'Tortured' potatoes transformed into cancer-fighting superfoods

An improbable-sounding research study into the effects of stress techniques upon potatoes has concluded that subjecting them to sonic blasts and electrocution causes the vegetables to generate significantly higher levels of antioxidants, which are known to combat heart disease and cancer in humans.

The method has been pioneered by agricultural scientists in northern Japan, who apparently constructed a mini "torture chamber" in their laboratory at Obihiro University to put their potatoes under extreme stress.

Study leader Dr Kazunori Hironaka said: "We knew from research done in the past that drought, bruising and other stresses could stimulate

the accumulation of beneficial compounds in fresh produce.

"We found that there hasn't been much research on the healthful effects of using mechanical processes to stress vegetables.

"So we decided in this study to evaluate the effect of ultrasound and electric treatments on antioxidants in potatoes."

The researchers placed whole potatoes in water and subjected them to 600 watt blasts of high-frequency sound for five or 10 minutes.

Other potatoes were immersed in a salt solution and given 15-volt electric shocks for 10, 20 and 30 minute-periods.

Tests showed that both treatments were effective in increasing antioxidant levels by up to 60 per cent, compared with untreated potatoes.

The findings were presented yesterday at the 240th national meeting of the American Chemical Society in Boston, Massachusetts.

While the study initially sounds somewhat bizarre, the reasoning behind it is relatively straight forward. Plants create antioxidants to help them survive stressful events such as drought, and attacks by pests and infections.

Potatoes – the world's fifth most widely-consumed plant food – are already a good source of antioxidants, including vitamin C and compounds called polyphenols.

The scientists reasoned that inducing further stress would cause them to create more of the health-giving chemicals.

Antioxidants work by combating the "free radical" oxidants within the body which attack healthy cells.

Free radicals can speed up the aging process, trigger a variety of cancers and cause heart disease, cataracts and arthritis.

Dr Hironaka said increasing levels of antioxidants in everyday produce could therefore bring major health benefits.

"Antioxidants found in fruits and vegetables are considered to be of nutritional importance in the prevention of chronic diseases, such as cardiovascular disease, various cancers, diabetes and neurological diseases," he said.

Food scientists have long been working to make everyday foods healthier for the consumer, but so far efforts have generally been concentrated on manufactured products.

Recent years have seen the rise of so-called "functional foods" designed to give positive health effects, such as margarine which promises to lower cholesterol and yoghurt with added bacteria to aid digestion.

Research into ways of increasing the health properties of raw fruit and vegetables has mostly involved genetically-modified crops, the sale of which are currently banned in the UK.

GM scientists in the Norwich, for example, announced last year that they have created tomatoes with various cancer-fighting properties after introducing genes from other plants.