Puha is more than just good kai - it could help to fight cancer.

Otago and Auckland University researchers have found traditional Maori food plants rival some European "wonder" foods for goodness.

The commonly eaten puha was found to have more than three times the antioxidant level of blueberries, but some less frequently eaten items, such as the fruit of the swamp maire (maire tawake), had up to 18 times more.

Blueberries are one of the most antioxidant-rich foods in the Western diet. Higher intakes of certain antioxidants lower the incidence of certain cancers, which may help to explain why pre-European Maori appear to have low levels of non-infectious diseases such as cancer.

But researchers warn against rushing out to obtain these plants as the study did not look into the body's ability to absorb these antioxidants.

"This is only a preliminary study," said Associate Professor Kevin Gould from Otago's botany department.

"What we haven't done is gone the subsequent steps, which are to show whether it would be effective inside the human body." In some cases, high levels might even be harmful, he said.

His and Auckland University Professor Lynn Ferguson's study, published in the New Zealand Journal of Botany, tested 17 indigenous and introduced plant species and found eight had considerably higher levels of antioxidants than blueberries.

"The thing that was so exciting about these data was that they were so unexpectedly high in antioxidants. Most people think of blueberries and blackberries as being the kings of the antioxidant world."

Of the eight, only puha is still widely eaten. But swamp maire fruit, titoki berries and rewarewa (New Zealand honeysuckle) flowers all had higher antioxidant levels than puha.

Of the 17 food plants studied, only puha, pikopiko (common shield fern fronds) and the Maori potato are commercially sold as foods, being most easily found in fresh produce markets. Rewarewa honey can also be bought.

Health foods

Indigenous foods high in antioxidants include:
* Swamp maire fruit.
* Titoki berries.
* Rewarewa (NZ honeysuckle) flowers.
* Puha.