Osteoporosis
Osteoporosis, which literally means "porous bones," is the
loss of bone mass that can occur with aging. As this condition
progresses, it becomes increasingly debilitating, painful and crippling.
More than eight million Americans are afflicted by osteoporosis today;
another 17 million have low bone mass, placing them at high risk of
developing the condition. It is one of the five leading causes of death
in women today.
The good news is, osteoporosis is preventable for many people. And it
can be treatable in those who already have it.
Women at Risk
While women and men can develop osteoporosis, women are eight times
more likely to be afflicted. By the age of 45, 20 percent of women may
have osteoporosis; by the age of 65, 80 percent will. Here are the main
reasons that women, especially older women, are at such high risk.
- Women have less bone mass at adulthood than men do. As women age,
they are therefore more vulnerable to any loss of bone.
- The male hormone testosterone protects men's bones as they age
into their 60s and 70s. Women, on the other hand, need the hormone
estrogen for bone health and density; after menopause, estrogen
levels fall.
- Younger women who have anorexia or super-athletes with amenorrhea
also may be at risk for bone mass loss due to decreased estrogen.
- Women typically consume less calcium-rich foods than men, often
because of lactose intolerance or for weight control reasons; this
may deprive women of sufficient dietary calcium for good bone
health.
Some women are at higher risk than others for osteoporosis. Caucasian
and Asian women, for example, have less bone mass than African women;
Hispanic women have one-third the risk of osteoporosis that Caucasian
women have. Women with a family history of osteoporosis are more likely
to develop the disease, and women with fair hair and complexion tend to
be more susceptible to it.
You can assess your risk for osteoporosis by answering these
questions.
- Are you Caucasian, Asian, Latin or Hispanic?
- Are you over 45?
- Do you have light skin and fair hair?
- Have your mother or sisters had bone fractures or been diagnosed
with osteoporosis?
- Have the elderly women in your family developed a "dowager's
hump"?
- Are you of slight build, small-boned or underweight?
- Do you smoke?
- Do you eat fewer than three servings a day of dairy products?
- Do you spend most of your waking time indoors, even when you
exercise?
- Do you get fewer than three 30-minute sessions of weight-bearing
exercise a week?
- Have you ever exercised so much that your period stopped?
- Do you go on and off diets?
- Do you drink coffee and soda (including diet soda) regularly?
- Did you have surgical menopause before the age of 45, or are you
in menopause?
- Are you on thyroid medication?
- Do you take, or have you taken for an extended period of time, any
of these medications that may contribute to bone loss?
- steroids
- insulin diuretics
- anti-ulcer
- anti-coagulants
- anti-convulsants
- Do you eat a high-protein diet?
- Do you not take calcium supplements?
- Do you drink a fair amount of alcohol?
The more "yes" answers you gave, the higher your risk.
Building Healthy Bones
Bone is a living tissue, just like skin or muscle. It is dynamic; in
fact, 20 percent of bone tissue is replaced every year, through the
process called bone remodeling. In this process, bone-eating cells
called osteoclasts break down bone, creating holes; then bone-building
cells called osteoblasts come along and fill up those holes with fresh
new bone. The whole process can take four to six months.
Calcium helps in the bone-building process by contributing to
increased bone density and strength. This is why infants -- who have far
more bone-building osteoblasts at work than bone-eating osteoclasts --
need so much calcium and Vitamin D to grow. During adolescence, bone
development really shifts into high gear; nearly half of all bone is
formed during the teen years. This is a time when people really require
a lot of calcium to build strong bones; unfortunately, it is also a time
when they miss out on a lot of the calcium they need.
By your early 20s, you are still in the prime bone-building years;
even though your bones may be as long as they are going to get, they can
still grow in density and strength. As you continue to build bone
through your early 30s, you create a reserve of bone -- a supply on
which to draw in the future, when you will be using up bone and calcium
faster than you can replace it. The peak bone mass that you reach in
your early 30s is the maximum amount of bone that you will ever have.
Between 35 and 45, you begin to use up calcium faster. Exercise and
continued intake of calcium are important for you to maintain your bone
density. By 45, you need to protect against a net loss of bone, which
occurs when you are losing more bone material than you are getting.
