Dr Dingle's Blog / plastics
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.
New research suggests that a 25% reduction in exposure to just 4 chemicals commonly found in the home would reduce diabetes cases by around 13% which could save billions of dollars in annual health costs.
Increasing evidence suggests that synthetic chemicals commonly found in the environment contribute to metabolic disorders, especially obesity and diabetes. Previous publications have associated prevalent diabetes with polychlorinated biphenyls (PCBs), persistent chlorinated pesticides, phthalates and perfluoroalkyl substances (PFASs). Separate studies found similar connections between diabetes and exposure to DDT, PCBs and perfluoroalkyl.
In this study of 1,016 participants they found significant connections between the four chemicals investigated and a number of different diseases and found reduced exposure to all four chemicals would lead to a likely reduction 13% in diabetes cases. This study confirms substantial contribution, especially of mixtures of endocrine-disrupting chemicals, to adult type 2 diabetes, and large annual costs of medical care. A previous reported a significant positive relationship between phthalates in the blood and lowered insulin secretion, increased insulin resistance or both.
While this study supports efforts to reduce chemical exposures to reduce the burden and costs of diabetes there are many other disease states including cardiovascular disease and cancer that would also likely be reduced.
Exposure to “obesogenic” chemicals has an important role in the obesity and diabetes pandemic. Studies dating back to the 1970s have shown that low-dose chemical exposures were associated with weight gain in experimental animals. Since then, a growing number of studies show links between toxins and weight gain, obesity and diabetes. Known or suspected culprits behind negative epigenetic changes include toxins such as heavy metals, pesticides, plastic compounds including BPA, diesel exhaust, tobacco smoke, polycyclic aromatic hydrocarbons, hormones, radioactivity, viruses, bacteria and endocrine disrupting chemicals.
The main role of fat cells is to store energy and release it when needed. Scientists now know that fat tissue acts as an endocrine (hormone) organ, releasing hormones related to appetite and metabolism. Research to date suggests that different obesogenic compounds may have different mechanisms of action, some affecting the number of fat cells, others the size of fat cells, and still others the hormones that influence appetite, satiety, food preferences, and energy metabolism. Another mechanism through which these chemical obesogens can contribute to weight gain is through their impact on the gut microbiome, linking gut ecology and environmental chemicals to obesity and diabetes.
BPA, or bisphenol-A, a chemical found in everything from plastic bottles to metal food containers, may be partly to blame for our excess weight. BPA has been shown to alter the body’s metabolism, increasing weight gain and making it difficult to lose weight. In a study of 1,326 children, girls between ages 9 and 12 with high BPA levels had double the risk of being obese than girls with low BPA levels, validating previous animal and human studies. The chemical can alter the body’s metabolism and make it harder to lose weight. Girls with high levels of BPA, two micrograms per litre or more, were twice as likely to be obese as girls with lower levels of BPA in the same age group. Girls with very high levels of BPA, more than 10 micrograms per litre, were five times more likely to be obese, the study showed. In animal experiments, a mother’s exposure to BPA is producing the same outcomes that we see in humans born light at birth: an increase in abdominal fat and glucose intolerance. BPA affected rodent fat cells at very low doses, 1,000 times below the dose that regulatory agencies presume causes no effect in humans.A growing body of evidence shows that the use of certain pesticides may also be associated with weight gain and diabetes risk. In animal experiments, mice fed high-fat diets gained about 30% more weight and had higher blood sugar than other mice eating the same high-fat diets when they also ingested doses of a brominated flame retardant, hexabromocyclododecane (HBCD), which is used in building materials and insulation. Perfluorooctanoic acid (PFOA) is a ubiquitous chemical, used in non-stick cookware, Gore-Tex™ waterproof clothing, Scotchgard™ stain repellent on carpeting and mattresses and is a potential endocrine disruptor. Researchers gave pregnant mice PFOA during pregnancy and when the offspring reached adulthood, they became obese, reaching significantly higher weight levels than controls. Phthalates are plasticizers that have been related to obesity in humans and occur in many PVC items as well as in scented items such as air fresheners, laundry products, and personal care products, and many plastics.