Anti-ageing discovery boost for blueberries

By PHILIPPA STEVENSON

A discovery that eating blueberries could reverse some effects of growing old is giving the fruit an unmatched reputation as a health food and boosting the small New Zealand industry.

American neuroscientist Jim Joseph, of the Human Nutrition Research Centre on Ageing at Tufts University, Boston, has done much of the groundbreaking research on the fruit.

At HortResearch's Ruakura base in the Waikato, where blueberry cultivars used worldwide have been developed, Dr Joseph said the main focus of his centre was to determine what made the human brain more vulnerable to disease.

Blueberries' anti-aging effects were unexpected and exciting, said the enthusiastic vegetarian.

Four years ago, research showed that blueberries had a high anti-oxidant rating.

Only a year later, new studies showed that they, along with boysenberries and blackcurrants, were second only to prunes at the top of the table.

In the bloodstream, anti-oxidants absorb oxygen free radicals, which science has long believed are behind such ailments as heart disease, cancer, arthritis, skin wrinkles, and impaired vision and memory.

In 1998, blueberries rolled to the front of the healthy food queue when Dr Joseph's team found that they not only halted some effects of ageing but reversed them.

Ageing rats fed blueberry extract had improved memory and motor abilities compared with those fed a regular diet.

In the US, where blueberries are a major industry with around 40,000ha of cultivated plantings augmented by wild fruit harvesting, the research spread like a rampant vine.

"The stuff flew off the shelves," Dr Joseph said.

New Zealand growers benefited when Japanese consumers responded to the research by buying up large.

"In the summer of 1998/99, the New Zealand fresh market moved from selling into the USA to almost exclusively selling into Japan because the prices were so good," said Alison Furniss, a director of New Zealand's biggest producer, Blueberry Country, and chairwoman of the industry organisation, Blueberries NZ.

"Jim's research is very dramatic. The results are just mindboggling. As he says, he could have believed it might halt memory loss and the loss of motor ability, but to reverse it is quite weird."

The good news is encouraging growers to expand operations or start new ones, though they are wary of over-hyping a sector in which investors were burned during its 1980s establishment.

"When people first started they thought blueberries were gold-lined and it was very easy money." Mrs Furniss said.

"That is not true and never was.

"Some people went in with that idea and then they found that it was horticulture, and there are difficulties in horticulture, and it was business, and there are difficulties in business, and you had to market your product.

"It is the realities of being in business. Wherever people think it is easy to go into business, they are going to get hurt."

New Zealand now has about 300ha of blueberries, mostly on Waikato peat soils.

Blueberry Country has 160ha in Waikato.

Harvest runs from November to April, producing around 1200 tonnes. Exports are worth about $6.6 million.

Mrs Furniss said supply and demand in America determined world trade, but New Zealanders' best profits were now coming from fresh fruit sold in Japan, and frozen fruit sales in Australasia.

"Japan has become so important because it has resulted in a whole-of-season lift of price.

"It has been good for New Zealanders because it has made it profitable for them to produce fruit right through the production season.

"Before that, there would be times when ... there wasn't a margin in doing fresh fruit because the prices were too low."

Markets prospects continue to look good, as Dr Joseph is promising more revelations about the fruit.

He said unpublished research by an Israeli scientist claimed that the leg muscles of blueberry-fed rats were like the muscles of younger animals.

And his own centre would soon publish work indicating an increase in neurogenesis, or the growth of new neurones, in rats fed the fruit.

The finding suggested that the beneficial effects of fruit and vegetable consumption, which had already been credited with forestalling the likes of cancer and heart disease, might now apply to the brain.

"What we've done is take this [effect] into the brain and say the stuff that applied to cancer and heart disease from consuming these fruits and vegetables now applies to the brain," he said.

"As you enter middle age you have made yourself a little less susceptible to whatever genetic changes that might result in these diseases.

"If we can solve the problems of why the brain gets more sensitive as we age then we can push back the start of diseases like Alzheimer's, and certain forms of Parkinson's disease related to ageing."

But the scientists do not know what it is about the blueberries that gives such benefits.

New research - to which HortResearch will contribute - will break blueberries into four families of compounds in an effort to find where they go in the brain and what they do.

"It could be that we are seeing the result of a lot of peripheral effects of these compounds, rather than essential ones, or possibly both," Dr Joseph said.

A book he is writing on the health benefits of a range of colourful fruit and vegetables, entitled The Colour of Health, should be published next year.

"The idea is to get as much fruits and vegetables of colour into your diet as you can," said the man who takes his own advice and always starts his day with a blueberry fruit smoothie.

Fresh blueberries are not always available, so the best alternative was to use them from frozen, he said.

"You can cook them in a pie but you want to eat it quickly, or keep it frozen. They are better absorbed if you cook them but then they degrade quickly."

His recipe for a breakfast fruit smoothie is to blend a cup of frozen blueberries, half a banana and a couple of scoops of whey protein.

People on the run could put it in an insulated sports drink-type container and sip it on the way to, or at, work.

But, he warned, blueberries would not offset a bad diet or other unhealthy activities. "If you smoke, quit smoking first, then worry about the blueberries."