Articles

Osteoporosis

Introduction

What should I know about Osteoporosis?

If you are a woman over forty, you may be starting to worry about bone health. Everyone loses bone as they age. By the time a women is told she has osteoporosis, her gradual loss of bone mass has been progressing for years. Men lose bone too, but only about half as fast as women. Medically speaking, osteoporosis is characterized by low bone density and structural deterioration of bone tissue. (1) The soft spongy bone in the wrists, hips, and spine are the most vulnerable to osteoporosis and prone to breakage as a result.

Fractures due to osteoporosis are a major health problem in industrialized nations. In the United States, approximately 150,000 hip fractures occur annually in women over age 65, sentencing many women to long-term stays in nursing homes. (2) These fractures can be fatal. By age 80, some 40 percent of all women will have a spinal compression fracture and suffer with back pain, loss of height, and disability. (3)

Unlike the dead, brittle skeleton hanging in the high school biology lab, bone is a living, metabolically active tissue. Throughout life, bone is constantly rebuilding itself. Bone serves as a storehouse for minerals, chiefly calcium, which can be tapped to meet the body’s mineral requirements. Bone is broken down through a process called “resorption," releasing its minerals into the general circulation. New bone is then formed to replace the reabsorbed bone, preventing a net loss of bone. This is called bone “remodeling." As we age, however, bone formation begins to fall behind, causing the gradual bone loss that culminates in osteoporosis.

Exactly why and how bone loss accelerates with aging is not completely understood. Many different physiologic changes appear to be involved. (4) Bone cells called “osteoblasts" that rebuild bone seem to falter with aging. Hormones of the thyroid and parathyroid glands control the movement of calcium in and out of bone: calcitonin secreted by the thyroid deposits calcium into bone while PTH from the parathyroids pull calcium out. As we age, calcitonin levels tend to fall coupled with a rise in PTH, tipping the scale toward bone breakdown. (5) , (6) Estrogen protects against bone loss and declining estrogen levels after menopause increase bone resorption. Add in the reduced absorption of dietary calcium that comes with aging and we have a constellation of interwoven factors favoring bone loss. (7) , (8)

While a certain amount of bone loss seems inevitable with the passage of time, the process is not entirely beyond our control. Dietary and lifestyle measures can, to some degree, help maintain bone health. Poor nutrition and other health habits such as smoking, alcohol abuse, and physical inactivity contribute to bone loss. Exercise, especially through activities like walking that put pressure on the weight-bearing bones, stimulates bone remodeling. Exposure to sunlight is helpful. Sunlight forms vitamin D in the skin, vitamin D in turn increases calcium absorption.

The risk of osteoporosis has been associated with heavy caffeine consumption. One study found that more than two cups of coffee or four cups of tea a day increased calcium excretion in the urine and the incidence of hip fractures. (9) Too much phosphorus in the diet favors bone loss by increasing excretion of both calcium and magnesium. High phosphorus foods such as animal protein and soft drinks should be consumed in moderation. In addition, older women with low blood levels of vitamin B12 had greater bone mineral loss. (10)

Milk drinking is commonly believed to promote strong healthy bones, but recent studies have raised questions about this. A Japanese study demonstrated that supplementing with calcium (200mg oyster shell with seaweed) more effectively suppressed parathyroid hormone than supplementing with milk. (11) Parathyroid hormone increases blood levels of phosphorus and increases calcium excretion in the urine. Sugar also stimulates calcium excretion. (12)

Statistic

International Osteoporosis Foundation, 2004.

  • Worldwide, lifetime risk for osteoporotic fractures in women is 30-50%. In men risk is 15-30%.

  • According to World Health Organization (WHO), osteoporosis is second only to cardiovascular disease as a global healthcare problem.

Arthritis Foundation of Malaysia, 2007.

  • In Malaysia, it is estimated that over 1 million people are at risk from osteoporosis, out of which 20% are men.

International Osteoporosis Foundation, 2004.

  • 1 out of 8 males and 1 out of 3 females in India suffers from osteoporosis.

