Six carotenoids in plasma used to assess recommended intake of fruits and vegetables in a controlled feeding study

Weight reduction and dietary improvements in a cluster-randomised controlled trial for adults with intellectual disabilities

Background

People with intellectual disabilities (IDs) have an increased risk of obesity and health concerns related to their nutritional status and dietary intake.

Objective

To assess the effectiveness of a multi-component intervention on weight, waist circumference (WC), clinical health parameters and dietary habits in a group of overweight and obese adults with mild-to-moderate ID.

Design

A 7-month cluster-randomised trial and a 7-month follow-up of the intervention group after the end of intervention when the group received usual care. The intervention consisted of monthly dietary-group courses tailored to the participants' cognitive abilities and practical skills, monthly nutritional courses for staff, use of behaviour change techniques and nudging. The control group received usual care during the intervention.

Results

There were 32 participants aged 22-61 years: 15 in the intervention group and 17 in the control group. After 7 months, a non-significant weight difference (median difference = -1.25 kg; 95% confidence interval [CI] = -2.00; 0.95 vs. +1.00 kg; CI = -1.15; 3.00, P = 0.08) and a significant WC difference were observed between the intervention and control groups (median difference = -3.75 cm; CI: -7.68; 0.11 vs. 0 cm; CI = -3.99; 1.00, P = 0.03), respectively. The median reduction in WC continued in the intervention group during the 7-month follow-up (median difference = -7.50 cm; CI: -13.57; -3.16, P = 0.002). A significant difference in frequency intake of fruit (P = 0.03) and berries (P = 0.004) was observed between the groups after 7 months, supported by a significant increase in measured serum-carotenoid levels in the intervention group after 7 months (median difference = 0.26 mmol/L; CI: -0.12; 0.52, P = 0.007).

Conclusions

A significant difference in WC was observed between the groups, accompanied by changes in blood parameters and dietary habits.

A nutritional biomarker score of the Mediterranean diet and incident type 2 diabetes: Integrated analysis of data from the MedLey randomised controlled trial and the EPIC-InterAct case-cohort study

BACKGROUND

Self-reported adherence to the Mediterranean diet has been modestly inversely associated with incidence of type 2 diabetes (T2D) in cohort studies. There is uncertainty about the validity and magnitude of this association due to subjective reporting of diet. The association has not been evaluated using an objectively measured biomarker of the Mediterranean diet.

METHODS AND FINDINGS

We derived a biomarker score based on 5 circulating carotenoids and 24 fatty acids that discriminated between the Mediterranean or habitual diet arms of a parallel design, 6-month partial-feeding randomised controlled trial (RCT) conducted between 2013 and 2014, the MedLey trial (128 participants out of 166 randomised). We applied this biomarker score in an observational study, the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study, to assess the association of the score with T2D incidence over an average of 9.7 years of follow-up since the baseline (1991 to 1998). We included 22,202 participants, of whom 9,453 were T2D cases, with relevant biomarkers from an original case-cohort of 27,779 participants sampled from a cohort of 340,234 people. As a secondary measure of the Mediterranean diet, we used a score estimated from dietary-self report. Within the trial, the biomarker score discriminated well between the 2 arms; the cross-validated C-statistic was 0.88 (95% confidence interval (CI) 0.82 to 0.94). The score was inversely associated with incident T2D in EPIC-InterAct: the hazard ratio (HR) per standard deviation of the score was 0.71 (95% CI: 0.65 to 0.77) following adjustment for sociodemographic, lifestyle and medical factors, and adiposity. In comparison, the HR per standard deviation of the self-reported Mediterranean diet was 0.90 (95% CI: 0.86 to 0.95). Assuming the score was causally associated with T2D, higher adherence to the Mediterranean diet in Western European adults by 10 percentiles of the score was estimated to reduce the incidence of T2D by 11% (95% CI: 7% to 14%). The study limitations included potential measurement error in nutritional biomarkers, unclear specificity of the biomarker score to the Mediterranean diet, and possible residual confounding.

CONCLUSIONS

These findings suggest that objectively assessed adherence to the Mediterranean diet is associated with lower risk of T2D and that even modestly higher adherence may have the potential to reduce the population burden of T2D meaningfully.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000602729 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363860.

