There are still some gaps in the research regarding the effect of
isoflavones on prostate cancer but the body of research in this area is growing rapidly.
Studies on the effects of
isoflavones on human estrogen levels are conflicting, and it's possible that they affect people differently.
Effect of soy
isoflavones on thyroid hormones in intact and ovariectomized cynomolgus monkeys (Macaca fascicularis).
• Effects of soy
isoflavones on the make - up of the gut microflora • Bacterial transformation of genetically modified soy DNA into gut bacteria capable of expressing toxic proteins that damage the intestinal lining • Effects of chemical contamination from glyphosate residues on neurological and gut function • Soy - induced activation of the immune system and altered production of inflammatory cytokines associated with febrile seizures
Biological Effects of a Diet of Soy Protein Rich in
Isoflavones on the Menstrual Cycle of Premenopausal Women.
At least three long - term trials testing the effects of soy
isoflavones on bone health are in progress, Weaver notes, but we've got a long way to go before we can say what works and what doesn't.
Not exact matches
Soy contains a group of phytoestrogens (compounds found in plants that mimic the activity of oestrogen) called
isoflavones, but the
isoflavone content of a soy protein isolate depends
on the method used to isolate it.
Women were sorted into four quartile groups based
on the amount of
isoflavone they were estimated to have consumed, calculated from self - reported food frequency questionnaires.
The most investigated of those are a group of hormonelike polyphenols called
isoflavones, which seem to have effects
on everything from kidney and cardiovascular disease and various cancers to hot flashes, bone calcium loss and other symptoms of menopause.
Experimental results sometimes conflict and the outcome likely depends
on a variety of factors, including the
isoflavone amount, duration of feeding, and hormonal state of the animal.
Researchers compared cow's milk to soy milk, rice milk, coconut milk, and almond milk, and soy milk came out
on top nutritionally, with more protein and beneficial compounds known as
isoflavones.
Effects of
isoflavone supplement
on healthy women.
One hundred grams of soy protein contains about 97 g total
isoflavones according to USDA - Iowa State University Database
on the
Isoflavone Content of Foods 1999.
Given that research confirms that soy
isoflavones easily find their way into milk, meat, and eggs, if you are soy sensitive, don't trust soy free labels unless the company also gives clarity
on their animal feeding practices.
Intake of
isoflavone is beneficial particularly for women who are already
on the menoupausal stage.
On the other hand, fermented soy stops the effect of phytic acid and increases the availability of
isoflavones.
On the other hand, a study conducted by researchers at the University of Guelph had 32 men eat low or high levels of
isoflavones from soy protein for 57 days, and found that it didn't affect semen quality.
Just as research
on glucosinolates helped to spark interest in cruciferous vegetables as potential goitrogenic foods, research
on isoflavones helped to sparked interest in soybeans for this same reason.
Since soybeans contain approximately 3.5 milligrams of
isoflavones per gram of protein, and since one cup of cooked soybeans contain about 29 grams of protein, we're talking about intake of approximately 100 milligrams of
isoflavones from 1 cup of cooked soybeans, or an amount about 40 % less than the supplemented amount that was found to have no impact
on thyroid function.
These studies — which include analysis of the
isoflavones genistein, daidzein, malonylgenistin, and malonyldaidzin — show a limited impact of soy food intake
on thyroid function, even when soy
isoflavones are consumed in supplement form at levels higher than expected from food.
Soy
isoflavones are also found to provide various health benefits for postmenopausal women - there is also numerous studies done
on this subject as well.
After 10 months, they found that there was a significant reduction in frequency of hot flushes among
isoflavone users (3.1 per day) when compared to those
on placebo (5.9 per day).
In one study performed at the Seoul National University in Korea, 34 young women were studied to investigate the effect of soybean and
isoflavone intake
on bone mineral density and its change among young Korean women over a period of 2 years.
