A study from the US has suggested that a low-fat diet rich in fruits, vegetables and fibre neither reduces the risk of breast cancer recurrence, nor increases chances for survival any more than eating the recommended five portions a day.

The findings, published in the July 18 issue of the Journal of the American Medical Association, are the result of the largest diet prevention study ever conducted. The Women’s Healthy Eating Living (WHEL) study was supported by the National Cancer Institute and enrolled 3,088 women previously treated for early stage breast cancer. Seven US institutions participated in the study, with the Moores Cancer Center at the University of California, San Diego, serving as the coordinating site.

“The WHEL’s findings are pivotal, because we always assumed that we were not eating enough fruits and vegetables and the more we ate, the more protected we would be against cancer,” said Lovell Jones, a PhD professor in the Department of Health Disparities Research Center who led the research.

The women were split into the comparison group, which ate a normal healthy diet, and the intervention group, which followed a low-fat, high-fibre diet rich in fruit and vegetables.

There was a 90 per cent compliance rate in the study and the women in the intervention group averaged an intake of nine servings of fruit and vegetables a day, both very impressive statistics, says Jones. The study’s primary endpoints were combined outcome of breast cancer recurrence or a new primary cancer diagnosis and death from any cause. The women were followed for 7.3 years.

But the study showed there was no statistical difference in either the recurrence or death rates in the two groups. During the study, 16.7 per cent of the women from the intervention group and 16.9 per cent of those from the comparison group had a recurrence of their breast cancer, or developed a second primary.

But Jones explained how the control group was eating the daily recommended portion of five a day. “With these findings, it is imperative that we do not discount the importance of a healthy diet and its role in cancer prevention,” said Jones.

“However, the study did not take into account what participants were eating prior to their enrolment in the study,” Jones added. “For the greatest preventative effect, women must make healthy changes to their diet long before a possible diagnosis of breast or any other type of cancer.”

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