Which plasma antioxidants are most related to fruit and vegetable consumption?

Validation of Diet ID™ in Predicting Nutrient Intake Compared to Dietary Recalls, Skin Carotenoid Scores, and Plasma Carotenoids in University Students

Background and Aim: Collecting accurate dietary information in the research setting is challenging due to the inherent biases, duration, and resource-intensive nature of traditional data collection methods. Diet ID™ is a novel, rapid assessment method that uses an image-based algorithm to identify dietary patterns and estimate nutrient intake. The purpose of this analysis was to explore the criterion validity between Diet ID™ and additional measures of dietary intake. Methods: This prospective cohort study (n = 42) collected dietary information using Diet ID™, the Nutrition Data System for Research (NDSR), plasma carotenoid concentrations, and the Veggie Meter^® to estimate carotenoid levels in the skin. Results: There were significant correlations between Diet ID™ and NDSR for diet quality, calories, carbohydrates, protein, fiber, and cholesterol. Vitamin A and carotenoid intake were significantly correlated, with the exception of α-carotene and lycopene. Significant correlations were observed for calcium, folate, iron, sodium, potassium, Vitamins B₂, B₃, B₆, C, and E. Skin carotenoid scores and plasma carotenoids were correlated with carotenoid intake from Diet ID™. Conclusions: Diet ID™ may be a useful tool in nutrition research as a less time-intensive and minimally burdensome dietary data collection method for both participants and researchers.

Improving Skin Carotenoid Levels in Young Students through Brief Dietary Education Using the Veggie Meter

The antioxidant and anti-inflammatory effects of carotenoid have been determined to aid in the prevention of a wide range of oxidative disorders, arteriosclerosis, obesity, and various types of cancers. In order to keep high carotenoid levels in the body, much of the vegetable and fruit (V/F) intake is mandatory. However, the actual intake of V/F is not enough in many countries. The aim of this study was to assess whether brief dietary education using the Veggie Meter (VM) that could measure skin carotenoid (SC) levels could induce the increase in carotenoid levels via V/F intake. Two hundred and sixty-one elementary and junior high school students (ages 7−14 years old) received brief educational session and SC evaluation by VM, and the changes in SC levels were examined after 6 months. The baseline VM scores ranged from 131 to 825, and the average significantly increased from 400.0 ± 124.7 (standard deviation) to 447.4 ± 140.4 at Month 6 (p < 0.0001). The percentage of increase at month 6 was negatively correlated with the baseline values (r = −0.36, p < 0.0001). This finding implies that subjects who became aware of their inferiority tended to make a significant effort to change their behavior. The multivariate logistic regression analysis demonstrated that subjects taking much of green and yellow vegetables, drinking vegetable/tomato juice, and eating any fruit had higher VM scores than the average value. In conclusion, the educational approach using VM was supposed to be an effective method of raising awareness of the V/F shortage and increasing V/F intake that could indue the increase in SC levels.

Association between serum carotenoids and premature mortality in a population-based case-control study

Carotenoids are abundant pigments mainly contained in vegetables and fruits, and show antioxidant properties by quenching free radicals in human body. Few studies have investigated associations between serum carotenoid levels and premature mortality. The objective of this study was to investigate the association between serum carotenoid level and premature mortality in a Japanese population. This study included 446 Japanese adults (174 men, aged of 40-64) recruited as participants in the Japan Collaborative Cohort (JACC) Study. Serum carotenoid level was measured by high-performance liquid chromatography. Premature mortality was defined as death before 65 years old during the follow-up period. Premature mortality was ascertained in 60 men (34.5%) and 65 women (23.9%). In men, compared to the 1^st tertile of serum β-cryptoxanthin and provitamin A, those who were in the 3^rd tertile had lower risks of premature all-cause mortality (OR, 95% CI: 0.19, 0.07-0.47 for β-cryptoxanthin, and 0.24, 0.09-0.61 for provitamin A). In women, compared to the 1^st tertile of serum β-cryptoxanthin, those who were in the 3^rd tertile had higher risks of premature all-cause mortality (OR, 95% CI: 1.94, 1.00-4.03). These significant associations were observed in analyses for premature cancer mortality. We found significant associations between higher levels of serum β-cryptoxanthin and provitamin A and lower risks of premature mortality among Japanese men, while a different directional association was found in women. Although these findings suggest roles of serum carotenoids on premature mortality, further studies are needed to validate this association in other populations.

Association of Plasma Carotenoid and Malondialdehyde Levels with Physical Performance in Korean Adolescents

Increased oxidative stress has been shown to lead to muscle damage and reduced physical performance. The antioxidant mechanism is most likely to reduce these relationships, but in the context of the action of carotenoids, more research is needed. This study aimed to investigate whether carotenoids modify the association between plasma malondialdehyde (MDA) and physical performance in Korean adolescents. The study sample consisted of 381 adolescents (164 boys, 217 girls) aged 13–18, who participated in the 2018 National Fitness Award Project. We quantified α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and MDA levels in plasma using HPLC with photodiode array detection. Among boys but not girls, plasma MDA level was negatively associated (β = −0.279, p = 0.0030) with total plasma carotenoid levels and marginally negatively associated (β = −0.907, p = 0.0876) with absolute hand grip strength. After adjustment for covariates in boys, the MDA level was negatively associated with absolute hand grip strength and relative hand grip strength; this association was observed only in groups with individual carotenoid and total carotenoid values below the median. These findings support a significant association between plasma MDA level and hand grip strength, and this association has been potentially modified by plasma levels of carotenoids in Korean male adolescents.

Plasma antioxidants and risk of dementia in older adults

INTRODUCTION

Plant-based diets rich in fruits and vegetables have been associated with lower risk of dementia, but the specific role of antioxidants, a key class of bioactive phytochemicals, has not been well ascertained.

METHODS

We measured antioxidants in a case-cohort study nested within the Ginkgo Evaluation of Memory Study. We included 996 randomly selected participants and 521 participants who developed dementia, of which 351 were diagnosed with Alzheimer's disease (AD) during a median of 5.9 years of follow-up. We measured baseline plasma levels of retinol, α-, and γ-tocopherol; zeaxanthin and lutein (combined); beta-cryptoxanthin; cis-lycopene; trans-lycopene; α-carotene; and trans-β-carotene by organic phase extraction followed by chromatographic analysis and related these to neurologist-adjudicated risks of all-cause dementia and AD.

RESULTS

Plasma retinol, α-, and γ-tocopherol, and carotenoids were not significantly related to risk of dementia or AD. Associations were not significant upon Bonferroni correction for multiple testing and were consistent within strata of sex, age, apolipoprotein E ε4 genotype, mild cognitive impairment at baseline, and intake of multivitamin, vitamin A or β-carotene, or vitamin E supplements. Higher trans-β-carotene tended to be related to a higher risk of dementia (adjusted hazard ratio [HR] per 1 standard deviation [SD] higher trans-β-carotene: 1.10; 95% confidence interval [CI]: 1.00, 1.20) and α-carotene tended to be associated with higher risk of AD only (adjusted HR per 1 SD higher α-carotene: 1.15; 95% CI: 1.02, 1.29).

DISCUSSION

Plasma antioxidants were not significantly associated with risk of dementia or AD among older adults. Similar studies in younger populations are required to better understand the association between plasma antioxidants and dementia risk.

Recommendations for the Use of the Veggie Meter® for Spectroscopy-Based Skin Carotenoid Measurements in the Research Setting

Carotenoids are a class of phytochemical compounds found in a variety of fruits and vegetables (F/V) and, therefore, are commonly used as a biomarker for F/V intake. The Veggie Meter® is a noninvasive research-grade instrument that detects and quantifies carotenoids in the skin. To determine current practices and examine variability among users, a survey was administered to researchers using the device (n = 19, response rate = 35.8%) and variation in anatomical site preparation, calibration, number of measurements, measurement site, and documentation was observed. A protocol was developed in partnership with Veggie Meter® users to outline the preparation, calibration, and data collection procedures for using this device for research purposes. Although many protocol conditions will benefit from additional validation, this standardized protocol supports the development of a universal data repository to establish usual observed ranges, with the ultimate goal of examining associations between skin carotenoid scores and diet-related health outcomes.

Higher Fruits and Vegetables Consumption Is not Associated with Risk of Breast Cancer in Iranian Women

We aimed to investigate the association of fruits and vegetables (FVs) and their all subgroups intakes with breast cancer (BC) risk in Iranian women.

