Going overboard with a healthy diet does not help prevent breast cancer recurrence. The standard “five-a-day” advice on fruit and vegetables, it seems, is just as good.
Researchers at the University of California in San Diego studied more than 3,000 women who had been treated for early-stage breast cancer, randomly assigning them to two groups. One group received a telephone counselling program supplemented with cooking classes and newsletters that promoted five vegetable servings a day plus 475 millilitres of vegetable juice, three fruit servings, 30 grams of fibre, and 15 to 20 per cent of calories from fat. The comparison group received printed material promoting the “five-a-day” dietary guidelines.
The counselling group achieved and maintained 65 per cent more servings of vegetables, 25 per cent more servings of fruit, 30 per cent more fibre and 13 per cent less fat intake than the comparison group.
But over the next seven years, about 17 per cent of the women in both groups had a recurrence of breast cancer, and about 10 per cent in each group died. Breast cancer was the cause of more than 80 per cent of the deaths.
“We found no evidence that adoption of a dietary pattern very high in vegetables, fruit and fibre, and low in fat versus a five-a-day fruit and vegetable diet prevents breast cancer recurrence or death among women with previously treated early-stage breast cancer,” researcher John Pierce and his colleagues conclude.