Likewise, estrogen affects female behavior. It has an influence on sexual arousal and can also affect food intake. High levels of estrogen tend to suppress appetite in females, while low levels have the opposite effect. This increase and reduction in appetite seems to be related to pregnancy, ensuring there is adequate nutrition for growing babies.
There is some evidence that links estrogen levels to eating disorders such as anorexia nervosa or bulimia. Also, if a female becomes very lean from dieting, exercise or starvation, her reproductive cycle will be inhibited. This again seems to be a natural safeguard that prevents pregnancy when there does not seem to be enough body fat to nourish a baby during pregnancy.
The hormones associated with puberty and sexual development are filling just one of the many roles hormones play in human metabolism. There are many examples of basic human systems that are under the control of hormones.
The hormone insulin is a great example. Insulin is essential in the ability of cells to take in glucose molecules that provide energy to our cells. Lack of adequate insulin restricts the cells’ ability to take in glucose, which results in a medical condition called diabetes. (See the article titled “Changing the Course of Diabetes” on p. 12 in this issue.)
Other hormones regulate blood pressure and heart rate, and a whole class of hormones serves to regulate other hormones. It is a complex and elegant system.
Anyone who has experience puberty can attest to the power and influence of hormones. Fortunately, the changes that accompany it don’t happen overnight, giving teenagers time to adjust. And after all, it could be worse: We could be walking around wearing gloves full of stinging ants!
Middlecamp, C. H. et al. Chemistry in Context: Applying Chemistry to Society, 7th ed., McGraw-Hill: New York, 2012.
Brink, S., Modern Puberty, Los Angeles Times, Jan 21, 2008.
Beamish, R. Steroids: A New Look at Performance Enhancing Drugs. ABC-CLIO, Santa Barbara, CA, 2011.
Berger, K. S. The Developing Person Through Childhood and Adolescence, Worth Publishers: New York, 2009.
Michael Tinnesand is a science writer and education consultant who lives in Portland, Ore. His latest ChemMatters article, “Harnessing Solar Power,” appeared in the October 2011 issue.