The present case-control study conducted on 150 age-matched women with newly diagnosed BC and apparently healthy controls. Anthropometric measures were collected and eventually, the mean intakes of total FVs and each subgroup were obtained from a validated 147-item food frequency questionnaire. Multivariate regression analysis was used to estimate odds ratios (OR) with 95% confidence intervals (CI).

Our findings revealed that the intake of only dark yellow vegetable was significantly higher in BC patients (P = 0.03) after controlling for covariates. OR of BC across tertiles of FVs intake, showed that there was not any statistical association of total FVs (OR: 1.83, CI: 0.54-6.24, P-trend = 0.3) and their subgroups intakes with BC risk. Except for berry fruits intake which was adversely associated with BC risk (OR: 0.36, CI: 0.09-1.37, P-trend = 0.02).

Our findings did not support the hypothesis that higher total FVs and their subgroups intakes reduce BC risk and suggested that only higher berry fruits intake may have an association with lower BC risk.

Modification of diet, exercise and lifestyle (MODEL) study: a randomised controlled trial protocol

INTRODUCTION

Most cardiovascular disease (CVD)-related events could be prevented or substantially delayed with improved diet and lifestyle. Providing information on structural vascular disease may improve CVD risk factor management, but its impact on lifestyle change remains unclear. This study aims to determine whether providing visualisation and pictorial representation of structural vascular disease (abdominal aortic calcification (AAC)) can result in healthful diet and lifestyle change.

METHODS AND ANALYSIS

This study, including men and women aged 60-80 years, is a 12-week, two-arm, multisite randomised controlled trial. At baseline, all participants will have AAC assessed from a lateral spine image captured using a bone densitometer. Participants will then be randomised to receive their AAC results at baseline (intervention group) or a usual care control group that will receive their results at 12 weeks. All participants will receive information about routinely assessed CVD risk factors and standardised (video) diet and lifestyle advice with three simple goals: (1) increase fruit and vegetable (FV) intake by at least one serve per day, (2) improve other aspects of the diet and (3) reduce sitting time and increase physical activity. Clinical assessments will be performed at baseline and 12 weeks.

OUTCOMES

The primary outcome is a change in serum carotenoid concentrations as an objective measure of FV intake. The study design, procedures and treatment of data will adhere to Standard Protocol Items for Randomized Trials guidelines.

ETHICS AND DISSEMINATION

Ethics approval for this study has been granted by the Edith Cowan University and the Deakin University Human Research Ethics Committees (Project Numbers: 20513 HODGSON and 2019-220, respectively). Results of this study will be published in peer-reviewed academic journals and presented in scientific meetings and conferences. Information regarding consent, confidentiality, access to data, ancillary and post-trial care and dissemination policy has been disclosed in the participant information form.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trial Registry (ACTRN12618001087246).

Fruit and vegetable consumption among South Asians: A systematic review and meta-analysis

BACKGROUND AND AIMS

Low consumption of fruit and vegetables is associated with high prevalence of non-communicable diseases, especially among South Asians. The aim of our study was to systematically review data published on fruit and vegetable intake among South Asian countries.

METHODS

This review included 43 studies conducted from December 1999 to 2019 among South Asians. Literature searching was undertaken in PubMed® database and World Health Organization website. The main outcomes were pooled using random effect meta-analysis.

RESULTS

The highest fruit consumption by both men and women (2.4 servings/day) was found in Bhutan (2004) while the lowest reports (0.43 servings/day) were from Sri Lanka (2011) and Bangladesh (2002). With regard to vegetable consumption, Indians (2007) had the lowest reported intake (0.9 servings/day), while the highest value, 3.8 servings/day, was reported in Bhutanese adults (2014). When both intakes were considered, the highest (4.28; 95% CI, 4.02 to 4.55; p=0.15; I²=51%, p<0.001) and the lowest (1.83; 95% CI, 1.41 to 2.25; p<0.001; I²=100%, p<0.001) pooled mean values, were attained for Bhutan and Bangladesh, respectively. The highest percentage of respondents (86.2%) achieved the World Health Organization recommendation of five fruit and vegetables (400 g) per day in Afghanistan (2013) whereas the lowest (0%) reported in Bangladesh (2005).

CONCLUSIONS

Residents of almost all South Asian countries appear to consume extremely low quantities of fruit and vegetables, lower than the World Health Organization recommendation. Hence, immediate initiatives should be implemented to enhance the intake of fruit and vegetables across the region.

Positive Association of Ascorbate and Inverse Association of Urate with Cognitive Function in People with Parkinson's Disease

Oxidative stress is thought to contribute to the aetiology of neurological disorders such as Parkinson’s disease. Ascorbate (vitamin C) is a potent antioxidant and is associated with neurological and cognitive function. In this study we assessed the ascorbate status of a cohort of people with Parkinson’s disease (n = 215), aged 50–90 years, compared with a cohort of age matched healthy controls (n = 48). The study sample’s cognitive status ranged from normal to mild cognitive impairment and dementia. There was no difference between the Parkinson’s disease and healthy control groups with respect to mean ascorbate status, however, a higher proportion of participants with Parkinson’s disease had hypovitaminosis C (i.e., <23 μmol/L) compared with healthy controls (20% vs. 8%, respectively). Within the Parkinson’s disease group, Montreal Cognitive Assessment (MoCA) scores correlated positively with ascorbate concentrations, with higher ascorbate status associated with better cognitive function (r = 0.14, p = 0.045). Participants with hypovitaminosis C had significantly lower MoCA scores relative to participants with ascorbate concentrations >23 µmol/L (p = 0.014). Ascorbate concentrations were significantly lower in the cognitively impaired subgroup compared with the normal cognition subgroup in the Parkinson’s disease cohort (p = 0.03). In contrast, urate showed an inverse correlation with cognitive function (r = −0.19, p = 0.007), with higher urate concentrations observed in the cognitively impaired subgroup compared with the normal cognition subgroup (p = 0.015). There was an inverse association between ascorbate status and urate concentrations (r = −0.15, p = 0.017). Plasma protein carbonyls, a measure of systemic oxidative stress, were not significantly different between the Parkinson’s disease cohort and healthy controls, and there was no association with cognitive function (r = 0.09, p = 0.19) or with ascorbate status (r = −0.05, p = 0.45). Overall, our study showed ascorbate status was positively associated with cognitive function in Parkinson’s disease, suggesting that longitudinal studies investigating the temporal sequence of cognitive decline and ascorbate status are warranted.

KiwiC for Vitality: Results of a Randomized Placebo-Controlled Trial Testing the Effects of Kiwifruit or Vitamin C Tablets on Vitality in Adults with Low Vitamin C Levels

Consumption of vitamin C-rich fruit and vegetables has been associated with greater feelings of vitality. However, these associations have rarely been tested in randomized controlled trials. The aim of the current study was to test the effects of eating a vitamin C-rich food (kiwifruit) on subjective vitality and whether effects are driven by vitamin C. Young adults (n = 167, 61.1% female, aged 18-35) with plasma vitamin C <40 µmol/L were randomized into three intervention conditions: kiwifruit (2 SunGold™ kiwifruit/day), vitamin C (250 mg tablet/day), placebo (1 tablet/day). The trial consisted of a two-week lead-in, four-week intervention, and two-week washout. Plasma vitamin C and vitality questionnaires (total mood disturbance, fatigue, and well-being) were measured fortnightly. Self-reported sleep quality and physical activity were measured every second day through smartphone surveys. Nutritional confounds were assessed using a three-day food diary during each study phase. Plasma vitamin C reached saturation levels within two weeks for the kiwifruit and vitamin C groups. Participants consuming kiwifruit showed significantly improved mood and well-being during the intervention period; improvements in well-being were sustained during washout. Decreased fatigue and increased well-being were observed following intake of vitamin C alone, but only for participants with consistently low vitamin C levels during lead-in. Diet records showed that participants consuming kiwifruit reduced their fat intake during the intervention period. Intervention effects remained significant when adjusting for age and ethnicity, and were not explained by sleep quality, physical activity, BMI, or other dietary patterns, including fat intake. There were no changes in plasma vitamin C status or vitality in the placebo group. Whole food consumption of kiwifruit improved subjective vitality in adults with low vitamin C status. Similar, but not identical, changes were found for vitamin C tablets suggesting that additional properties of kiwifruit may contribute to improved vitality.