Root Vegetables-Composition, Health Effects, and Contaminants

Root vegetables are known all over the world, but they are being less and less consumed by individuals. The main purpose of this article was to summarize the benefits, health effects, and threats associated with the consumption of carrot, celery, parsley, beetroot, radish, turnip, and horseradish. They are characterized by high nutritional value due to their richness in dietary fiber, vitamins, and minerals. One of their most important features is their high content of bioactive compounds, such as polyphenols, phenols, flavonoids, and vitamin C. These compounds are responsible for antioxidant potential. Comparison of their antioxidant effects is difficult due to the lack of standardization among methods used for their assessment. Therefore, there is a need for a reference method that would allow for correct interpretation. Moreover, root vegetables are characterized by several health-promoting effects, including the regulation of metabolic parameters (glucose level, lipid profile, and blood pressure), antioxidant potential, prebiotic function, and anti-cancer properties. However, due to the type of cultivation, root vegetables are vulnerable to contaminants from the soil, such as toxic metals (lead and cadmium), pesticides, pharmaceutical residues, microplastics, and nitrates. Regardless, the low levels of toxic substances present in root vegetables do not pose health risks to the average consumer.

Improving the Bioaccessibility and Bioavailability of Carotenoids by Means of Nanostructured Delivery Systems: A Comprehensive Review

Carotenoids are bioactive compounds provided by the diet playing a key role in maintaining human health. Therefore, they should be ingested daily in an adequate amount. However, even a varied and well-balanced diet does not guarantee an adequate intake, as both the bioaccessibility and bioavailability of the compounds significantly affect their absorption. This review summarizes the main results achieved in improving the bioaccessibility and bioavailability of carotenoids by means of nanostructured delivery systems, discussing in detail the available lipid-based and biopolymeric nanocarriers at present, with a focus on their formulation and functional efficiency. Although the toxicity profile of these innovative delivery systems is not fully understood, especially for long-term intake, these systems are an effective and valuable approach to increase the availability of compounds of nutritional interest.

Harvest for Health, a Randomized Controlled Trial Testing a Home-Based, Vegetable Gardening Intervention Among Older Cancer Survivors Across Alabama: An Analysis of Accrual and Modifications Made in Intervention Delivery and Assessment During COVID-19

BACKGROUND

Accelerated functional decline is a concern among older cancer survivors that threatens independence and quality of life. Pilot studies suggest that vegetable gardening interventions ameliorate functional decline through improved diet and physical activity.

OBJECTIVE

The aim of this article was to describe the rationale, recruitment challenges, and enrollment for the Harvest for Health randomized controlled trial (RCT), which will test the impact of a home-based, vegetable gardening intervention on vegetable and fruit consumption, physical activity, and physical functioning among older cancer survivors. Modifications made to the intervention and assessments to assure safety and continuity of the RCT throughout the COVID-19 pandemic also are reported.

DESIGN

Harvest for Health is a 2-year, 2-arm, single-blinded, wait-list controlled RCT with cross-over.

PARTICIPANTS/SETTING

Medicare-eligible survivors of cancers with ≥60% 5-year survival were recruited across Alabama from October 1, 2016 to February 8, 2021.

INTERVENTION

Participants were randomly assigned to a wait-list control or a 1-year home-based gardening intervention and individually mentored by extension-certified master gardeners to cultivate spring, summer, and fall vegetable gardens.

MAIN OUTCOME MEASURES

Although the RCT's primary end point was a composite measure of vegetable and fruit consumption, physical activity, and physical functioning, this article focuses on recruitment and modifications made to the intervention and assessments during COVID-19.

STATISTICAL ANALYSES PERFORMED

χ2 and t tests (α < .05) were used to compare enrolled vs unenrolled populations.

RESULTS

Older cancer survivors (n = 9,708) were contacted via mail and telephone; 1,460 indicated interest (15% response rate), 473 were screened eligible and consented, and 381 completed baseline assessments and were randomized. Enrollees did not differ from nonrespondents/refusals by race and ethnicity, or rural-urban status, but comprised significantly higher numbers of comparatively younger survivors, those who were female, and survivors of breast cancer (P < .001). Although COVID-19 delayed trial completion, protocol modifications overcame this barrier and study completion is anticipated by June 2022.

