Scientists have found that women who eat large amounts of fruit and vegetables do not have a better chance of surviving breast cancer.
A study of more than 3,000 women who had been treated for the disease shows that increased fruit and vegetable consumption did not help them live longer.
Those who took steps to eat a lot of fruit and veg over a seven-year period were just as likely to die or suffer a recurrence of breast cancer as those on a healthy "five-a-day" diet, it added.
The research, published in the Journal of the American Medical Association, shows cancer returned in about 17% of cases in both groups, and 10% of the women died.
But Professor Marcia Stefanick, from Stanford University School of Medicine in California, who led the Women's Healthy Eating and Living study, said: "I would certainly hope that people don't interpret these results as evidence that eating a lot of vegetables doesn't make a difference in breast cancer.
"What it shows is that getting more than the recommended amounts doesn't change the recurrence rate for women who have already completed treatment for early-stage breast cancer."
Antonia Dean, nurse specialist at the charity Breast Cancer Care, said: "It is notoriously difficult to examine the potential role of diet on breast cancer, as it is hard to isolate its effects from other lifestyle factors or establish how they might interact with each other.
"More research is needed to fully understand its role."