Selenium yeast may reduce joint inflammation: Rodent data

Supplementing the diet with selenium-enriched yeast may reduce inflammation linked to arthritis, suggests new research from Brazil.

Using an inactive yeast (Saccharomyces cerevisiae) enriched with organic selenium, researchers report that the mineral was associated with a reduction in pro-inflammatory compounds in joint tissue of lab mice and rats, and a reduction in fluid build-up in the paws.

“[The branded ingredient] Selemax is associated with amelioration of several inflammatory and functional parameters in models of arthritis, suggesting that this selenium-enriched yeast should be evaluated further in patients with rheumatoid arthritis,” said researchers from Federal University of Minas Gerais,.

If the results can be repeated in additional studies, particularly human studies, it could see selenium considered a joint health ingredient.

The joint health market is dominated by glucosamine. Euromonitor International puts the value of the global market for glucosamine supplements at $2bn, and cites an annual growth rate of 7% from 2004 to 2009.

The mineral

Selenium is an essential macronutrient, and is considered to be an antioxidant. High levels of selenium have been inversely associated with risk of developing several cancers, including bladder, prostate and thryroid.

The trace element occurs naturally in the soil and is absorbed by plants and crops, from where it enters the human food chain - either directly or through consumption of meat and other products from grazing animals.

The mineral is included in between 50 and 100 different proteins in the body, with multifarious roles including building heart muscles and healthy sperm. However, cancer prevention remains one of the major benefits of selenium, and it is the only mineral that qualifies for a Food and Drug Administration (FDA)-approved qualified health claim for general cancer reduction incidence.

Study details

For the new study, the Brazil-based researchers tested different doses of the selenium-enriched yeast (0.01, 0.1, 1 and 10% in food) in lab mice and rats. Control animals were fed non-selenium-enriched inactivated yeast.

Results showed that all doses were associated with “significantly decreased the number of inflammatory cells recruited to the knee cavity”.

The selenium-fed animals also had lower levels of proinflammatory compounds, including TNF-alpha, and interleukin (IL)-1beta.

Additional studies should evaluate if such results can be obtained in humans.

Importance of selenium

A recent review paper by Joyce McCann and Bruce Ames from the Nutrition and Metabolism Center at Children’s Hospital Oakland Research Institute in Oakland (CHORI) indicated that moderate deficiency in selenium may have long-term detrimental effects (FASEB Journal, 2011, Vol. 25, pp. 1793-1814).

Source: British Journal of Nutrition

Published online ahead of print, FirstView Articles, doi: 10.1017/S0007114512000013

“Treatment with Selemax, a selenium-enriched yeast, ameliorates experimental arthritis in rats and mice”

Authors: A.T. Vieira, K.D. Silveira, M.C.C. Arruda, et al.