Nutrition and Osteoporosis
Calcium is essential for healthy bones. The recommended amount for
adults is 1,000 milligrams a day; a lifetime of consuming under 1,000
milligrams a day can contribute to osteoporosis. To ensure that you get
enough calcium, follow these guidelines.
- Consume three calcium-rich dairy foods a day, along with generous
amounts of green leafy vegetables.
- Choose non-dairy foods that have been fortified with extra
calcium, such as orange juice and rice.
- If you need to, use calcium supplements to assist in meeting the
requirement for 1000 milligrams a day.
- See our section on calcium for more information about foods rich
in calcium and about recommended amounts for your age.
In the United States, the recommendations for daily calcium intake
are twice as high as in other countries because Americans have greater
urinary losses of calcium. There are several theories about why this is
true.
- Typical U.S. diets have a high ratio of phosphorus to calcium,
about 5:1. This ratio should be 1:1. High levels of phosphates
reduce calcium absorption, contributing to slow, continuous
demineralization of the bone.
- Our diets also tend to be high in protein, and loss of urinary
calcium increases with protein intakes that exceed normal
recommendations (see protein). Protein food sources are high in
phosphorus and low in calcium, adding to the imbalance.
Other Nutritional Factors and Osteoporosis
- Alcohol, caffeine, sodas: Calcium absorption is blocked if you
drink more than two alcoholic drinks a day. The caffeine in coffee,
tea and soda (at levels of about 10 cups a day) also interferes with
calcium absorption. Some sodas, particularly diet sodas, are high in
phosphorus, further upsetting the body's balance of phosphorus and
calcium.
- Crash diets: Food plans that limit dairy products and force high
protein intake can deplete the bones of calcium. Vegetarians who
avoid milk products may be at risk unless they are careful to get
enough calcium in their daily diets.
- Lactase: People with inadequate amounts of this digestive enzyme
may develop lactose intolerance, a condition which makes it
difficult to ingest milk products without discomfort. This can
result in calcium deficiencies in people who avoid dairy foods
because they cannot tolerate them comfortably. Fortunately,
lactose-reduced milk and dairy products are now available, as well
as lactase tablets that can be taken with dairy products.
- Magnesium: High intakes of calcium may interfere with magnesium,
which is important in building the bone matrix that helps bone
absorb shock. To help counteract this effect, eat foods rich in
magnesium, such as whole grains, legumes; and leafy green
vegetables. If you take calcium supplements, consider those which
contain magnesium.
- Sodium: In excess amounts, sodium increases urinary calcium loss.
If you consume the recommended amount of sodium (2,400 mg), you need
about 1,200 mg of calcium. If your sodium intake is higher, you
probably need more calcium.
- Vitamin D: Vitamin D enables the absorption of calcium. To absorb
calcium, you must get 400 IU of vitamin D a day from fortified foods
and supplements. Because sunlight is required for the body to
synthesize Vitamin D, people who live in northern areas may have
deficiencies even if they get enough calcium. Milk is fortified with
vitamin D to guard against this problem.
Calcium Supplements
Calcium is not a cure for osteoporosis, but it is essential for
enhancing bone health in everyone, including people who already have the
disease.
There are several types of calcium supplements available.
- Calcium carbonate is the most common form of calcium. It is
available as a pill, in chewable-tablet form, and as an ingredient
in some antacids. Some women may have a little difficulty digesting
it, complaining of constipation. Calcium carbonate is best consumed
after meals so that the acid in your stomach can digest and absorb
it.
- Calcium citrate may be more readily absorbed and should be taken
on an empty stomach. Calcium citrate malate is a new supplement
that seems to be easier on the stomach and better absorbed.
- Some supplements include additional vitamin D and magnesium as
well as calcium; if you feel that you fall short of vitamin D in
your diet, consider these.
- Calcium supplements made from bone meal, oyster shells or
dolomite may be contaminated with lead, but most brand-name
products are safe.
Your body can best absorb calcium in doses of 500 mg or less.
Figure out how many tablets (of 500 mg or less) you need to take
through the day to get the recommended daily amount.
