Estrogen is the primary female sex hormone and plays an important role throughout a woman's life. In teens, estrogen contributes to healthy bone growth and development and influences reproductive processes such as menses and fertility. Estrogen also plays a role in the development of other body systems, including the heart. While estrogen occurs naturally in females, some things can disrupt the balance and availability of estrogen, sometimes leading to decreased bone density and amenorrhea, or the cessation of monthly periods.
Estrogen and Female Reproductive System
Female estrogen is produced and secreted from the ovaries. In early childhood, the ovaries are relatively dormant and serve as a sort of warehouse for eggs. Once puberty kicks in, the pituitary gland stimulates the ovaries to begin to produce estrogen and progesterone, which in turn engenders the onset of menses and the process of sexual maturity.
Estrogen and Bone Health
Estrogen has been found to play a pivotal role in bone development and growth in both boys and girls. In fact, the growth spurt girls experience at an earlier age than boys is thought to be due to higher estrogen levels at the onset of puberty. Low estrogen levels early in life can lead to postmenopausal osteoporosis in females.
Estrogen and Breast Health
As girls begin puberty, increasing levels of estrogen cause breast development. The rate and size of breast growth is largely genetic, although nutrition can play a role, either in increasing the fatty tissue of the breasts or depleting it. Most girls begin to grow breasts in early puberty, from ages nine to 11 years. In a 1969 study by Marshall and Tanner in which the development of 192 schoolgirls was observed, it was found that breast growth from onset to completion took approximately four years.
Eating Disorders and Estrogen Depletion
Eating disorders common to teenage girls such as anorexia or bulimia can severely disrupt the normal maturation process. Malnourishment due to eating disorders can lead to amenorrhea and the accompanying drop in estrogen levels. Low estrogen caused by disordered eating has been linked to poor bone development and heart disease.
Female Athlete Triad
The female athlete triad--a combination of disordered eating, amenorrhea and osteoporosis--is a syndrome common to teenage athletes who train rigorously. It is initially triggered by inadequate nutrition relative to the amount of energy expended each day. Sometimes, this syndrome develops because girls perceive their newly developing bodies as being "fat." Coaches, trainers and other athletes or parents may reinforce this negative body image as their young athlete grapples with unwelcome changes. Development of the breasts and hips causes a redistribution of weight, shifting the center of gravity. These changes may initially interfere with athletic performance. Girls will often begin to diet at this stage. Over time, over-training and undernourishment lead to amenorrhea. This in turn leads to low estrogen production, which interferes with bone density. Girls afflicted with this syndrome become highly vulnerable to bone fractures and may be prone to osteoporosis later in life if the cycle is not broken. Coaches should be cognizant of this syndrome, as its effects can impede an athlete's development and performance.
Ensuring Healthy Estrogen Levels in Teens
Parents can help their teenage daughters maintain healthy estrogen levels by helping them develop a healthy body image and strong self-esteem. In so doing, girls will be less vulnerable to eating disorders. Parents should also be aware of the regularity with which their teen menstruates and how many calories she is eating relative to the amount of energy expended daily. Provide your teen with plenty of healthy, nutritious food, and discourage diet-based drinks and junk food with empty calories and no nutritional value.