OSTEOPOROSIS...No. 1 Health Concern for Women

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Osteoporosis affects one in four women ... More women die of hip fractures than of cancer of the breast, cervix and uterus combined. Since there is no cure for osteoporosis, the emphasis must be on prevention: Physical activity to promote bone growth; adequate calcium and fluoride intake; estrogen replacement therapy for some (possibly all) women at and after menopause.

Dr. Alan Dixon, British National Osteoporosis Society The Lancet, July, 1986

With proper nutrition, bone mass increases rapidly during childhood and adolescence through a process called mineralization. This process continues until the skeleton reaches maturity around the mid-30s. There is a short period when bone loss and gain are equal. Then sometime after age 35, a slow and steady decline in bone mass begins in both men and women.

Women lose about 10 percent per decade compared with about five percent for men. However, at the time of menopause and for several years there is a sudden acceleration of bone loss to a rate of 5 - 8 percent per year. According to Lawrence Lamb, M.D., a well-known syndicated columnist, this vulnerable period is one factor that causes women of age sixty or over to have osteoporosis.

Bone density is influenced by factors such as heredity, sex, race, nutritional status, physical activity level and general health. Bone mass is about 30 percent greater in men than in women, and 10 percent greater in blacks than in whites. In general, women are at greater risk for osteoporosis than men because they have less bone tissue. One out of four women over 60 experience a bone fracture due to osteoporosis and 17 percent of those who sustain hip fractures die within three months of the fracture. Even coughing or simple bending can cause painless vertebral fractures that shorten height and lead to the rounding of the spine known as "dowager's hump." In 1984, the National Institutes of Health formed a panel on the prevention and treatment of osteoporosis. The panel concluded that the best osteoporosis prevention is "estrogen replacement in postmenopausal women, adequate nutrition including an elemental calcium intake of 1000-1500 mg per day, and a program of modest weight-bearing exercise."

Research has lead to the general agreement among physicians and researchers that the progression of bone loss can be halted in post menopausal women with estrogen replacement therapy (ERT). In a recent article for Let's Live, David Steenblock, D.O. writes, "A lack of estrogen in postmenopausal women prevents the absorption and utilization of calcium and is the single most important factor in the development of osteoporosis in older women." (February, 1989)

A study reported in the November 5, 1987 New England Journal of Medicine established that taking estrogen at any time after menopause cuts the risk of hip fracture by a third. The risk is cut to two-thirds after taking estrogen for two years. Although not cited by the investigators, this phenomenon might account in part for the results of a study appearing in a 1983 edition of the Journal of the American Medical Association. In this study, taking estrogen as a medication appeared to give users an advantage over nonusers in relative risk of death. The investigators speculated that this advantage might be related to the ability of estrogen to raise blood levels of high density lipoprotein cholesterol. (High level HDLs protect against heart disease.)

Although ERT can reduce the risk of osteoporosis if taken within three to five years after menopause, according to an article in Medical Self-Care, taking it also entails increased risks of some kinds of cancer and heart and gallbladder disease. (May/June, 1988) Less serious side effects of ERT include enlarged and tender breasts, nausea, skin discoloration, water retention, weight gain, headache, and heartburn.

Estrogen use prevents further bone loss; however, it does not replace bone that has been lost. Dr. Steenblock relates that taking progesterone with estrogen, along with calcium, boron, magnesium, silica, zinc, vitamins B[6], C, and D, exercising regularly, and eating a proper diet, not only curtails bone loss, but can actually strengthen bones.[ 1] He goes on to write: "Contrary to popular belief, this combination of hormones, vitamins and minerals also reduces the rates of cancer and heart disease."

Many women consider the use of ERT to be unecological for their bodies. Although no studies have been done to investigate the effects of women's herbals on calcium absorption or bone tissue maintenance, these formulas were created for their usefulness in hormone balance. Here is a list of herbs commonly considered useful as sex hormone precursors: Mexican wild yam, sassafras, licorice, lady's slipper, life root, passion flower, black cohosh, Honduras sarsaparilla, false unicorn root, elder and dong quai.[ 2] Siberian ginseng is also present in some herbal formulas for menopause. Dr. Steenblock has recommended it for women who can't or don't wish to use ERT.

