Four week supplementation with mixed fruit and vegetable juice concentrates increased protective serum antioxidants and folate and decreased plasma homocysteine in Japanese subjects

Fruit and vegetable consumption has been inversely associated with the risk of chronic diseases including cancer and cardiovascular disease, with the beneficial effects attributed to a variety of protective antioxidants, carotenoids and phytonutrients. The objective of the present study was to determine the effect of supplementation with dehydrated concentrates from mixed fruit and vegetable juices (Juice Plus+R) on serum antioxidant and folate status, plasma homocysteine levels and markers for oxidative stress and DNA damage. Japanese subjects (n=60; age 27.8 yrs; BMI 22.1) were recruited to participate in a double-blind placebo controlled study and were randomized into 2 groups of 30, matched for sex, age, BMI and smoking status (39 males, 22 smokers; 21 females, 13 smokers). Subjects were given encapsulated supplements containing mixed fruit and vegetable juice concentrates or a matching placebo for 28 days, with blood and urine samples collected at baseline, day 14 and day 28 for analytical testing. Compared with the placebo, 28 day supplementation significantly increased the concentration of serum beta-carotene 528% (p<0.0001), lycopene 80.2% (p<0.0005), and alpha tocopherol 39.5% (p<0.0001). Serum folate increased 174.3% (p<0.0001) and correlated with a decrease in plasma homocysteine of -19.9% (p<0.03). Compared with baseline, measures of oxidative stress decreased with serum lipid peroxides declining -10.5% (p<0.02) and urine 8OHdG decreasing -21.1% (p<0.02). Evaluation of data from smokers only (n=17) after 28 days of active supplementation showed comparable changes. Conclusion: In the absence of dietary modification, supplementation with the fruit and vegetable juice concentrate capsules proved to be a highly bioavailable source of phytonutrients. Important antioxidants were elevated to desirable levels associated with decreased risk of disease while markers of oxidative stress were reduced, and folate status improved with a concomitant decrease in homocysteine, and these benefits occurred to a similar extent in smokers when compared to non-smokers.     

Effect of increased vegetable and fruit consumption on plasma folate and homocysteine concentrations

OBJECTIVE: We assessed the effects of an intervention aimed at increasing the consumption of fruits and vegetables on plasma folate and homocysteine concentrations. METHODS: Seventy-one healthy non-smoking women (mean +/- SD 41 +/- 4 y of age) were randomized to an intervention or a control group. Participants in the intervention group (n = 36) received weekly packets containing fruits and vegetables free of charge and were asked to consume a daily amount of >or=200 g of vegetables and two pieces of fruit (the Dutch recommended intake level) over a period of 1 mo. Control subjects did not receive any intervention. RESULTS: Compared with the control group, reported fruit and vegetable intakes in the intervention group increased by 133 g/d (95% confidence interval [CI] 87-179, P < 0.001) for fruits and juice and 64 g/d (95% CI 37-91, P < 0.001) for vegetables and estimated folate intake from fruits and vegetables increased by 40 microg/d (95% CI 22-58, P < 0.001). However, no effect was observed on plasma folate concentrations (intervention effect 0.3 nmol/L, 95% CI -1.8 to 2.8, P = 0.77) or homocysteine concentrations (intervention effect 0.26 micromol/L, 95% CI -0.34 to 0.87, P = 0.39). CONCLUSION: The results suggest that 4 wk of increased fruit and vegetable consumption to the recommended amounts may be insufficient to change plasma folate and homocysteine concentrations.     

Health effects of mixed fruit and vegetable concentrates: a systematic review of the clinical interventions

