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Visa fullständig version : Soja ökar aggressiviteten hos hanapor


dessbee
2007-11-17, 11:12
Hittade en artikel om sojas effekt på hanapor:


Increased aggressive behavior and decreased affiliative behavior in adult male monkeys after long-term consumption of diets rich in soy protein and isoflavones

Estrogen produced by aromatization of gonadal androgen has an important facilitative role in male-typical aggressive behavior that is mediated through its interaction with estrogen receptors (ER) in the brain. Isoflavones found in soybeans and soy-based dietary supplements bind ER and have dose- and tissue-dependent effects on estrogen-mediated responses. Yet, effects of isoflavone-rich diets on social and aggressive behavior have not been studied. We studied the effects of long-term (15 months) consumption of diets rich in soy isoflavones on spontaneous social behavior among adult male cynomolgus macaques (Macaca fascicularis) (n = 44) living in nine stable social groups. There were three experimental conditions which differed only by the source of dietary protein: casein and lactalbumin (no isoflavones), soy protein isolate containing 0.94 mg isoflavones/g protein, and soy protein isolate containing 1.88 mg isoflavones/g protein. In the monkeys fed the higher amount of isoflavones, frequencies of intense aggressive (67% higher) and submissive (203% higher) behavior were elevated relative to monkeys fed the control diet (P's < 0.05). In addition, the proportion of time spent by these monkeys in physical contact with other monkeys was reduced by 68%, time spent in proximity to other monkeys was reduced 50%, and time spent alone was increased 30% (P's < 0.02). There were no effects of treatment on serum testosterone or estradiol concentrations or the response of plasma testosterone to exogenous gonadotropin-releasing hormone (GnRH). The results indicate that long-term consumption of a diet rich in soy isoflavones can have marked influences on patterns of aggressive and social behavior.

Neal G. Simon a, Jay R. Kaplan b, Shan Hu a, Thomas C. Register b and Michael R. Adams b, ,
a Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
b Department of Pathology/Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
Received 20 August 2003; Revised 17 December 2003; accepted 19 December 2003. Available online 18 March 2004.

Absinteh
2007-11-17, 18:07
Konstigt.

dessbee
2007-11-18, 07:30
Konstigt.

Dom spekulerar i flera olika orsaksmekanismer men en kan vara lägre serotoninnivåer:

"In nonhuman primates, only ERβ are found in 5-HT neurons (Bethea et al., 2002b and Gundlah et al., 2001). Estradiol normally acts in these cells to enhance serotonergic tone by increasing tryptophan hydroxylase synthesis and decreasing 5-HT transporter expression (Lu and Bethea, 2002 and Lu et al., 2003). The level of isoflavones from the high-dose diet could result in competition for ERβ binding."