The goal of this study was to test the hypothesis that increased consumption of vegetables and fruit would reduce markers of oxidative cellular damage that can be assessed in blood or urine. Twenty-eight women participated in a 14 day dietary intervention. The primary end-points assessed were: 8-hydroxydeoxyguanosine (8-OHdG) in DNA isolated from peripheral lymphocytes, determined by HPLC with electrochemical detection; 8-OHdG excreted in urine, measured by ELISA; malondialdehyde (MDA) in urine, measured by fluorimetric detection following derivatization with thiobarituric acid and separation via HPLC; urinary 8-isoprostane F-2alpha (8-EPG) detected by ELISA. Pre- and post-intervention plasma levels of selected carotenoids were determined by HPLC. Subjects were free living and consumed a completely defined recipe-based diet that increased their average daily consumption of vegetables and fruit from 5.8 servings at baseline to 12.0 servings throughout the intervention. Overall, the level of 8-OHdG in DNA isolated from lymphocytes and in urine and the level of 8-EPG in urine were reduced by the intervention, whereas urine concentrations of MDA were minimally affected. The reduction in lymphocyte 8-OHdG was greater in magnitude (32 versus 5%) in individuals with lower average pre-intervention levels of plasma alpha-carotene (56 ng/ml) than in individuals with higher average pre-intervention plasma levels of alpha-carotene (148 ng/ml). The results of this study indicate that consumption of a diet that significantly increased vegetable and fruit intake from a diverse number of botanical families resulted in significant reductions in markers of oxidative cellular damage to DNA and lipids.

Results are reported from a large (n = 3,402) four-group randomized trial to increase fruit and vegetable consumption among callers to the National Cancer Institute's (NCI's) Cancer Information Service (CIS) using tailored print materials. Following a baseline telephone interview, which included a brief educational message (BEM), participants were assigned randomly within CIS offices to one of four groups: single untailored (SU) group-one untailored set of materials; single tailored (ST) group-one tailored booklet; multiple tailored (MT) group-four tailored materials; and multiple retailored (MRT) group-four tailored materials with retailoring based on new information obtained at 5 months follow-up. Follow-up telephone interviews were conducted at 5 (n = 2,233) and 12 months (n = 1,927) after baseline. The main outcome measure was self-reported fruit and vegetable consumption using a seven-item food frequency questionnaire. At 12 months follow-up, there was a significant linear trend across groups of 0.21 servings (p = 0.0002). Specific nested hypotheses then were tested and revealed significant mean serving differences between SU (5.07) vs. MT (5.64) (p = 0.002) and SU vs. MRT (5.71; p < 0.001). Although the mean for ST (5.40) was greater than that for SU (5.07), the difference was not statistically significant (p = 0.07), and no difference was found between MT vs. MRT (p = 0.69). A higher proportion of recipients of tailored materials reported reading all of the materials and believing that they were written especially for them. No differences by experimental condition were found for the perceived usefulness or motivational impact of the print materials. In this trial, MT print materials were more effective at increasing fruit and vegetable (FV) consumption than were SU materials. The intervention mechanisms responsible for this effect merit further research. Retailoring did not produce a significant difference when compared with longitudinal baseline tailoring.

A significant reduction in the excretion of 8-iso-PGF2alpha was induced by the run-in diet and the high-VF diet. The degree of reduction was related to the subject's baseline urinary concentration of 8-iso-PGF2alpha.

This relatively low-intensity intervention appealed to a large, generally representative sample of patients, was well implemented, and produced improvement in targeted behaviours. Implications of this practical clinical trial for dissemination are discussed.