Osteoporosis

Osteoporosis

OSTEOPOROSIS

Br J Biomed Sci 1994 Sep;51(3):228-40: The role of nutrition in osteoporosis.

Bunker VW

School of Pharmacy and Biomedical Sciences, University of Portsmouth, England, UK.

Osteoporosis-related bone fractures are a significant cause of mortality and morbidity, with women being particularly affected. Osteoporosis is a condition of bone fragility resulting from micro-architectural deterioration and decreased bone mass; adult bone mass depends upon the peak attained and the rate of subsequent loss; each depends on the interaction of genetic, hormonal, environmental and nutritional factors. An adequate supply of calcium is essential to attain maximum bone mass, and adult intakes below about 500 mg/day may predispose to low bone mass. Supplementation with calcium may conserve bone at some skeletal sites, but whether this translates into reduced fracture rates is not clear. Chronically low intakes of vitamin D--and possibly magnesium, boron, fluoride and vitamins K, B12, B6 and folic acid (particularly if co-existing)--may pre-dispose to osteoporosis. Similarly, chronically high intakes of protein, sodium chloride, alcohol and caffeine may also adversely affect bone health. The typical Western diet (high in protein, salt and refined, processed foods) combined with an increasing sedentary lifestyle may contribute to the increasing incidence of osteoporosis in the elderly.

Drinking tea is associated with a higher bone mineral density in women even though high caffeine consumption is associated with osteoporosis. I believe the reason is the high levels of gallium compounds found in tea. Gallium is an extremely potent promoter of bone growth--see the gallium file for additional information.

Am J Clin Nutr 2000 Apr;71(4):1003-7

Tea drinking and bone mineral density in older women.

Hegarty VM, May HM, Khaw KT

Clinical Gerontology Unit, University of Cambridge School of Medicine, Addenbrooke's Hospital, Cambridge, United Kingdom.

BACKGROUND: High caffeine intake is reportedly a risk factor for reduced bone mineral density (BMD) in women. Most studies, however, are from populations in which coffee drinking predominates and is the major caffeine source. Tea contains caffeine but also has other nutrients, such as flavonoids, that may influence bone mass in different ways. OBJECTIVE: We examined the relation between tea drinking and BMD in older women in Britain, where tea drinking is common. METHODS: We measured BMD at the lumbar spine, femoral neck, greater trochanter, and Ward's triangle in 1256 free-living women aged 65-76 y in Cambridge, United Kingdom. Tea drinking was assessed by self-completed questionnaire and women were categorized as tea drinkers or non-tea drinkers. RESULTS: There were 1134 tea drinkers (90.3%) and 122 non-tea drinkers (9.7%). Compared with non-tea drinkers, tea drinkers had significantly greater ( approximately 5%) mean BMD measurements, adjusted for age and body mass index, at the lumbar spine (0.033 g/cm(2); P = 0.03), greater trochanter (0.028 g/cm(2); P = 0.004), and Ward's triangle (0.025 g/cm(2); P = 0.02). Differences at the femoral neck (0.013 g/cm(2)) were not significant. These findings were independent of smoking status, use of hormone replacement therapy, coffee drinking, and whether milk was added to tea. CONCLUSIONS: Older women who drank tea had higher BMD measurements than did those who did not drink tea. Nutrients found in tea, such as flavonoids, may influence BMD. Tea drinking may protect against osteoporosis in older women.

PMID: 10731510, UI: 20197843

Ther Umsch 2000 Mar;57(3):152-60: [Osteoporosis diet].

[Article in German]

Morselli B, Neuenschwander B, Perrelet R, Lippuner K

Universitatsspital/Inselspital Bern.

Bone requires a wide variety of nutrients to develop normally and to maintain itself after growth. Most important--in the sense that bony abnormalities are associated with their deficiencies--are protein, calcium, phosphorus, vitamin D, C and K, zinc, manganese and copper. The nutrients most likely to be deficient in citizens of industrialized countries are calcium and vitamin D. In this review of the current literature about nutritional aspects of osteoporosis, we have focused on factors influencing calcium requirement: the principal interacting nutrients are sodium, protein, caffeine, fiber, oxalate, phytate, and the acid/alkaline ash character of the overall diet. Fiber and caffeine decrease calcium absorption from the gut and typically exert relatively minor effects, while sodium, protein and the acid/alkaline balance of the diet increase urinary excretion of calcium and are of much greater significance for the calcium homeostasis. Alkali buffers, whether vegetables or fruits reverse this urinary calcium loss. As long as accompanied by adequate calcium intake, protein-rich diet is not deleterious to bone: a calcium-to-protein ratio of 20:1 (mg calcium/g protein) is recommended. Whether a nutrition-based therapeutic approach to osteoporosis is feasible in the near future is yet unclear: at least there are some recent promising data from in-vitro as well as from rat studies showing that extracts taken from various vegetables, mainly from the onion family inhibit bone resorption in a dose-dependent manner.

