In the middle of chapter IV, titled “Hey, Bud, Can
You Do Me A Fava?”, Dr. Moalem considers AP Biology Big Idea 3, which states
that “Living systems store, retrieve, transmit and respond to information
essential to life processes” on pages 78-79. He explains that some plants, the
most notable of which are clover, sweet potato, and soy, contain chemicals
called phytoestrogens. Phytoestrogens mimic the effect of animal sex hormones
such as estrogen. Each of these plants produces a specific phytoestrogen that either
protects the plant from predators or allows for the development of certain
products. For example, the European clover is described to have a phytoestrogen
called formononetin, which acts as a defense against predators. Also, a sweet
potato – specifically the Mexican yam – produces a phytoestrogren called
disogenin, which was used as a base to synthesize the first marketable
contraceptive pill in 1951. Lastly, soy contains a phytoestrogen called
genistein which appears in many processed foods.
What are phytoestrogens and why is it necessary for them to be produced in some plants? After answering this question, conduct some
research to find out how certain plants create phytoestrogen reserves.
Specifically focus on one of the three plants addressed above (clover, sweet
potato, or soy) and how that plant produces its respective phytoestrogen
(formonentin for clover, disogenin for sweet potato, and genistein for soy).
Does this production have any harmful effects on the plant? Then, determine
what benefits the presence of phytoestrogens has for that particular plant. Disogenin,
a phytoestrogen found in the Mexican yam, was found to be related to birth
control, along with other phytoestrogens, thus making the chemical a source of “botanical
birth control” (79). How do the structure and/or function of phytoestrogens
relate to their birth control capabilities? Lastly, examine the potential
long-term effects of having a great level of phytoestrogens present in our
diet.
I'll take this
ReplyDeletePhytoestrogens are chemicals that mimic estrogen, or the primary female sex hormone. It is necessary for them to be produced in plants because it is a natural defense created over time from evolution. See, with excess amounts of “estrogen-like compounds wreaks havoc on their reproductive capability” (78). Since this only happens in animals, when an animal does eat a plant with phytoestrogens, it significantly hurts the animal. Therefore, plants have evolved to create this natural defense in order to prevent consumption of themselves. Certain plants create phytoestrogen reserves as a natural dense and to defer their opponent (in this case, animals who may consume them). Plants such as clover, sweet potato, and soy create phytoestrogen reserves to do this job. Therefore, relating to Big Idea #3 that “Living systems store, retrieve, transmit and respond to information essential to life processes,” Plants that create phytoestrogen fill this description perfectly. See, these plants store and transmit phytoestrogens as a natural defense mechanism. It is essential to their life processes since it provides harm to an animal’s reproductive system. Therefore, they are prevented to eat from that plant again, which allows that plant to both survive and reproduce.
ReplyDeletePlants make phytoestrogens, and most have different kinds of phytoestrogens. Now, lets take, for example, Genistein. Genistein is “one of the most studied of the soy isoflavone phytoestrogens” (Cornell). Phytoestrogens are naturally occurring chemical constituents that may interact with estrogen receptors to produce weak estrogenic or anti-estrogenic effects. They are composed of a wide group of “nonsteroidal compounds similar in structure and function to human estrogens” (Zero Breast Cancer).
As I said before, evolution is what allowed phytoestrogens to become a defense mechanism. Therefore, the creation of phytoestrogens do not provide any disadvantages to the plant. Instead, it provides advantages for the plant toward survival and reproduction.
As I said before, phytoestrogens mimic estrogen. The chemical structure of phytoestrogens is similar to estrogen. On the other hand, phytoestrogens also have effects that are different from those of estrogen. As the primary female sex hormone, if it is in excess amounts, it wreaks havoc on the reproduction system. Fetuses develop and grow in a female through the reproduction system. If an excess of estrogen were to come into the female body, the reproduction system would reject all fertilized eggs from developing. Therefore, it acts as a birth control since pregnancy is consistently prevented.
The long term effects of having a great amount of phytoestrogens in one’s body is a lot. For example, research from Cornell University shows that phytoestrogens from soy foods can cause breast cancer. While more studies must be done to completely prove this correlation, it is believed by researchers that an increase in soy foods leads to a higher risk for breast cancer. More research was done on phytoestrogens as well. Five years of treatment with soy phytoestrogens was given to postmenopausal women. What occurred was “long-term treatment (up to 5 years) with soy phytoestrogens was associated with an increased occurrence of endometrial hyperplasia. These findings call into question the long-term safety of phytoestrogens with regard to the endometrium (Public Health).” Endometrial hyperplasia is a condition with the extra proliferation of cells in the inner lining of the uterus. The endometrium is the inner lining of the uterus.
Noella James
noellajames@gmail.com
Sources:
http://envirocancer.cornell.edu/factsheet/diet/fs1.phyto.cfm
http://www.ncbi.nlm.nih.gov/pubmed/15237003
http://www.zerobreastcancer.org/research/bcerc_factsheets_phytoestrogen_genistein.pd