Dominant, aggressive women are more likely to have sons than daughters, scientists believe.
A study in New Zealand found a possible link between high testosterone levels in women and giving birth to boys.
The findings question the idea that the sex of babies is determined by chance.
A team led by Dr Valerie Grant of the Department of Medical and Health Sciences at the University of Auckland, found a link between high levels of the malehormone testosterone in cows‘ wombs and their likelihood to have a bull calf.
The link could explain patterns in human populations such as the phenomenon dubbed the “war time effect” – in which disproportionate numbers of boys are born at the end of periods of hardship such as wars.
Previous studies have found links between dominant behaviour in female animals and higher levels of testosterone. Stress is also believed to boost levels of the hormone.
The team extracted follicles from cow ovaries and tested for testosterone before fertilising the eggs. Those eggs which had been exposed to higher levels of testosterone were more likely to develop into male embryos.
“Results showed that follicular testosterone levels were significantly higher for subsequently male embryos,” the team wrote.
The findings suggest that sperm carrying “Y” chromosomes – present in male animals – are more likely to fertilise an egg if it has been exposed to testosterone.
While in cows high testosterone was linked to dominant behaviour, in humans it was associated with everything from lower divorce rates to right wing political views and spatial ability.
Doping in professional baseball has trained a spotlight on two hormones that many pro athletes use to get ahead of the competition — anabolic steroids and human growth hormone.
But the use of those drugs isn’t limited to the professionals athletes.
They also can be found in colleges, high schools and even middle schools. And it’s not just athletes who are using them.
Young people experimenting with the hormones — using one or “stacking” two or more at a time and usually at doses much higher than would ever be medically prescribed — are just flirting with disaster, adolescent physicians and sports specialists say.
Misuse of the drugs can lead to serious consequences, including heart problems, diabetes and personality changes.
Jay Hoffman knows well some of those side effects:
Now a professor of health and exercise science at the College of New Jersey, Hoffman used anabolic steroids in NFL training camps with the Philadelphia Eagles and the New York Jets in the 1980s, a time when their use was legal.
He encountered what he called the “normal side effects”– hypertension, acne, fluid retention — but stopped using the drugs when he became overly aggressive after taking Anadrol, an oral steroid notorious for its potency.
“I decided that it just didn’t pay for me, every year to struggle to make a club and to use that,” said Hoffman, who now helps advise baseball’s Texas Rangers and other teams about steroid use. “I just didn’t like what was going on.”
Hoffman and others believe that pro athletes, such as Roger Clemens, have a responsibility as role models to younger athletes in terms of proper training techniques.
Clemens was the biggest name in a report headed by former Senate majority leader George Mitchell on the use of steroids and other performance-enhancement drugs in baseball. The FBI is investigating Clemens to determine whether he lied to a congressional panel when he denied taking steroids and HGH.
Anabolic steroids, also called anabolic-androgenic steroids, are synthetic versions of testosterone, a hormone that occurs naturally in the body. We need testosterone, which is produced the adrenal gland or testicles, and human growth hormone at different times to grow and develop normally. Anabolic means to “build up,” and androgenic refers to the development and maintenance of male sexual characteristics, such as deeper voice, body hair and muscle mass.
Young people feel the pressure:
Dr. Joe Congeni, sports medicine director at Akron Children’s Hospital, estimates that between 8 percent and 10 percent of high school athletes in our region use anabolic steroids, a number that has not changed much recently.
“I think there’s a lot of pressure on these kids to experiment,” said Congeni. “They don’t care about the future; they care about the now. That’s a natural trait of teenagers.”
A child who takes anabolic steroids before he or she is done growing faces a potentially irreversible side effect: closure of the growth plates, which are areas of cartilage that allow the bones to grow through adolescence. One progressive course of steroids is enough to permanently close the growth plates and stunt growth, according to Dr. Bernard Griesemer, a St. Louis expert on steroid use in young athletes.
HGH is produced by the pea-sized pituitary gland located at the base of the brain. HGH stimulates growth and cell production, causing increased height in childhood and maintenance of muscle and tissue throughout life.
HGH is often lumped together with steroids as a performance enhancer. While several studies have found that it reduces body fat and increases muscle mass, there is little evidence it increases strength or stamina.
Many athletes use HGH, to sculpt the muscles, in combination with anabolic steroids, which add strength. HGH also has become popular with nonathletes and recently has been tied to musicians, rappers and other celebrities.
And when celebrities are using it, the kids who want to look like them will usually try it too, said Griesemer.
