Editorial Comment: Directions for Research on the Relationship of Estrogen and Appetite
Dr. Geary presents a competent review of the literature concerning the role that estradiol may play in the disordered eating patterns experienced by many women today. Anorexia and bulimia may be the results of disordered eating, but, more often, excess adiposity of varying degrees is the result. Dr. Geary establishes the foundation that estrogen may be responsible for the differences in disordered eating between men and women and may explain the resultant weight gain. He then reviews research that has examined neural and hormonal pathways and feedback mechanisms that control appetite. Estradiol may play a role in the inhibition of eating for women.
Dr. Geary's thoughtful article is appropriate today, especially in light of the recent NIH recommendation that persons who are overweight by just 30 pounds or less may be better off not trying to lose weight to prevent rebound weight gain along with its negative health implications. Americans have continued to get fatter in spite of health initiatives to reduce dietary intake of fat and calories and to increase physical activity. Dr. Geary calls for research that has practical implications for a permanent solution to the problem of weight gain.
With that in mind, I would like the reader to consider the following recommendations to Dr. Geary's call for further research. The reader should be advised that my research into weight loss has been with human subjects, which no doubt influences my suggestions, which follow:
Some studies on estrogen and appetite must be conducted on free-living individuals. While I understand that we, as scientists, want to control as much as we can, living in a metabolic ward for weeks or even months alters the environment of the individual too greatly. The woman must be exposed to the toxic food environment with its visual and olfactory cues before we can conclude any treatment for obesity as successful. (The term "toxic food environment" is attributed to Kelly Brownell in a presentation at the 1998 American College of Sports Medicine meeting in Orlando, Fla.)
Exercise exerts a tremendous influence on all human hormonal responses. Research should examine populations of women who are initiating an exercise program and those who exercise regularly. This research question might be similar to this: Specific to appetite, does exercise cause a change in hormonal levels, thereby leading to an increased estrogen response that may suppress appetite, or would altering the estrogen response via pharmacologic means cause a woman to exercise more?
Finally, research should examine naturally occurring substances as well as pharmacologic interventions. Specifically, phytoestrogens from food sources may have an effect on appetite similar to that of estrogen, as these plant substances appear capable of binding to estrogen receptors. Food sources of phytoestrogens are soy, flaxseed oil, and nuts.
Dr. Geary's article provides a strong argument for further research on the relationship of estrogen to appetite. There are many steps before an actual treatment is developed, but this article has provided a direction to follow.
Chet Zelasko, PhD
The Better Life Institute
Grand Rapids, Mich.
Medscape General Medicine. 1998;1(3) © 1998
Cite this: The Effect of Estrogen on Appetite - Medscape - Nov 19, 1998.