Dietary starch may raise risk of breast cancer recurrence
An increase in carbohydrate intake—particularly starch intake—has been linked with breast cancer recurrence in a study presented at the CTRC-AACR San Antonio Breast Cancer Symposium, held December 6-10, 2011, in San Antonio, Texas.
Jennifer A. Emond, MS, a public health doctoral student at the University of California, San Diego, and colleagues conducted a subset analysis of 2,651 women who participated in the Women's Healthy Eating and Living (WHEL) Dietary Intervention Trial for survivors of breast cancer—a plant-based intervention trial that did not have a carbohydrate goal. Participants were followed for an average of 7 years.
The investigators obtained information on patients' carbohydrate consumption from multiple 24-hour dietary recalls at baseline and at 1 year, and from annual phone interviews in which the women reported everything they had eaten in the preceding 24 hours.
Baseline carbohydrate intake was 233 g/day. Women who experienced a breast cancer recurrence had a mean increase in carbohydrate intake of 2.3 g/day over the first year. By comparison, those who did not have a recurrence had a mean decrease in carbohydrate intake of 2.7 g/day). Change in starch intakes accounted for nearly half (48%) of the change in carbohydrate intake: Mean first-year change in starch intake, which was achieved independent of the study intervention, was –4.1 g/day among women with recurrences and –8.7 g/day among the others.
When starch intake changes during 1 year were grouped into quartiles of change, women who increased their starch intake the most during that period had a recurrence rate of 14.2%, compared with 9.7% among the women who reduced their starch intake the most. In an adjusted model, an increase in starch of 5 g/day related to a 3% increased risk of recurrence. The increased risk was limited to women diagnosed with low-grade tumors.
The results suggest that dietary modifications targeting starch intake should be investigated further as a preventive measure against breast cancer recurrence.