The following study shows that cadmium interferes with calcium metabolism and may therefore be a contributor to osteoporosis. This is very likely the mechanism by which smokers, especially female smokers (from estrogen acceleration of cadmium uptake) develop osteoporosis.

Changes in tissue metals after cadmium intoxication and intervention with chlorpromazine in male rats.

Yang XF, Wang SY, Zhao RC, Ao SQ, Xu LC, Wang XR

Institute of Applied Toxicology, Nanjing Medical University, China. xfyang@njmu.edu.cn

[Medline record in process]

Cadmium (Cd), one of the most dangerous heavy metals, has a very similar ionic radius to calcium (Ca). The interference of cadmium in calcium homeostasis may play an important role in cadmium toxicity. Recent reports indicate that calmodulin (CaM) inhibitors such as trifluoperazine and chlorpromazine (CPZ) could protect rodents against cadmium toxicity. It was also reported that pretreatment of mice with zinc (Zn) could reduce the adverse effects induced by cadmium. The aim of this study is to determine whether Cd changes the balance of other essential metals such as Zn and copper (Cu) in rat tissues, and whether CPZ can reverse these changes which are induced by cadmium intoxication. Adult male Sprague-Dawley (SD) rats were injected intraperitoneally (i.p.) with cadmium chloride (CdCl2) (0.2, 0.4, 0.8 mg Cd/kg body weight) alone and 0.4 mg Cd/kg in association with CPZ (5 mg/kg) daily for a week. The control animals were injected with normal saline only. The results showed that the cadmium content in the liver, kidney and testis increased significantly with a dose-response relationship. Cadmium treatment markedly increased the Zn and Ca content in some of the tissues. Hepatic and renal metallothionein (MT) increased significantly after cadmium intoxication. CPZ treatment, however, reduced cadmium content in liver, but not blood and kidney. CPZ seemed to decrease the content of MT in liver and significantly increase the amounts of MT in kidney. These data suggest that the intervention of cadmium with tissue essential metals may play a role in cadmium toxicity in rats, and calmodulin inhibitors to some extent can reduce the adverse effect of cadmium by decreasing the cadmium load in tissues and reversing the unbalance of essential metals.

The following study shows that vanadium supplementation can increase bone mineral levels and that there is an interaction between vanadium and vitamin C in cholesterol metabolism.

Magnes Trace Elem 1991-92;10(5-6):327-38: Vanadium and ascorbate effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase, cholesterol and tissue minerals in guinea pigs fed low-chromium diets.

Seaborn CD, Mitchell ED, Stoecker BJ

Department of Nutritional Sciences, Oklahoma State University, Stillwater.

Vanadium has been reported to affect numerous physiological processes; however, a demonstration that vanadium deficiency consistently impairs biological function is lacking. The purpose of this study was to determine if the activity of hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting enzyme in cholesterol synthesis, is affected by dietary supplementation of vanadate and/or chronic ascorbic acid deficiency. To determine if vanadium and/or ascorbic acid affected mineral metabolism, tissue minerals also were analyzed. Weanling male guinea pigs were assigned randomly to groups of 10 in a 2 x 2 factorial design. The dietary variables were ascorbate, 0.5 or 10 mg/day, and vanadium < 0.01 microgram or 0.5 microgram/g diet as NH4VO3 in a low Cr diet containing < 0.07 microgram Cr/g diet. After 21 weeks on this diet, guinea pigs receiving more ascorbate had lower liver weight/body weight ratios and increased bone copper. Testes weight/body weight ratios, hepatic glycogen and bone copper decreased while hepatic lipids, fecal bile acids, plasma cortisol and bone calcium and magnesium were increased by vanadium supplementation. An interaction between vanadium and ascorbate affected cholesterol excretion in feces, hepatic iron, plasma cholesterol concentration and the activity of HMG CoA reductase. This study provides evidence of increased bone mineral concentrations with vanadium supplementation and of an interaction between vanadium and ascorbate which affected cholesterol metabolism.

Girl Bone Breaks Linked To Cola

June 15, 2000

CHICAGO (AP) - Teen-age girls who drink soda - particularly cola - are far more likely to break a bone, a Harvard study found.

Grace Wyshak, an associate professor at the Harvard School of Public Health and Harvard Medical School, speculated that girls drinking soda aren't getting enough milk, which contains calcium that strengthens bones.

But she also suggested that a chemical in colas - phosphoric acid - may actually weaken bones.

The study, published in this month's Archives of Pediatrics & Adolescent Medicine, was based on questionnaires filled out by 460 ninth- and 10th-grade girls in a Boston-area high school.

The risk of broken bones was three times greater for girls who drank carbonated beverages in general and five times greater for active girls who drank colas. The study did not specify how much soda the girls drank.

