Scientist Links Chemical Cocktails to Male Infertility and Birth Defects

Environmental Chemicals Linked to Birth Defects

Professor Richard Sharpe of the Medical Research Council highlighted in a report commissioned by CHEM Trust published last week that chemicals in consumer products may contribute to human male reproductive disorders that manifest at birth (cryptorchidism – undescended testes, hypospadias –where the opening of the urethra is abnormally positioned somewhere along the underside of the penis, between the base and just below the tip), or in young adulthood (impaired semen quality or testicular germ cell tumours). Such disorders are collectively referred to as Testicular Dysgenesis Syndrome, a phrase coined by Professor Niels E Skakkebaek MD.

In recent decades incidences of malformation of the penis, low sperm counts and testicular cancer have all increased. Incidences of testicular cancer have almost doubled over the last 25 years, according to the report and are six times more common in the developed world than in developing countries. Perhaps even more startling is the data revealing that across Western Europe, more than 1 in 6 young men have an abnormally low sperm count, which will adversely impact on their fertility.

Sharpe believes that exposure to hormone disrupting chemicals (in particular exposure to mixtures of such chemicals) may contribute to the deteriorative state of men’s reproductive health, the origins of which can be traced to development in the womb.

According to Sharpe, “TDS disorders are common: indeed, some have increased in incidence in a time-frame that implicates environmental causes, and experimental animal and wildlife studies suggest that TDS-like disorders are induced by, or associated with, fetal exposure to certain environmental chemicals.”

Testosterone is required to form a normal penis and make the testicles drop, but Sharpe suggests that everyday chemicals in the environment and consumer products have the potential to block the action of testosterone in the womb and harm future male reproductive health.

Sharpe said; “Because it is the summation of effect of hormone disrupting chemicals that is critical, and the number of such chemicals that humans are exposed to is considerable, this provides the strongest possible incentive to minimise human exposure to all relevant hormone disruptors, especially women planning pregnancy, as it is obvious that the higher the exposure the greater the risk”.

Evidence from experimental studies in rats has established that a growing number of environmental chemicals can inhibit androgen production/action (androgens are hormones in charge of developing and preserving male sexual characteristics – the main one being testosterone), and cause testicular dysgenesis syndrome-type disorders. Studies looking at mixtures of chemicals have demonstrated that environmental chemicals display additive effects, even though the individual chemicals at those levels are without significant effect (this is often referred to as the ‘cocktail effect.’)

Experiments on rats have confirmed that if hormones are blocked during 8-12 weeks gestation, animals suffered from fertility problems such as undescended testes and low sperm counts. During this time window androgens must act to ensure later correct development of the male reproductive system. Testicular Dysgenesis Syndrome-type disorders arise if there is insufficient androgen action during this time frame.

Phthalate exposure has been linked in one study with cryptorchidism in male offspring and with reduced anogenital distance (distance between the genitals and the anus – which is a potential sign of feminisation as the anogenital distance is shorter in girls than in boys). Other studies have shown that phthalates may reduce neonatal testosterone production in three-month old boys and neonatal marmasets. Although Sharpe suggests that the role phthalates may play in testicular dysgenesis syndrome is currently uncertain.

Phthalates are the most abundant man-made chemicals in the environment, regulated as pollutants when released into the environment by industry, and used in all manner of consumer products, including cosmetics.

I interviewed Professor Richard Sharpe for my latest book Toxic Beauty, and he discussed Testicular Dysgenesis Syndrome, saying,

“Our present understanding is that a central feature of the disorder is dysfunction of the production or the action of testosterone – the male sex hormone, which is made in foetal life and is responsible for essentially modifying the phenotype of a foetus to change it from a female to a male.”

The term “phthalate syndrome” has been coined, according to Professor Sharpe, “to cover the range of abnormalities that are seen after in utero exposure of rats to certain (not all) phthalates.” In animals exposed to certain phthalates “the epididymis may degenerate postnatally, initially forming but not getting enough testosterone support to remain viable after birth…the testis forms more or less normally but develops certain scattered abnormal features (called focal dysgenesis) after birth. The gubernaculum is a cord of tissue that connects the testis and epidymis to the abdominal wall, a connection that is essential for the testis to migrate through the abdomen, then through the abdominal wall into the scrotum.” Maintenance and development of the gubunaculum relies on a secretion from the Leydig cells (responsible for testicular androgen production), which is “reduced by phthalate exposure, hence the occurrence of cryptorchidism.”

Although, Professor Sharpe is not yet convinced that phthalates definitely cause problems in humans, he does recommend caution on the part of mothers-to-be, in using cosmetic products.

“We have a special case where mothers are potentially exposing the foetus to environmental chemicals via her lifestyle choices. The foetus has no say in that and will just bear the consequences. My recommendation is that it is extremely prudent for women who are planning to become pregnant, to embark upon a programme of reducing their exposure, certainly via the use of cosmetics and creams. It is too late once they are pregnant. In that way they can benefit the foetus and not suffer unduly themselves, just for giving up for that period of time…”

You can read the report online at Chemtrust.org.uk.