Diets rich in fruits and vegetables (FV) have been associated with a reduced risk of chronic disease, including cardiovascular disease. Unfortunately, public health campaigns to increase FV intake have had limited success. A number of mixed concentrated FV products have been studied, which may help certain individuals improve nutrient status. However, the possible health benefits of FV supplements have not been systematically reviewed. We, therefore, undertook a systematic search of MEDLINE and EMBASE to identify clinical interventions that examined the effect of commercially available concentrated mixed FV supplements on cardiovascular disease risk factors. Twenty-two reports, which used commercially available products, were identified. None of the studies reported any serious adverse effects. Overall, daily consumption of FV supplements significantly increased serum concentrations of the major antioxidant provitamins and vitamins found in plant foods (β-carotene, vitamins C and E) and folate. Functional changes, such as reduced serum homocysteine and markers of protein, lipid, and DNA oxidation, were also reported; in addition, the health advantages on markers of inflammation, immunity, and endothelial function are promising. Limitations of the available studies were related to the diversity of studies conducted with respect to design and study population and the variability in the measured outcomes and assays utilized. While mixed FV supplements may serve as an efficacious complement for individuals who have difficulty achieving their daily FV intake requirement, further research on additional retail preparations is warranted. Key teaching points: Mixed fruit and vegetable supplements produced from plant foods may serve as an efficacious complement to the habitual diet in individuals who have suboptimal intake or variety of nutrient-dense fruits and vegetables. Current research indicates that fruit and vegetable concentrates significantly increase serum levels of antioxidant provitamins and vitamins (β-carotene, vitamins C and E) and folate and reduce homocysteine and markers of oxidative stress. Mechanistic studies and larger, randomized, placebo-controlled double-blind trials in both healthy and high-risk populations are necessary to better understand the health effects of these supplements.     

A mixed fruit and vegetable concentrate increases plasma antioxidant vitamins and folate and lowers plasma homocysteine in men

Fruit and vegetable consumption is inversely associated with coronary heart disease (CHD) risk. The aim of the present study was to determine the effect of supplementation with dehydrated juice concentrates from mixed fruit and vegetables on selected plasma vitamins and antioxidant status. We assessed CHD risk by measuring the concentrations of homocysteine, lipids, lipoproteins, glucose and insulin. Men were recruited to participate in a randomized double-blind, crossover trial with 2 periods of 6 wk, separated by a 3-wk wash-out period. Supplementation with the encapsulated mixed extract (Juice Plus) was compared with physically similar placebo capsules. Thirty-two men (13 smokers, 19 nonsmokers) completed the study with a mean compliance of 88%. Compared with placebo, supplementation increased the concentrations of plasma beta-carotene (0.24 +/- 0.15 vs. 1.12 +/- 0.70 micro mol/L; mean +/- SD; P < 0.0001), retinol (1.87 +/- 0.33 vs. 2.00 +/- 0.43 micro mol/L; P < 0.05), alpha-tocopherol (16.8 +/- 7.3 vs. 19.3 +/- 6.8 micro mol/L; P < 0.01), ascorbic acid (72.1 +/- 19.4 vs. 84.1 +/- 13.5 micro mol/L; P < 0.002) and folic acid (24.5 +/- 10.0 vs. 44.9 +/- 16.9 nmol/L; P < 0.0001). Plasma homocysteine was reduced (8.2 +/- 1.5 vs. 7.6 +/- 1.1; P < 0.05) and inversely related (r = -0.40, P < 0.001) with serum folate concentrations. Plasma vitamin C was positively correlated with the resistance of LDL to oxidation (r = 0.26, P < 0.05) and the plasma ferric reducing/antioxidant power (FRAP) tended to be greater after supplementation than after the placebo period (1125.5 +/- 144.1 vs. 1180.3 +/- 158.1 micro mol/L; P < 0.065). Plasma glucose, insulin and lipid concentrations were unaffected. Responses of smokers and nonsmokers did not differ. In the absence of dietary modification, supplementation with a fruit and vegetable concentrate produced responses consistent with a reduction in CHD risk.     

Low-income young adults report increased variety in fruit and vegetable intake after a stage-tailored intervention

The objective of this study was to determine if a fruit and vegetable (FV) intervention, previously demonstrated to increase amount of FV per day, also increased the variety consumed. Variety in FV intake was assessed using a 26-item FV (12 fruit and 14 vegetable) food frequency questionnaire on 1255 low-income adults, with ages from 18 to 24 years (control = 684 vs experimental = 571), after completion of a stage-tailored intervention to increase FV intakes. The food frequency questionnaire was administered at 12 months to assess how often and how much participants ate of each item over the previous year. Variety was defined as the number of different types of fruits and vegetables consumed. At completion, the experimental group vs the control group had significantly greater variety in number of fruit items (9.5 ± 0.1 vs 9.1 ± 0.1, P ≤ .001) and vegetable items (11.5 ± 0.1 vs 11.2 ± 0.1, P < .01) as well as greater total intake of fruits (2.73 ± 0.09 vs 2.33 ± 0.11 cups, P < .01) and vegetables (1.87 ± 0.10 vs 1.62 ± 0.01 cups, P ≤ .001) and a greater consumption of the categories of seasonal fruits (P < .05), juices (P < .01), and high-β-carotene vegetables (P ≤ .001). This is one of the first studies to document an increase in FV variety as a result of an educational intervention for low-income young adults.     

