The Women’s Healthy Eating and Living (WHEL) study is a multi-center, randomized controlled trial studying a total of 3088 women diagnosed with early stage breast cancers –stage I-IIIa who were diagnosed within the previous four years. Subjects in the WHEL study were randomized into either a treatment group, who’s diet consisted of; a daily dose of 5 servings of vegetables, 16 oz of vegetable juice, 3 servings of fruit, 30 g of fiber and 15% to 20% of energy intake from fat and a control group which consumed a regular diet of 5 servings of vegetables and fruit, more than 20 g of fiber and less than 30% total energy intake from fat.
The main outcome was a recurrence of breast cancer, a new primary breast cancer, or death from any cause. After an average follow-up of a 7.3 years , there were no differences in breast cancer events or all-cause mortality between women in the two dietary groups despite the treatment group eating 65% more vegetables, 25% more fruit, 30% more fiber and 13% less fat.
16.7% of the women in the dietary intervention group developed an invasive breast cancer event and 10.1% died vs. 16.9% in the regular diet group with 10.3% having died.
Pierce J, et al. Influence of a diet very high in vegetables, fruits, and fiber and low in fat on prognosis following treatment for breast cancer. JAMA 2007;298(3):289-298.
Commentary: This is a discouraging bit of news from those of us who work with breast cancer survivors advising them on dietary changes. It can be noted that in the WHEL study, women who had undergone chemotherapy were not included. It may be that we would see better results in women receiving chemotherapy undergoing dietary changes vs. those that don’t. In addition, with a one on one clinical practice, we would often achieve better compliance with more success in eating more vegetables, fruit, fiber and less fat. Other reports on dietary fat show that those studies that reduce fat intake to 15% -20% of total calories consumed, may not achieve results, while studies that reduce fat intake to 10%of calories and focus on fish, seeds, nuts and olive oil as a source of fats, do in fact bode well for future breast health. The current WHEL study also failed to achieve two important results in the dietary intervention group — there was no reduction in total calories and no difference in weight loss, two important influences on breast health.
While many dietary factors have been shown to have influence on risks of breast cancer in observational studies, these relatively small changes in vegetable, fruit and fat intake in the WHEL study, did not make much difference. The message here: we need to eat even more vegetables and fruits, lower fat to 10% and focus on the good fats, eat less in general and do a better job of managing our weight. Sigh…..
