Hormones are chemicals released into the bloodstream from glands.
Different hormones act on different target tissues, but each plays a
role in regulating some aspect of human metabolism. Small amounts can
have powerful effects, and the balance of hormones is as important as
their absolute amounts in the body.
Hormones alter the gene expression of DNA throughout the body. The pituitary gland (the "master gland") under the influence of the brain/hypothalamus can thus influence the physiology of cells throughout the body. The hormones DHEA, melatonin, thyroid, and somatotropin (GH) decline with age. Women experience menopause, with the loss of progesterone and estradiol secretion from the ovaries. Specific areas of the brain show age-related declines in the levels of the neurotransmitters dopamine, acetylcholine, norepinephrine, GABA and serotonin.
Hormones are chemical signals that are produced by glands and other tissues that then (mostly) circulate in the blood and control biological functions in other cells. These functions in some cases involve the production of yet more hormones that then form parts of a more complex logic structure. At least 50 human hormones have been identified and more are expected. It is thought that all cells are affected by at least some hormones but usually particular hormones affect specific target cells. Hormones are very heavily involved in growth, the reproduction process, food acquisition (hunger), digestion, nutrient utilization, and many other normal biological processes.
Human Growth Hormone
Human Growth Hormone (hGH), produced naturally by the pituitary gland, is only available as a supplement by prescription under a doctor's supervision. The claims for hGH are similar those for DHEA--that it will reduce signs of aging by increasing muscle, decreasing fat, and giving people a feeling of well-being and energy.
Growth hormone is a small protein molecule containing 191 amino acids in a single polypeptide chain. It is the most abundant hormone secreted by the pituitary gland. Its rate of production peaks during adolescence when accelerated growth occurs. Production rate decreases 14% every decade into old age. Generally, however, it remains in abundant supply waiting to be secreted into the body. For some cause yet to be identified, this all-important gland ceases to secrete the hormone, which tells the body to repair the cells. By receiving decreased amounts of growth hormone over time the body begins to age. Daily secretion from the pituitary gland diminishes with age to the extent that a 60 year old man secretes 25% of the hGH secreted by a 20 year old man. Actually secretion decreases due to lack of instructions from the hypothalamus to growth hormone releasing hormones, which are, as their name implies, hormones which act to release. Adding to this already decreasing dimension is the fact that receptor sites for hGH also become desensitized after a certain age. This causes less growth hormone to be released.
Melatonin is produced naturally by the pineal gland in the brain; melatonin decreases with age in some people. Available without a prescription, melatonin supplements have been touted as "an anti-aging rememdy, a sleep remedy, and an antioxidant. Melotonin is a hormone with powerful antioxidant properties. It is reportedly an immune booster, cancer fighter, heart helper mood elevator, and natural sleeping agent. The organ, which secretes melotonin, is the pineal gland, the timekeeper of the brain and that that controls our circadian rhythms. Dosage varies from person to person. Low dosages of .3mg to l mg. can reduce the time to fall asleep as well as increase the quality of sleep.
DHEA (dehydroepiandrosterone) is an adrenal hormone that is the precursor for steroid hormones such as testosterone and estrogen. DHEA declines precipitously with advancing age in both men and women. There have been many studies showing that oral DHEA can improve neurological function, immune function, stress disorders, and that it can be protective against some types of cancer and cardiovascular disease. DHEA is the most abundant of all steroids and is released from the adrenal glands. Cholesterol actually makes DHEA and is told to do so when the pituitary releases ACTH, which in turns signals the cholesterol. DHEA is involved in the manufacturing of testosterone, estrogen, progesterone and coritcosteroids. The decline of DHEA parallels that of growth hormone. By age 65, the body makes only 10-20% of DHEA that was made at age 20.
Human growth hormone
Human Growth Hormone (hGH), produced naturally by the pituitary gland, is only available as a supplement by prescription under a doctor's supervision. The claims for hGH are similar those for DHEA--that it will reduce signs of aging by increasing muscle, decreasing fat, and giving people a feeling of well-being and energy. Growth hormone is a small protein molecule containing 191 amino acids in a single polypeptide chain. It is the most abundant hormone secreted by the pituitary gland.
Testosterone, thought of as a male hormone, is actually produced by both men and women, though in larger quantities in men. Supplements are available by prescription for men who do not produce enough of the hormone naturally. Men who might need supplements are those whose pituitary or testes glands have been damaged by infection or tumors. For these men, the supplements are clearly beneficial by restoring normal levels of the hormone. On the other hand, too much testosterone is clearly harmful, as demonstrated by athletes who have damaged their health through steroid (i.e. testosterone) supplements. Testosterone replacement therapy (TRT) is as powerful an anti-aging effect as estrogen or progesterone replacement in women. Many benefits are associated with taking testosterone such as renewed strength, improved balance, raised blood cell count, increased libido, lowered LDL and cholesterol. It also stems the loss of bone mass in men. However, TRT is not without side effects. These are known to be: higher levels of PSA (prostrate specific Antigen) and a rise in hematocrit.
Estrogen represents an entire family of female related hormones. For one it reduces heart diseases and controls LDL cholesterol. It is often used to prevent hot flashes and mood swings associated with menopause. Other benefits include: the preventing of heart disease and rapid decline of bone density after menopause, the improvement of body composition, protecting against Alzheimer and stimulating GH. Estrogen replacement therapy, available by prescription, can counteract these increased risks for certain women. Early studies also suggest that estrogen supplements might delay the onset of Alzheimer's disease, though this is preliminary. On the other hand, estrogen supplements might contribute to increased risk of blood clots, uterine cancer, and possibly breast cancer.
Progesterone - functions in many capacities. It is often taken to counter the effects of estrogen, normally used by women during postmenopausal. It also goes by the prescription . Natural progesterone is available as well and is known to have far fewer side effects. Progesterone has many functions. First, it is both a precursors to other adrenal hormones and a GH stimulant as well. It likewise promotes lipolysis (breakdown of fat) and protects against endometrial cancer. It is known to eliminate the risk of endometrial cancer when given with estrogen for 10 or more days per cycle. Lastly, progesterone normalizes levels of blood sugar, zinc and copper. Progesterone stimulate the walls of the uterus to prepare it for implantation of the fertilized ovum. If pregnancy occurs, progesterone inhibits ovulation (by suppressing FSH & LH) and promotes uterine development until the placenta becomes more mature. (Progesterone is so-named because it promotes gestation, ie, the growth of offspring in the womb).