Bioavailability of Phytochemical Constituents From a Novel Soy Fortified Lycopene Rich Tomato Juice Developed for Targeted Cancer Prevention Trials

Abstract

Studies suggest that tomato and soy foods may contribute to a lower risk of certain cancers. We developed a novel soy germ tomato juice to be used in controlled cancer prevention trials. This study describes an initial test of compliance, phytochemical bioavailability, and effects on biomarkers of blood lipids. Healthy men and women (n = 18) consumed a soy germ-fortified juice daily (300 mL supplying 66 mg isoflavones and 22 mg lycopene) for 8 wk. A single-dose bioavailability study was completed on day 1 and isoflavones in plasma and urine, and lycopene in the plasma, were measured. All subjects completed the trial, with 97.7% ± 3.5% (mean ± SD) of the scheduled juice consumed. No adverse effects were documented. The postprandial study indicated that 3.1% ± 2.3% of lycopene was absorbed and that 49.3% ± 12.1% isoflavones ingested were recovered in 24-h urines. Lycopene plasma concentration changed from 0.60 ± 0.22 to 1.24 ± 0.30 μmol/L during 8 wk of consumption. Juice consumption significantly improved resistance of LDL+VLDL-C to Cu²⁺-mediated oxidation (P = 0.039), HDL-C (47.3 ± 15.8 to 51.7 ± 14.8 mg/dL, P < 0.001), and the ratio of total-C/HDL-C (4.25 ± 1.59 to 3.63 ± 1.16, P < 0.001) at 8 wk. A well-characterized soy-fortified tomato juice can be produced in large scale for multiinstitutional long-term cancer prevention trials and showed excellent compliance with no toxicity, while demonstrating absorption of biologically active phytochemicals.

ACKNOWLEDGMENTS

The work was carried out at the Ohio State University, Columbus, Ohio, both at the General Clinical Research Center and at the Department of Food Science and Technology. We thank Paul Keida for assisting in the development and manufacturing the food product, Dr. Elizabeth Miller Grainger for guidance regarding the clinical trial implementation, and Ms. Valerie DeGroff for technical and administrative assistance.

The work was supported by USDA IFAFS Grant No. 2001-52102-11333; the General Clinical Research Center (GCRC) at Ohio State University (OSU); Grant M01-RR00034 from the National Center of Research Resources, National Institutes of Health, National Cancer Institute R01-CA112632; the Comprehensive Cancer Center, OSU Grant P30-CA16058; and Ohio Agricultural Research and Development Center (OARDC)–AgBiosciences Initiative Grant (2005–2009, for Schwartz, S.J., Clinton, S.K., Failla, M.L., Ralston, R.A.): Center for Advanced Functional Food Research and Entrepreneurship. We appreciate the financial support of H.J. Heinz & Co. to the Prostate Cancer Prevention fund of the James Cancer Hospital and Solove Research Institute.