Criterion-Related Validity of Spectroscopy-Based Skin Carotenoid Measurements as a Proxy for Fruit and Vegetable Intake: A Systematic Review

Carotenoids are a category of health-promoting phytonutrients that are found in a variety of fruits and vegetables and have been used as a biomarker to approximate dietary fruit and vegetable (F/V) intake. Carotenoids are consumed, metabolized, and deposited in blood, skin, and other tissues. Emerging evidence suggests spectroscopy-based skin carotenoid measurement is a noninvasive method to approximate F/V intake. Spectroscopy-based skin carotenoid measurement overcomes bias and error inherent in self-reported dietary recall methods, and the challenges in obtaining, storing, and processing invasive blood samples. The objective of this systematic review was to examine criterion-related validity of spectroscopy-based skin carotenoid measurement as a proxy for F/V intake. The 3 methods examined were resonance Raman spectroscopy (RRS), pressure-mediated reflection spectroscopy (RS), and spectrophotometers. A comprehensive literature search of PubMed, Excerpta Medica Database (Embase), Cumulative Index of Nursing and Allied Health Literature (CINAHL), ProQuest, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials (CENTRAL) was performed in December 2018, yielding 7931 citations. Studies that examined associations between spectroscopy, blood carotenoids, and/or dietary intake were identified and reviewed independently by ≥2 reviewers to determine eligibility for inclusion. Twenty-nine articles met the inclusion criteria and all 29 studies found significant correlations or associations between spectroscopy-based skin carotenoids and plasma or serum carotenoids and/or dietary F/V intake. A majority of the studies evaluated carotenoid concentration in adults; however, 4 studies were conducted in infants and 6 studies evaluated children. Twenty studies specified the racial/ethnic groups from which the samples were drawn, with 6 including ≥20% of the sample from a minority, nonwhite population. The findings of this systematic review support the use of spectroscopy for estimating F/V intake in diverse human populations, although additional validation is needed, particularly among racially/ethnically diverse populations and populations of varying ages.

Micronutrient Inadequacy in Short Sleep: Analysis of the NHANES 2005-2016

One third of U.S. adults report short sleep (<7 h), which has been linked to negative health outcomes. Inadequate intake of micronutrients across the U.S. adult population has been reported, and a relationship between sleep conditions and micronutrient intake is emerging. This cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES 2005–2016) (n = 26,211) showed that participants with short sleep duration had a lower usual intake (Food + Supplements) of calcium, magnesium, and vitamin D in all adults aged 19+ years, and vitamin K in adults aged 19–50 years, even after adjusting for covariates. In addition, participants reporting short sleep had a higher percentage of individuals with intake lower than the estimated average requirement (EAR) across multiple nutrients. Age and gender differences were observed in the prevalence of inadequate intake across multiple nutrients. Adults aged 51–99 years with short sleep duration had inadequate intake with respect to more nutrients. In females there was an association between short sleep and a higher prevalence of inadequate intake (Food + Spp) for calcium, magnesium, and vitamins A, C, D, E, and K (above adequate intake). Conversely, males reporting short sleep only had an inadequate intake of vitamin D. Overall, we demonstrate that short sleep is associated with increased nutrient inadequacy, emphasizing the possible need for dietary supplementation.

Immunomodulatory and Antimicrobial Effects of Vitamin C

Humans have lost their vitamin C-synthesizing capacities during evolution. Therefore, the uptake of this essential compound from external sources is mandatory in order to prevent vitamin C-deficient conditions resulting in severe morbidities such as scurvy. The potent antioxidant, immunomodulatory, and antiinfectious effects of vitamin C are known since the 1930s. We here (i) review the impact of vitamin C on innate and adaptive immune functions, (ii) provide an overview of its antimicrobial, antibacterial, antiviral, antiparasitic, and antifungal properties, and finally, (iii) discuss vitamin C as an adjunct treatment option for the combat of human infections by bacteria, particularly by emerging multidrug-resistant species.

Development and validation of a Brief Diet Quality Assessment Tool in the French-speaking adults from Quebec

Background

The objective of this study was to develop and validate a short, self-administered questionnaire to assess diet quality in clinical settings, using the Alternative Healthy Eating Index (AHEI) as reference.

Methods

A total of 1040 men and women (aged 44.6 ± 14.4 y) completed a validated web-based food frequency questionnaire (webFFQ) and had their height and weight measured (development sample). Participants were categorized arbitrarily according to diet quality (high: AHEI score ≥ 65/110, low: AHEI score < 65/110) based on dietary intake data from the webFFQ. The Brief Diet Quality Assessment Tool was developed using a classification and regression tree (CART) approach and individual answers to the webFFQ among participants considered to have a plausible energy intake (ratio of reported energy intake to basal metabolic rate ≥ 1.2 and < 2.4; n = 1040). A second sample of 3344 older adults (aged 66.5 ± 6.4 y) was used to test the external validity of the Brief Diet Quality Assessment Tool (external validation sample).

Results

The decision tree included sequences of 3 to 6 binary questions, yielding 21 different pathways classifying diet quality as being high or low. In the development sample, the area under the receiver operating characteristic (ROC) curve of the predictive model was 0.92, with sensitivity, specificity and agreement values of 89.5, 83.9 and 87.2%. Compared with individuals having a low-quality diet according to the Brief Diet Quality Assessment Tool (mean AHEI 56.7 ± 11.4), individuals classified as having a high-quality diet (mean AHEI 71.3 ± 11.0) were significantly older, and had lower BMI, percent body fat and waist circumference, and had lower blood pressure, triglycerides, cholesterol/HDL ratio and fasting insulin as well as higher HDL-cholesterol concentrations (all P < 0.05). Similar results were observed in the external validation sample, although overall performance of the Brief Diet Quality Assessment Tool was slightly lower than in the development sample, with an area under the ROC curve of 0.79 and sensitivity, specificity and agreement values of 73.0, 69.0 and 71.3%, respectively.

Conclusion

The CART approach yielded a simple and rapid Brief Diet Quality Assessment Tool that identifies individuals at risk of having a low-quality diet. Further studies are needed to test the performance of this tool in primary care settings.

Electronic supplementary material

The online version of this article (10.1186/s12966-019-0821-6) contains supplementary material, which is available to authorized users.

Hyperglycemia and Carotenoid Intake Are Associated with Serum Carotenoids in Youth with Type 1 Diabetes

BACKGROUND

Serum carotenoids are commonly used as biomarkers of fruit and vegetable (F/V) intake in the general population. Although hyperglycemia induces oxidative stress, it is unknown whether this pathway is associated with lower serum carotenoid concentrations in individuals with type 1 diabetes. Consequently, the utility of serum carotenoids as markers of F/V intake in individuals with type 1 diabetes is unclear.

OBJECTIVE

The study objectives were: 1) to investigate the relationship of glycemic control, oxidative stress, dietary carotenoid and F/V intake with serum carotenoid concentrations in youth with type 1 diabetes and 2) to determine whether glycemic control or oxidative stress moderates the association of carotenoid and F/V intake with serum carotenoids.

DESIGN

The study was a secondary analysis of baseline data from youth with type 1 diabetes. Blood samples were drawn from youth with type 1 diabetes to assess carotenoids and markers of glycemic control (glycated hemoglobin and 1,5-anhydroglucitol); urine samples were used to assess oxidative stress (8-iso-prostaglandin F_2α); and 3-day diet records completed by families were used to determine F/V and carotenoid intake.

PARTICIPANTS/SETTING

The study participants were youth with type 1 diabetes (n=136; age range: 8 to 16.9 years; diabetes duration ≥1 year; glycated hemoglobin: 5.8% to 11.9%) enrolled in a nutrition intervention trial from 2010 to 2013 at a tertiary diabetes center in Boston, MA.

MAIN OUTCOME MEASURES

Serum carotenoids (total carotenoids and α-carotene, β-carotene, lycopene, β-cryptoxanthin, and lutein+zeaxanthin).

STATISTICAL ANALYSIS

Regression analyses were used to estimate the association of glycemic control, oxidative stress, F/V and carotenoid intake with serum carotenoids, as well as the role of glycemic control and oxidative stress in moderating diet-serum carotenoid associations.

