View Full Version : Soy nuts for me bad or good?

08-07-2003, 11:01 PM
All right so I have read soy can cause estrogen levels in men to go up, but can it really do that much harm? I have found a new source of protein that I would like to start taking since it is extensively cheap. Honey roasted soy nuts under 1 cent per gram of protein. I would like to take enough servings to equal 90 grams of protein daily. Would this be a bad idea?

08-08-2003, 03:56 AM
After reading various sources of information regarding soy and soy protein isolate I am still unsure as to what level of soy protein would be beneficial and at what point a certain intake of soy might become detrimental. There is definitely plenty of debate on the topic, but according to the link below 90g per day would be too much.

"Thirty subjects were randomized into a WPI group or a SPI group for a double blind, twelve- week pilot trial. Subjects underwent resistance training three times per week. Both groups were instructed to ingest two servings of 30g each per day of their respective protein source.

The results showed that the WPI group had significantly increased glutathione stores while the SPI group exhibited significantly decreased glutathione levels. Males in the WPI group did not show a significant change in T4 thyroid activity, whereas males in the SPI group had significantly decreased T4 thyroid hormone. Females ingesting the WPI experienced a significant decrease in estradiol levels compared to those in the SPI group. Both sexes showed similar decreases in body fat, cholesterol, triglycerides and LDL cholesterol regardless of ingesting whey protein or soy protein. However, serum levels of cystine, methionine and lysine were significantly higher in the whey protein group."

08-08-2003, 11:43 AM
I wouldn't worry about the soy estrogen connection - it's a red herring.

If you have no known thyroid problems then knock yourself out with soy nuts. Just watch out if they are roasted in oil because you may have trans fats to worry about.

08-08-2003, 02:18 PM
In the article below the author advocates the use of soy protein isolate which he states can have a beneficial effect on the thyroid. This contradicts what I posted above, but then again it could be related to the amounts of soy protein ingested. Also in the article it refers mainly to using soy protein isolate as opposed to soy based foods (soy milk, etc.). I am unsure if this would have any bearing, but I am curious as to whether you could see different effects by consuming SPI as opposed to soy protein, due to the different amounts of isoflavones. Any thoughts?

"Soy protein has been shown to raise thyroid hormone output which could be a real advantage to bodybuilders trying to shed some fat. The intake of various high quality proteins has been associated with higher levels of thyroid hormone, but soy appears to have thyroid hormone raising abilities unique to that of other proteins. Though some research has shown changes in T3 and thyroid stimulating hormone (TSH), the real effect appears to be with T4 which is elevated consistently in the studies done using animals-and to a lesser degree people-eating soy proteins."

08-08-2003, 02:20 PM
the phyto-estrogens in soy are so similar to human estrogen they can bind to estrogen receptors and exert an estrogenic effect

however, the effect is very weak and some suggest since the phyto-estrogen occupies the receptor it blocks the human estrogen

08-12-2003, 01:52 AM
Ok, so now I will go by (opinions only). In your guy’s opinion do you think it is ok to take in that much soy protein? I would really like to eat it since it taste good and is high in protein.

So confused...

BTW: Hemants, could you please give some more info on trans fats. There are two kinds of soy nuts I'm looking at. One is honey roasted the other is just plain. Thanks

08-12-2003, 02:47 AM
Originally posted by lazyman79
Ok, so now I will go by (opinions only). In your guy’s opinion do you think it is ok to take in that much soy protein? I would really like to eat it since it taste good and is high in protein.

I have never seen anything good associated with that high of a soy intake, and I would not recommend making soy my primary protein source. Although from what I have read soy isolate would be a better choice as far as soy protein is concerned.

08-12-2003, 03:03 AM
Inverse association of soy product intake with serum androgen and estrogen concentrations in Japanese men.

Nagata C, Inaba S, Kawakami N, Kakizoe T, Shimizu H.

Department of Public Health, Gifu University School of Medicine, Japan.

The cross-sectional relationships of soy product intake and serum testosterone, estrone, estradiol, sex hormone-binding globulin, and dihydrotestosterone were examined in 69 Japanese men. Soy product intake was estimated from a semiquantitative food frequency questionnaire. Serum estradiol concentration was significantly inversely correlated with soy product intake (r = -0.32, p = 0.009), and serum estrone concentration was nonsignificantly inversely correlated with soy product intake (r = -0.24, p = 0.05) after controlling for age, body mass index, smoking status, and ethanol intake. Total and free testosterone concentrations were inversely correlated with soy product intake after controlling for the covariates, but these correlations were of border line significance (r = -0.25, p = 0.05 and r = -0.25, p = 0.06, respectively). Similar correlations were observed for these hormones with isoflavone intake from soy products. The data suggest that soy product intake may be associated with the endogenous hormone levels in Japanese men.


Here are a few things about trans fats that might be of interest.:)

08-12-2003, 06:07 AM
My advice is if you're eating foods then knock yourself out on soy products like tofu or veggie burgers.

If you're going to use powder then stick to whey.

Soy milk is good too.

Although they may not taste as good, plain soy nuts would be better than honey roasted unless they are dry roasted. Even then, honey is basically sugar so check the nutrient content and add it to your daily tally.