BPA and Insulin Resistance

By Tagert Ellis

BPA and Insulin Resistance

• Insulin resistance is a

precursor to type II diabetes.

• The chemical Bisphenol A, or BPA, is used in plastics and other applications.

• There is now a proven link between BPA and insulin resistance in adult mice.

The Pancreas

BPA and Insulin Resistance- Outline

• What is insulin resistance?

• What is BPA?

• How are they linked?

• What is being done?

Insulin Resistance

• Under normal conditions, beta cells in the pancreas create insulin, which helps tissues take in glucose.

• Insulin resistance occurs when tissues are unable to respond properly to insulin.

• This causes the pancreas to release even more insulin.

• A greater amount of insulin is now needed.

From http://www.medicinenet.com/insulin_resistance/article.htm#tocc

and http://www.aafp.org/afp/20010315/1159.html

Insulin Resistance

• Insulin resistance has been linked to hypertension, dyslipidemia, heart disease, and diabetes.

• These diseases are often present with one another but a conclusive cause-and-effect relationship has not yet been demonstrated.

• However insulin resistance is always present before the onset of Type II Diabetes, and so can be used as a predictor or at least a warning.

From http://www.aafp.org/afp/20010315/1159.html

Insulin Resistance

• The specific cause of the disorder is unknown, but its onset and acceleration are promoted by a sedentary lifestyle, obesity, and smoking.

• Your BMI, weight, and waist-to-hip ratio are all used in determining risk.

• Once you have insulin resistance, losing weight and getting more cardiovascular activity can help prevent diabetes, but there is no known cure for the disorder.

From http://diabetes.niddk.nih.gov/dm/pubs/insulinresistance/#7

BPA

• Bisphenol A, or BPA, was first synthesized in 1891, but not widely used until later, when scientists found they could polymerize it for plastic.

• However the ester bonds linking the BPA monomers to each other and forming a polymer, are not stable.

• The BPA decays over time, and releases BPA into whatever it comes into contact with.

From http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/bpauses.htm

BPA

• BPA is not only used to make plastic, but also certain types of polyester resin.

• It has been used as an inert ingredient in pesticides, and also as a fungicide, flame retardant, and antioxidant.

• You find BPA in microwave ovens, plastic containers, floorings, artificial teeth, compact discs, parts of automobiles, milk and water.

From http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/bpauses.htm

BPA

• Basically, BPA is everywhere in our life, but it has invaded our surrounding environment as well.

• BPA does not easily degrade in the environment.

• BPA can be found in rivers in concentrations up to 1900 nanograms per liter and in sediment load levels of over 100 micrograms per kilogram.

From http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/bpauses.htm

BPA and Insulin Resistance

• A research team led by Dr. P. Alonso-Magdalena injected adult mice with a dose of BPA approximating the amount humans are exposed to daily.

• The BPA doses were between 10 and 100 micrograms. This is still 5000 times lower than what the EPA defines as the lowest level that has effects.

from http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0921alonso-magdalenaetal.htm

BPA and Insulin Resistance

• The mice who were injected with the control solution, corn oil, experienced a rise in blood sugar within 30 minutes.

• The rise in blood sugar in the mice injected with BPA was significantly lower, indicating that BPA interferes with glucose regulation.

• After four consecutive days of injections, both the mice injected with 10 micrograms and those injected with 100 micrograms experienced a significant increase in blood insulin content.

from http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0921alonso-magdalenaetal.htm

BPA and Insulin Resistance

• During a fasting glucose tolerance test, glucose levels rose much higher and dropped much slower than in normal mice.

• The fact that mice injected with BPA demonstrated 1.5 times the normal level of insulin needed for the amount of blood glucose clearly demonstrates the symptoms of insulin resistance.

from http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0921alonso-magdalenaetal.htm

BPA and Insulin Resistance

• Insulin resistance often goes ignored by the public.

• But insulin resistance is the precursor to type II diabetes.

• Diabetes causes thousands of deaths every year in the US alone, and a young person with type II diabetes is three times more likely to die early than those without the disease.

• This is the first time an experimental link has been proven between diabetes and endocrine disruption.

From http://news.bbc.co.uk/1/hi/health/4966174.stm

and http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0921alonso-magdalenaetal.htm

and http://www.defeatdiabetes.org/Articles/death040721.htm

Other Issues with BPA

• Insulin resistance is only one of many disorders or disruptions that have been associated with BPA.

• Since BPA acts as an estrogen, there are a number of demonstrated reproductive effects in animals, such as early puberty, decreased sperm count, and changes in maternal behavior.

• Animals exposed to BPA also had changes in brain chemistry, changes in the formation of synapses in the brain, and a reversal in brain sexual dimorphism.

from http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0921alonso-magdalenaetal.htm

Other Issues with BPA

• In animals exposed to BPA, changes in behavior were also seen, from aggressiveness and hyperactivity to learning impairments and increased susceptibility of addiction to drugs like amphetamine.

• Nearly all of this research has come out in the past decade, yet the EPA continues to use standards for safety that were drawn out in the year 1982.

from http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0921alonso-magdalenaetal.htm

What is being done?

• A bill, AB319, was introduced in the California legislature to ban the use of BPA in products such as bottles for children under the age of three.

• The plastic industries cited the 1982 EPA standards as evidence of their product’s safety. Due mainly to their pressure, the bill has since died.

from http://www.ourstolenfuture.org/Policy/2006/2006-0107ab319.html

What is being done?

• BPA effects, like those of tobacco, are difficult to prove without a long-term, nearly lifelong study.

• Until those results come in, which they should start to do very soon, the plastics industry will be able to weave its way around any criticism quite easily. After all, effects on animals do not always equal effects on humans.

• However, with the wide variety of ill effects caused by BPA, it is very unlikely that every one of them is unique to mice.

from http://www.ourstolenfuture.org/Policy/2006/2006-0107ab319.html

Further Readings

• http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2005/2005-0413vomsaalandhughes.htm

• http://familydoctor.org/660.xml

• http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1332699

• http://drcranton.com/nutrition/plastics_diabetes_obesity.htm