Breast cancer survivors who consume fresh fruit and vegetables can cut their chances of a tumour relapse by up to a third, a study revealed.

Surgery and radiation therapy remain more effective in battling malign breast cancer but diet and lifestyle changes can contribute a lot more than previously thought, US research has said.

It suggested women who measure high on estrogen stand a higher chance of tumour relapse. Eating lots of fruit and vegetables acts on the surging levels, thus lowering harmful estrogen levels, thereby cutting down the chances of a come back.

But the findings preclude women who suffer hot flushes and thus have lower estrogen levels, a side effect of breast cancer treatment.

The results of the study published in the Journal of Clinical Oncology are based on an assessment of 3,000 breast cancer patients averaging 53 years.

John Pierce of the University of California San Diego, said: "It appears that a dietary pattern high in fruits, vegetables and fibre, which has been shown to reduce circulating estrogen levels, may only be important among women with circulating estrogen levels above a certain threshold.”

The participants were randomly put on a normal diet (as per the government recommendations of 5 A DAY dietary guidelines) or one topped up with another five servings of fruits and vegetables a day for six years (1995 to 2000). Nearly 30 per cent experienced hot flushes at the start of the therapy.

While 23.6 per cent in the normal diet group reported a cancer relapse during the seven-year follow-up, recurrence rate was only 16.1 per cent in the second group who had doubled up on fruits and vegetables.

A diet top-up slashed the risk of cancer relapse by 31 per cent among women who did not suffer hot flushes, the researchers highlighted.

Olga Azarenko, author of new research published in Carcinogenesis journal, said: "Breast cancer can be protected against by eating cruciferous vegetables such as cabbage and near relatives of cabbage such as broccoli and cauliflower." "These vegetables contain compounds called isothiocyanates which we believe to be responsible for the cancer-preventive and anti-carcinogenic activities in these vegetables. Broccoli and broccoli sprouts have the highest amount of the isothiocyanates."