15 Sep 2009 --- A dietary ingredient derived from a melon rich in antioxidant superoxide dismutase enzymes has been shown to relieve stress. In a double-blind, randomised, placebo-controlled trial, published in BioMed Central's open access Nutrition Journal, researchers found that the supplement decreased the signs and symptoms of perceived stress and fatigue in healthy volunteers.

Marie-Anne Milesi from Seppic, France, worked with a team of researchers to evaluate its anti-stress effects in 70 volunteers. She said: "Several studies have shown that there is a link between psychological stress and intracellular oxidative stress. We wanted to test whether augmenting the body's ability to deal with oxidative species might help a person's ability to resist burnout. The 35 people in our study who received capsules containing superoxide dismutase showed improvement in several signs and symptoms of perceived stress and fatigue."

The researchers found a strong placebo effect in the volunteers who received inactive starch capsules, as can be expected when studying subjective feelings like stress. However, the improvements seen in the supplement group were significantly greater, especially after 28 days.

According to Milesi: "The placebo effect was only present during the first 7 days of supplementation and not beyond. It will be interesting to confirm these effects and better understand the action of antioxidants on stress in further studies with a larger number of volunteers and a longer duration."