In recent years, exercise has proven to be one of the best ways to build and to prevent bone loss. Women who have been athletic in their youth are less likely to develop osteoporosis. In addition, even in postmenopausal women, regular weight bearing exercise (often described as one hour, three times per week) such as walking, jogging or dancing helps increase bone mineral content and slows the amount of bone loss.

A recent study at Tufts University compared 15 active women between 55 and 70 with eight sedentary women. The runners, who had been running at least 10 miles per week for two or more years, averaged 20 pounds lighter than the sedentary women and had five percent less body fat even though they consumed more calories. Bone density measurements showed that the runners had more dense bones for their weight than the sedentary women. Since none of the runners began running until after menopause and had the same activity level as the sedentary group before that time, the investigators concluded that they did not start with more bone mass but gained it through exercise.

A study appearing in the Archives of Internal Medicine (1987; 148:121-123) used premenopausal women with an average age of 39. The women were sedentary but had differing levels of physical activity. The study found that those women with greater amounts of physical activity had higher total body calcium levels and higher bone density of the spine (one of the most common sites of osteoporotic fractures).

Another study from the British Medical Journal (1988; 295:1441-1444), involved 58 healthy postmenopausal women who were homemakers or white collar workers, aged 50-62. They had an average daily calcium intake of 1/2-1 gram. They were divided into three groups: a group who did aerobic exercise plus light weights; a group who did aerobic exercise only; and a control group who did not exercise. During the year long study, none of the groups increased their calcium intake or took estrogen or vitamin D.

At the end of the year, all groups were measured by the calcium bone index. Women in the control group lost small amounts of calcium in their spinal column. However, both of the exercise groups had a significant increase in bone mass compared with the control group. The group that used aerobics and light weights had the greatest improvement albeit not significantly different from the aerobics only group.

A final example is a study reported in The Physician and Sports Medicine. (August, 1987) This study involved 12 women who were 18 months to five years into menopause. Labeled the immediate postmenopause interval, this is the most vulnerable time for bone loss. After only eight weeks of endurance and flexibility exercises performed for 50 minutes, three times weekly, these women reversed the biochemical changes that lead to bone loss. These changes were not evident in 10 women who served as controls. A very important aspect of this study is that the average calcium intake of both groups of women was only about 550 mg, strengthening the view that exercise is an integral part of preventing and controlling bone loss.

Many studies support the need for women to increase their calcium intake. While existing surveys show that most North American women consume 450-550 mg per day, this average is definitely on the up swing. Over the past five years, calcium supplement sales have risen from $18 million to $240 million annually. This is a strong indicator that women are getting the message about the importance of calcium intake.

It is thought that the current RDA of 800 mg/day is outdated. Recent recommendations for daily calcium intakes given by the NIH panel are 1,000 mg for women under 35 (this is especially important for adolescent women)[ 3]; 1,200 mg for women 35 - 50; and 1,500 mg for post-menopausal women.

In a current issue Nutrition Today reports, "...1,500 mg is the average calcium requirement of postmenopausal women to maintain calcium balance. If the usual allowance is is made for individuals with above average requirements...the RDI would become 1,950 milligrams. If any allowance is made for a decreased efficiency of calcium absorption at very high intakes, the RDI would become at least 2,000 milligrams."

Even in studies where no relationship could be established between the amount of calcium intake and bone loss, researchers recommended that postmenopausal women consume at least a gram of calcium per day in their diet. In 1981, Avioli reported that dietary inadequacy alone could lead to a bone loss of 1.5 percent per year. Other factors contributing to poor bone status include lack of physical activity, high protein diets, vitamin deficiencies, smoking, and, of course, a decreased ability to absorb calcium in older women. Further contributing factors are chronic megadosing with vitamin A, diabetes mellitus, and chronic alcohol abuse. (Federation Processes, 40, 2418-2422)

Dietary calcium is classically the preferred method of ingesting this mineral. Dairy foods are the source of choice. A woman whose calcium requirement is 1500 mg/day would have to drink five glasses of nonfat milk daily to meet this amount. In addition, there are many people who are lactose intolerant or simply do not use dairy products. Foods such as canned sardines and salmon (with bones), dark leafy greens, and broccoli are also advised.