RESULTS

Greater F/V intake (β=0.35, P<0.001) and carotenoid intake (β=0.28, P<0.01) were associated with higher total serum carotenoids, and no moderation by glycemic control or oxidative stress was observed. Greater hyperglycemia, as indicated by lower 1,5-anhydroglucitol (β=0.27, P<0.01), was related to lower serum carotenoids; however, glycated hemoglobin was not associated with serum carotenoids. 8-Iso-prostaglandin F2α was not associated with glycemic control or serum carotenoids.

CONCLUSIONS

Findings support the validity of serum carotenoids as markers of F/V and carotenoid intake in youth with type 1 diabetes.

The nutritional and health attributes of kiwifruit: a review

PURPOSE

To describe the nutritional and health attributes of kiwifruit and the benefits relating to improved nutritional status, digestive, immune and metabolic health. The review includes a brief history of green and gold varieties of kiwifruit from an ornamental curiosity from China in the 19th century to a crop of international economic importance in the 21st century; comparative data on their nutritional composition, particularly the high and distinctive amount of vitamin C; and an update on the latest available scientific evidence from well-designed and executed human studies on the multiple beneficial physiological effects. Of particular interest are the digestive benefits for healthy individuals as well as for those with constipation and other gastrointestinal disorders, including symptoms of irritable bowel syndrome. The mechanisms of action behind the gastrointestinal effects, such as changes in faecal (stool) consistency, decrease in transit time and reduction of abdominal discomfort, relate to the water retention capacity of kiwifruit fibre, favourable changes in the human colonic microbial community and primary metabolites, as well as the naturally present proteolytic enzyme actinidin, which aids protein digestion both in the stomach and the small intestine. The effects of kiwifruit on metabolic markers of cardiovascular disease and diabetes are also investigated, including studies on glucose and insulin balance, bodyweight maintenance and energy homeostasis.

CONCLUSIONS

The increased research data and growing consumer awareness of the health benefits of kiwifruit provide logical motivation for their regular consumption as part of a balanced diet. Kiwifruit should be considered as part of a natural and effective dietary strategy to tackle some of the major health and wellness concerns around the world.

Serum and Erythrocyte Biomarkers of Nutrient Status Correlate with Short-Term Α-Carotene, Β-Carotene, Folate, and Vegetable Intakes Estimated by Food Frequency Questionnaire in Military Recruits

OBJECTIVE

Food frequency questionnaires (FFQs) estimate habitual dietary intake and require evaluation in populations of interest in order to determine accuracy. Thus, the purpose of this study was to determine agreement between circulating biomarkers and FFQ estimated dietary intake in a military population consuming all meals in a dining facility over 12 weeks.

METHODS

2014 Block FFQs were administered and fasted blood samples were drawn to assess nutritional biomarkers at the end of a 12-week training period in male (n = 141) and female (n = 125) Marine recruits undergoing initial military training. FFQ estimates of alpha- and beta-carotene, folate, and fruit and vegetable intake and circulating concentrations of serum alpha- and beta-carotene and serum and erythrocyte folate were measured. Partial correlations were used in the full model, and weighted kappa coefficients were used to determine agreement between ranking quartiles of dietary intake estimates with corresponding biomarker status quartiles.

RESULTS

Serum and dietary intake of alpha-carotene were positively associated in males (p = 0.009) and females (p < 0.001), as was serum and intake of beta-carotene (males, p = 0.002; females, p < 0.001). Alpha-carotene was positively associated with vegetable intake in males (p = 0.02) and beta-carotene with vegetable intake in females (p = 0.003). Serum folate in males (p = 0.002) and erythrocyte folate in females (p = 0.02) were associated with dietary folate intake. In females, the relationships between biomarker and dietary estimates yielded significant kappa coefficients. In males, a significant kappa coefficient was observed for erythrocyte folate and dietary intake of folate only. The kappa coefficient for serum and estimated intake of beta-carotene was not significant in males.

CONCLUSION

Twelve-week habitual intake of alpha-and beta-carotene and folate were correlated with circulating biomarkers in a military training population. The 2014 Block FFQ was able to accurately rank females into quartiles of nutrient status based on intake, while males were ranked less accurately than females.

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Intravenous Vitamin C for Cancer Therapy - Identifying the Current Gaps in Our Knowledge

The use of intravenous vitamin C (IVC) for cancer therapy has long been an area of intense controversy. Despite this, high dose IVC has been administered for decades by complementary health care practitioners and physicians, with little evidence base resulting in inconsistent clinical practice. In this review we pose a series of questions of relevance to both researchers and clinicians, and also patients themselves, in order to identify current gaps in our knowledge. These questions include: Do oncology patients have compromised vitamin C status? Is intravenous the optimal route of vitamin C administration? Is IVC safe? Does IVC interfere with chemotherapy or radiotherapy? Does IVC decrease the toxic side effects of chemotherapy and improve quality of life? What are the relevant mechanisms of action of IVC? What are the optimal doses, frequency, and duration of IVC therapy? Researchers have made massive strides over the last 20 years and have addressed many of these important aspects, such as the best route for administration, safety, interactions with chemotherapy, quality of life, and potential mechanisms of action. However, we still do not know the answers to a number of fundamental questions around best clinical practice, such as how much, how often and for how long to administer IVC to oncology patients. These questions point the way forward for both basic research and future clinical trials.

The Association of Serum Carotenoids, Tocopherols, and Ascorbic Acid With Rapid Kidney Function Decline: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

Nutritional intervention targeting dietary intake modification is a major component of treatment for chronic kidney disease; however, little is known about the relationship between dietary intake and kidney function decline in individuals with preserved kidney function.

DESIGN AND METHODS

In this prospective cohort study we examined the association of biomarkers of dietary intake with kidney function decline over a 5-year interval in 2,152 men and women with cystatin-C-based estimated glomerular filtration rate > 60 mL/minute/1.73 m² from the Coronary Artery Risk Development in Young Adults study. The biomarkers of interest included carotenoids, tocopherols, and ascorbic acid. Multivariable logistic regression was used to explore the relationship between serum concentrations of the sum of 4 carotenoids (α-carotene, β-carotene, β-cryptoxanthin, and lutein/zeaxanthin), lycopene, α-tocopherol, γ-tocopherol, and ascorbic acid and rapid kidney function decline, defined as .15% decline in cystatin-C-based estimated glomerular filtration rate over 5 years.

RESULTS

During the 5-year follow-up, 290 participants (13.5%) experienced rapid kidney function decline. Relative to individuals in the lowest quartile of serum carotenoids, those in the highest quartile had significantly lower odds of rapid kidney function decline in the fully adjusted model (odds ratio, 0.51; 95% confidence interval [CI], 0.32-0.80; P trend, .02). No association of levels of serum tocopherols, ascorbic acid, or lycopene with kidney function decline was found. There was no evidence that results differed for individuals with hypertension or diabetes.

CONCLUSIONS

These results demonstrate that higher serum carotenoid levels, reflective of a fruit- and vegetable-rich dietary pattern, inversely associate with rapid kidney function decline in early middle adulthood and provide insight into how diet might play a role in chronic kidney disease prevention.

The value of facial attractiveness for encouraging fruit and vegetable consumption: analyses from a randomized controlled trial

BACKGROUND

An effect of increased fruit and vegetable (FV) consumption on facial attractiveness has been proposed and recommended as a strategy to promote FV intakes, but no studies to date demonstrate a causal link between FV consumption and perceived attractiveness. This study investigated perceptions of attractiveness before and after the supervised consumption of 2, 5 or 8 FV portions/day for 4 weeks in 30 low FV consumers. Potential mechanisms for change via skin colour and perceived skin healthiness were also investigated.

METHODS

Faces were photographed at the start and end of the 4 week intervention in controlled conditions. Seventy-three independent individuals subsequently rated all 60 photographs in a randomized order, for facial attractiveness, facial skin yellowness, redness, healthiness, clarity, and symmetry.

RESULTS

Using clustered multiple regression, FV consumption over the previous 4 weeks had no direct effect on attractiveness, but, for female faces, some evidence was found for an indirect impact, via linear and non-linear changes in skin yellowness. Effect sizes, however, were small. No association between FV consumption and skin healthiness was found, but skin healthiness was associated with facial attractiveness.

CONCLUSIONS

Controlled and objectively measured increases in FV consumption for 4 weeks resulted indirectly in increased attractiveness in females via increases in skin yellowness, but effects are small and gradually taper as FV consumption increases. Based on the effect sizes from this study, we are hesitant to recommend the use of facial attractiveness to encourage increased FV consumption.