CONCLUSIONS

This RCT will provide evidence on the effects of a mentored vegetable gardening program among older cancer survivors. If efficacious, Harvest for Health represents a novel, multifaceted approach to improve lifestyle behaviors and health outcomes among cancer survivors-one with capacity for sustainability and widespread dissemination.

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.

Maternal Serum Antioxidants in Mid Pregnancy and Risk of Preterm Delivery and Small for Gestational Age Birth: Results from a Prospective Pregnancy Cohort

Background: Preterm delivery (PTD) and poor fetal growth are major contributors to neonatal mortality and morbidity that can extend from birth onward. Although overt maternal nutrient deficiencies are associated with adverse pregnancy outcomes, such deficiencies are rare in developed countries. However, some evidence suggests that even within the normal range, higher levels of antioxidant nutrients are protective against adverse pregnancy outcomes. Materials and Methods: Using data from the prospective Pregnancy Outcomes and Community Health (POUCH) Study (n = 301 preterm; n = 246 term), we examined associations between maternal blood levels of selected antioxidants and pregnancy outcomes. Serum collected at 16-27 weeks' gestation was analyzed for carotenoids, retinol, and α- and γ-tocopherol. Using weighted polytomous regression, these nutrient concentrations were assessed in relation to (1) PTD (<37 weeks gestation) overall and grouped as spontaneous or medically indicated; and (2) small for gestational age (SGA) defined as birthweight-for-gestational age <10th percentile of a national reference population. Results: Women with total serum carotenoids in the upper quartile (Q4) had significantly lower odds of medically indicated PTD compared with women in the lower quartiles (Q1-Q3) even after adjustment for maternal characteristics (aOR = 0.4; 95% CI: 0.2-0.9). Odds ratios for SGA were consistently ≤0.5 among women with any of the serum nutrients in Q4 as compared with Q1-Q3, but final models did not reach statistical significance. Conclusion: Results support the possibility that high maternal serum antioxidants and/or the larger dietary or lifestyle pattern they represent may play a protective role in preventing adverse pregnancy outcomes.

Development of a short food frequency questionnaire to assess diet quality in UK adolescents using the National Diet and Nutrition Survey

BACKGROUND

UK adolescents consume fewer fruits and vegetables and more free sugars than any other age group. Established techniques to understand diet quality can be difficult to use with adolescents because of high participant burden. This study aimed to identify key foods that indicate variation in diet quality in UK adolescents for inclusion in a short food frequency questionnaire (FFQ) and to investigate the associations between adolescent diet quality, nutritional biomarkers and socio-demographic factors.

METHODS

Dietary, demographic and biomarker data from waves 1-8 of the National Diet and Nutrition Survey rolling programme were used (n=2587; aged 11-18 years; 50% boys; n=≤997 biomarker data). Principal component analysis (PCA) was applied to 139 food groups to identify the key patterns within the data. Two diet quality scores, a 139-group and 20-group, were calculated using the PCA coefficients for each food group and multiplying by their standardised reported frequency of consumption and then summing across foods. The foods with the 10 strongest positive and 10 strongest negative coefficients from the PCA results were used for the 20-group score. Scores were standardised to have a zero mean and standard deviation of one.

RESULTS

The first PCA component explained 3.0% of variance in the dietary data and described a dietary pattern broadly aligned with UK dietary recommendations. A correlation of 0.87 was observed between the 139-group and 20-group scores. Bland-Altman mean difference was 0.00 and 95% limits of agreement were - 0.98 to 0.98 SDs. Correlations, in the expected direction, were seen between each nutritional biomarker and both scores; results attenuated slightly for the 20-group score compared to the 139-group score. Better diet quality was observed among girls, non-white populations and in those from higher socio-economic backgrounds for both scores.

CONCLUSIONS

The diet quality score based on 20 food groups showed reasonable agreement with the 139-group score. Both scores were correlated with nutritional biomarkers. A short 20-item FFQ can provide a meaningful and easy-to-implement tool to assess diet quality in large scale observational and intervention studies with adolescents.

Association of plasma biomarkers of fruit and vegetable intake with incident type 2 diabetes: EPIC-InterAct case-cohort study in eight European countries

OBJECTIVE

To investigate the association of plasma vitamin C and carotenoids, as indicators of fruit and vegetable intake, with the risk of type 2 diabetes.

