Low-fat dietary pattern and risk of cardiovascular disease: the Women's Health Initiative Randomized Controlled Dietary Modification Trial. One-year results from a brief, computer-assisted intervention to decrease consumption of fat and increase consumption of fruits and vegetables. Effects of fruit and vegetable consumption on plasma antioxidant concentrations and blood pressure: a randomised controlled trial. Exploring the feasibility and effects of a high-fruit and -vegetable diet in healthy women. Increasing vegetable and fruit intake: randomized intervention and monitoring in an at-risk population. High vegetable and fruit diet intervention in premenopausal women with cervical intraepithelial neoplasia.
Multiple epidemiologic studies and some trials have linked diet with cardiovascular disease (CVD) prevention, but long-term intervention data are needed.
                To test the hypothesis that a dietary intervention, intended to be low in fat and high in vegetables, fruits, and grains to reduce cancer, would reduce CVD risk.
                Randomized controlled trial of 48,835 postmenopausal women aged 50 to 79 years, of diverse backgrounds and ethnicities, who participated in the Women's Health Initiative Dietary Modification Trial. Women were randomly assigned to an intervention (19,541 [40%]) or comparison group (29,294 [60%]) in a free-living setting. Study enrollment occurred between 1993 and 1998 in 40 US clinical centers; mean follow-up in this analysis was 8.1 years.
                Intensive behavior modification in group and individual sessions designed to reduce total fat intake to 20% of calories and increase intakes of vegetables/fruits to 5 servings/d and grains to at least 6 servings/d. The comparison group received diet-related education materials.
                Fatal and nonfatal coronary heart disease (CHD), fatal and nonfatal stroke, and CVD (composite of CHD and stroke).
                By year 6, mean fat intake decreased by 8.2% of energy intake in the intervention vs the comparison group, with small decreases in saturated (2.9%), monounsaturated (3.3%), and polyunsaturated (1.5%) fat; increases occurred in intakes of vegetables/fruits (1.1 servings/d) and grains (0.5 serving/d). Low-density lipoprotein cholesterol levels, diastolic blood pressure, and factor VIIc levels were significantly reduced by 3.55 mg/dL, 0.31 mm Hg, and 4.29%, respectively; levels of high-density lipoprotein cholesterol, triglycerides, glucose, and insulin did not significantly differ in the intervention vs comparison groups. The numbers who developed CHD, stroke, and CVD (annualized incidence rates) were 1000 (0.63%), 434 (0.28%), and 1357 (0.86%) in the intervention and 1549 (0.65%), 642 (0.27%), and 2088 (0.88%) in the comparison group. The diet had no significant effects on incidence of CHD (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.90-1.06), stroke (HR, 1.02; 95% CI, 0.90-1.15), or CVD (HR, 0.98; 95% CI, 0.92-1.05). Excluding participants with baseline CVD (3.4%), the HRs (95% CIs) for CHD and stroke were 0.94 (0.86-1.02) and 1.02 (0.90-1.17), respectively. Trends toward greater reductions in CHD risk were observed in those with lower intakes of saturated fat or trans fat or higher intakes of vegetables/fruits.
                Over a mean of 8.1 years, a dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD in postmenopausal women and achieved only modest effects on CVD risk factors, suggesting that more focused diet and lifestyle interventions may be needed to improve risk factors and reduce CVD risk.
                ClinicalTrials.gov Identifier: NCT00000611. Current cancer prevention recommendations include reducing consumption of fat and increasing consumption of fruits and vegetables.
                Healthy women health maintenance organization members (n = 616) ages 40-70 were randomly assigned to either a nutrition intervention or a control intervention unrelated to diet. Intervention included two 45-min counseling sessions plus two brief follow-up telephone contacts. Counseling sessions included a 20-min, interactive, computer-based intervention using a touch-screen format. Intervention goals were reducing dietary fat and increasing fruit and vegetable consumption. Outcome measures included a food frequency questionnaire and the Fat and Fiber Behavior Questionnaire (FFBQ). Total serum cholesterol was also measured at baseline and 12 months.
                Twelve-month follow-up data showed improvements on all dietary outcome variables. Compared to the control, intervention participants reported significantly less fat consumption (3.75 points less for percentage of energy from fat), significantly greater consumption of fruit and vegetables combined (0.93 more servings per day), and a significant reduction in a behavioral measure of fat consumption (0.20 point change in the FFBQ). Group differences in total serum cholesterol, while in the desired direction, were not significant.
                In appropriate circumstances, moderate-intensity dietary interventions can show significant effects for periods of at least 1 year. High dietary intakes of fruit and vegetables are associated with reduced risks of cancer and cardiovascular disease. Short-term intensive dietary interventions in selected populations increase fruit and vegetable intake, raise plasma antioxidant concentrations, and lower blood pressure, but long-term effects of interventions in the general population are not certain. We assessed the effect of an intervention to increase fruit and vegetable consumption on plasma concentrations of antioxidant vitamins, daily fruit and vegetable intake, and blood pressure.
                We undertook a 6-month, randomised, controlled trial of a brief negotiation method to encourage an increase in consumption of fruit and vegetables to at least five daily portions. We included 690 healthy participants aged 25-64 years recruited from a primary-care health centre.
