Anti-inflammatory effects of heated vs unheated ginger

Ginger (Zingiber officnale) exerts anti-inflammatory effects, and heat treatment of ginger has been suggested to enhance its pain relieving effects.

Now, researchers from Georgia College and State University, in Milledgeville report the results of 2 studies in adults.

First, the details.

• 74 volunteers consumed 2 grams of either raw (study 1) or heated (study 2) ginger, or placebo for 11 days.
• Participants performed 18 eccentric actions of the elbow flexors (movement of the forearm around the elbow joint that bends the arm) to induce pain and inflammation.
  • Eccentric contractions are common and occur when the external force on the muscle is greater than the force the muscle can generate.
• Pain intensity, perceived effort, blood levels of prostaglandin E(2), arm volume, range-of-motion and isometric strength were assessed prior to and for 3 days after exercise.
• In both studies, neither the patients nor researchers knew the treatment given — double blind.

And, the results.

• Raw and heat-treated ginger resulted in similar pain reductions 24 hours after eccentric exercise compared to placebo.
• Smaller effects were noted between both types of ginger and placebo on other measures.
• Daily supplementation with ginger reduced muscle pain caused by eccentric exercise.
  • Heat-treating the ginger did not enhance this effect.

The bottom line?

The authors concluded, “Daily consumption of raw and heat-treated ginger resulted in moderate-to-large reductions in muscle pain following exercise-induced muscle injury.”

The authors also tell us that these results “agree with those showing hypoalgesic effects of ginger in osteoarthritis patients and further demonstrate ginger’s effectiveness as a pain reliever.”

It’s not clear based on what’s reported in the abstract how the authors reached this conclusion for osteoarthritis, but others disagree. A review of the evidence by researchers at Bethesda North Hospital Pharmacy, in Cincinnati, Ohio, published in Alternative Therapy and Health Medicine concluded that the evidence does not support the use of ginger for the treatment of osteoarthritis or rheumatoid arthritis.

5/3/10 10:47 JR