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Monday, 18 December, 2000, 01:23 GMT
Soya 'may reduce cancer risk'
Soya in diet could prevent breast cancer tumours forming
Soya in diet could prevent tumours forming
Teenagers eating soya products may help prevent them getting breast cancer in later life, say experts.

Hawaiian researchers have suggested a long-term diet rich in soya could reduce risk by up to 50%.

The link between soya and the prevention of the cancer has been made before, but this is the first time girls still in their teens have been advised to eat the foods.

Scientists measured levels of the chemical isoflavones, found in large quantities in soya, but in small amounts in other plants.

Women with high levels of isoflavones had the lowest breast cancer risk.

The study, presented to the 2000 International Chemical Congress if Pacific Basin Societies in Honolulu on Sunday, measured isoflavone levels in the urine of 120 Asian women.

Soy 'is the key'

Lead researcher Professor Adrian Franke said inclusion of soy in women's diets over a long period of time was the key to risk-reduction.

Quoting previous studies in animals which have indicated teenage years were the best time to start eating soy, he said: "These findings support a potential breast cancer preventative effect achieved by soy consumption in populations that eat soy food habitually."

The evidence overall remains inconclusive

Dr Tim Key
Imperial Cancer Research Fund

Professor Franke pointed out diet was not the only factor which played a preventative role.

He said Japanese people living in Japan were at an extremely low risk of developing breast cancer.

If they moved to America the risk was still low, but their children were at the same risk as the Caucasian population and the danger was higher for their grandchildren.

Professor Franke said no-one knew why this happened, but he speculated that diet - along with work or psycho-social issues - were factors.

"It's the environment that changes, and one big factor in the environment is the diet."

Soy is used in a range of foods including tofu, soy milk and butter.

Heart experts have also suggested soy protein can reduce cholesterol levels.

Doubts over soya

Earlier this year, a study said fears that soya foods could actually lead to breast cancer were unfounded.

There had been suggestions that soya could interfere with a woman's hormone levels, and encourage the growth of some breast tumours.

Dr Tim Key, an expert on diet and cancer for the Imperial Cancer Research Fund, said: "This is just one of a handful of studies that have been carried out into soy and breast cancer, but the evidence overall remains inconclusive.

"Some studies have shown that soy can have a protective effect, others have shown it has no effect.

"More research is needed before we can conclusively say what role, if any, soy has in the development of breast cancer.

"It is difficult to evaluate these findings further until they have appeared in a peer reviewed journal."

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See also:

05 Apr 00 | Health
Soya breast cancer link dismissed
17 Mar 00 | C-D
Breast Cancer
08 Jun 00 | Health
Row over breast cancer diet claim
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