TRIAL REGISTRATION

Clinical trial Registration Number NCT01591057 ( www.clinicaltrials.gov ). Registered: 27th April, 2012.

Associations between Specific Redox Biomarkers and Age in a Large European Cohort: The MARK-AGE Project

Oxidative stress and antioxidants play a role in age-related diseases and in the aging process. We here present data on protein carbonyls, 3-nitrotyrosine, malondialdehyde, and cellular and plasma antioxidants (glutathione, cysteine, ascorbic acid, uric acid, α-tocopherol, and lycopene) and their relation with age in the European multicenter study MARK-AGE. To avoid confounding, only data from countries which recruited subjects from all three study groups (five of eight centers) and only participants aged ≥55 years were selected resulting in data from 1559 participants. These included subjects from (1) the general population, (2) members from long-living families, and (3) their spouses. In addition, 683 middle-aged reference participants (35–54 years) served as a control. After adjustment for age, BMI, smoking status, gender, and country, there were differences in protein carbonyls, malondialdehyde, 3-nitrotyrosine, α-tocopherol, cysteine, and glutathione between the 3 study groups. Protein carbonyls and 3-nitrotyrosine as well as cysteine, uric acid, and lycopene were identified as independent biomarkers with the highest correlation with age. Interestingly, from all antioxidants measured, only lycopene was lower in all aged groups and from the oxidative stress biomarkers, only 3-nitrotyrosine was increased in the descendants from long-living families compared to the middle-aged control group. We conclude that both lifestyle and genetics may be important contributors to redox biomarkers in an aging population.

Serum antioxidant capacity, biochemical profile and body composition of breast cancer survivors in a randomized Mediterranean dietary intervention study

PURPOSE

Increasing evidence suggests that Mediterranean Diet (MD) is correlated with reduced risk of breast cancer (BC) and cancer mortality, since it modifies patients' serum antioxidant capacity, body composition and biochemical parameters. The aim of the study was to investigate whether a dietary intervention based on MD has a beneficial effect on these factors.

METHODS

In this intervention study, seventy female BC survivors were randomly assigned to (1) the intervention group (personalized dietary intervention based on MD) and (2) the control group (received the updated American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and ad libitum diet). Both groups were assessed twice [beginning, end of study (after 6 months)] regarding their anthropometric and biochemical parameters, serum vitamin C, vitamin A, a-tocopherol and CoQ10 levels, dietary intake and adherence to MD. An additional intermediate analysis was conducted on participants' body composition and biochemical profile.

RESULTS

Concerning the intervention group, body weight, body fat mass, waist circumference, body mass index as well as HDL-cholesterol were significantly decreased (P < 0.2%). An increase was observed in the vitamin C levels in blood (P < 0.2%). In the control group, body weight, body fat mass and serum total cholesterol rose (P < 0.2%). At the end of the study the two groups were significantly different considering blood glucose, vitamin C, polyunsaturated fatty acids, vitamin A and a-tocopherol levels.

CONCLUSIONS

This randomized dietary intervention based on MD managed to ameliorate serum antioxidant capacity, body composition, adherence to MD and glycemic profile of postmenopausal BC survivors.

Vitamin C and Infections

In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose-response, for the duration of common cold symptoms, with up to 6-8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3-4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.

A community-based primary prevention programme for type 2 diabetes mellitus integrating identification and lifestyle intervention for prevention: a cluster randomised controlled trial

Background

Prevention of type 2 diabetes mellitus (T2DM) is a global priority; however, there is a lack of evidence investigating how to effectively translate prevention research into a primary care setting.

Objectives

(1) To develop and validate a risk score to identify individuals at high risk of T2DM in the UK; and (2) to establish whether or not a structured education programme targeting lifestyle and behaviour change was clinically effective and cost-effective at preventing progression to T2DM in people with prediabetes mellitus (PDM), identified through a risk score screening programme in primary care.

Design

A targeted screening study followed by a cluster randomised controlled trial (RCT), with randomisation at practice level. Participants were followed up for 3 years.

Setting

A total of 44 general practices across Leicestershire, UK. The intervention took place in the community.

Participants

A total of 17,972 individuals from 44 practices identified through the risk score as being at high risk of T2DM were invited for screening; of these, 3449 (19.2%) individuals attended. All received an oral glucose tolerance test. PDM was detected in 880 (25.5%) of those screened. Those with PDM were included in the trial; of these, 36% were female, the average age was 64 years and 16% were from an ethnic minority group.

Intervention

Practices were randomised to receive either standard care or the intervention. The intervention consisted of a 6-hour group structured education programme, with an annual refresher and regular telephone contact.

Main outcome measures

The primary outcome was progression to T2DM. The main secondary outcomes were changes in glycated haemoglobin concentrations, blood glucose levels, cardiovascular risk, the presence of metabolic syndrome, step count and the cost-effectiveness of the intervention.

Results

A total of 22.6% of the intervention group did not attend the education and 29.1% attended all sessions. A total of 131 participants developed T2DM (standard care,n = 67; intervention,n = 64). There was a 26% reduced risk of T2DM in the intervention arm compared with standard care, but this did not reach statistical significance (hazard ratio 0.74, 95% confidence interval 0.48 to 1.14;p = 0.18). There were statistically significant improvements in glycated haemoglobin concentrations, low-density lipoprotein cholesterol levels, psychosocial well-being, sedentary time and step count in the intervention group. The intervention was found to result in a net gain of 0.046 quality-adjusted life-years over 3 years at a cost of £168 per patient, with an incremental cost-effectiveness ratio of £3643 and a probability of 0.86 of being cost-effective at a willingness-to-pay threshold of £20,000.

Conclusions

We developed and validated a risk score for detecting those at high risk of undiagnosed PDM/T2DM. We screened > 3400 people using a two-stage screening programme. The RCT showed that a relatively low-resource pragmatic programme may lead to a reduction in T2DM and improved biomedical and psychosocial outcomes, and is cost-effective.

Limitations

Only 19% of those invited to screening attended, which may limit generalisability. The variation in cluster size in the RCT may have limited the power of the study.

Future work

Future work should focus on increasing attendance to both screening and prevention programmes and offering the programme in different modalities, such as web-based modalities. A longer-term follow-up of the RCT participants would be valuable.

Trial registration

Current Controlled Trials ISRCTN80605705.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Fruit and vegetable intake and cardiovascular risk factors in people with newly diagnosed type 2 diabetes

BACKGROUND/OBJECTIVES

The cardiovascular benefit of increasing fruit and vegetable (F&V) intake following diagnosis of diabetes remains unknown. We aimed to describe how quantity and variety of F&V intake, and plasma vitamin C, change after diagnosis of type 2 diabetes and examine whether these changes are associated with improvements in cardiovascular risk factors.

SUBJECTS/METHODS

A total of 401 individuals with screen-detected diabetes from the ADDITION-Cambridge study were followed up over 5 years. F&V intake was assessed by food frequency questionnaire and plasma vitamin C at baseline, at 1 year and at 5 years. Linear mixed models were used to estimate associations of changes in quantity and variety of F&V intake, and plasma vitamin C, with cardiovascular risk factors and a clustered cardiometabolic risk score (CCMR), where a higher score indicates higher risk.

RESULTS

F&V intake increased in year 1 but decreased by year 5, whereas variety remained unchanged. Plasma vitamin C increased at 1 year and at 5 years. Each s.d. increase (250g between baseline and 1 year and 270g between 1 and 5 years) in F&V intake was associated with lower waist circumference (-0.92 (95% CI: -1.57, -0.27) cm), HbA1c (-0.11 (-0.20, -0.03) %) and CCMR (-0.04 (-0.08, -0.01)) at 1 year and higher high-density lipoprotein (HDL)-cholesterol (0.04 (0.01, 0.06) mmol/l) at 5 years. Increased plasma vitamin C (per s.d., 22.5 μmol/l) was associated with higher HDL-cholesterol (0.04 (0.01, 0.06) mmol/l) and lower CCMR (-0.07 (-0.12, -0.03)) between 1 and 5 years.

CONCLUSIONS

Increases in F&V quantity following diagnosis of diabetes are associated with lower cardiovascular risk factors. Health promotion interventions might highlight the importance of increasing, and maintaining increases in, F&V intake for improved cardiometabolic health in patients with diabetes.