Five of the 57 active girls who didn't drink colas suffered fractures, compared with 38 of the 107 active girls who reported drinking colas.

A spokesman for the National Soft Drink Association, Sean McBride, said: "We strongly question the results of the journal article." He said there is no scientific evidence that anything in colas causes fractures.

The study comes amid growing concern among experts, who say Americans are not getting nearly as much calcium as they need, in part because they are drinking soft drinks instead of milk.

"This should be a wake-up call for parents and health care professionals alike," said Bonnie Liebman, director of nutrition at the Center For Science in the Public Interest, a consumer advocacy group.

In an accompanying editorial, Dr. Neville H. Golden, director of the Eating Disorders Center in the Division of Adolescent Medicine at Schneider Children's Hospital in New Hyde Park, N.Y., said the study suggests that "osteoporosis is a pediatric disease as opposed to a disease of older people and that we can have some impact on it early."

In a previous study, Wyshak found increased bone fractures among adult women who drank carbonated beverages.

Stronger Bones, More Breast Cancer?

June 19, 2001

By Lisa Ellis
InteliHealth News Service

Elderly women with strong bones are less likely to break them, but it appears they may face a different risk — breast cancer.

A study published in the June 20, 2001, issue of the Journal of the National Cancer Institute adds to a volume of evidence that postmenopausal women with low bone-mineral density — the "brittle bones" disease called osteoporosis — are less likely to get breast cancer, but women with healthy bones may be at least twice as likely to do so.

The research points to one of the paradoxes of women's health care — that risk factors for some diseases may be protective against others. Moderate alcohol consumption, for instance, can provide some protection against heart disease in women after menopause, but it simultaneously may increase their breast-cancer risk.

What does the research on bone-mineral density mean for women trying to protect their health?

"It's not clear what the real implication of this is for most patients," says Harold Burstein, M.D., Ph.D., an instructor in medicine at Harvard Medical School and a breast-cancer researcher at Dana-Farber Cancer Institute.

He says the increased risk is relatively small. "Most older women do not get breast cancer," he notes. "While the data show an association between bone mineral density and breast cancer risk, it is by no means clear that changing bone mineral density — up or down — changes that risk."

Indeed, the study's authors caution that the association between bone density and breast cancer does not mean that strong bones cause cancer or that women should stop trying to maintain bone mass through taking calcium or medications.

Rather, the cancer and the bone-mineral density both are likely to be related to a long-term, complex relationship among hormones and certain other body chemicals, the authors say.

Many researchers believe the chief cause may be "a shared risk factor, lifetime exposure to estrogen," Dr. Burstein says. Osteoporosis, a thinning of the bones that can lead to fractures, tends to develop after menopause, when women's estrogen production drops. Breast-cancer risk is higher among women who have greater lifetime exposure to estrogen, including early menstruation and late menopause.

Some women take estrogen supplements after menopause to ease the symptoms of this life change or to help protect against osteoporosis. But there are many other means of preventing or treating osteoporosis that do not involve estrogen, Dr. Burstein says.

Calcium and Vitamin D supplements, weight-bearing exercise and quitting smoking all reduce the risk of osteoporosis, and certain medications can help to slow the rate of bone loss, he says.

The study published in the Journal of the National Cancer Institute enrolled more than 8,900 women, ages 65 and older, who were examined at medical centers in Pittsburgh, Minneapolis, Baltimore and Portland, Ore., between 1986 and 1988. During an average of 6.5 years of follow-up, 315 women developed breast cancer.

Those who had the highest bone-mineral density, a measure of bone mass or thickness, at all three sites measured — the wrist, arm and heel — were 2.7 times more likely to develop breast cancer than those who had the lowest bone-mineral density at all sites.

What is more, the women with the highest bone-mineral density were even more likely to get advanced cancer — 5.6 times more likely than the women with the most brittle bones.

The relationship between bone-mineral density and breast-cancer risk is well established at this point, Dr. Burstein says.

"The novel finding (in the new study) is that women who have higher bone mass seem to have a more advanced tumor stage, so it seems to increase your risk of having a slightly more advanced breast cancer," Dr. Burstein says.

But he noted that only 74 of the 315 women who developed cancer had these more advanced tumors. He says larger studies would be needed to prove that women with stronger bones have higher risk not only for breast cancer, but also for more invasive forms of the cancer.

The multi-center study, which used data from the long-term Study of Osteoporotic Fractures, reinforces similar results from a shorter-term study involving the same group of participants and a much smaller study of about 1,300 women in Framingham, Mass. Other studies have found that women who have bone fractures are less likely to get breast cancer.

Researchers in the current study found that the association between high bone density and breast cancer persisted even when they allowed for certain factors that are associated with a greater chance of breast cancer — obesity, use of estrogen supplements, and record of fewer screening mammograms.