International Osteoporosis Foundation, 2004.

  • In New Zealand, osteoporosis causes 15,000 fractures each year, of which around 3,000 are hip fractures.

  • Osteoporosis affects more than half of women, and nearly a third of men over age 60.

International Osteoporosis Foundation, 2004.

  • 2 million Australians are affected by osteoporosis.

National Institute of Arthritis and Musculoskeletal and Skin disease (NIAMS), 2003.

    10 million Americans are affected with osteoporosis. 18 million people are at risk for developing osteoporosis. Osteoporosis' cost to health care is $15-20 billion a year.

National Osteoporosis Foundation, 2003.

    80% of the population with Osteoporosis are women. 1 in 2 women and 1 in 8 men 50 yrs. and over will have osteoporosis related fractures. Osteoporosis is responsible for more than 1.5 million fractures annually.
      300,000 hip fractures 250,000 vertebrae 250,000 wrists 300,000 other bone fractures

Signs and Symptoms

[span class=alert]The following list does not insure the presence of this health condition. Please see the text and your healthcare professional for more information.[/span]

Osteoporosis is often called the "silent disease" because bone loss occurs without symptoms. People may not know that they have osteoporosis until their bones become so weak that a sudden strain, bump, or fall causes a hip fracture or a vertebra to collapse. Collapsed vertebra may initially be felt or seen in the form of severe back pain, loss of height, or spinal deformities such severely stooped posture or the tell-tale "dawager’s hump."

General

  • Bone weakness, increase in fractures, bone collapse in areas of the spine
  • Loss of height
  • Severe back pain
  • Stooped posture

Treatment Options

Conventional

“An ounce of prevention is worth a pound of cure" aptly applies to osteoporosis. The goal is to slow down bone loss enough to reduce the risk of fractures. Along with weight-bearing exercise, calcium and vitamin D, your doctor may prescribe from among the following treatments:

    Hormone Replacement Therapy
    Hormone replacement therapy (HRT) is now a popular treatment for preventing osteoporosis in postmenopausal women. (13) Estrogen may stop bone loss even replace some of the bone already lost. (14) , (15) In some studies, women taking estrogen for at least five years after menopause have had a 35 to 50 percent reduction in fractures of the hip, spine and wrist. (16)

    Natural estrogens (estradiol, conjugated estrogens) are preferred for replacement therapy over the synthetic ones (ethinyl estradiol), because they are shorter acting and less likely to cause adverse effects. For the woman with a uterus, the most serious adverse effect when using estrogen replacement therapy is a marked increase in the risk of endometrial cancer. (17) Taking progesterone along with estrogen can eliminate this risk. (18) However, in July of 2002 a study was published greatly questioning not only the benefits of HRT but also the now confirmed risks of using HRT. (19) This study was part of The Women's Health Initiative (WHI) and involved greater than 16,000 women. The trial was stopped early when data showed that women taking a combination of estrogen and progestin had an increased risk of breast cancer and cardiovascular events among others. Other large trials have raised similar concerns as the WHI trial, (20) , (21) but the WHI was the first to confirm this increase breast cancer risk in healthy women with a uterus. The dilemma for patients with osteoporosis is that the trial showed a reduced risk of hip fracture with this hormone combination. Raloxifene
    Raloxifene is known as a SERM or selective estrogen receptor modulators because of their tissue-specific effects. Potentially, these drugs provide the benefits of estrogen without the accompanying risks. This tissue selectivity allows raloxifene to have "anti"-estrogen effects on breast and endometrial tissue and estrogen-"like" effects on bone and cholesterol. (22) , (23) Bisphosphonates
    Biphosphonates are synthetic compounds that inhibit bone resorption by attaching to the minerals in bone. (24) These drugs increase the mineral content of bone and help prevent fractures. They work best in people with low bone density and results take at least two years.