Carotenoids as biomarkers of fruit and vegetable intake in men and women

High fruit and vegetable (FAV) intake is associated with a lower prevalence of chronic diseases. Identifying the ideal number of FAV servings needed to reduce chronic disease risk is, however, difficult because of biases inherent to common self-report dietary assessment tools. The aim of our study was to examine the associations between daily FAV intake and plasma carotenoid concentrations in men and women enrolled in a series of fully controlled dietary interventions. We compiled and analysed data from a group of 155 men and 109 women who participated in six fully controlled dietary interventions and compared post-intervention fasting plasma carotenoid (α-carotene,β-carotene,β-cryptoxanthin, lutein, lycopene, zeaxanthin) concentrations with regard to the daily FAV servings consumed by the participants. We found that plasmaβ-cryptoxanthin, lutein and zeaxanthin concentrations were positively associated with daily FAV servings (P≤0·005). However, daily FAV intake was negatively associated with plasmaα-carotene (P<0·0005) and lycopene (P<0·0001) concentrations, whereas no association was noted with plasmaβ-carotene. When men and women were analysed separately, we found that for any given number of FAV servings consumed women had higher circulating lutein concentrations compared with men (P<0·01). Significant sex×FAV (P<0·0001) and sex×dietaryβ-cryptoxanthin (P<0·0005) interactions were also noted favouring higher plasmaβ-cryptoxanthin concentrations in women than in men for a given FAV consumption. Results from these fully controlled dietary feeding studies indicate that plasmaβ-cryptoxanthin and lutein concentrations can be used as robust biomarkers of FAV consumption. They also suggest the existence of sex differences influencing circulatingβ-cryptoxanthin and lutein concentrations following FAV consumption.

Plasma carotenoids, vitamin C, tocopherols, and retinol and the risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Carotenoids and vitamin C are thought to be associated with reduced cancer risk because of their antioxidative capacity.

OBJECTIVE

This study evaluated the associations of plasma carotenoid, retinol, tocopherol, and vitamin C concentrations and risk of breast cancer.

DESIGN

In a nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort, 1502 female incident breast cancer cases were included, with an oversampling of premenopausal (n = 582) and estrogen receptor-negative (ER-) cases (n = 462). Controls (n = 1502) were individually matched to cases by using incidence density sampling. Prediagnostic samples were analyzed for α-carotene, β-carotene, lycopene, lutein, zeaxanthin, β-cryptoxanthin, retinol, α-tocopherol, γ-tocopherol, and vitamin C. Breast cancer risk was computed according to hormone receptor status and age at diagnosis (proxy for menopausal status) by using conditional logistic regression and was further stratified by smoking status, alcohol consumption, and body mass index (BMI). All statistical tests were 2-sided.

RESULTS

In quintile 5 compared with quintile 1, α-carotene (OR: 0.61; 95% CI: 0.39, 0.98) and β-carotene (OR: 0.41; 95% CI: 0.26, 0.65) were inversely associated with risk of ER- breast tumors. The other analytes were not statistically associated with ER- breast cancer. For estrogen receptor-positive (ER+) tumors, no statistically significant associations were found. The test for heterogeneity between ER- and ER+ tumors was statistically significant only for β-carotene (P-heterogeneity = 0.03). A higher risk of breast cancer was found for retinol in relation to ER-/progesterone receptor-negative tumors (OR: 2.37; 95% CI: 1.20, 4.67; P-heterogeneity with ER+/progesterone receptor positive = 0.06). We observed no statistically significant interaction between smoking, alcohol, or BMI and all investigated plasma analytes (based on tertile distribution).

CONCLUSION

Our results indicate that higher concentrations of plasma β-carotene and α-carotene are associated with lower breast cancer risk of ER- tumors.

Plasma Ascorbic Acid, A Priori Diet Quality Score, and Incident Hypertension: A Prospective Cohort Study

Vitamin C may reduce risk of hypertension, either in itself or by marking a healthy diet pattern. We assessed whether plasma ascorbic acid and the a priori diet quality score relate to incident hypertension and whether they explain each other's predictive abilities. Data were from 2884 black and white adults (43% black, mean age 35 years) initially hypertension-free in the Coronary Artery Risk Development in Young Adults Study (study year 10, 1995-1996). Plasma ascorbic acid was assessed at year 10 and the diet quality score at year 7. Eight-hundred-and-forty cases of hypertension were documented between years 10 and 25. After multiple adjustments, each 12-point (1 SD) higher diet quality score at year 7 related to mean 3.7 μmol/L (95% CI 2.9 to 4.6) higher plasma ascorbic acid at year 10. In separate multiple-adjusted Cox regression models, the hazard ratio of hypertension per 19.6-μmol/L (1 SD) higher ascorbic acid was 0.85 (95% CI 0.79-0.92) and per 12-points higher diet score 0.86 (95% CI 0.79-0.94). These hazard ratios changed little with mutual adjustment of ascorbic acid and diet quality score for each other, or when adjusted for anthropometric variables, diabetes, and systolic blood pressure at year 10. Intake of dietary vitamin C and several food groups high in vitamin C content were inversely related to hypertension, whereas supplemental vitamin C was not. In conclusion, plasma ascorbic acid and the a priori diet quality score independently predict hypertension. This suggests that hypertension risk is reduced by improving overall diet quality and/or vitamin C status. The inverse association seen for dietary but not for supplemental vitamin C suggests that vitamin C status is preferably improved by eating foods rich in vitamin C, in addition to not smoking and other dietary habits that prevent ascorbic acid from depletion.

Fruit and vegetable intake assessed by food frequency questionnaire and plasma carotenoids: a validation study in adults

Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (α- and β-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for α-carotene, β-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of α-carotene, β-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence.

The association between a biomarker score for fruit and vegetable intake and incident type 2 diabetes: the EPIC-Norfolk study

BACKGROUND/OBJECTIVES

Biomarkers for a mixed fruit and vegetable (FV) diet are needed to provide a better understanding of the association between FV intake and type 2 diabetes. We aimed to examine the prospective association between a composite score comprised of three biomarkers of FV intake in free-living populations and incident diabetes.

SUBJECTS/METHODS

A total of 318 incident diabetes cases and 926 controls from the EPIC (European Prospective Investigation of Cancer)-Norfolk study aged 40-79 years at baseline (1993-1997), completed 7-day prospective food diary and had plasma vitamin C and carotenoid measures. A composite biomarker score (CB-score) comprising the sum of plasma vitamin C, beta-carotene and lutein was derived. Odds ratios (ORs) and 95% confidence intervals (CIs) for incident diabetes were estimated using multivariable logistic regression.

RESULTS

A strong inverse association was found between the CB-score and incident diabetes. The ORs (95% CI) of diabetes comparing quartiles Q2, Q3 and Q4 of the CB-score with Q1 (reference category) were 0.70 (0.49, 1.00), 0.34 (0.23, 0.52) and 0.19 (0.12, 0.32), respectively, and 0.49 (0.40, 0.58) per s.d. change in CB-score in a model adjusted for demographic and lifestyle factors. The association was marginally attenuated after additionally adjusting for body mass index and waist circumference (0.60 (0.49 and 0.74) per s.d. change in CB-score).

CONCLUSIONS

A combination of biomarkers representing the intake of a mixed FV diet was strongly inversely associated with incident diabetes. These findings provide further support for measuring dietary biomarkers in studies of diet-disease associations and highlight the importance of consuming FV for the prevention of diabetes.

Protocol for Get Moving: a randomised controlled trial to assess the effectiveness of three minimal contact interventions to promote fitness and physical activity in working adults

BACKGROUND

Web-based interventions for physical activity offer several advantages over face-to-face, print-and telephone-based interventions and are scalable and potentially cost-effective. Recent reviews of web-based interventions in adults show that they have positive but small effects on physical activity but identify a number of limitations including a reliance on self-report measures of outcome. This trial used an objective measure of physical activity to assess the effectiveness of three minimal contact interventions: 1) A multi-component web-based intervention incorporating objective monitoring and graphical feedback of physical activity; 2) A version of the first intervention that consisted only of objective monitoring plus web-based graphical feedback; and 3) Self-monitoring of physical activity using a paper diary.