“It’s becoming more common, because it’s now no longer just for the athlete population, it’s for the kids who want to look like they’ve just walked off the magazine cover,” said Griesemer, who was an anti-doping investigator for the 1998 Winter Olympics. “They’re using [HGH] for cosmetic purposes only.”
HGH is not addictive, but it can cause high cholesterol and problems with cardiovascular health and may increase the risk for diabetes, said Leona Cuttler, chief of pediatric endocrinology at Rainbow Babies & Children’s Hospital. Because HGH triggers an increase in cell production and growth, many doctors worry there is an increased cancer risk with its use.
The fight to control HGH
HGH is not a controlled substance like anabolic steroids. The federal government regulates the manufacture, distribution and use of drugs classified as controlled substances.
But many feel it is much too easy for people, including teenagers, to get their hands on HGH, and in December, Sen. Charles Schumer, a New York Democrat, and Sen. Charles Grassley, an Iowa Republican, introduced legislation that would make HGH a controlled substance.
That move has frustrated endocrinologists who treat patients, primarily children, with a legitimate medical need for the hormone. Cuttler, who also is director of the Center for Child Health and Policy at UH, calls it a misguided effort that has “sort of lumped growth hormone and steroids as drugs that are abused by athletes without sorting out their medical needs.
“I think there is a momentum to do something and to avoid it being used by athletes, and avoid it being in the culture of young people and adolescents,” she said. “But I’m just not sure this is the right way to approach it.”
Griesemer disagrees.
“I don’t see the logic of their lack of support,” he said. “This stuff is not coming in by the package. It’s not coming in by the truckload. It’s coming into this country by the container-load. It’s a mess.”
Hoffman is concerned about teens using these black-market hormones without supervision simply because they see their idols doing it and think it must be safe.
“If you spend five minutes in a locker room, you realize these guys should not be role models,” he said. “I don’t think there’s enough research out there, and you’re running the risk of some serious, irreversible side effects.”
WHEN PEOPLE NEED TO TAKE STEROIDS: People often are confused about steroid abuse because there are several different kinds of steroid hormones that serve different purposes in the body. All are lipid soluble, meaning they dissolve in fats. They pass easily through the cell membrane and bind to a specific receptor in the cell.
Glucocorticoids: A type of steroid that includes prednisone, dexamethasone and hydrocortisone. Often prescribed to treat inflammatory conditions, such arthritis, pneumonia and asthma, or to prevent organ rejection. “This is often what people mean when they say their grandmother took steroids,” said Dr. Thomas Murphy, director of the Division of Endocrinology at MetroHealth Medical Center.
Anabolic-androgenic steroids: Includes testosterone and its synthetic equivalents. Used to replace testosterone in people with a deficiency. Any disease or damage to the testicles, pituitary gland or hypothalamus, as well as genetic abnormalities, chemotherapy, tumors, infection and glandular malformations can cause such a deficiency.
There is little data on the long-term consequences of anabolic steroid use or about what happens when they are used in very high levels, as is often reported by athletes and bodybuilders. At medical doses, common but reversible side effects include hair loss, acne, development of breast tissue in males, infertility and decreased testicular size, said Murphy.
More serious recognized side effects include hypertension and a small but significant effect on cholesterol levels that can increase chances of a heart attack or a stroke.
A child who takes a course of these steroids before he or she is done growing could permanently close the bone’s growth plates, irreversibly stunting growth.Lack of proof: Dr. Bernard Griesemer, an expert on steroid use in teens, often is frustrated by the argument that none of the side effects of steroid use has been proven.
“When people [use that argument] you have to point out that they’re never going to be able to prove this,” he said. “You’re not going to take a child and put him in a double-blind crossover study using a potentially lethal medication.”
Regardless of the cause, stress sets in motion certain automatic changes in the body that are designed to give it a quick burst of energy. The pattern of changes has been called the “fight-or-flight” response because it most likely evolved from our prehistoric ancestors, who faced daily dangers in their search for food and shelter and had to either flee or do battle. Of course, we no longer face such dangers, but our bodies continue to react as if we did. So instead of responding to a saber-tooth tiger lurking behind a tree, the body reacts to petty annoyances like getting caught in traffic, being reprimanded by a supervisor, or worrying about bills.
Regardless of the type of stress, the body goes through the following changes:
1.The adrenal glands release adrenaline and other stress hormones that prime certain organs to go into action.
2.The breathing becomes faster and more shallow to allow the body to take in more oxygen.
3.The liver releases more glucose (blood sugar) to provide extra energy.