DESIGN

Prospective case-cohort study.

SETTING

Populations from eight European countries.

PARTICIPANTS

9754 participants with incident type 2 diabetes, and a subcohort of 13 662 individuals from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort of 340 234 participants: EPIC-InterAct case-cohort study.

MAIN OUTCOME MEASURE

Incident type 2 diabetes.

RESULTS

In a multivariable adjusted model, higher plasma vitamin C was associated with a lower risk of developing type 2 diabetes (hazard ratio per standard deviation 0.82, 95% confidence interval 0.76 to 0.89). A similar inverse association was shown for total carotenoids (hazard ratio per standard deviation 0.75, 0.68 to 0.82). A composite biomarker score (split into five equal groups), comprising vitamin C and individual carotenoids, was inversely associated with type 2 diabetes with hazard ratios 0.77, 0.66, 0.59, and 0.50 for groups 2-5 compared with group 1 (the lowest group). Self-reported median fruit and vegetable intake was 274 g/day, 396 g/day, and 508 g/day for participants in categories defined by groups 1, 3, and 5 of the composite biomarker score, respectively. One standard deviation difference in the composite biomarker score, equivalent to a 66 (95% confidence interval 61 to 71) g/day difference in total fruit and vegetable intake, was associated with a hazard ratio of 0.75 (0.67 to 0.83). This would be equivalent to an absolute risk reduction of 0.95 per 1000 person years of follow up if achieved across an entire population with the characteristics of the eight European countries included in this analysis.

CONCLUSIONS

These findings indicate an inverse association between plasma vitamin C, carotenoids, and their composite biomarker score, and incident type 2 diabetes in different European countries. These biomarkers are objective indicators of fruit and vegetable consumption, and suggest that diets rich in even modestly higher fruit and vegetable consumption could help to prevent development of type 2 diabetes.

Nutritional Importance of Carotenoids and Their Effect on Liver Health: A Review

The consumption of carotenoids has beneficial effects on health, reducing the risk of certain forms of cancer, cardiovascular diseases, and macular degeneration, among others. The mechanism of action of carotenoids has not been clearly identified; however, it has been associated with the antioxidant capacity of carotenoids, which acts against reactive oxygen species and inactivating free radicals, although it has also been shown that carotenoids modulate gene expression. Dietary carotenoids are absorbed and accumulated in the liver and other organs, where they exert their beneficial effects. In recent years, it has been described that the intake of carotenoids can significantly reduce the risk of suffering from liver diseases, such as non-alcoholic fatty liver disease (NAFLD). This disease is characterized by an imbalance in lipid metabolism producing the accumulation of fat in the hepatocyte, leading to lipoperoxidation, followed by oxidative stress and inflammation. In the first phases, the main treatment of NAFLD is to change the lifestyle, including dietary habits. In this sense, carotenoids have been shown to have a hepatoprotective effect due to their ability to reduce oxidative stress and regulate the lipid metabolism of hepatocytes by modulating certain genes. The objective of this review was to provide a description of the effects of dietary carotenoids from fruits and vegetables on liver health.

Mechanisms of Transport and Delivery of Vitamin A and Carotenoids to the Retinal Pigment Epithelium

Vision depends on the delivery of vitamin A (retinol) to the retina. Retinol in blood is bound to retinol-binding protein (RBP). Retinal pigment epithelia (RPE) cells express the RBP receptor, STRA6, that facilitates uptake of retinol. The retinol is then converted to retinyl esters by the enzyme lecithin:retinol acyltransferase. The esters are the substrate for RPE65, an enzyme that produces 11-cis retinol, which is converted to 11-cis retinaldehyde for transport to the photoreceptors to form rhodopsin. The dietary xanthophylls, lutein (LUT) and zeaxanthin (ZEA), accumulate in the macula of the eye, providing protection against age-related macular degeneration. To reach the macula, carotenoids cross the RPE. In blood, xanthophylls and β-carotene mostly associate with high-density lipoprotein (HDL) and low-density lipoprotein (LDL), respectively. Studies using a human RPE cell model evaluate the kinetics of cell uptake when carotenoids are delivered in LDL or HDL. For LUT and β-carotene, LDL delivery result in the highest rate of uptake. HDL is more effective in delivering ZEA (and meso-ZEA). This selective HDL-mediated uptake of ZEA, via a scavenger receptor and LDL-mediated uptake of LUT and β-carotene provides a mechanism for the selective accumulation of ZEA > LUT and xanthophylls over β-carotene in the macula.

