Eating two kiwifruit a day can improve mood and energy levels, a new University of Otago study shows.

Researchers at the university's Canterbury campus tested 54 young male students who had lower than desirable vitamin C levels because they generally ate little fresh fruit.

The group was split - with some eating two kiwifruit a day and others half a kiwifruit.

Those eating two kiwifruit were found to experience significantly less fatigue and depression than the others. They also felt they had more energy.


Kiwifruit are an exceptional source of vitamin C, said the findings, which were published recently in the Journal of Nutritional Science.

The work was part of an ongoing study led by Professor Margreet Vissers from the campus' centre for free radical research into the critical role of vitamin C in the human body.

Professor Vissers said eating two kiwifruit a day ensured the study group's vitamin C levels were "optimal", and this was needed to see an effect on mood and energy.

"Our study provides good evidence to support the view that there are measurable health benefits to be obtained from eating a good amount of fruit and vegetables daily. For best benefit, it is important to include high vitamin C foods in your daily diet."

Vitamin C helps activate a number of enzymes in the body that enhance the levels of metabolic energy and different neurochemicals in the brain, she added.

"This means taking in more vitamin C could decrease feelings of fatigue and increase physical and mental energy."

The work was funded by the Ministry of Business, Innovation and Employment, the University of Otago and kiwifruit company Zespri International.