Dr Dingle's Blog / animals
Since the 1980's, there has been a growing amount of research toward the potential interaction between these environmental estrogens and wild animals, with a number of reports detailing the emergence of 'feminised wildlife’ around the world, and a range of adverse effects in humans including decreased sperm count, increased cases of testicular cancer and testicular abnormalities, increased breast cancer in men and women and premature or precocious puberty. Other adverse health outcomes linked with EDC’s include headache, migraine, depression, gastrointestinal disturbances, insomnia, changes in breast tissue and in vaginal bleeding. More chronic symptoms affect the cardiovascular system, the skin (itching, rash, abnormal pigmentation), the gallbladder, and tumours particularly of the breast but also uterus, cervix, vagina and liver. While other studies have shown increases in the organ weight of estrogen-sensitive tissues such as the uterus, and calcium and bone metabolism are all examples of the estrogenic effects. Even how we age and age at menopause can be affected by these chemicals. In support of this at least one professional and very conservative group, the Endocrine Society, has concluded that sufficient evidence now exists linking endocrine disrupting chemicals (EDCs) to adverse human reproductive effects, including possible epigenetic and trans-generational effects.
Unfortunately, our babies are being born pre-polluted with chemicals detectable in their blood, in the placenta and in amniotic fluid because of exposure to these chemicals during pregnancy and throughout the mother’s life. The placental barrier has been shown to allow these chemicals to cross, as many of them have been measured in human fetal cord blood, fetal serum, human amniotic fluid and even newborn stools (meconium). Exposure to these chemicals before birth poses a serious health risks to developing fetus, infants and young children as shown by the increasing adverse effects including negative birth outcomes, childhood obesity and increasing intellectual disabilities. It is believed that current levels of environmental estrogen exposure results in lower birth weights, smaller head circumferences, poorer neuromuscular maturity and visual recognition, delays in psychomotor development, short term memory problems, and growth retardation in newborn babies. Fetal exposure to these environmental estrogens are suspected of disrupting thyroid functioning, sexual differentiation of the brain in foetal development and cognitive motor function and cause anxious behaviour. They are also able to bind to neurotransmitters such as epinephrine, neuroepinophrine and dopamine enabling estrogens to influence the body's central nervous system (CNS). Environmental estrogens have also been shown to effect the body’s immune system.
Studies have found strong links with exposure to excessive levels of estrogen in males with penis abnormalities, lower libido, congenital anomalies, failure of the testes to descend and testicular cancer, reduced penis size and increased embryo mortality.
What is most concerning regarding control of these chemicals is that there are no indications given or regulations set regarding the minimal age at which they should be used or exposed to them. Increasingly, pregnant mothers, infants, pre-pubescent and pubescent children are being exposed to a large number of products containing these chemicals, with no research to show that exposure is safe during these critical periods of development.
Equally strong is the evidence that these same chemicals can cause some of the most common cancers: prostate and testicular cancer in men and breast cancer in women. One of the most troubling is their association with breast cancer. Breast cancer is the major cancer affecting women in the Western world and one of the most disturbing and well documented current trends is the alarming increase in breast cancer incidence over the past few decades. Fifty years ago the risk rate was one woman in 20; today it is one in 8 and approximately two-thirds of breast tumors are estrogen receptive, and environmental estrogens like parabens, phthalates and BPA are known to bind to estrogen receptors. Estrogen-dependent cancers, such as breast cancer, are known to be highly responsive to estrogens for growth. Even more disturbing is the increase in numbers of young girls developing breast cancer.
Evidence from animal studies shows that prenatal exposure to bisphenol A (BPA), a ubiquitous endocrine-disrupting chemical, is associated with adverse reproductive outcomes in females and males. In females exposure during early gestation, a critical period for reproductive development, is of particular concern. The Anogenital distance (AGD) is a sensitive biomarker of the fetal hormonal balance and a measure of reproductive toxicity in animal studies. In some studies, the daughters of BPA-exposed dams have shorter AGD than controls.
The results of this study showed BPA was detectable in 94% of women. In analysis of the 381 eligible subjects, maternal BPA concentration was inversely associated with infant AGD-AC
In support of animal studies this human study shows that BPA may have toxic effects on the female reproductive system in humans, as it does in animal models. Higher first-trimester BPA exposure was associated with significantly shorter AGD in daughters, suggesting that BPA may alter the hormonal environment of the female fetus.
Bisphenol A (BPA) is a synthetic chemical widely used in consumer products, including food and drink containers, thermal receipts, medical equipment, and other plastic products. BPA is detectable in over 90% of the population in the United States, and may act on the endocrine system in numerous ways, including binding to and activating numerous nuclear and membrane endocrine receptors, and stimulating changes in estrogen, androgen, progesterone, and thyroid hormone activity.
Dozens of studies in humans have examined BPA exposure in relation to a wide range of health end points, including reproductive, perinatal, and pediatric outcomes. Many animal studies and in vitro studies show that many tissues and organ systems (including the mammary gland, prostate gland, adipose tissue, reproductive system, and brain) are sensitive to BPA. In animal and human studies, BPA can cross the placenta to enter fetal circulation. Because fetal development is a period of rapid cell proliferation and differentiation, tissue development, and organ growth, prenatal exposure to environmental chemicals such as BPA may be of particular concern.
There is increasing evidence emerging from the scientific community which suggests that mass-medication in the form of water fluoridation is in fact having a serious and adverse effect on the public’s health. A recent report from the US National Research Council 1 concluded that adverse effects of high fluoride concentrations in drinking-water may be of concern. Animal studies have shown Fluoride may cause neurotoxicity, including effects on learning and memory 2,3. Recent experiments where the rat hippocampal neurons were incubated with various concentrations of sodium fluoride showed that fluoride neurotoxicity may target hippocampal neurons.
Fluoride readily crosses the placenta exposing the developing brain, which is much more susceptible to injury caused by toxicants than is the mature brain, may possibly lead to damage of a permanent nature 4
In a study conducted by Tianjin Medical University in China, a comparison in the Intelligence Quotient (IQ) was measured between 60 children living in a high fluoride area and 58 children living in a low fluoride area. The IQ of the 60 children living in the high fluoride area was lower than that of the 58 children living in the low fluoride area. 21.6% of the children in the high fluoride area were retarded compared to 3.4% of retarded children living in the low fluoride area 5.
In a study at Tokyo University Medical School, water fluoridation was linked to Down syndrome. The study found that - as well as the aging of mothers - the number of excess Down syndrome births caused each year by water fluoridation was estimated to be several thousand cases throughout the world 6.
In the most recent meta analysis of 27 eligible epidemiological studies found that children in high fluoride areas had significantly lower IQ scores than those who lived in low fluoride areas 7. The conclusions of the study “support the possibility of an adverse effect of high fluoride exposure on children’s neurodevelopment.”
Some of the other adverse health effects of fluoride include lowered levels of collagen synthesis, depleted energy reserves and lowered immunity, irritable bowel syndrome,thyroid disorders, Skeletal fluorosis, Osteosarcoma, Osteoporosis and bone fractures as well as Alzheimer's disease.