METHODS/DESIGN

Get Moving is an individually randomised controlled trial with allocation of 488 participants to one of three interventions or to a no-intervention control group. Participants are physically inactive working adults aged 18-65 years. They attended a baseline assessment session at which anthropometric, biological and questionnaire measures were taken and they completed a treadmill exercise test. They then wore a combined movement and heart rate monitor for six days and nights before being randomised to one of the four trial arms. The baseline measures were repeated at the follow-up assessment which took place approximately 12 weeks post-randomisation, conducted by staff blind to group allocation. Participants wore the movement and heart rate monitor for six days and nights before this. The co-primary outcomes are: physical activity energy expenditure measured using individually calibrated combined heart-rate and movement data; and cardiorespiratory fitness measured using a sub-maximal treadmill exercise test.

DISCUSSION

Strengths of the trial include the use of an objective measure of physical activity, a measure of cardiorespiratory fitness, relatively large sample size and the use of robust methods of randomisation, allocation concealment and blinding to outcome assessment. Get Moving will contribute to the evidence base on minimal contact interventions for increasing physical activity. The interventions could be implemented in other settings such as primary care.

TRIAL REGISTRATION

ISRCTN31844443. Registered 18 June 2010.

Iron Deficiency Anemia Prevalence at First Stroke or Transient Ischemic Attack

Background:

Iron deficiency anemia (IDA) has been implicated in the etiology of transient ischemic attack and ischemic stroke. This study aimed to: 1) document IDA prevalence in patients ≥ 65 years of age admitted to hospital with transient ischemic attack or first ischemic stroke, and 2) investigate dietary intake as a predictor of iron status.

Methods:

Ninety-four patients were enrolled. An algorithm containing values for hemoglobin, ferritin, total iron binding capacity, transferrin saturation, and serum transferrin receptor measured at admission was used to identify IDA. Usual dietary intake was assessed with the Clue II food frequency questionnaire.

Results:

Prevalence estimates were 6.4% for IDA, 2.1% for iron deficiency without anemia, and 6.4% for anemia from other causes. IDA prevalence was significantly higher than published National Health and Nutrition Examination Survey III (NHANES III) estimates for gender-specific age groups ≥ 70 years (One-Sample Proportion Test; males p = 0.038 [n= 37]; females p = 0.002 [n=44]). A comparison of IDA prevalence against selected controls from the NHANES III database yielded an odds ratio (OR) of 6.3, 95% confidence interval (CI) 0.8 to 53.7, which was not statistically significant (Fisher's Exact Test; n=94; p = 0.118). Multivariate linear regression analysis of dietary intake with indicators of iron status (n=58) revealed only iron supplements (p = 0.013) and heme iron intake (p = 0.038) as negative predictors of total iron binding capacity (p<0.05).

Conclusions:

These findings support the initiation of a prospective case control study to investigate IDA as a risk factor for ischemic stroke in elderly patients.

A novel combined biomarker including plasma carotenoids, vitamin C, and ferric reducing antioxidant power is more strongly associated with fruit and vegetable intake than the individual components

BACKGROUND

Monitoring of fruit and vegetable (F&V) intake is fraught with difficulties. Available dietary assessment methods are associated with considerable error, and the use of biomarkers offers an attractive alternative. Few studies to date have examined the use of plasma biomarkers to monitor or predict the F&V intake of volunteers consuming a wide range of intakes from both habitual F&V and manipulated diets.

OBJECTIVE

This study tested the hypothesis that an integrated biomarker calculated from a combination of plasma vitamin C, cholesterol-adjusted carotenoid concentration and Ferric Reducing Antioxidant Power (FRAP) had more power to predict F&V intake than each individual biomarker.

METHODS

Data from a randomized controlled dietary intervention study [FLAVURS (Flavonoids University of Reading Study); n = 154] in which the test groups observed sequential increases of 2.3, 3.2, and 4.2 portions of F&Vs every 6 wk across an 18-wk period were used in this study.

RESULTS

An integrated plasma biomarker was devised that included plasma vitamin C, total cholesterol-adjusted carotenoids, and FRAP values, which better correlated with F&V intake (r = 0.47, P < 0.001) than the individual biomarkers (r = 0.33, P < 0.01; r = 0.37, P < 0.001; and r = 0.14, respectively; P = 0.099). Inclusion of urinary potassium concentration did not significantly improve the correlation. The integrated plasma biomarker predicted F&V intake more accurately than did plasma total cholesterol-adjusted carotenoid concentration, with the difference being significant at visit 2 (P < 0.001) and with a tendency to be significant at visit 1 (P = 0.07).

CONCLUSION

Either plasma total cholesterol-adjusted carotenoid concentration or the integrated biomarker could be used to distinguish between high- and moderate-F&V consumers. This trial was registered at www.controlled-trials.com as ISRCTN47748735.

Associations between low consumption of fruits and vegetables and nutritional deficiencies in Brazilian schoolchildren

Objective

We examined associations between the frequency of fruit and vegetable (F&V) consumption and nutritional deficiencies among Brazilian schoolchildren.

Design

A cross-sectional, population-based study was performed. A short FFQ was used to assess consumption of fruits and vegetables (F&V) over the past month. The prevalence ratios (PR) and 95 % confidence intervals for stunting, obesity, anaemia, vitamin A and folate deficiencies, vitamin E and vitamin D insufficiencies were estimated for low F&V consumption frequency (vegetables ≤3 times/month and fruits ≤3 times/week) and compared with children with usual F&V consumption frequency (vegetables ≥1 time/week and fruits ≥4 times/week).

Setting

Acrelândia, Western Brazilian Amazon.

Subjects

A total of 702 children aged 4–10 years.

Results

Only 5 % of children consumed F&V ≥5 times/d. Prevalence of deficiency was 31 %, 15 %, 9 % and 2 % for vitamins D, A, E and folate, respectively. Overall, 6·3 % of children were anaemic, 3·3 % were stunted, 2·7 % were obese and 33 % had multiple nutritional deficiencies. Low frequency of F&V consumption was associated with lower plasma concentrations of carotenoids and vitamin E. Nutritional deficiencies were higher among non-consumers of F&V when compared with usual consumers: anaemia (PR=1·9; 95 % CI 1·0, 3·7), vitamin E insufficiency (PR=2·5; 95 % CI 1·5, 4·2), vitamin D insufficiency (PR=1·5; 95 % CI 1·1, 1·9) and stunting (PR=2·6; 95 % CI 1·1, 6·1).

Conclusions

In our study, the occurrence of nutritional deficiencies in children with low F&V consumption was twice as high as in children with usual F&V consumption, reinforcing the importance of effective actions to promote the consumption of F&V.

Do improvements in dietary behaviour contribute to cardiovascular risk factor reduction over and above cardio-protective medication in newly diagnosed diabetes patients?

BACKGROUND/OBJECTIVES

A healthy diet is an integral component of successful diabetes management. However, the comparative importance of adopting a healthy diet for cardiovascular risk factor reduction over and above medication use among newly diagnosed diabetes patients remains unclear.

SUBJECTS/METHODS

We computed a dietary score consistent with American Diabetes Association and Diabetes UK recommendations in 574 newly diagnosed diabetes patients by summing standardised values for the intake of total energy, saturated fat, sodium, fibre and plasma vitamin C. In linear regression analyses, stratified by cardio-protective medication use (yes/no), we quantified the comparative longitudinal associations of baseline diet and change in diet over 1 year with change in blood pressure, HbA1c and lipids.

RESULTS

Baseline diet was generally not predictive of change in cardiovascular risk factor levels at 1 year. In contrast, dietary change over 1 year among patients prescribed and not prescribed cardio-protective medication after baseline was associated with comparative (p-interaction all ⩾0.95) reductions in diastolic blood pressure (-2.38 vs -2.93 mm Hg, respectively) and triglycerides (-0.31 vs -0.21 mmol/l, respectively), independent of potential confounding factors and change from baseline to follow-up in physical activity and smoking status.

CONCLUSIONS

Modest dietary change over the first year following diagnosis of diabetes was associated with reductions in blood pressure and triglycerides, over and above the effects of cardio-protective medication. Our findings support the notion that dietary change should be viewed as an integral component of successful diabetes self-management, irrespective of medication use.

Diet patterns and risk of squamous cell oesophageal carcinoma: a case-control study in Uruguay

BACKGROUND

Oesophageal cancer presents high incidence rates in the so-called Brazilian-Uruguayan belt.

MATERIALS AND METHODS

The present study included 1,170 participants (234 cases and 936 controls) which were analyzed by unconditional multiple logistic regression in order to examine risk of oesophageal squamous cell carcinoma (OESCC) associated with several food groups.