4.The heart beats faster and blood pressure rises to increase the distribution of oxygen and nutrients throughout the body.
5.Blood flow to the brain and muscles is increased and, at the same time, reduced to digestive organs.
6.Sweating increases to allow the body to burn more calories without a rise in body temperature. (In theory, sweating also makes the skin slippery and more difficult for a predator to grab.)
After the stressor disappears, the body returns to its normal state (homeostasis). If, however, stress is chronic — as it is for many people — the body stays on high alert. The many damaging consequences include a rise in cholesterol levels, high blood pressure, damaged blood vessels, decreased mental skills, and a weakened immune system.
What is selenium?…..click & see
An essential trace element, selenium is nonmetallic, gray in appearance, and similar to sulfur in its chemical composition. It is often available in single or multivitamin supplements.
Why do we need it?
Selenium is needed to activate a number of hormones produced by the thyroid gland. It also activates an antioxidant enzyme called glutathione peroxidase, which may help protect the body from cancer, and has been shown to induce “apoptosis” (programmed cell death) in cancer cells. Selenium also plays a vital role in the functioning of the immune system. Studies have found that selenium supplementation stimulates the activity of white blood cells. It also enhances the effect of vitamin E, one of three vitamins that act as antioxidants.
Adult men: 55 micrograms/day
Adult women: 55 micrograms/day
Children aged 7-10: 30 micrograms/day
Infants: between 10-15 micrograms/day
Pregnant/lactating women: between 65-75 micrograms/day
What are some good sources of selenium? Brazil nuts are the best source of selenium. Yeast, whole grains, garlic and seafood are also good sources. Some vegetables may contain considerable amounts of selenium depending on the content of selenium in the soil.
What can happen if I don’t get enough selenium?
While most people do not consume enough selenium on a daily basis, severe deficiency is rare. Soils in some areas are selenium deficient, and people who eat foods grown primarily on selenium-poor soils can be at greater risk for deficiency. The most notable condition caused by selenium deficiency is Keshan disease, which causes an abnormality of the heart muscle. Some studies have shown that patients with AIDS have abnormally low levels of selenium. Other research has demonstrated an association between heart disease and depleted levels of selenium.
What can happen if I take too much?
Taking large amounts (more than 1,000 micrograms) of selenium per day can cause the loss of fingernails, teeth, and hair; nausea; and fatigue. In conjunction with iodine-deficiency induced goiter, selenium supplementation has been reported to increase the severity of low thyroid function.
An essential trace element, selenium is nonmetallic, gray in appearance, and similar to
sulfur in its chemical composition. It is often available in single or multivitamin
supplements.
Why do you need it?
Selenium is needed to activate a number of hormones produced by the thyroid gland. It also activates an antioxidant enzyme called glutathione peroxidase, which may help protect the body from cancer, and has been shown to induce “apoptosis” (programmed cell death) in cancer cells. Selenium also plays a vital role in the functioning of the immune system. Studies have found that selenium supplementation stimulates the activity of white blood cells. It also enhances the effect of vitamin E, one of three vitamins that act as antioxidants.
How much selenium should you take?
According to the National Academy of Sciences, the recommended daily allowance (RDA) of selenium is as follows:
* Adult men: 55 micrograms/day
* Adult women: 55 micrograms/day
* Children aged 7-10: 30 micrograms/day
* Infants: between 10-15 micrograms/day
* Pregnant/lactating women: between 65-75 micrograms/day
What are some good sources of selenium? Brazil nuts are the best source of selenium. Yeast, whole grains, garlic and seafood are also good sources. Some vegetables may contain considerable amounts of selenium depending on the content of selenium in the soil.Mustard seeds emerged from food ranking system as a very good source of selenium .
What can happen if you don’t get enough selenium?
While most people do not consume enough selenium on a daily basis, severe deficiency is
rare. Soils in some areas are selenium deficient, and people who eat foods grown primarily
on selenium-poor soils can be at greater risk for deficiency. The most notable condition
caused by selenium deficiency is Keshan disease, which causes an abnormality of the heart
muscle. Some studies have shown that patients with AIDS have abnormally low levels of
selenium. Other research has demonstrated an association between heart disease and depleted levels of selenium.
What can happen if you take too much?
Taking large amounts (more than 1,000 micrograms) of selenium per day can cause the loss of fingernails, teeth, and hair; nausea; and fatigue. In conjunction with iodine-deficiency induced goiter, selenium supplementation has been reported to increase the severity of low thyroid function.
