Scientists may have uncovered a natural way to combat stress - eat a melon.
The key ingredient is an enzyme called superoxide dismutase, thought to have beneficial antioxidant properties which prevent damage to the body's tissues. Volunteers given a capsule containing the enzyme reported fewer symptoms of stress and fatigue than those given a dummy capsule.
The researchers found a strong placebo effect in the 35 volunteers who received the dummy capsules, which were filled with inactive starch. However, this effect only lasted for the first seven days of the study.
In contrast, the positive effects on perceived stress and fatigue reported in the group of 35 who took the enzyme capsules were much greater - and much longer lasting.
Taking the enzyme appeared to boost concentration, cut feelings of weariness and irritability and improve problems with sleeping. The researchers said the placebo effect might have been relatively high because the people who took part in the study had everyday levels of fatigue and stress which were not out of the ordinary. They suggest the results might have been more pronounced if people with higher levels of fatigue and stress had taken part.
It is thought that the enzyme may help to minimise the damage caused by a chemical process known as oxidative stress, which releases harmful atoms called free radicals into the body's tissues.