An apple a day... no really

By JO BARNSDALE of NZPA

Scientific research into the cancer-beating qualities of apples has lent new strength to the old saying: "An apple a day keeps the doctor away". And it has shown grandma was right when she said the best part was the skin.

Italian research in published Europe's Journal of Agriculture showing the antioxidant activity in apples - especially peel - is potent enough to stop cancer cells growing.

The study supported previous findings that antioxidant concentrations vary according to apple varieties.

In New Zealand, Crop and Food Research scientist Dr Carolyn Lister said the health benefits of antioxidants in apples were largely untapped, but there was a lot of scope for development of new "functional" foods to be made from processed apples.

"Until recently Crop and Food's breeding programme concentrated on producing apples with better visual appearance, disease resistance and flavour," she said. It now had the added target of improved health benefits.

Dr Lister, research leader in nutrition and health at Crop and Food, said her team aimed to develop products based on the health benefits of antioxidants, compounds which protect the body's cells.

These molecules battle cell and DNA damage involved in cancer, heart disease, diabetes and possibly brain degeneration, by neutralising "free radicals", which are thought to destroy some cells.

Dr Lister wrote her PhD thesis at Canterbury University on apples and has since developed expertise in nutrition, including the effects of antioxidants. These include many of the several hundred flavanoids found in plants - compounds which affect colour, aroma and flavour.

She said that in the past, apple skins were discarded in food products such as juices because the flavanoids in the skin caused cloudiness in the juice.

Now Crop and Food was developing products that would not only keep the flavanoids for their health benefits but also retain other desirable characteristics, such as taste.

"Some of the flavanoids are relatively stable, so their health benefits are not lost in processing."

Dr Lister's role is to help direct breeding programmes to produce apples retaining high levels of flavanoids from the wide range of flavanoid levels in different cultivars.

"The Granny Smith breed is high in flavanoids," she said.

But health benefits of flavanoids would ordinarily only be gained if people ate apples with skins on.

"We know people don't eat enough fruit and vegetables."

Dr Lister said long sunny days and cold nights in regions such as Central Otago enhanced flavanoid production in the skins of apples grown there. "Plants use skin to protect against the sun - they are nature's sunscreen."

In March the NZ Treecrops Association reported highlights of cancer research related to apples.

Project coordinator Mark Christensen said there were more antioxidants in "heritage" varieties of apples - such as Monty's Surprise and Hetlina - than modern commercial cultivars.