| [Background & Objective]Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality was reported from some European countries such as Belgium, Denmark, France, and Great Britain. Furthermore, the percentage of motile and normal spermatozoa also decreased significantly, while semen volume remained unchanged. Deterioration of sperm counts as well as motility among semen donor candidates during the past two decades was also observed in a Belgian study. A few of reports exhibited that male sperm quality declined during 1981 to 1996 in China. The speed of semen quality declination was faster in China than in some western countries though the semen quality was better than that of these countries. All in all, in the past 50 years, the sperm count decreased about half.In addition, in this period, the incidences of testicular and prostatic cancers have increased. Testicular cancer is now the most common malignancy of young men in many countries. The lifetime risk of developing testicular cancer now approaches 1% in a country such as Denmark. Prostatic cancer also is the most common cancer among men in most western countries. The incidence and mortality of both malignancies vary greatly from country to country. Testicular and protastic cancers are relatively rare in China when compared with those in western countries.According to some reports from WHO, the incidence rates of breast and ovarian cancers, which are hormone associated tumors, have increased in many counties. Breastcancer is one of the most frequent malignancies among women. For example, approximately 796 000 new cases of breast cancer are estimated to occur annually throughout the world. The highest incidence of breast cancer is generally found in the US, where the recent age-adjusted incidence rate attains 80-100 per 100 000. Ovarian cancer is a moderately frequent malignancy but is a leading cause of death from gynecological cancers. In the US, ovarian cancer ranks the fourth among the most frequent causes of cancer death in women, after lung, breast, and colorectal cancers. Each year, approximately 26 000 women are diagnosed with ovarian cancer in the US, and 14 000 of them have a fatal outcome. The incidence rates of the both female malignant tumors in our country are the lowest when compared with those in some developed countries.On the other hand, survey of girls between 3 and 12 years of age indicated that breast and pubic hair development occur significantly earlier than suggested by the guidelines. Moreover, menarche comes in girls as early as 3 years old.From the above we can conclude that the ^averse prenatal factors may influence the production capacity of the perm in adult life. A hypothesis was put forward that some environmental chemicals having estrogen-like effects might be the contributing factors. In particular, it was suggested that fetal exposure to an excess of estrogenic compounds was a key risk factor.There are several routes for human exposure to environmental contaminants and natural factors, which possess estrogenic activity. However, this contaminant exposure mainly occurs tin-ought diet. Therefore, we are particularly concerned about food consumptions and want to conduct the food study to provide clues for protection and promotion of human reproductive health.[Materials and Methods]1 Ecological studyThe incidence rates of testicular , prostastic , breast and ovarian cancers in 42 countries (region) were correlated with the dietary practices in these countries using the cancer rate database from IARC (1988-92) and the food supply database from FAO (1961-90). The age specific death numbers of these cancers and populations from the database of Vital Statistics of Japan were published by Japan Department of Health, which were used for the birth death cohort study. All data concerned were input into the computer and the statistical software of SPSS was used to analysis and calculates. The 0.05 level of probability was used as the criteri... |
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