An Onion a Day Keeps the Orthopedist Away

From the WebMD Archives

Sept. 21, 1999 (Boston) -- Chalk up another one for home cooking: eating salads, herbs, and cooked vegetables -- especially onions -- may help prevent osteoporosis, say Swiss researchers in today's issue of the journal Nature.

When given daily doses of onion, both male rats and 'postmenopausal' female rats had significant increases in bone mineral content, density, and thickness compared with rats who did not receive the daily doses, report Roman C. Mühlbauer, MD, and Feng Li, PhD, of the University of Bern. The researchers also observed significant decreases in what is called bone resorption. Human and animal bone tissue is constantly being made and broken down by the body; resorption refers to the breakdown process.

One gram of dried onion per day was slightly better at inhibiting resorption than was calcitonin, a drug used to treat postmenopausal osteoporosis. Tossing other vegetables or herbs into the mix -- including lettuce, arugula, garlic, parsley, and dill -- boosted the effect, the authors note.

The results indicate that several common vegetables in the human diet can alter bone metabolism in the rat, and could, if replicated in humans, serve as an inexpensive, effective, and tasty means for preventing osteoporosis and associated disabilities.

"There are a lot of differences between human bone turnover and the basic mechanism [in rats], but things which are valid in the rat will be valid in man," says Mühlbauer, in an interview with WebMD. "Actually, rats are more active, so it might well be that we find even larger effects in humans. I personally expect that we will have effects, but we have to do the experiments, because you're never sure."

The study complements a report published in April of this year in the American Journal of Clinical Nutrition, which showed that among elderly men and women, elevated dietary levels of potassium and magnesium -- but not calcium -- were significantly associated with greater bone mineral density.