Nutritional Suplementation


Calcium

Calcium is the most abundant mineral in the human body. Bones and teeth hold 99 percent of the total. While everyone agrees that calcium is important for maintaining healthy bones the studies are not clear on the relationship between calcium intake and osteoporosis. Calcium deficiency certainly contributes to bone loss. There is no evidence that increasing dietary calcium can reverse osteoporosis and it may only partially prevent it. It seems more likely that calcium works best in combination with other vitamins and minerals. Two studies bear this out, showing that calcium given along with a broad spectrum of vitamins and minerals produces greater bone improvement than calcium alone or calcium combined with hormone replacement. (25) , (26)

Calcium alone is not the answer to preventing osteoporosis. Still, inadequate intake of dietary calcium is a risk factor. Unfortunately, many Americans are not getting enough calcium and other minerals in the diet. The U.S. Department of Agriculture’s Nationwide Food Consumption Survey revealed that a majority of people in the United States consume less than the RDA of calcium. (27) At the same time, taking large amounts of calcium by itself may actually interfere with the absorption of other nutrients such as iron, zinc, and magnesium. Traditionally, calcium and magnesium have been recommended in a 2:1 ratio. Some health professionals are now recommending a 1:1 ratio of calcium and magnesium.

Dairy products are the primary source of calcium for most Americans. However, many people have problems digesting milk and dairy products due to lactose intolerance. Milk is one of the most common food allergies. Many people who are concerned about dietary cholesterol and fat switch to low fat milk and dairy products. Other excellent sources of calcium include dark leafy green vegetables, broccoli, legumes, nuts, whole grains, and fortified soymilk.

Microcrystalline calcium hydroxyapatite compound (MCHC) is a well-absorbed form of calcium derived from whole cattle bone meal. MCHC contains all of the minerals along with substance found in living bone tissue called “glycosaminoglycans." The factors form the “connective tissue" which provides the structural matrix of bone. Supplements are available that contain MCHC processed with a low temperature method that preserves its nutritional value. MCHC is not the same as ordinary bone meal, which is typically treated with heat and caustic solvents that destroy the glycosaminoglycans. MCHC has been reported in human studies to increase trabecular bone mass and decrease thinning of cortical bone. (28) Preliminary studies also suggest that supplementing with MCHC relieves back pain associated with osteoporosis, and it may prevent or partially restore lost bone. (29) , (30)


Magnesium

With all the attention on calcium, magnesium is sometimes forgotten. This is unfortunate, because magnesium is an important bone mineral. Bone contains some 50 percent of all the magnesium in the body. (31) Magnesium is involved in calcium metabolism, the synthesis of vitamin D, and the formation of bone. Magnesium deficiency was shown to be associated with abnormal calcification of bone in one study of osteoporotic women. (32) In another trial, postmenopausal women who took a high magnesium supplement along with hormones achieved an 11 percent increase in bone mass while women only taking hormones showed a 0.7 percent increase. The supplement also included a range of other nutrients known to be important in bone health. This study is important because it documents the greater effectiveness in treating osteoporosis with a broad range of nutrients rather than with just calcium. (33)

Magnesium is another essential nutrient that is frequently deficient in the diet. The USDA’s Nationwide Food Consumption Survey found that the average daily magnesium intake of all Americans, except for children age 5 and younger, falls below the Recommended Dietary Allowance (RDA). Magnesium consumption was particularly low among adolescent females, adult females, and elderly men. (34)


Vitamin K

Vitamin K is essential for bone formation. The body requires vitamin K to produce a protein that binds calcium to bone. Recent research indicates that vitamin K deficiency contributes to osteoporosis, while supplementation may help prevent or reverse bone loss. One study of women with osteoporosis found they had 74 percent less vitamin K than normal. (35) The main dietary source of vitamin K is dark green leafy vegetables.


Manganese

Manganese helps strengthen connective tissue, which is the “glue" that holds bone together. (36) Research indicates that dietary manganese deficiency can be a factor in osteoporosis. A recent study showed that women with osteoporosis had blood levels of this trace element 75 percent lower than women of the same age without osteoporosis. (37)

Manganese is missing in refined foods such as white breads, flours, pastas, and other processed foods, so a diet that relies on these foods may leave one prone to manganese deficiency. (38) There is no RDA for manganese, but a general guideline for supplementation is 5 to 25mg per day.


