Cholesterol is a waxy substance used to make chemicals like vitamin D. The body manufactures some cholesterol, and the diet provides the rest. Cholesterol serves as the basis for the production of all steroid hormones including cortisol, testosterone, progesterone and estrogen. Each of these hormones, in turn, affects circulating levels of cholesterol. It's important to have some cholesterol, but excessive amounts can contribute to cardiovascular disease.
Glucocorticoids
Cortisol, a glucocorticoid, responds to psychological and physiological stress. Overproduction of cortisol causes depression, insomnia and memory loss. It also contributes to atherogenesis, a hardening of the arteries. An investigation by T. P. de Prada and his team in Spain studied the relationship between cholesterol intake and cardiovascular health. Laboratory animals received a diet containing excessive amounts of cholesterol for 12 weeks. Results, presented in the April 2007 issue of "Atherosclerosis," indicated that the rabbits tested had elevated cortisol production when compared to the control group. Such increases in cortisol normally cause inflammation, but this response was prevented by the high levels of circulating cholesterol. Over time, the rabbits instead developed arterial lesions.
Androgens
Testosterone, dehydroepiandrosterone and other androgens play an important role in tissue growth and body healing. Yet, too much androgenic activity can cause side effects like excessive hair growth and unwanted breast development. A report by K. Ploumidou and co-workers in the December 2010 edition of "Urology" looked at the effects of high cholesterol intake. These researchers showed that rats fed an enriched diet for 20 weeks had excessive levels of free testosterone relative to controls. This increase changed the rats' prostate glands, possibly indicating pathology.
Progestagens
Progesterone supports the fetus during pregnancy and contributes to the immune system. Excessive amounts of progesterone may cause fatigue and contribute to obesity. A study by M. J. Elmes and colleagues described in the Nov. 15, 2010 issue of "Reproduction" evaluated the hormonal results of cholesterol intake. Compared to control animals, pregnant rats displayed greater progesterone levels following six weeks of a high-fat diet. They also gained more weight.
Estrogens
High levels of cholesterol contribute to the development of obesity. As noted, they also increase circulating cortisol, testosterone and progesterone. Activating the estrogen system may combat these unwanted changes. A paper by M. Yepuru and associates in the Oct. 8, 2010 edition of "Journal of Biological Chemistry" analyzed the impact of estrogen ligands. These chemicals target estrogen receptors throughout the body. Giving obese mice estrogen ligands for several weeks reduced their overall weight relative to controls. These changes in body composition were achieved by a reduction in fat mass. The authors speculated that the ligands had enhanced physical activity and thereby increased energy expenditure.
References
- "Atherosclerosis"; Atherogenesis Takes Place in Cholesterol-Fed Rabbits When Circulating Concentrations of Endogenous Cortisol are Increased and Inflammation Suppressed; T. P. de Prada et al.; April 2007
- "Urology"; Effect of a Hypercholesterolemic Diet on Serum Lipid Profile, Plasma Sex Steroid Levels, and Prostate Structure in Rats; K. Ploumidou et al.; December 2010
- "Reproduction"; The Effects of a High Fat High Cholesterol Diet on Markers of Uterine Contractility During Parturition in the Rat; M. J. Elmes et al.; Nov. 15, 2010
- "Journal of Biological Chemistry"; Estrogen Receptor-{beta}-Selective Ligands Alleviate High-Fat Diet- and Ovariectomy-Induced Obesity in Mice; M. Yepuru et al.; Oct. 8, 2010
