Hormones

Hormones

A sullen teenager, an extra pound, a grumpy mood. "It''''s all hormonal," you sigh.

And you''''re right. Almost all our human ups and downs are hormonal. Hormones are powerful chemicals that tell us to grow up, to turn our food into fuel, to continue the human race. They prepare us to fight for our lives or our children''''s. They''''re the soldiers in the endocrine system, an army commanded by organs called glands.

"A hormone is formed within one gland in the body and then carried in the bloodstream to other organs and tissues, where it influences their functions and activities. For instance, estrogen is made in the ovaries. Then it goes to a large number of organs, including breast tissue, the lining of the uterus, the lining of the arteries, the liver and the bones," says JoAnn E. Manson, M.D., associate professor of medicine at Harvard Medical School and co-director of Women''''s Health at Brigham and Women''''s Hospital in Boston.

Nobody knows how many hormones the body makes. The adrenal gland alone spits out more than 25. But the most telling chemicals can be divided into three categories: sex, food and stress hormones.

After puberty the ovaries begin producing increased levels of sex hormones that prepare the uterus, ovaries and fallopian tubes for ovulation, fertilization or menstruation.

Probably the best known of these sex hormones, estrogen, does double duty, affecting sex and fertility as well as the way our bodies process food. It also helps prevent the bone loss of osteoporosis.

Besides estrogen, there are a number of other hormones that play a big role in food processing:

* Insulin guides blood sugar through the bloodstream and helps regulate the way it''''s absorbed by cells.

* Parathyroid hormone (PTH) is important in controlling the calcium balance of the blood. The calcium balance is necessary for chemical reactions and muscular contractions needed for voluntary movement and even heartbeat.

* Thyroxine from the thyroid gland helps regulate the way that we burn up calories.

Other hormones come into play when you deal with stress.

* Adrenaline makes your muscles clench. It speeds up your heart, slows your digestion and accelerates blood clotting if you''''re injured.

* Cortisol, another stress-related hormone, helps reduce swelling around wounds. But because it also pumps up blood pressure, having too much cortisol in your system can lead to high blood pressure.

The best way to keep all your hormones balanced and happy is to eat a healthy diet, get a good night''''s sleep and exercise, says Jerilynn C. Prior, M.D., professor of endocrinology at the University of British Columbia in Vancouver.

On the nutritional front, it''''s particularly important for women to eat plenty of food rich in calcium. If you don''''t, the hormone PTH could start to plunder this crucial mineral from your bones.

Weight control also helps balance hormones. "Obesity alters the way hormones are made and function. So it''''s important to maintain a healthy weight," says Dr. Manson.