Factors associated with fruit and vegetable consumption among adults

Background: The higher consumption of fruit and vegetables is considered to be an indicator of healthy eating and the protective effects of fruit and vegetable (FV) consumption for noncommunicable diseases have been investigated extensively. The present study aimed to investigate the association between fruit and vegetable intake (FVI), health behaviours and socio‐demographic factors among adult Canadians. Methods: This analysis was based on the information from the Canadian Community Health Survey, Cycle 3.1. Daily intake of fruit and vegetables from a total number of 15 512 apparently healthy individuals, aged 18–64 years, were assessed using a structured questionnaire, which included 20 questions on the frequency of consumption of different types of fruit and vegetables. Multiple logistic regression models were used to determine the association between FVI and some socio‐economic factors and lifestyle behaviour among adult Canadians. Results: In total 77% of Canadian adults consumed fruit and vegetables less than five times per day. Females were more likely to consume more fruit [odds ratio (OR) 2.05; 95% confidence interval (CI) 1.75–2.4], vegetables (OR 1.95; 95% CI 1.65–2.29) and FV (OR 2.52; 95% CI 2.20–2.90) than males. Single/never married individuals, individuals with higher levels of education, never smokers, former drinkers and older people reported more consumption of fruit and vegetables than others. Conclusions: The results obtained in the present study indicate an association between FVI and some socio‐economic and healthy lifestyle behaviours, and that a substantial gap exists between the recommended level and the actual intake of the FV among the Canadian population. Because a higher intake of FV improves public health, it is imperative to tailor nutrition education at the individual and community levels in Canadian populations.     

Sources of folate and serum folate levels in older adults

This study examined dietary folate intake in 173 older adults. A subsample (n=128) also provided data about folic acid from vitamin/mineral supplements and serum folate. Subjects were community-dwelling men and women 60 years of age and older. Overall, this sample had healthful dietary patterns with adequate dietary folate. Mean dietary intake converted to dietary folate equivalents (DFE) was 464 microg DFE/day. However, 20% (n=36) had inadequate and 2% (n=3) had high dietary DFE (>1,000 microg DFE/day). A subsample (n=128) completed a dietary supplement questionnaire and biochemical assessment of folate. Adding folic acid from vitamin/mineral supplements to dietary folate (total DFE), intake increased to 766 microg DFE/day; 13% (n=16) had inadequate, 75% (n=95) had adequate, and 13% (n=13) had high total DFE. No subject with low total DFE reported supplement use, but 94% (n=39) with high total DFE intake did so. In the subsample, all subjects had acceptable serum folate levels (mean serum folate=28.0+/-13.8 ng/mL [63.5+/-31.3 nmol/L]). In conclusion, vitamin/mineral supplements should be included in nutrition assessment of older adults. Older adults may be at risk for inadequate folate intake if their energy intake is low, they do not take a vitamin/mineral supplement, or are not consuming fortified cereals. However, older adults may be at risk for excess folic acid intake if they consume both a supplement and fortified cereals.     