Proteomic responses of carotenoid and retinol administration to Mongolian gerbils

Various health benefits of carotenoids have been described. However, while human observational studies generally suggest positive health effects, supplementation with relatively high doses of individual carotenoids (supplements) have partly produced adverse effects. In the present study, we investigated the effect of several carotenoids on the proteomic response of male Mongolian gerbils (aged 6 weeks). Five groups of gerbils (n = 6 per group) received either retinol (vitamin A/53 mg per kg bw), all-trans β-carotene (pro-vitamin A/100 mg kg-1), the non-pro vitamin A carotenoid lutein (100 mg kg-1), the acyclic carotenoid lycopene (100 mg kg-1) or vehicle (Cremophor EL), via oral single gavage. Gerbils were 12 h post-prandially sacrificed and blood plasma, liver, and white adipose tissue were collected. For liver and adipose tissue, a 2D-DIGE (difference gel electrophoresis) approach was conducted; for plasma, proteomic analyses were achieved by liquid chromatography-mass spectrometry. Compared to controls (vehicle), various proteins were showing significant abundance variations in plasma (66), liver (29) and adipose tissue (19), especially regarding structure (22), protein metabolism (15) and immune system/inflammation (19) functions, while proteins related to antioxidant effects were generally less abundant, suggesting no in vivo relevance. Surprisingly, a large overlap in protein regulation was found between lycopene and retinol exposure, while other carotenoids, including all-trans β-carotene, did not show this overlap. Mainly retinoid acid receptor co-regulated proteins may mechanistically explain this overlapping regulation. This overlapping regulation may be related to common nuclear hormone receptor mediated signalling, though further studies using synthetic ligands of retinoid receptors targeting protein regulation are needed for confirmation.

Carotenoid Intake and Serum Concentration in Young Finnish Children and Their Relation with Fruit and Vegetable Consumption

Fruit and vegetable intake has been associated with a reduced risk of many chronic diseases. These foods are the main dietary source of carotenoids. The aim of the present study was to evaluate the associations between dietary intake and serum concentrations of α- and β-carotene in a sample of young Finnish children from the population-based birth cohort of the Type 1 Diabetes Prediction and Prevention (DIPP) Study. The current analysis comprised 3-day food records and serum samples from 207 children aged 1, 2 and 3 years. Spearman and partial correlations, as well as a cross-classification analyses, were used to assess the relationship between dietary intake and the corresponding biomarkers. Serum concentrations of α- and β-carotene were significantly higher among the 1-year-old compared to the 3-year-old children. Dietary intakes of α- and β-carotene correlated significantly with their respective serum concentrations in all age groups, the association being highest at the age of 1 year (α-carotene r = 0.48; p < 0.001 and β-carotene r = 0.47; p < 0.001), and lowest at the age of 3 years (α-carotene r = 0.44; p < 0.001 and β-carotene r = 0.30; p < 0.001). A cross-classification showed that 72⁻81% of the participants were correctly classified to the same or adjacent quartile, when comparing the reported dietary intakes and the concentrations of the corresponding carotenoid in serum. The 3-day food record seems to be reasonably valid in the assessment of root vegetable consumption among young Finnish children. Root vegetables were the main dietary source of both carotenoids in all age groups. The high consumption of commercial baby foods among the 1-year-old children was reflected in the relatively high dietary intake and serum concentration of both carotenoids.

Reduced Carotenoid and Retinoid Concentrations and Altered Lycopene Isomer Ratio in Plasma of Atopic Dermatitis Patients