Soy
isoflavones come from the soy bean, and it provides various health benefits including providing relief for menopause symptoms, protects against breast cancer, and also has a favorable effect
on bone mass for postmenopausal women.
They concluded that the soy
isoflavone extract exerted favorable effects
on vasomotor symptoms and good compliance, providing a safe and effective alternative therapeutic for postmenopausal women.
For example, one study done at the Schools of Public Health and Medicine at the University of North Carolina concluded based
on their study results that a soy
isoflavone - rich supplement appears to have little or no effect
on bone in young adult women with normal ovarian function during the course of their one year study.
Effect of soybean processing
on content and bioaccessibility of folate, vitamin B12 and
isoflavones in tofu and tempe.
Also according to my ALCAT, the only grain I'm not allergic to is millet — which, of course I learned
on page 80 of The Root Cause, should be avoided due to
isoflavones.
Similarly, a Japanese population study of over 75 thousand men and women found a decreased risk of lung cancer among people who consumed soy products
on a regular basis (
Isoflavone intake and risk of lung cancer: a prospective cohort study in Japan.
In fact, some have shown benefits, such as a 2010 study
on menopausal women, who were administered soy
isoflavones for two years, which concluded that «soy and soy
isoflavones may provide a mild benefit to hot flashes, lipids, and bone health for some menopausal women» (Clinical outcomes of a 2 - y soy
isoflavone supplementation in menopausal women Am J Clin Nutr February 2011 93: 356 - 367)
However, soy protein appears to have several other mechanisms by which it lowers cholesterol (i.e.
isoflavones, endocrine effects, fiber, saponins, etc.) The specific effects of dietary protein
on plasma cholesterol concentrations are well documented: animal proteins tend to be hypercholesterolemic as compared to plant proteins.
Scientists looking at the correlation of soy foods and «brain aging» have focussed
on isoflavones, but there are a number of components in soy foods that can contribute to reduced mental function.
RESULTS: «No significant effects of soy protein or
isoflavone intake
on T (Testosterone), SHBG (Sex Hormone Binding Globulin), free T (Testosterone), or FAI (Free Androgen Index) were detected regardless of statistical model.
On balance, soy
isoflavones appear to be selective estrogen receptor modulators that may reduce estrogen levels where this is helpful (cancer) and boost them where helpful (bones and cognitive function).
Although these chickens had grown up
on the regular 25 percent soy protein feed, no trace of soy
isoflavones remained in their eggs ten days after switching to the soyfree alternative.
Soy protein isolates of varying
isoflavone content exert minor effects
on serum reproductive hormones in healthy young men.
As evidence
on the toxicity of soy
isoflavones accumulates, warnings have begun to appear in the popular press.
In fact, over the past few decades, many researchers have found that phytoestrogens have adverse effects
on both the production and utilization of hormones in males.16 - 18 Indeed, scientists have even induced «testosterone deprivation» in animals simply by feeding them diets rich in soy
isoflavones.19
On the other hand, a study conducted by researchers at the University of Guelph directed 32 men to eat low or high levels of
isoflavones from soy protein for 57 days.
That's why, about six years ago, a few researchers performed a meta - analysis of existing studies
on isoflavones.
While the phytoestrogens (
isoflavones) likely play a small role in the overall healthiness of soy, they probably don't have much benefit (or do much damage)
on their own.
Eating soy (or any sort of
isoflavone supplement) has no measurable effect
on free testosterone levels.
There has also been interest in the idea that
isoflavones in soymilk and tofu might protect bone health, but the findings
on this are conflicting.
They looked at all the studies out there
on soy, phytoestrogens, and
isoflavones to see whether they had any effect
on testosterone levels.
Instead a review of studies headed by Ian C. Monro comes to the following conclusion: «Whereas results in some studies are limited or conflicting, when viewed in its entirety, the current literature supports the safety of
isoflavones as typically consumed in diets based
on soy or containing soy products [emphasis ours].»