Exposure to genistein does not adversely affect the reproductive system in adult male mice adapted to a soy-based commercial diet

Genistein, a soybean-originated isoflavone, is widely consumed by humans for putative beneficial health effects but its estrogenic activity may affect adversely the development of male reproductive system. Five-week-old ICR mice were purchased and fed with a soybean-based Purina Chow diet until 6 months of age. The animals were exposed by gavage to genistein (2.5 mg/kg/day) or 17beta-estradiol (7.5 microgram/kg/day) for five weeks. Corn oil was used for the negative control. The animals were fed the caseinbased AIN-76A diet throughout the experimental periods. There were no significant differences in body and organ weights of mice among experimental groups. No significant differences in sperm counts and sperm motile characteristics were found between the control and the genistein groups. Treatment of 17beta-estradiol caused a significant decrease in epididymal sperm counts compared to the control (p<0.05). The level of phospholipid hydroxide glutathione peroxidase in the epididymis of mice exposed to genistein was significantly higher than that of the control mice (p<0.05). 17beta-estradiol treatment caused a reduction of germ cells in the testis and hyperplasia of mucosal fold region in the prostate of mice. Genistein treatment did not cause any lesion in the testis, epididymis, and prostate. These results suggest that dietary uptake of genistein at adult stage of life may not affect male reproductive system and functions.

Growth and Development of Infants Fed Soy-Based Formulas over 3 Months / 대한지역사회영양학회지

The objective of this study was conducted to investigate growth and development status of infants fed soy-based formulas over 3 months. The height and weight were measured and Z-scores were calculated by using standard of the same age groups. Their mothers were interviewed using questionnaires including general and environmental characteristics, total food intakes, soy based formula intakes and Ewha infant development screening test. Main results were as follows: 1) Nutrient intake levels of subjects were similar to or more than the level of Korean Recommended Dietary Allowances except for intakes of vitamin E (79.89% RDA), and the average status of nutrient intakes of infants were fairly good. 2) Z-scores of height for age (HAZ) and Z-scores of weight for age (WAZ), Kaup index, WLI and Ewha Infant Developmental Screening Test score of subjects were in the normal growth range. 3) There were no significant differences among soy based formula intake percentile groups in HAZ, WAZ, Kaup index, WLI and Ewha Infant Developmental Screening Test score. 4) Total energy intake was positively correlated with HAZ (p < 0.01), WAZ (p < 0.01), and WLI (p < 0.05) in infants less than 12 month. Also, soy based formula energy intake was positively correlated with HAZ (p < 0.05) in infants less than 12 month. However, energy and soy based formula intake levels of infants over 12 month were not significant among variables. Considering results of this study, infants fed soy-based formulas over 3 months showed normal growth and development status. Further studies are needed to evaluate long-term growth and development in infants fed soy based formulas.