RESULTS

Boiled red meat (OR 2.59, 95%CI 1.69-3.97), lamb meat (OR 1.64, 95%CI 1.07-2.51), processed meat (OR 1.49, 95%CI 1.01-2.21), whole milk (OR 1.78, 1.19-1.68), fresh vegetables and fruits (OR 0.42, 95%CI 0.27-0.63), mate consumption (OR 2.04, 95%CI 1.32- 3.16), and black tea (OR 0.10, 95%CI 0.04-0.28) were significantly associated with risk of OESCC.

CONCLUSIONS

Hot beverages (mate) and hot foods (boiled meat) appear to be important determinants in the risk of OESCC, allowing the penetration of carcinogens in tobacco and alcohol into the oesophageal mucosa.

Vitamin C intake, circulating vitamin C and risk of stroke: a meta-analysis of prospective studies

Background

Though vitamin C supplementation has shown no observed effects on stroke prevention in several clinical trials, uncertainty remains as to whether long‐term, low‐dose intake influences the development of stroke among general populations. Furthermore, the association between circulating vitamin C and the risk of stroke is also unclear. For further clarification of these issues, we conducted a meta‐analysis of prospective studies.

Methods and Results

PubMed and EMBASE databases were searched, and the bibliographies of the retrieved articles were also reviewed to identify eligible studies. Summary relative risk (RRs) with corresponding 95% confidence intervals (CIs) were computed with a random‐effects model. The summary RR for the high‐versus‐low categories was 0.81 (95% CI: 0.74 to 0.90) for dietary vitamin C intake (11 studies), and 0.62 (95% CI: 0.49 to 0.79) for circulating vitamin C (6 studies). The summary RR for each 100 mg/day increment in dietary vitamin C was 0.83 (95% CI: 0.75 to 0.93) (10 studies), and for each 20 μmol/L increment in circulating vitamin C was 0.81 (95% CI: 0.75 to 0.88) (5 studies). Few studies reported results for vitamin C supplements (RR for high‐versus‐low intake=0.83, 95% CI: 0.62 to 1.10, 3 studies).

Conclusions

This meta‐analysis suggests significant inverse relationships between dietary vitamin C intake, circulating vitamin C, and risk of stroke.

Use of food frequency questionnaire to assess relationships between dietary habits and cardiovascular risk factors in NESCAV study: validation with biomarkers

BACKGROUND

Validation of Food frequency questionnaire (FFQ) is particularly important element, as incorrect information may lead to false associations between dietary factors and diseases. The aim of the study was to evaluate the validity of the FFQ used in NESCAV (Nutrition, Environment and Cardiovascular Health) study, by comparing the estimated intakes of fruits and vegetables and of several micro-nutrients with corresponding nutritional biomarkers.

METHODS

Relative validity was assessed in a sample of 922 subjects (452 men and 470 women). Comparisons between FFQ-estimates and their corresponding biomarkers were performed through correlation and cross classification into quintiles by using both crude and energy-adjusted FFQ-estimates. Correlations adjusted for confounders were also computed. All analyses were performed separately for men and women.

RESULTS

Concerning micro-nutrients, significant correlations were found for vitamin B9, D, E, B12 β-carotene and iodine in both men and women. Energy-adjustment led to an increase of all correlations cited previously. However, after excluding supplement users, correlations for vitamin D were not significant anymore. Concerning fruits and vegetables, all correlations were significant. Vegetables alone and fruits and vegetables correlated better in men (r around 0.2) than in women (r around 0.1). In men, correlation was also better for vegetables alone and fruits and vegetables than fruits alone.

CONCLUSION

These data demonstrate that this FFQ is a reasonable tool to assess intakes of fruits and vegetables and of several micro-nutrients. We conclude that our FFQ is suitable to be used in NESCAV study, although protein and vitamin D estimates should be interpreted with caution.

Synthetic or food-derived vitamin C--are they equally bioavailable?

Vitamin C (ascorbate) is an essential water-soluble micronutrient in humans and is obtained through the diet, primarily from fruits and vegetables. In vivo, vitamin C acts as a cofactor for numerous biosynthetic enzymes required for the synthesis of amino acid-derived macromolecules, neurotransmitters, and neuropeptide hormones, and is also a cofactor for various hydroxylases involved in the regulation of gene transcription and epigenetics. Vitamin C was first chemically synthesized in the early 1930s and since then researchers have been investigating the comparative bioavailability of synthetic versus natural, food-derived vitamin C. Although synthetic and food-derived vitamin C is chemically identical, fruit and vegetables are rich in numerous nutrients and phytochemicals which may influence its bioavailability. The physiological interactions of vitamin C with various bioflavonoids have been the most intensively studied to date. Here, we review animal and human studies, comprising both pharmacokinetic and steady-state designs, which have been carried out to investigate the comparative bioavailability of synthetic and food-derived vitamin C, or vitamin C in the presence of isolated bioflavonoids. Overall, a majority of animal studies have shown differences in the comparative bioavailability of synthetic versus natural vitamin C, although the results varied depending on the animal model, study design and body compartments measured. In contrast, all steady state comparative bioavailability studies in humans have shown no differences between synthetic and natural vitamin C, regardless of the subject population, study design or intervention used. Some pharmacokinetic studies in humans have shown transient and small comparative differences between synthetic and natural vitamin C, although these differences are likely to have minimal physiological impact. Study design issues and future research directions are discussed.

Mood improvement in young adult males following supplementation with gold kiwifruit, a high-vitamin C food

Enhanced intakes of fruit and vegetables have been associated with improved psychological well-being. We investigated the potential mood-enhancing effects of kiwifruit, a fruit rich in vitamin C and a number of other important micronutrients. Young adult males (n 35) were supplemented with either half or two kiwifruit/d for 6 weeks. Profile of Mood States questionnaires were completed at baseline and following the intervention. No effect on overall mood was observed in the half a kiwifruit/d group; however, a 35 % (P = 0·06) trend towards a decrease in total mood disturbance and a 32 % (P = 0·063) trend towards a decrease in depression were observed in the two kiwifruit/d group. Subgroup analysis indicated that participants with higher baseline mood disturbance exhibited a significant 38 % (P = 0·029) decrease in total mood disturbance, as well as a 38 % (P = 0·048) decrease in fatigue, 31 % (P = 0·024) increase in vigour and a 34 % (P = 0·075) trend towards a decrease in depression, following supplementation with two kiwifruit/d. There was no effect of two kiwifruit/d on the mood scores of participants with lower baseline mood disturbance. Dietary intakes and body status of specific micronutrients indicated a significant increase in the participants' vitamin C intakes and corresponding plasma levels of the vitamin. The results indicate that enhanced intake of kiwifruit by individuals with moderate mood disturbance can improve overall mood.

Reproducibility and relative validity of a brief quantitative food frequency questionnaire for assessing fruit and vegetable intakes in North-African women

BACKGROUND

In the context of a rapidly increasing prevalence of noncommunicable diseases, fruit and vegetables could play a key preventive role. To date, there is no rapid assessment tool available for measuring the fruit and vegetable intakes of North-African women. The present study aimed to investigate the reproducibility and relative validity of an eight-item quantitative food frequency questionnaire that measures the fruit and vegetable intakes (FV-FFQ) of Moroccan women.

METHODS

During a 1-week period, 100 women, living in the city of Rabat, Morocco (aged 20-49 years) completed the short FV-FFQ twice: once at baseline (FV-FFQ1) and once at the end of the study (FV-FFQ2). In the mean time, participants completed three 24-h dietary recalls. All questionnaires were administered by interviewers. Reproducibility was assessed by computing Spearman's correlation coefficients, intraclass correlation (ICC) coefficients and kappa statistics. Relative validity was assessed by computing Wilcoxon signed-rank tests and Spearman's correlation coefficients, as well as by performing Bland-Altman plots.

RESULTS

In terms of reproducibility, Spearman's correlation coefficient was 0.56; ICC coefficient was 0.68; and weighted kappa was 0.35. In terms of relative validity, compared with the three 24-h recalls, the FV-FFQ slightly underestimated mean fruit and vegetable intakes (-10.9%; P = 0.006); Spearman's correlation coefficient was 0.69; at the individual level, intakes measured by the FV-FFQ were between 0.39 and 2.19 times those measured by the 24-h recalls.

CONCLUSIONS

The brief eight-item FV-FFQ is a reliable and relatively valid tool for measuring mean fruit and vegetable intakes at the population level, although this is not the case at the individual level.