Calcium supplementation is the most convenient -- and perhaps the most effective -- method of insuring calcium intake. In the last few years, research and development at major supplement manufacturers has made high tech calcium formulations readily available for purchase through health food stores across the nation.

Most calcium supplement containers will list an elemental value on the label, indicating the amount of calcium available for absorption. Several vitamins and minerals enhance calcium absorption as does bonding calcium with various chelating agents. Vitamin A (no more than 25,000 IU/day...too much prohibits absorption), vitamin B[6], vitamin C and vitamin D, plus the minerals magnesium, manganese, zinc, silica (from horsetail herb, equisetum), and boron all play an important role in maintaining healthy bone tissue.

Researchers for the U.S. Department of Agriculture have recently found that boron helps to prevent osteoporosis. Twelve women given modest boron supplements (3 mg/day) showed significantly reduced losses of calcium, magnesium and phosphorus, indicating that these minerals were not being lost from bone tissue. Plant foods like apples, pears, and broccoli are rich in boron; meat and fish are not.

Various chelating agents allow calcium to be taken up by more cell receptors, increasing absorption. These agents may have unfamiliar names. Lysinate, orotate, aspartate and alpha-ketoglutarate are some examples. Calcium carbonate is the most common form of calcium supplement. It is difficult to digest and should be taken in small amounts throughout the day, possibly with a digestive aid such as hydrochloric acid. Some calcium combinations include HCI. Formulas frequently include both calcium and magnesium. Currently calcium-magnesium citrate with a pH of 5.8 is considered to be an especially well absorbed supplement.

The newest calcium supplement on the market contains only 133 mg of calcium BUT it contains the protein mineral matrix of bone. Called microcrystalline hydroxyapatite concentrate (MCHC), it is the only nutritional supplement shown to re-mineralize bone. Animal studies comparing bone healing abilities of calcium carbonate and MCHC showed complete healing occurred only with the latter.

Truly a high technology product, MCHC is produced cryogenically in an environment of 50 below zero. Because this substance is present in all bone, bonemeal product can claim to contain it; however, bonemeal is heat processed and will not give the same results. In addition, bonemeal is typically washed with a chemical solvent. MCHC is not. The "good stuff" will guarantee that the product has been processed below human body temperatures (98.6 F or 37 C). This information will be on the label.

In addition to assuring calcium intake, calcium supplementation has two other factors to recommend it. First, it balances the calcium to phosphorus ratio of the body. Phosphorus is also necessary to bone health and is found in many foods. It is especially abundant in meat, processed food, and carbonated soda beverages (read the labels). The ideal ratio is 1:1. Because of the preponderance of these foods in the diet, many women (men and children too for that matter) have so much phosphorus in their systems that they sustain a calcium/phosphorus imbalance. This is related to a marked loss of bone density.

A study of 38 women aged 43-65 with a habitual calcium intake of 448 mg was conducted. The participants were given supplements to increase their calcium intake to 1100 mg/day. Their original calcium to phosphorus ratio was 1:1.65. The additional calcium reduced this to 1:1.20. Bone densities increased during the test periods of 28 to 38 months. The 42 women participating as controls showed a continuing ratio of 1:1.7 with significant decreases in bone density.

Secondly, calcium supplementation can reduce the estrogen dose needed to prevent bone loss. In a study published by Science, women took half the normal estrogen dose and 1500 mg calcium daily. The combination was effective in preventing bone loss. (August, 1986)

The best way to prevent osteoporosis is to use a program of adequate calcium intake and regular weight bearing exercise throughout life. The earlier such a program begins the better the results. However, as several of the studies in this newsletter have indicated, it is never too late to improve your bone tissue health. A good diet, with low fat, moderate protein intake, low phosphorus (watch those sodas) and featuring lots of fresh, whole foods, plus calcium supplements and regular exercise should be on your agenda starting today and continuing for the rest of your life.

FOOTNOTES
[1] Postmenopausal women who are on estrogen/ progesterone therapy may experience some menstrual-like bleeding (usually far lighter than a normal period).

[2] This list is by no means conclusive and favorite formulas may contain these and/or other herbs.

[3] In a sample of adolescent girls, more than one out of four had calcium intakes below 400 mg.

References available upon request.

The information in this article is not intended as medical advice, but only as a guide when working with your health practitioner.

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