Texas Tech University researchers revealed that humans exposed to a combination of both toxicants were almost twice as likely to develop cancerous cells in their prostate. The study is published in the peer-reviewed journal The Prostate.
While it is established that both arsenic and estrogen can cause cancer, the research raises concerns about the dangers of chemicals in combination, and the efficacy of regulations that are established by testing one chemical at a time. Kamaleshwar Singh, PhD., is an assistant professor at the Institute of Environmental and Human Health at Texas Tech. “The majority of cancers are caused by environmental influences,” Dr. Singh remarked to Texas Tech Today, “Only about 5 to 10 percent of cancers are due to genetic predisposition. Science has looked at these chemicals, such as arsenic, and tested them in a lab to find the amounts that may cause cancer. But that’s just a single chemical in a single test. In the real world, we are getting exposed to many chemicals at once.”
The study contributes to the growing body of research on the interactive effects of pesticides on human health and the environment. For example, Tyrone Hayes, PhD., professor of integrative biology at UC Berkeley conducted research on the interactive effects of atrazine and other pesticides in a study on frogs. The study compared the impact of exposure to realistic combinations of small concentrations of corn pesticides on frog metamorphosis. The study concluded that frog tadpoles exposed to mixtures of pesticides took longer to metamorphose to adults and were smaller at metamorphosis than those exposed to single pesticides, with consequences for frog survival. The study revealed that “estimating ecological risk and the impact of pesticides on amphibians using studies that examine only single pesticides at high concentrations may lead to gross underestimations of the role of pesticides in amphibian declines.” (Watch Dr. Hayes’ talk, Protecting Life: From Research to Regulation.)
Because arsenic has historically been used as a pesticide in orchard production, along with lead-based pesticides, Consumers Union, publisher of Consumers Reports, recently published an in-depth article looking at contamination in apple and grape juice. This is of particular concern because children drink a disproportionate amount of fruit juice, in terms of their body weight.
There have also been widespread press reports of a recent Dartmouth study that focused on contamination in rice syrup, a sweetener. That study included a look at infant formula and soy-based formulas are particularly of concern.
To make matters worse, Nestle and Mead Johnson Nutrition recently dismissed calls to remove genetically-modified organisms (GMO) from their infant formula products in the US and now evidence is coming forth on long-term risks related to infant formulations.
True cancer of the prostate, carcinoma, is seldom seen in infants and children, but other forms of malignant tumors may develop and more cases are appearing in developed nations where the link appears to center around soy infant formula.
While many claims have been made about the health benefits of these estrogen-like compounds, animal studies indicate that soy (both conventional and organic) contain powerful endocrine disrupters that alter growth patterns and cause sterility. Toxicologists estimate that an infant exclusively fed soy formula receives the estrogenic equivalent of at least five birth control pills per day. By contrast, almost no phytoestrogens have been detected in dairy-based infant formula or in human milk, even when the mother consumes soy products. A recent study found that babies fed soy-based formula had 13,000 to 22,0000 times more isoflavones in their blood than babies fed milk-based formula. Scientists have known for years that isoflavones in soy products can depress thyroid function, causing autoimmune thyroid disease and even cancer of the thyroid. But what are the effects of soy products on the hormonal development of the infant, both male and female?
Male infants undergo a “testosterone surge” during the first few months of life, when testosterone levels may be as high as those of an adult male. During this period, the infant is programed to express male characteristics after puberty, not only in the development of his sexual organs and other masculine physical traits, but also in setting patterns in the brain characteristic of male behavior. In monkeys, deficiency of male hormones impairs learning and the ability to perform visual discrimination tasks-such as would be required for reading-and retards the development of spatial perception, which is normally more acute in men than in women.
It goes without saying that future patterns of sexual orientation may also be influenced by the early hormonal environment. Pediatricians are noticing greater numbers of boys whose physical maturation is delayed, or does not occur at all, including lack of development of the sexual organs. Learning disabilities, especially in male children, have reached epidemic proportions. Soy infant feeding-which floods the bloodstream with female hormones that could inhibit the effects of male hormones-cannot be ignored as a possible cause for these tragic developments.
As for girls, an alarming number are entering puberty much earlier than normal, according to a recent study reported in the journal Pediatrics. Investigators found that one percent of all girls now show signs of puberty, such as breast development or pubic hair, before the age of three; by age eight, 14.7 percent of white girls and a whopping 48.3 percent of African-American girls had one or both of these characteristics. New data indicate that environmental estrogens such as PCBs and DDE (a breakdown product of DDT) may cause early sexual development in girls and a study in Puerto Rico implicated soy feeding as a cause of early menarche. The use of soy formula in the WIC program, which supplies free formula to welfare mothers, may explain the astronomical rates of early menarche in African American girls.
The consequences are tragic. Young girls with mature bodies must cope with feelings and urges that most children are not well-equipped to handle. And early maturation in girls is frequently a harbinger for problems with the reproductive system later in life including failure to menstruate, infertility and breast cancer.
Other problems that have been anecdotally associated with children of both sexes who were fed soy-based formula include extreme emotional behavior, asthma, immune system problems, pituitary insufficiency, thyroid disorders and irritable bowel syndrome.
The new study by Texas Tech researchers on arsenic and estrogen confirms that co-exposures have a greater impact on human health, particularly for the development of prostate cancer. Researchers treated human prostate cells with arsenic, estrogen and a combination of the two once a week for six months to determine changes in prostate cells. The results have major implications because estrogen mimics are ubiquitous, such as bisphenol A (BPA) used as a liner in food cans. Similarly, while most arsenate pesticides were banned for use in agriculture in the U.S. in the 1980s, monosodium methanearsonate (MSMA) may still be used legally on cotton crops. Copper sulfate fertilizers have been found to be contaminated with arsenic. Other sources of exposure to arsenic include rice, an arsenic accumulator, and non-organically produced chicken. Poultry has become one of the most contaminated sources of meat available to humans, particularly due to approved arsenic-based additives which 80% of all chickens consume in their daily diet.
With exposure to both arsenic and estrogen together showing synergistic impacts on human health, the research also highlights the deficiencies of EPA’s risk assessment process which fail to look at chemical mixtures, synergistic effects, as well as certain health endpoints such as endocrine disruption. These deficiencies contribute to its severe limitations in defining real world poisoning.
Source: Prevent Disease
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