Article: "Bare-bone Facts About Bone Health", By Deborah Vogel
You may be at risk for osteoporosis, a serious and painful disease that
causes loss of bone mass. Find out how to safeguard yourself and your students.
Dance may be one of the best preventive exercises for girls and women
susceptible to the bone disease known as osteoporosis, but that does not mean
dancers and dance teachers aren't still at risk. In fact, certain habits
characteristic of a dancer’s lifestyle may actually increase the chances of
developing it. Fortunately, there are ways you can protect yourself and your
students.
Healthy bone with normal density
Osteoporotic bone deteriorating
What Is Osteoporosis?
Bone is composed of living tissue and nonliving substances. The living
tissues include blood, collagen, nerves and cells such as osteoblasts, which
help form new bone, and osteocytes, which eat away bone, causing it to be
reabsorbed back into the body. This regeneration process continues throughout
your life and, typically, osteoblasts form new bone at a faster rate than
osteocytes absorb it. Osteoporosis, however, develops when bones are regenerated
at a slower rate than they are reabsorbed, leading to significantly lower bone
mass.
It's important to understand that osteoporosis is a disease and not a normal
part of aging. While everyone's bone mass will decrease by a small amount over
time, especially in postmenopausal women, osteoporosis causes unusually large
losses in bone mass that are not only painful, but life-altering. Luckily, there
are ways to lower the risk of developing the disease: regular weight-bearing
exercise, a nutritious diet rich in calcium and vitamins D and K and ensuring
that your body produces enough estrogen.
Weight-Bearing Exercise: Is Teaching Dance Enough?
Combined with a balanced diet, weight-bearing exercise such as dancing and
jogging is vital to bone health. While swimming and other non-weight-bearing
exercises may increase cardiovascular health, they do little to promote bone
growth.
In order to lower the risk of developing osteoporosis, typical exercise
guidelines recommend 30 to 60 minutes of weight-bearing activity three to four
times per week. Dancers spend far more time than that in class: jumping, leaping
and turning. Teaching, on the other hand, depending on how active you are in
class, may not be enough to maintain healthy bones. Evaluate how much time you
actually spend demonstrating and supplement class with walking, using equipment
such as an elliptical trainer or taking another teacher's dance class three to
four times per week.
Note, however, that it is possible to exercise too much, whether you're a
teacher or a dancer. Food intake must reflect activity levels. Dr. Nicola Keay,
an osteoporosis researcher in the United Kingdom, writes, "If you're doing
too much exercise and don't eat enough, or if you don't do any exercise and eat
lots of fast food, those extremes obviously aren't good." she said.
"The message is to get a balance: do enough exercise, eat a reasonable diet
and don't go on a crash diet."
Raging Hormones
Low-calorie diets and rigorous exercise regimes are typical of a dancer's
lifestyle, but can cause hormone fluctuations, which can lead to osteoporosis
later in life. Thin dancers with very low body fat may not produce enough
estrogen, which can delay the onset of their menstrual cycles (primary
amenorrhea) or cause irregular menstruation (secondary amenorrhea). This is
especially dangerous for women between the ages of 20 and 25 because peak bone
mass is reached during these years. The more density developed in the early 20s,
the less chance of osteoporosis later. Encourage your students with amenorrhea
to visit their doctors to find out if hormone therapy is necessary and seek the
advice of a nutritionist to make sure caloric intake is sufficiently appropriate
for activity levels.
Balancing hormones should be a priority whether you are an adolescent or a
pre- or postmenopausal woman because it can prevent or slow osteoporosis, but it
may not increase bone mass unless other lifestyle factors also are changed. For
example, recent research by Dr. Michelle P. Warren and her colleagues at
Columbia University found that hormone therapy does not reverse bone loss in
amenorrheic ballet dancers. Warren surmises that the "exercise-induced
amenorrhea may be due to a metabolic imbalance caused by a caloric intake that
is insufficient for the level of activity." In other words, exercising for
hours at a time, while eating as little as possible may actually cause the
hormonal imbalances that will eventually lead to osteoporosis.
Bone density tests are a good gauge of bone health and typically are given to
postmenopausal women under the age of 65 who have one or more risk factors for
osteoporosis. If you or your students have any of the risk factors: such as
being thin, smoking, excessive alcohol consumption, eating disorders, amenorrhea
or early or surgically induced menopause, make sure you request a bone density
test, too. The DEXA scan is considered the most accurate.
Eat Your Veggies, Get Some Sun (Carefully)
It is widely known that a calcium-rich diet promotes healthy bones, but
vitamins D and K are equally important. Vitamin K is commonly found in dark
leafy greens such as spinach and kale. According to Dr. Joseph Mercola, studies
have shown vitamin K to be as effective as Fosamax-type drugs prescribed to
treat osteoporosis.
Vegetables are critical for good bone density for two main reasons. First of
all, they neutralize acidity in the body, which tends to increase as you age and
is less conducive to bone growth. Secondly, vitamin K acts as 'glue' to bind
calcium directly to the bone matrix. An adequate daily amount is typically
90-120 micrograms. For most women, daily leafy green vegetables should suffice,
but for borderline or osteoporotic women, it may be a good idea to take
supplements.
Vitamin D also helps the body absorb calcium. Since skin produces vitamin D
when exposed to sunshine, don't be afraid to spend a little time outdoors.
(Don't take this as permission to get sunburned or absorb inappropriate
quantities of ultraviolet rays, which can cause skin cancer.) Twenty minutes per
day with just your face and arms exposed should be sufficient. During the winter
months when you are bundled up in a coat, supplement your diet with foods such
as cod liver oil, which contains large quantities of vitamin D. Salmon, eggs and
fortified milk are other good sources, as well.
But be cautious. Unlike vitamin K, too much vitamin D can be harmful, though
it is impossible to make too much vitamin D through sun exposure. During the
summer months, if you spend time outdoors, supplement your diet with fish oil,
which has less vitamin D than cod liver oil. Have your vitamin D levels tested
if you are concerned that you are getting too much or too little.
The body is continually replacing its cells, and how well that replication
process happens is inextricably linked to the food choices you make. In all the
preventive measures you take, balance is the operative word. Seek medical
advice, eat the right foods and, if you or your students exercise rigorously,
make sure that estrogen levels aren't falling dangerously low. Remember that
even if you develop osteoporosis, these healthy habits may slow it down.
Top 5 best snacks 1. Water 2. Fruits and vegetables 3. Cheese and yogurt 4.
Lean cold-cut sandwiches 5. Health bars
Top 5 worst snacks 1. Candy 2. Greasy food such as doughnuts and hot dogs 3.
Processed snacks such as potato chips 4. Soda 5. Sugary, caffeinated energy
drinks
Neuromuscular specialist Deborah Vogel directs the Institute for Performance
Studies in Ohio and cofounded the Center for Dance Medicine in New York City.
Her videos on stretching and strengthening are available at http://www.thebodyseries.com.