Carotenoids and retinoids are known to alter the allergic response with important physiological roles in the skin and the immune system. In the human organism various carotenoids are present, some of which are retinoid precursors. The bioactive derivatives of these retinoids are the retinoic acids, which can potently activate nuclear hormone receptors such as the retinoic acid receptor and the retinoid X receptor. In this study, we aimed to assess how plasma carotenoid and retinoid concentrations along with the ratio of their isomers are altered in atopic dermatitis (AD) patients (n = 20) compared to healthy volunteers (HV, n = 20). The study indicated that plasma levels of the carotenoids lutein (HV 198 ± 14 ng/mL, AD 158 ± 12 ng/mL, p = 0.02; all values in mean ± SEM), zeaxanthin (HV 349 ± 30 ng/mL, AD 236 ± 18 ng/mL, p ≤ 0.01), as well as the retinoids retinol (HV 216 ± 20 ng/mL, AD 167 ± 17 ng/mL, p = 0.04) and all-trans-retinoic acid (HV 1.1 ± 0.1 ng/mL, AD 0.7 ± 0.1 ng/mL, p = 0.04) were significantly lower in the AD-patients, while lycopene isomers, α-carotene, and β-carotene levels were comparable to that determined in the healthy volunteers. In addition, the ratios of 13-cis- vs. all-trans-lycopene (HV 0.31 ± 0.01, AD 0.45 ± 0.07, p = 0.03) as well as 13-cis- vs. all-trans-retinoic acid (HV 1.4 ± 0.2, AD 2.6 ± 0.6, p = 0.03) were increased in the plasma of AD-patients indicating an AD-specific 13-cis-isomerisation. A positive correlation with SCORAD was calculated with 13-cis- vs. all-trans-lycopene ratio (r = 0.40, p = 0.01), while a negative correlation was observed with zeaxanthin plasma levels (r = -0.42, p = 0.01). Based on our results, we conclude that in the plasma of AD-patients various carotenoids and retinoids are present at lower concentrations, while the ratio of selected lycopene isomers also differed in the AD-patient group. An increase in plasma isomers of both lycopene and retinoic acid may cause an altered activation of nuclear hormone receptor signaling pathways and thus may be partly responsible for the AD-phenotype.

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.

Genetic and Common Environmental Contributions to Familial Resemblances in Plasma Carotenoid Concentrations in Healthy Families

Carotenoids have shown an interindividual variability that may be due to genetic factors. The only study that has reported heritability of serum α- and β-carotene has not considered the environmental component. This study aimed to estimate the contribution of both genetic and common environmental effects to the variance of carotenoid concentrations and to test whether their phenotypic correlations with cardiometabolic risk factors are explained by shared genetic and environmental effects. Plasma carotenoid concentrations (α-carotene, β-carotene, β-cryptoxanthin, lutein, lycopene, zeaxanthin, and total carotenoids) of 48 healthy subjects were measured. Heritability estimates of carotenoid concentrations were calculated using the variance component method. Lutein and lycopene showed a significant familial effect (p = 6 × 10^-6 and 0.0043, respectively). Maximal heritability, genetic heritability, and common environmental effect were computed for lutein (88.3%, 43.8%, and 44.5%, respectively) and lycopene (45.2%, 0%, and 45.2%, respectively). Significant phenotypic correlations between carotenoid concentrations and cardiometabolic risk factors were obtained for β-cryptoxanthin, lycopene, and zeaxanthin. Familial resemblances in lycopene concentrations were mainly attributable to common environmental effects, while for lutein concentrations they were attributable to genetic and common environmental effects. Common genetic and environmental factors may influence carotenoids and cardiometabolic risk factors, but further studies are needed to better understand the potential impact on disease development.

Combining traditional dietary assessment methods with novel metabolomics techniques: present efforts by the Food Biomarker Alliance

FFQ, food diaries and 24 h recall methods represent the most commonly used dietary assessment tools in human studies on nutrition and health, but food intake biomarkers are assumed to provide a more objective reflection of intake. Unfortunately, very few of these biomarkers are sufficiently validated. This review provides an overview of food intake biomarker research and highlights present research efforts of the Joint Programming Initiative 'A Healthy Diet for a Healthy Life' (JPI-HDHL) Food Biomarkers Alliance (FoodBAll). In order to identify novel food intake biomarkers, the focus is on new food metabolomics techniques that allow the quantification of up to thousands of metabolites simultaneously, which may be applied in intervention and observational studies. As biomarkers are often influenced by various other factors than the food under investigation, FoodBAll developed a food intake biomarker quality and validity score aiming to assist the systematic evaluation of novel biomarkers. Moreover, to evaluate the applicability of nutritional biomarkers, studies are presently also focusing on associations between food intake biomarkers and diet-related disease risk. In order to be successful in these metabolomics studies, knowledge about available electronic metabolomics resources is necessary and further developments of these resources are essential. Ultimately, present efforts in this research area aim to advance quality control of traditional dietary assessment methods, advance compliance evaluation in nutritional intervention studies, and increase the significance of observational studies by investigating associations between nutrition and health.

