Environmental Oestrogens and Sperm
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Posted On :
Nov-01-2011
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Article Word Count :
609
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Recent research has linked exposure to increased levels of the female hormone, oestrogen, with the observed falling sperm counts.
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Recent research has linked exposure to increased levels of the female hormone, oestrogen, with the observed falling sperm counts.
This is based on the effects of a synthetic oestrogen (diethyl-stilboestrol) prescribed to millions of pregnant women between 1945 and 1971 to prevent a threatened miscarriage. The male offspring of these pregnancies, who were exposed to diethylstilboestrol in the womb, had an increased risk of undescended testicles, abnormal penis development and future testicular cancers. As adults, they also produced low semen volumes and low sperm counts.
Over the last 30-50 years, these same birth defects have become more common in men who have not knowingly been exposed to synthetic oestrogens in the womb. At the same time, semen volume and sperm counts in adult males have fallen dramatically [see page 78). Scientists suggest that men are exposed to weak environmental oestrogens from many sources. These weak environmental oestrogens may have an effect on the developing male foetus and on the rapidly maturing testes at puberty. They are thought to inhibit the division of Sertoli cells in the testes and to inhibit the development of the testicular Leydig cells.
Sertoli cells are essential for sperm maturation, but each one can only support a certain number of sperm. If there are less Sertoli cells, a lower sperm count is inevitable. Leydig cells manufacture testosterone, and less cells would mean less circulating levels of androgens. This would increase the risk of undescended testes and of future low sperm counts. The environmental oestrogen theory needs further investigation, but observation of animals in the wild seems to back it up. Recent research also suggests that men who drink more milk than usual - and are therefore exposed to higher quantities of cow's oestrogen - are at increased risk of developing testicular cancer
Exercise And Sperm
It is well known that excessive exercise can affect the fertility of female athletes by stopping the normal menstrual cycle (a condition known as 'runners' amenorrhea'). New research shows that overtraining can damp down fertility in males, too.
Fit males who routinely took part in endurance training like running, swimming, cycling for more than 4 days per week were asked to double their average weekly mileage for a two-week period.
Their semen and blood hormone levels were analyzed for six months before the period of overtraining, again immediately afterwards, and three months later.
Immediately after overtraining, their sperm counts fell by as much as 43 per cent. After three months, sperm counts had dropped to 52 per cent lower than before they over trained. The number of immature and non-viable sperm increased. All semen samples stayed within the accepted fertile range, however, and this would not be expected to interfere with fertility except where sperm counts were already low.
The blood levels of testosterone hormone also fell significantly by over a third (36 per cent) immediately after overtraining but returned to normal within three months. In contrast, blood levels of the steroid hormone, Cortisol, increased by almost 50 per cent.
Cortisol is a steroid secreted in times of stress. It encourages breakdown of muscle and is linked with the muscle wasting that can occur with prolonged overtraining. Cortisol also damps down the secretion of testosterone by Leydig cells in the testis, and is the probable cause of this observed decrease in sperm count. This would also fit in with anecdotal findings that stressed people are less fertile. It is important to realize, however, that the overtraining only occurred for a two-week period in this particular study. The effects of long-term overtraining on male fertility are likely to be more profound.
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Article Source :
http://www.articleseen.com/Article_Environmental Oestrogens and Sperm_98499.aspx
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Author Resource :
Andre Willams a certified health care and Generic Cialis expert. He is considered to be the leading authority in health and skin care treatment. He also writes articles on popular sites about health and erectile dusfunction. His main areas of research are health and Cheap Cialis.
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Keywords :
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Category :
Health and Fitness
:
Men's Issues
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