Citrus Might Help Strengthen Bones

A recent study conducted by researchers at Texas A&M University, College Station, has shown that components in grapefruit and orange juices can positively affect bone strength via increased antioxidant levels in the bloodstream. The researchers involved with the study included Bhimanagouda S. Patil, Ph.D., director of the school's Vegetable and Fruit Improvement Center, and Farzad Deyhim, Ph.D., director of the school's Didactic Program in Dietetics. Both men also teach in the Department of Horticultural Sciences. The study results were published in the May 2006 issue of Nutrition (see http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=16472977&dopt=Abstract).

During the course of the study, male rats were fed either orange juice or grapefruit juice for a period of 60 days. One control group did not receive either juice. Analysis subsequently showed increased bone density, which was attributed to the presence of higher antioxidant levels in the rats' systems; oxidants affect a reduction in bone density. The researchers hope to show how citrus juice can enhance serum antioxidant levels to help prevent osteoporosis.

"There are about 400 compounds in citrus," said Patil in a June 5 Texas A&M news release. "So we need to find out which compound in citrus caused this." He hypothesizes that limonoids are primarily responsible for the positive effects, but at least 40 different types exist. These limonoids, phytochemicals that occur in abundance in citrus fruits, will form the next phase of the study.

Deyhim notes that the juice study was also followed by a similar test involving orange and grapefruit pulp. Although the results of that research have not been released, he notes that it, too, showed enhanced bone density. The researchers are also conducting similar studies on female rats.

On a related note, recent studies by Edward G. Miller, Ph.D., professor, Department of Biomedical Sciences, Baylor College of Dentistry, Dallas, have shown that limonoids and their corresponding glucosides can inhibit cancer. The concentration of limonoid glucosides in orange juice and grapefruit juice are respectively 320 parts per million (ppm) and 190 ppm.