy nuts, or the concentrated soy isolate found
in plant-based meats, protein bars, or protein powder; still fine.
Still got a big range here.
This study suggested 5 to 10 servings a day was bad— increased IGF—so we’re kind
of slowly but surely narrowing down the safety window.
Same year in Japan; three servings a day cleared the IGF radar.
And then, that’s it.
That’s all the science we have so far.
The bottom line is legumes should be a part of everyone’s daily diet, which means lentils,
peas, and/or beans, ideally with each of our meals—of which soy is an excellent choice.
But, I recommend that we should probably stick to no more than 3 to 5 servings a day.