Chronic cigarette smoking is associated with diminished folate status, altered folate form distribution, and increased genetic damage in the buccal mucosa of healthy adults

BACKGROUND: Smoking causes genetic damage in buccal cells and increases the risk of oral cancer. Because folate is instrumental in DNA synthesis and repair, it is a determinant of genetic stability and therefore might attenuate the genotoxic effects of smoking. OBJECTIVE: Our aim was to compare the presence of folate metabolites and select indicators of genetic damage in the mouths of chronic smokers and nonsmokers. DESIGN: Dietary, biochemical, and molecular correlates of folate status were measured in healthy smoker (n = 35) and nonsmoker (n = 21) groups of comparable age, sex, and body mass indexes. RESULTS: After correction for dietary intake, the smokers displayed lower plasma, erythrocyte, and buccal mucosal cell (BMC) folate (20%, 32%, and 50% lower, respectively; P < 0.05) and lower plasma vitamin B-12 and pyridoxal 5-phosphate (P < 0.05) than did nonsmokers. Folate in the BMCs of smokers comprised significantly greater proportions of pteroylmonoglutamate, formyltetrahydrofolate, and 5,10-methenyltetrahyrofolate than did folate in the BMCs of nonsmokers. Although the degree of genomic methylation and uracil incorporation in the buccal cells of the 2 groups were not significantly different, the BMC micronucleus index, a cytologic indicator of genetic damage, in the smokers was 2-fold that of the nonsmokers (9.57 compared with 4.44 micronuclei/1000 cells; P < 0.0001). Neither systemic nor oral folate status was an independent predictor of micronuclei. CONCLUSIONS: Chronic smoking is associated with a lower systemic status of several B vitamins, reduced oral folate, and changes in folate form distribution in the mouth. However, the cytologic damage that is evident in the mouths of smokers does not correlate with oral folate status.     

Sex differences in fruit and vegetable intake in older adults

Fruits and vegetables are important components of a healthy diet, but intakes in most Western countries are well below the recommended five servings a day. Men in particular are eating too little. The aim of this study is to understand the processes underlying this gender difference. Fruit and vegetable intake, nutrition knowledge, taste preferences, attitudes to fruit and vegetable intake, and dieting status, were assessed in a simple questionnaire in 1,024 older adults attending population-based cancer screening across the UK. The results confirmed the pattern of men consuming fewer servings of fruit and vegetables daily than women (2.52 vs 3.47; p<0.01). Fewer men than women knew the current recommendations for fruit and vegetable intake, and fewer were aware of the links between fruit and vegetable consumption and disease prevention. Women rated their liking for vegetables but not fruit higher, and there were no differences in attitudes. Men were less likely to be dieting to lose weight. Multivariate analysis showed that the gender difference in intake was substantially attenuated by controlling for nutrition knowledge. There were no significant attenuating effects of preferences, attitudes or dieting status. These results indicate that men's poorer nutrition knowledge explains a significant part of their lower intake of fruit and vegetables.     

Validation of a fruit,juice, and vegetable availability questionnaire

OBJECTIVE: To assess the validity of a self-reported fruit, juice, and vegetable home availability measure. DESIGN: Cross-sectional. SETTING: In-home interviews. PARTICIPANTS: Forty-eight parents of fourth to sixth grade children. MAIN OUTCOME MEASURES: Scales assessing self-reported home availability of fruit, 100% fruit juice, and vegetables over the past 7 days compared with an observed home inventory conducted on the interview day. ANALYSES: Cohen's kappa of agreement, specificity and sensitivity, and correlations, with significance level <.05. RESULTS: There was substantial agreement between self-reported and observed home inventories of many fruit, 100% fruit juice, and vegetables among participating families in this study. CONCLUSIONS AND IMPLICATIONS: Self-reported shelf inventories can be an effective tool for use in assessing the availability of fruit, juice, and vegetables in the home.     

Mothers' involvement in a school-based fruit and vegetable promotion intervention is associated with increased fruit and vegetable intakes – The Pro Children study

Background  

Several school-based fruit and vegetable interventions include activities to involve parents, but not much is know about the effectiveness of such a family component on child and parent intake levels. The current study evaluated the effects of the multi-component school-based intervention, 'the Pro Children Study', on mothers' intake levels. Furthermore, associations between level of involvement in the project and improvement in the mothers' intake levels were assessed.     

Relation between C-reactive protein and serum and dietary antioxidants in older adults at increased risk for cardiovascular disease

The purpose of this study was to determine the relation between serum and dietary antioxidants, and C-reactive protein (CRP) concentrations in middle-aged and older individuals at risk for cardiovascular disease. We used data from adults aged > or = 40 at increased risk for cardiovascular disease selected from the NHANES III database. The relation between serum and dietary antioxidants, and CRP concentrations was examined using multiple logistic regression analysis. Serum antioxidants and CVD risk factors were significant predictors of detectable CRP concentrations (R2 = 0.07; p < 0.001). Dietary antioxidants (except vitamin C) were not significant predictors of detectable CRP concentrations.     