Lutein exerts anti-inflammatory effects in patients with coronary artery disease

BACKGROUND AND AIMS

Many coronary artery disease (CAD) patients exhibit chronic low-grade inflammation. Carotenoids are anti-oxidants with potential anti-inflammatory properties. Here, we first assessed relationships between interleukin (IL)-6 and individual carotenoids in plasma from CAD patients. Based on the results, we proceeded to assess anti-inflammatory effects of one carotenoid, lutein, in peripheral blood mononuclear cells (PBMCs) from CAD patients.

METHODS

Lutein + zeaxanthin (isomers with lutein being dominant), β-cryptoxanthin, lycopene, α- and β-carotene and IL-6 were measured in plasma from 134 patients with stable angina (SA) and 59 patients with acute coronary syndrome. In 42 patients, plasma measurements were also performed 3 months after coronary intervention. PBMCs from SA patients were pre-treated with lutein (1, 5 and 25 μM) for 24 h followed by 24 h incubation ± lipopolysaccharide (LPS). Cell pellets were collected for IL-6, IL-1β and TNF mRNA and intracellular lutein. Cytokine secretion was measured in cell media.

RESULTS

Only lutein + zeaxanthin were inversely correlated with IL-6 in SA patients at baseline (r = -0.366, p < 0.001) and follow-up (r = -0.546, p < 0.001). Ex vivo, lutein was taken up by PBMCs from SA patients in a dose- and time-dependent manner. Pre-treatment with lutein dose-dependently lowered LPS-induced secretion of IL-6, IL-1β (p < 0.01) and TNF (p < 0.05), and also reduced IL-6, IL-1β and TNF mRNA expression (p < 0.05).

CONCLUSIONS

Clinical findings highlighted the inverse association between lutein and IL-6 in CAD patients. Anti-inflammatory effects of lutein in PBMCs from CAD patients were consolidated in ex vivo experiments. Taken together, these results show that lutein has the potential to play a role in resolution of chronic inflammation in CAD patients.

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.

Mechanisms of selective delivery of xanthophylls to retinal pigment epithelial cells by human lipoproteins

The xanthophylls, lutein and zeaxanthin, are dietary carotenoids that selectively accumulate in the macula of the eye providing protection against age-related macular degeneration. To reach the macula, carotenoids cross the retinal pigment epithelium (RPE). Xanthophylls and β-carotene mostly associate with HDL and LDL, respectively. HDL binds to cells via a scavenger receptor class B1 (SR-B1)-dependent mechanism, while LDL binds via the LDL receptor. Using an in-vitro, human RPE cell model (ARPE-19), we studied the mechanisms of carotenoid uptake into the RPE by evaluating kinetics of cell uptake when delivered in serum or isolated LDL or HDL. For lutein and β-carotene, LDL delivery resulted in the highest rates and extents of uptake. In contrast, HDL was more effective in delivering zeaxanthin and meso-zeaxanthin leading to the highest rates and extents of uptake of all four carotenoids. Inhibitors of SR-B1 suppressed zeaxanthin delivery via HDL. Results show a selective HDL-mediated uptake of zeaxanthin and meso-zeaxanthin via SR-B1 and a LDL-mediated uptake of lutein. This demonstrates a plausible mechanism for the selective accumulation of zeaxanthin greater than lutein and xanthophylls over β-carotene in the retina. We found no evidence of xanthophyll metabolism to apocarotenoids or lutein conversion to meso-zeaxanthin.

