GMO

BPA and hormones in our fruits and vegetables!

BPA and hormones in our fruits and vegetables!

A group of biology peeps in Florida took a stroll to the nearby supermarket to grab some samples for chemical testing. Unlike most of us, they are well-aware of the fact that industrial farms have been regularly irrigating our food with wastewater (2). Though there may be some advantages to this irrigation method within developing countries, in our own heavily medicated and polluted country the consequences to using water laced with plastic byproducts, prescription medicine and contraceptives create potential biohazards for our children and us.

Some of the chemicals these scientists found have been making recent headlines. Bisphenol A, which you may know as “BPA” from the slew of “BPA-Free” baby products hitting the market, is being found in produce like tomatoes and potatoes in quantities that have been linked to deleterious effects in the reproductive system as well as increased cancer rates. BPA is a very controversial chemical; expert panels argue that it “is associated with organizational changes in the prostate, breast, testis, mammary glands, body size, brain structure and chemistry, and behavior of laboratory animals” (3). Despite BPA’s extensively documented effects on the reproductive system of lab animals, its effects on humans are highly controversial; for a large number of studies, the scientists have not been able to clearly separate its effects from the effects of female hormones that are also being found in your grocery bag. To boot, the Center for Disease Control has found that 90% of us have high levels of BPA in our bodies.

Estradiol is another chemical these Floridian scientists have discovered in our lettuce and citrus. Every human being, whether male or female, has a chemical receptivity to the hormone estrogen; estradiol binds with our body’s estrogen receptors and BPA has also been shown to mimic estradiol. For males, high levels of estradiol may result in feminine traits or cause sterility (4). Since BPA has been found to change the expression of key developmental genes that affect the female reproductive system (5), this chemical cocktail of BPA+Estradiol can be perceived as the equivalent of a hormone treatment for the reproductive system. How this combination of chemicals may be affecting our children, few are hypothesizing due to the complex range of chemical reactions that may take place in the human body. Nevertheless, the estimated amount of this compound that you and I may be ingesting is considered “beyond the recommended intake” according to the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Another chemical disruptor of our natural hormones, nonylphenol, was also detected in our food. Nonylphenol is a compound that also weakly mimics estrogen. It comes from detergents or pesticides and like estradiol and BPA, is not easily removed during wastewater treatment. Since Nonylphenol and Bisphenol A mimic the activity of natural hormones like estrogen and estradiol, this class of chemicals are called endocrine disruptors. As a whole, endocrine disruptors are known to cause birth defects, learning disabilities, deformations of the body, sexual developmental issues, and cancerous tumors.

For decades, the onset of puberty in our children has been happening earlier, especially for girls. Testosterone levels and sperm count have also been steadily decreasing in males for at least fifty years. The fact that these hormones and hormone disruptors have been in our meat and animal products is not news, though little has ever been done to regulate the industry. This most recent study now warns us of further exposure from our fruits and vegetables and will undoubtedly solicit more studies of endocrine disrupting chemicals (EDCs) in our food.

 

Editor’s Note: This is my application essay for an internship. Reproduced because I think it’s a big deal, too.

(1) Jian Lu, Jun Wu, Peter J Stoffella, Patrick Wilson. Analysis of Bisphenol A, Nonylphenol and Natural Estrogens in Vegetables and Fruits Using Gas Chromatography-Tandem Mass Spectrometry. J Agric Food Chem. 2012 Dec 6. Epub 2012 Dec 6. PMID: 23215552

(2) Bartram, J., Carr, R. “Guidelines for the safe use of wastewater, excreta, and grey water, Volume 2: Wastewater use in Agriculture”. World Health Organization, 2006.

(3) Vogel, S. (2009). “The Politics of Plastics: The Making and Unmaking of Bisphenol A ‘Safety'”. American Journal of Public Health 99 (S3): 559–566.

(4) Sharpe, RM; Skakkebaek, NE (1993). “Are oestrogens involved in falling sperm counts and disorders of the male reproductive tract?”. Lancet 341 (8857): 1392–5. doi:10.1016/0140-6736(93)90953-E. PMID 8098802.

(5) Smith CC, Taylor HS (January 2007). “Xenoestrogen exposure imprints expression of genes (Hoxa10) required for normal uterine development”. FASEB J. 21 (1): 239–46. doi:10.1096/fj.06-6635com. PMID 17093138.

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