ORIGINALLY APPEARED IN MEDSCAPE.CBSHEALTHWATCH.COM NOVEMBER 1, 2001

Research on both humans and the lowly rat is coming up with some promising news on natural preventions for osteoporosis.

Osteoporosis stealthily causes bone loss, resulting in pain and brittle or broken bones. It is the single most important known risk factor for fractures in older women.

Preventing bone loss and encouraging bone densitythrough a healthy lifestyle are the keys to combating this disease. The only proven treatments are prescription drugs, vitamins including calcium and vitamin D, and weight bearing exercises.

Researchers are finding that there might be more natural alternatives for strengthening bones: tea, onions and other salad vegetables, and soybeans.

TEA FOR YOU

Researchers at the University of Cambridge Medical School in the United Kingdom have found evidence supporting the benefit of tea on bone mass. “Tea drinking may protect against osteoporosis in older women,” says study author Verona Hegarty.

The study, conducted in Britain, focused on 1,256 women ages 65-76. The positive effect of drinking tea is notable in the results.

According to the authors of the study, “Tea drinkers had 5% higher average bone mass density at various sites [tested on the body] than did non-tea drinkers.” And higher bone mass density (BMD) means stronger bones and less chance of fracture. In fact, the authors estimate a 10-20% decrease in risk of fracture for the tea drinkers.

What, then, is the secret hidden in the tea leaves? Tea contains patterns of nutrients called flavonoids and isoflavonoids, nutrients that may act like a mild form of estrogen in the body and increase BMD. That’s especially good news for postmenopausal women.

SALAD DAYS

Researchers at the Bone Biology Group, University of Bern, Switzerland, have found that onions, lettuce, and other salad vegetables increase bone density in rats. (These furry pests are a well-known animal model for researching osteoporosis.)

Researchers at the Bone Biology Group found diets of onions, lettuce and other salad vegetables to have a much stronger influence on bone density in this study that did the high protein diets of milk, animal or soy protein. The aromatic onion, in fact, was found to increase both density and thickness of the bone. “Onion was chosen as the primary vegetable for detailed investigation. It increases bone mass and inhibits bone loss,” says Roman C. Muhlbauer, group leader of the Bone Biology Group. He adds, however, that more studies will be needed to identify the exact element of the vegetables that influenced the increase in bone density.

The leafy, green vegetables also used in this study are known to be high in calcium, an important nutrient in preventing osteoporosis. But Dr. Muhlbauer says the study’s results can’t be traced just to the presence of calcium. “Our results…suggest that vegetables inhibit bone loss on top of the effect of calcium,” he says.

There’s a substantial evolutionary leap between the rat and your average person. Will the results in rats be comparable to those in humans?

Very likely says Dr. Muhlbauer. The rats used in his study had bone traits that are similar to those of postmenopausal women, a high-risk group for osteoporosis. “We are confident that our results are valid not just of the rat. However, the effects must be confirmed in human studies before a final answer can be given,” he says.

SOY STORY

It’s no secret that soybeans are considered good for you. They are low in fat and high in protein and fiber–all pluses for a healthy diet. Soy is also rich in isoflavonoids.

“Soy foods and isoflavones have received considerable attention for their potential role in preventing and treating cancer and osteoporosis,” says Mark Messina, PhD, founder of Vegetarian Nutrition: An International Journal.

He references several studies, including a 1998 study in lab animals “clearly suggesting that the isoflavones are responsible for these beneficial effects of soy.” Two other studies on humans “associated [soy] with favorable effects on bone density,” says Messina. But he cautions, “The results of these studies should be considered preliminary.”

Further studies will be needed to determine the exact amounts and benefits of soy that help keep your bones healthy. But Messina calls the relation between bone health and isoflavones found in soy “proactive.”

DOCTOR’S CALL

Experts still recommend a healthy diet and the use of prescription drugs, calcium, vitamin D, and weight bearing exercises when necessary for prevention and treatment of osteoporosis.

Dr. David Trock of the Yale University School of Medicine encourages people at risk of osteoporosis to follow doctor’s orders. His advice “depends on what a person’s bone density is and what his or her risk of osteoporosis is. If I think they are at risk, I encourage them to take adequate amounts of calcium and vitamin D.”

Although Dr. Trock is optimistic about future alternatives, he says that “the strongest medications available are the prescription drugs–the bisphosphates.”

KIMBERLY NELSON IS A FREELANCE MEDICAL WRITER.

REVIEWER: BETH ISRAEL DEACONESS MEDICAL CENTER. REVIEWED FOR MEDICAL ACCURACY BY PHYSICIANS AT BETH ISRAEL DEACONESS MEDICAL CENTER (BIDMC), HARVARD MEDICAL SCHOOL. BIDMC DOES NOT ENDORSE ANY PRODUCTS OR SERVICES ADVERTISED ON THIS WEB SITE.

SOURCE: MEDSCAPE HEALTH

POSTED ON THIS SITE: SEP 2000

PUBLICATION DATE: SEP 2000