Baseline glucoregulatory function moderates the effect of dairy milk and fruit juice on postprandial cognition in healthy young adults

Purpose

Few studies have examined acute cognitive effects of dairy products. Prior work suggests baseline glucoregulatory function may moderate the relationship between macronutrient profile and postprandial cognition. This study examined the role of glucoregulatory function in postprandial cognition after milk, fruit juice, and a water control. We hypothesized juice would improve cognition in those with lower fasting glucose, while milk would improve cognition in those with higher fasting glucose.

Design

86 non-diabetic, non-hypoglycemic young adults attended three 8 AM testing sessions after fasting overnight. Fasting glucose was assessed via fingerstick at each session. Participants consumed 8 oz of 1% milk (12 g carbohydrates), apple juice (29 g carbohydrates), or water in a randomized, counterbalanced order, and completed repeatable standard and running memory continuous performance (SCPT—vigilance; RMCPT–working memory) and go/no-go (GNG–inhibitory control) tasks 30, 90, and 120 min post-ingestion.

Results

Participants with fasting glucose above 107.69 mg/dL made significantly fewer GNG commission errors overall after milk versus water, while the converse was observed when fasting glucose was below 70.85 mg/dL (p = 0.003). At 30 min, participants with fasting glucose above 105.80 mg/dL made significantly more RMCPT correct responses per minute after milk versus juice, while the opposite occurred when fasting glucose was below 76.85 mg/dL (p = 0.006). For both tasks, differences greatened as fasting glucose increased or decreased beyond these upper and lower bounds, respectively.

Conclusions

Consideration of baseline glucoregulatory function is crucial when assessing postprandial cognition, even in non-diabetic and non-hypoglycemic samples. Dairy milk may improve cognition in persons with higher fasting glucose.

     

Predictors of fruit and vegetable intakes in young adults by gender

The objective of this study was to identify predictors of fruit and vegetable consumption by gender in collegiate young adults to guide interventions to help increase intakes. A sample of 294 subjects reported demographics, self-efficacy, dietary patterns, and food group intakes from 3 days of food records. Average daily servings of fruits and of vegetables were 1.9 ± 2.0 and 3.9 ± 2.6, respectively, for men, and 2.0 ± 1.6 and 2.9 ± 1.7, for women. For both genders, living in a residence hall and frequency of eating breakfast were positively associated with intakes of fruit and of fruit juice, whereas vegetable intakes were positively associated with intakes of energy and discretionary fat (P < .01). Self-efficacy to eat fruit predicted 8% and 9% of the variance in fruit intakes for women and men, respectively, with percentages increasing to 11% and 17% when juice was removed from the total. Self-efficacy to eat vegetables did not predict vegetable intake in men as it did for women. Predictors of fruit and vegetable intakes in this group of young adults varied by gender and by whether juice was included with fruit and fried potatoes with vegetables.     

Effect of fruit and vegetable antioxidants on total antioxidant capacity of blood plasma

For a long time, the increased consumption of fruits and vegetables was considered critical in protecting humans against a number of diseases, such as cancer, diabetes, neurodegenerative diseases, and heart and brain vascular diseases. Presently, it is thought that the protective properties of these foods result from the presence of low-molecular antioxidants that protect the cells and their structures against oxidative damage. The alleged effect of reducing the risk for many diseases is not only due to the effect of individual antioxidants, such as α-tocopherol, ascorbic acid, or β-carotene, but also may be the result of antioxidant compounds not yet known or synergy of several different antioxidants present in fruits and vegetables. Studies on macromolecules (DNA, nucleotides, proteins) free-radical–related damage showed that diets enriched with extra servings of fruits and vegetables rich in β-carotene, tocopherols, and ascorbic acid had only limited effect on the inhibition of oxidation processes. A number of studies have shown, however, that consuming less common fruits and vegetables contribute much more to the reduction of free-radical processes, most likely because they contain a large amount of non-vitamin antioxidants, such as polyphenols and anthocyanins.