T Nation

Eat Soy to Grow Big Balls...

Differential effects of soy-containing diets on the reproductive tissues growth and reproductive hormone secretion in male rats.

The effects of feeding a breeding diet containing soy products to pregnant and lactating females on reproductive tissues and secretion of the reproductive hormones in their male progeny, immediately after weaning (postnatal day - PND 22) and after reaching puberty (PND 60) were studied. Similarly, the response of adult males to a soy maintenance diet over shorter (PND 160) and longer (PND 280) periods of time was examined. The relative weights (standardized by body weight) of the testes, epididymis and prostate, and the concentrations of luteinizing hormone (LH), testosterone and prolactin (PRL) were used as the examined endpoints. In rats on PND 22, no significant differences in the relative organs weights and the plasma hormones concentrations were found between the experimental and control groups. In rats on PND 60 which continued consuming a soy breeding diet, the relative tissue weights did not differ significantly, while the mean plasma LH and PRL concentrations were higher (p<0.01-0.001) compared to the controls. In rats on PND 160 fed soy maintenance diet, the higher relative testes (p<0.01) and epididymis (p<0.05) weights as well as plasma testosterone (p<0.001) concentration were recorded compared to the controls. In rats on PND 280 fed a soy maintenance diet, the relative weights of all reproductive tissues were similar to those of controls, however, the weight of the body and the real weights of the reproductive tissues were lower (p<0.05) than in controls. The mean plasma concentrations of the reproductive hormones did not differ significantly between the two groups. In conclusion, a supplement of soy in the rat diet may affect growth and/or development of the reproductive tissues in male rats and also affect concentrations of reproductive hormones. The effects depend on the period of life when the soy diet is applied.

What worries me is the word “relative” there.

fuck soy

cool read tho


Yeah, the “relative” thing is kind of funky. So, the rats were smaller and had smaller testes, but they were still proportional in relative terms?

If that’s what they are saying, I’m not sure I’m getting much of an endorsement out of that…

I don’t have access to the study, but an article in Dutch quotes from it.
“A decrease in the body weight was reported earlier in both male and female rodents exposed to different doses of soy or soy-derived isoflavones. That was explained, in part, by an increased locomotor activity and/or lesser food intake.”

So perhaps the reduced weight is mostly fat???

Also, there’s this study: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstract&list_uids=16775579

Serum prostate-specific antigen but not testosterone levels decrease in a randomized soy intervention among men.

[i]BACKGROUND: Low prostate cancer incidence and high soy intake in Asian countries suggest a possible protective effect of soy foods against prostate cancer. The goal of this pilot study was to evaluate the feasibility of a randomized, crossover soy trial among men and to investigate the effects of daily soy intake on serum prostate-specific antigen (PSA) and testosterone levels.

METHODS: We randomized 24 men to a high or a low soy diet for 3 months. After a 1-month washout period, the men crossed over to the other treatment. During the high soy diet, the men consumed two daily soy servings; during the low soy diet, they maintained their usual diet. During the entire study each man donated four blood samples and five overnight urine samples. Dietary compliance was assessed by soy calendars, 24-h dietary recalls, and urinary isoflavone excretion measured by high-pressure liquid chromatography with photodiode array detection.

Blood samples were analyzed for serum testosterone and PSA by radioimmunoassay. When necessary, variables were log transformed. Two sample t-tests compared the two groups before each study period. Mixed models incorporating the repeated measurements were used to evaluate the effect of the soy diet on urinary isoflavone excretion and serum analytes.

RESULTS: Twenty-three men aged 58.7+/-7.2 years completed the study. The compliance with the study regimen was high according to self-reported soy food intake and urinary isoflavone excretion. No significant between-group and within-group differences were detected. During the high soy diet, dietary isoflavone intake and urinary isoflavone excretion increased significantly as compared to the low soy diet.

A 14% decline in serum PSA levels (P=0.10), but no change in testosterone (P=0.70), was observed during the high soy diet in contrast to the low soy diet. CONCLUSION: The high adherence as shown by three measures of compliance in this pilot trial demonstrated the feasibility of an intervention based on soy foods among free-living men.[/i]

I’m just saying, there are studies out there indicating that soy doesn’t deserve it’s rep of ball-busting food.

Given that most soy containing products aren’t tremendously healthy to begin with, I’ll stick to avoiding it- except in miso soup- when possible.

your testes get larger because leydig cells are being inhibited in proper function(creating test for one). Your body responds by stimulating more proliferation of leydig cells(or activity?) to compensate the lack of activity, but soy just keeps fucking this up.

This is called hyperplasia if the number of cells increase or hypertrophy if they just get larger and not in number. either way its a sign that your shits not working right down there.