Young female professional dancers and other young female athletes both face the same health risks when they don’t eat enough to replace the calories they expend, and stop menstruating as a consequence, according to new research from The Medical College of Wisconsin.
“These two components of the female athlete tetrad put them at higher risk for the other two; the cardiovascular and bone density deficits of much older, postmenopausal women,” says lead researcher Dr. Anne Hoch, associate professor of orthopaedic surgery.
22 professional ballerinas from the Milwaukee Ballet Company were studied, to find out prevalence of eating disorders, low bone density, amenorrhea (lack of menstruation), and abnormal vascular function. Dancers filled out questionnaires on their eating habits and menstrual patterns, and had blood tests for hormonal levels. 77 percent were in caloric deficit, and 36% had disordered eating habits.
Arterial ultrasound showed that 64 percent had abnormal artery dilation in response to blood flow. Twenty-seven percent were currently amenorrheic, 23 percent had low bone mass density and nine percent were taking birth control.
“It was unknown if professional dancers without menstrual periods have evidence of vascular dysfunction, yet some characteristics of the tetrad were common in this group,” says Dr. Hoch. “Eighty-six percent had one or more components, and fourteen percent had all four.”
Precautions for Young Female Athletes
It is important for parents, coaches and athletes to be aware of components of the female athlete tetrad
1. Disordered eating- Pre exercise carbohydrates and hydration (2 hrs. prior to exercise) and a recovery meal (within 30 minutes of exercise) are very important
2. Menstrual dysfunction– The average age of menarche in US is 12.5. It’s abnormal if periods don’t start by age 15.
3. Osteoporosis – “Irregular” weight bearing exercise, between ages 7 and 12, is beneficial for long-term bone mineral density. Calcium requirements for ages 11 to 24, per the National Institutes of Health, are 1,500 mg of calcium and 400 mg of Vitamin D daily
4. Early Cardiovascular Disease Risk – consider folic acid (vitamin B9) supplementation to alleviate vascular disfunction (see below)
Vascular Function and High-dose Folic Acid Supplements
In a separate study, researchers at The Medical College of Wisconsin in Milwaukee found that folic acid (vitamin B9) supplementation in four to six weeks of high-dosage improved vascular function in young female runners who were amenorrheic.
This is significant since folic acid may not just decrease cardiovascular risks but could also improve athletic performance. Children and adults need folic acid to prevent anemia and produce healthy red blood cells.
“Previous studies have shown that amenorrheic women runners have decreased dilation in the main (brachial) artery of the arm in response to blood flow,” says lead author Stacy Lynch, M.D. “Athletic amenorrhea has a hormonal profile similar to menopause, when the earliest sign of cardiovascular disease is reduced vascular dilation, which can limit oxygen uptake and affect performance.”
Approximately 23 million women and nearly three million girls in high school sports run at least six times a week. Benefits for women of a more active lifestyle are wide ranging and deep, however, the occurrence of athletic-associated amenorrhea among these runners is now estimated at an alarming 44 percent.
The folic acid study’s researchers followed 16 female college or recreational runners, ages 18 to 35, who had been running at least 20 miles a week for the past 12 months and were not on birth control pills. There were six otherwise healthy women with reduced vascular function and irregular or absent menstrual periods, and a control group of ten with normal periods.
Vascular function was measured before and after folic acid dosages (10 mg/day of folic acid for 4 to 6 weeks). Vascular function returned to average in the amenorrheic women after folic acid supplementation, and it remained at normal levels in the control group despite supplementation.