                Plasma concentrations of alpha-carotene, beta-carotene, lutein, beta-cryptoxanthin, and ascorbic acid increased by more in the intervention group than in controls (significance of between-group differences ranged from p=0.032 to 0.0002). Groups did not differ for changes in lycopene, retinol, alpha-tocopherol, gamma-tocopherol, or total cholesterol concentrations. Self-reported fruit and vegetable intake increased by a mean 1.4 (SD 1.7) portions in the intervention group and by 0.1 (1.3) portion in the control group (between-group difference=1.4, 95% CI 1.2-1.6; p<0.0001). Systolic blood pressure fell more in the intervention group than in controls (difference=4.0 mm Hg, 2.0-6.0; p<0.0001), as did diastolic blood pressure (1.5 mm Hg, 0.2-2.7; p=0.02).
                The effects of the intervention on fruit and vegetable consumption, plasma antioxidants, and blood pressure would be expected to reduce cardiovascular disease in the general population. Based on reports that fruits and vegetables may protect against breast cancer, this randomized intervention study tested the feasibility of increasing fruit and vegetable intake among healthy women to 9 daily servings through individual dietary counseling and group activities. Adherence to the dietary recommendations was monitored by 24-h food recalls, log sheets, and plasma carotenoid assessments. To explore possible cancer protective mechanisms of fruits and vegetables, we investigated the treatment effect on plasma phenol levels and on thiobarbituric acid-reactive substances measured as malondialdehyde equivalents, a possible marker of oxidative damage. At baseline, women in the intervention (n = 13) and control (n = 16) group reported an average daily consumption of 3.3 and 3.2 fruit and vegetable servings, respectively. After 3 and 6 months of intervention, intake in the intervention group had increased to 8.3 and 7.4 servings, whereas the control group reported an average of 4.2 and 4.1 daily servings. An increase of plasma carotenoid levels from 1249 microg/liter at baseline to 1854 and 1827 microg/liter after 3 and 6 months confirmed compliance with the dietary recommendations in the intervention group. Plasma carotenoid levels among controls changed slightly from 1165 to 1231 and 1291 microg/liter Whereas total phenol levels did not respond according to our hypothesis, malondialdehyde levels decreased slightly in the intervention group. These results suggest that motivated women can substantially increase their fruit and vegetable intake, which leads to a notable increase in plasma carotenoid levels. High vegetable and fruit (V&F) consumption has been associated with a lower risk of several cancers. However, little is known about the ability of individuals to increase their intakes markedly. In this 1-year randomized, controlled diet intervention study of men and women with a recent history of adenomas, the intervention group (n = 100) was asked to increase V&F intake to at least eight servings per day; the control group (n = 101) continued eating their usual diet. End-point measures included V&F intake assessed by 3-day diet records, plasma carotenoids, serum lipids, urinary sodium and potassium, and body weight. The intervention group increased their daily V&F intake an average of 5.5 servings over 1 year; the control group had an average decrease of 0.5 servings per day (P < 0.001). Plasma total carotenoids, alpha-carotene, beta-carotene, beta-cryptoxanthin, and lutein/zeaxanthin were each statistically significantly elevated over baseline (11-54%) in the intervention group compared with the control group over the duration of follow-up (P < 0.001). Urinary potassium excretion was elevated 14% over baseline in the intervention group compared with no change in the control group (P < 0.001). Modest decreases in the intervention but not the control group were observed for total and low-density lipoprotein cholesterol. Plasma lycopene, triglycerides, high-density lipoprotein cholesterol, body weight, and urinary sodium were not affected by the intervention. V&F intake was significantly increased in this motivated population at higher risk of colon cancer and maintained for at least 12 months, as assessed using diet records and an ensemble of biomarkers. To examine whether diet intervention can promote increased vegetable and fruit intake, as reflected in increased plasma carotenoid and decreased plasma total homocysteine concentrations, in premenopausal women with cervical intraepithelial neoplasia, a precancerous condition.
                Randomized controlled diet intervention study.
                Fifty-three free-living premenopausal women who had been diagnosed with cervical intraepithelial neoplasia, were randomly assigned to an intervention (n = 27) or a control (n = 26) group.
                Individualized dietary counseling to increase vegetable and fruit intake.
                Diet was assessed by food frequency questionnaire. Plasma carotenoids and total homocysteine were measured at enrollment and at 6 months follow up.
                Associations between baseline plasma concentrations of carotenoids and homocysteine and influencing factors were examined with multiple regression analysis. Repeated measures analysis of variance was used to test for group by time effects in these plasma concentrations. Plasma carotenoids at baseline and 6 months in the study groups, and differences in homocysteine concentrations from baseline to 6 months, were compared with independent sample t tests.
                Repeated measures analysis of variance showed significant group by time effects (P<.01) in plasma carotenoid and homocysteine concentrations. In the intervention group, total plasma carotenoids increased by an average of 91%, from 2.04+/-0.13 (mean+/-standard error of the mean) to 3.90+/-0.56 micromol/L and plasma total homocysteine was reduced by 11%, from 9.01+/-0.40 to 8.10+/-0.44 micromol/L (P<.003). Neither changed significantly in the control group.
                Individualized dietary counseling can effectively promote increased vegetable and fruit intake in premenopausal women. This dietary pattern may reduce risk for cancer and other chronic diseases and also promote an improvement in folate status.
There are very few studies to date examining provision of, or advice to increase the consumption of, fruit and vegetables in the absence of additional dietary interventions or other lifestyle interventions for the primary prevention of CVD. The limited evidence suggests advice to increase fruit and vegetables as a single intervention has favourable effects on CVD risk factors but more trials are needed to confirm this.