Just Say No To Soy!

[Ben2285]

Originally Posted by Ordo Ab Chao

I gathered that. I meant is soy consumption really a concern or is it difficult to consume enough to receive a PE dose high enough to activate ampk.

That is a good point and I am wondering the same thing... How much is really an issue because most of us only take in residual soy.

[President Wilson]

All great points. One thing is with animal studies, the investigator will give the animal usually 6 times the dosage because when doing pharmacokinetic calculations, it turns out that 'equivalent" dosages between rodents and humans are different by roughly a factor of 6, which takes into account a number of factors, but mainly accounts for the metabolic rate differences between small rodents and humans. I remember when looking into an animal study I want to do with HMB, that the amount of HMB to give them was 0.25 grams/kg body weight. If this is what we as humans consumed it would mean we would take in nearly 20 grams of HMB per day. so the same would apply in this study, you can compare the dosage as 6 times less per kg and that would be how it applies to us

For people who live on cheap protein bars, or vegetarians it may be an issue. For people who just get neglegable soy as Ben suggests, it probably won't have an effect. The main thing is that the study indicates that we should stear clear of purposely consuming soy as a source of solid protein.

[Ben2285]

Originally Posted by President Wilson

All great points. One thing is with animal studies, the investigator will give the animal usually 6 times the dosage because when doing pharmacokinetic calculations, it turns out that 'equivalent" dosages between rodents and humans are different by roughly a factor of 6, which takes into account a number of factors, but mainly accounts for the metabolic rate differences between small rodents and humans. I remember when looking into an animal study I want to do with HMB, that the amount of HMB to give them was 0.25 grams/kg body weight. If this is what we as humans consumed it would mean we would take in nearly 20 grams of HMB per day. so the same would apply in this study, you can compare the dosage as 6 times less per kg and that would be how it applies to us

For people who live on cheap protein bars, or vegetarians it may be an issue. For people who just get neglegable soy as Ben suggests, it probably won't have an effect. The main thing is that the study indicates that we should stear clear of purposely consuming soy as a source of solid protein.

Excellent synopsis! I did read most of the study and I do think it is quite interesting, especially the graphs which showed the larger losses of body fat and weight, I know this is due to the AMPK activation but again according to the graphs large losses were seen in % fat mass not ffm. Although it does inhibit protein synthesis I think it could have useful applications as they suggest.

Another important thing to note is that there are many other high sources of phytoestrogens (though I believe soy is the most potent) such as flax oil, beans, and certain grains.

[Ordo Ab Chao]

Originally Posted by Ben2285

Another important thing to note is that there are many other high sources of phytoestrogens (though I believe soy is the most potent) such as flax oil, beans, and certain grains.

What makes you say this? From what I understand, the PE's in soy bind weakly to hormone receptor sites. Do the other PE sources have even weaker bonds?

[Ben2285]

Originally Posted by Ordo Ab Chao

What makes you say this? From what I understand, the PE's in soy bind weakly to hormone receptor sites. Do the other PE sources have even weaker bonds?

The study is labeled "Dietary Phytoestrogens Activate AMP-Activated Protein Kinase With Improvement in Lipid and Glucose Metabolism".

I said it because soy is not the only dietary source of phytoestrogen so it is not the only thing to be wary of, but again it is likely the most potent source. I wasn't really referring to the estrogenic effects of phytoestrogens, but more on the activation of AMPK.

[Ordo Ab Chao]

Originally Posted by Ben2285

The study is labeled "Dietary Phytoestrogens Activate AMP-Activated Protein Kinase With Improvement in Lipid and Glucose Metabolism".

I said it because soy is not the only dietary source of phytoestrogen so it is not the only thing to be wary of, but again it is likely the most potent source. I wasn't really referring to the estrogenic effects of phytoestrogens, but more on the activation of AMPK.

thats not what I was asking, sorry if that was misleading. I was hoping you would elaborate on why you think soy PE's are more potent

[Ben2285]

"Phytoestrogen content of foods--a compendium of literature values."

Plant compounds with estrogenic activity may play a role in cancer prevention, moderation of menopausal symptoms, and other health effects. To facilitate research on these possible actions, the literature was reviewed for quantitative data on the levels of known phytoestrogens (daidzein, genistein, coumestrol, formononetin, and biochanin A) in food plants. For comparative purposes, all phytoestrogen levels were recalculated on a wet weight basis. Details on analytic procedures are given as well. High-performance liquid chromatography was the method most often used to analyze these compounds in foods. Most significant sources of isoflavone and coumestan phytoestrogens include soybeans, soy flour, soy flakes, isolated soy protein, traditional soy foods such as tofu and soy drinks, second-generation say foods, sprouts, and other legumes. Finally, medians among reported values of phytoestrogen content are provided for some of the most commonly eaten foods with quantitative data available. These may be used to calculate dietary intake of daidzein, genistein, coumestrol, formononetin, and biochanin A.

"Dietary phytoestrogens."

"Broadly defined, phytoestrogens include isoflavones, coumestans, and lignans. A number of these compounds have been identified in fruits, vegetables, and whole grains commonly consumed by humans. Soybeans, clover and alfalfa sprouts, and oilseeds (such as flaxseed) are the most significant dietary sources of isoflavones, coumestans, and lignans, respectively. Studies in humans, animals, and cell culture systems suggest that dietary phytoestrogens play an important role in prevention of menopausal symptoms, osteoporosis, cancer, and heart disease. Proposed mechanisms include estrogenic and antiestrogenic effects, induction of cancer cell differentiation, inhibition of tyrosine kinase and DNA topoisomerase activities, suppression of angiogenesis, and antioxidant effects. Although there currently are no dietary recommendations for individual phytoestrogens, there may be great benefit in increased consumption of plant foods."

Honestly before I looked into it my assumption was just based on suspicion since soy is always the first mentioned when phytoestrogen is discussed. These studies back up my suspicions