Toenails point to arthritis risk

Low selenium level in nails is associated with osteoarthritis of the knees

Low levels of the mineral selenium in toenails have been linked with an increased risk for having worn out knee joints.

The finding suggests selenium supplements may someday have a role in treating or preventing osteoarthritis, the wear-and-tear form of arthritis, says Dr. Joanne Jordan, an associate professor of medicine and orthopedics at the University of North Carolina in Chapel Hill.

"These data are preliminary but they certainly clear the way for future studies to confirm these results and to examine whether selenium supplements, taken in the right quantities, can reduce the development and progression of osteoarthritis."

She says toenails, which grow slowly, provide a better estimate of selenium in the body over a longer period of time than blood testing.

Jordan and her colleagues analysed toenails for selenium in 940 people whose average age was 60 years.

"The lower the selenium level was, the more severe the osteoarthritis. Looked at another way, for every 0.1 part per million increase in the toenail selenium level, the odds of having knee osteoarthritis went down by about 15 per cent."

People with the most selenium in their toenails were 40 per cent less likely to have knee osteoarthritis than those with the lowest levels.

Jordan says this is the first study of its kind to show this, so more studies will be needed to verify the findings.