Boron

Boron is a trace mineral that has been recently recognized as an essential nutrient for humans. Studies suggest that boron helps the body retain calcium. In a study led by a USDA scientist, boron supplements reduced urinary loss of calcium in a group of postmenopausal women. (39) Their estrogen levels went up as well. Another study suggests that boron supplementation may be helpful in preventing osteoporosis in postmenopausal women not taking estrogen. Boron raised serum calcium to levels comparable with a second group of women on estrogen replacement. (40)


Vitamin D

Vitamin D plays a major role in regulating calcium absorption. When blood calcium levels drop, vitamin D boosts calcium absorption from the intestinal tract. Postmenopausal women with osteoporosis are often deficient in vitamin D, (41) , although there is a global deficiency as well. (42) Inadequate sunlight and poor dietary intake are largely responsible for reduced vitamin D levels. The most common sources are vitamin D-fortified dairy products, fish, eggs, and liver. Supplementation is recommended for women with low dietary vitamin D intakes who do not get regular exposure to sunlight. Vitamin D is an especially important concern for people in northern climates. Vitamin D supplementation may prevent fractures. (43)


Soy Isoflavones

In Asia and other cultures where soy products are consumed in abundance, women’s health problems, certain cancers, and cardiovascular disease are reported to be less prevalent. (44) Increasing the intake of soy products in the diet increases the intake of phytoestrogens, which have a similar, though weaker, effect as the estrogens found in the body. Soy isoflavones (genistein and daidzein) are rich in phytoestrogens and are thought to reduce the symptoms of menopause, decrease the loss of bone, and decrease the risk of certain cancers. (45) , (46)

There has been recent interest in the reported use of soy isoflavones in women for decreasing bone loss caused by estrogen deficiency that naturally occurs in the aging process. (47) , (48) , (49) Results of these studies indicate that genistein may have an estrogen-like action in bone and bone marrow, preventing bone loss. This benefit is being challenged. A well-designed study evaluated the use of ipriflavone, a synthetic isoflavone, in more than 470 postmenopausal women with osteoporosis. Ipriflavone did not prevent bone loss when compared to placebo. (50)

Herbal Suplementation


Horsetail

Horsetail, also called “Shavegrass," is a common perennial plant that grows in moist soils and along riverbanks all over North America. Horsetail is rich in silica, an important mineral for strengthening connective tissue. Because silica supports hair and skin, horsetail is often included in shampoos, cosmetics, and skin care products. (51) Horsetail is also said to benefit teeth, bones, tendons, and ligaments. Silica’s connective tissue support seems to be especially significant for bone and cartilage. (52) , (53) Silica also works with calcium and other minerals to strengthen bone. Studies have shown that lab animals on silica-fortified diets have healthier cartilage. (54)


Red Clover

Red clover is one of the most abundant herbs found in fields, parks, and yards throughout North America and Europe. Although considered a weed, red clover has been valued for generations as an herbal “blood purifier." Red clover contains isoflavones, plant substances that have a mild estrogen-like effect on the body. Isoflavones are a topic of current interest, thanks to research highlighting their potential benefits for postmenopausal women. (55) A patented extract of red clover containing a standardized amount of isoflavones shows promise for relieving menopause symptoms. In a recent study, isoflavones from red clover increased arm bone density in human subjects. (56)

Diet & Lifestyle

    Be sure to get enough calcium, but don’t neglect the other important bone minerals such as magnesium and zinc. Strong, healthy bones also depend on an adequate intake of trace minerals. Eat a mineral rich diet that includes a variety of fruits and vegetables. Seaweeds are a good source of trace minerals. Exercise daily, emphasizing walking, “rebounding” and other weight-bearing exercises. Spend time in the sun, especially if you live in the North. Reduce caffeine consumption by cutting back on coffee and black tea. Eat animal protein in moderation. Cut down on sugar and refined carbohydrates. Avoid tobacco, it’s bad for your bones along with the rest of you!

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