Associations of soluble fiber, whole fruits/vegetables, and juice with plasma Beta-carotene concentrations in a free-living population of breast cancer survivors.

Objective: Soluble fiber and the physical state of fruits/vegetables affect plasma ß-carotene concentrations; however, most of this research was conducted in laboratory-based settings. These analyses investigated the relationship between soluble fiber and juiced versus whole fruits/vegetables to plasma ß-carotene concentrations in a free-living population.

Method: This cross-sectional analysis used 12-month follow-up data from the Women's Healthy Eating & Living Study (1995-2006), a study to improve diet in breast cancer survivors in the Western United States. The dietary nutrients considered in this analysis included intake of soluble fiber (g), ß-carotene from fruit/vegetable juice (mg), and ß-carotene from whole fruits/vegetables (mg). A linear regression model was used to assess the relationship of the variables to plasma ß-carotene concentrations.

Results: Out of 3,088 women enrolled in the Women's Healthy Eating & Living Study, 2,397 women had complete data (mean age = 54). The final model accounted for approximately 49% of the explained variance in plasma ß-carotene concentrations. Fruit/vegetable juice had the largest positive relation to plasma ß-carotene concentrations (standardized parameter estimate = 0.23, p < 0.01), followed by whole fruits/vegetables (standardized parameter estimate = 0.09, p < 0.01).

Conclusion: Soluble fiber may inhibit ß-carotene absorption; therefore, consumption of juice may increase plasma ß-carotene concentrations more than whole fruits/vegetables in free-living populations.