Comparative validity of vitamin C and carotenoids as indicators of fruit and vegetable intake: a systematic review and meta-analysis of randomised controlled trials

Circulating vitamin C and carotenoids are used as biomarkers of fruit and vegetable intake in research, but their comparative validity has never been meta-analysed. PubMed, EMBASE, CENTRAL, CINAHL and Web of Science were systematically searched up to December 2013 for randomised trials of different amounts of fruit and vegetable provision on changes in blood concentrations of carotenoids or vitamin C. Reporting followed PRISMA guidelines. Evidence quality was assessed using the GRADE system. Random effects meta-analysis combined estimates and meta-regression tested for sub-group differences. In all, nineteen fruit and vegetable trials (n1382) measured at least one biomarker, of which nine (n667) included five common carotenoids and vitamin C. Evidence quality was low and between-trial heterogeneity (I2) ranged from 74 % for vitamin C to 94 % forα-carotene. Groups provided with more fruit and vegetables had increased blood concentrations of vitamin C,α-carotene,β-carotene,β-cryptoxanthin and lutein but not lycopene. However, no clear dose–response effect was observed. Vitamin C showed the largest between-group difference in standardised mean change from the pre-intervention to the post-intervention period (smd0·94; 95 % CI 0·66, 1·22), followed by lutein (smd0·70; 95 % CI 0·37, 1·03) andα-carotene (smd0·63; 95 % CI 0·25, 1·01), but all CI were overlapping, suggesting that none of the biomarkers responded more than the others. Therefore, until further evidence identifies a particular biomarker to be superior, group-level compliance to fruit and vegetable interventions can be indicated equally well by vitamin C or a range of carotenoids. High heterogeneity and a lack of dose–response suggest that individual-level biomarker responses to fruit and vegetables are highly variable.

Prediction of fruit and vegetable intake from biomarkers using individual participant data of diet-controlled intervention studies

Fruit and vegetable consumption produces changes in several biomarkers in blood. The present study aimed to examine the dose–response curve between fruit and vegetable consumption and carotenoid (α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein and zeaxanthin), folate and vitamin C concentrations. Furthermore, a prediction model of fruit and vegetable intake based on these biomarkers and subject characteristics (i.e. age, sex, BMI and smoking status) was established. Data from twelve diet-controlled intervention studies were obtained to develop a prediction model for fruit and vegetable intake (including and excluding fruit and vegetable juices). The study population in the present individual participant data meta-analysis consisted of 526 men and women. Carotenoid, folate and vitamin C concentrations showed a positive relationship with fruit and vegetable intake. Measures of performance for the prediction model were calculated using cross-validation. For the prediction model of fruit, vegetable and juice intake, the root mean squared error (RMSE) was 258·0 g, the correlation between observed and predicted intake was 0·78 and the mean difference between observed and predicted intake was − 1·7 g (limits of agreement: − 466·3, 462·8 g). For the prediction of fruit and vegetable intake (excluding juices), the RMSE was 201·1 g, the correlation was 0·65 and the mean bias was 2·4 g (limits of agreement: − 368·2, 373·0 g). The prediction models which include the biomarkers and subject characteristics may be used to estimate average intake at the group level and to investigate the ranking of individuals with regard to their intake of fruit and vegetables when validating questionnaires that measure intake.

Dietary aspects related to health and obesity in Williams syndrome, Down syndrome, and Prader-Willi syndrome

Background

Dietary aspects that might contribute to development of obesity and secondary conditions are not well documented in genetic subgroups associated with intellectual disability.

Objective

To describe the intake frequencies of selected foods in participants with Prader–Willi syndrome (PWS), Down syndrome (DS), and Williams syndrome (WS), and investigate the association with body mass index (BMI). To explore food-related autonomy and intake frequencies among persons with DS in different living arrangements.

Methods

Self-reported intake frequencies and measurement of plasma carotenoids and erythrocyte content of omega-3 fatty acids (FAs) were investigated in persons aged 16–42 years, with WS (n=21), DS (n=40), and PWS (n=20).

Results

A larger proportion of participants with PWS showed high-frequency intake of fruits (p=0.012) and vegetables (p=0.004), and had higher plasma carotenoids (p<0.001) compared to participants with DS and WS. Furthermore, a larger proportion of participants with WS were low-frequency consumers of fish (p=0.005), less likely to use omega-3 FA supplements (p=0.023), and had reduced erythrocyte concentrations of long-chain omega-3 FAs (p<0.001), compared to participants with PWS and DS. In DS, BMI was negatively associated with plasma carotenoids. Increased proportions of participants living in communities showed high-frequency intake of precooked meals (p=0.030), and a tendency toward high-frequency consumption of soft drinks (p=0.079), when compared to peers living with relatives. Participants in community residences were also more likely to participate frequently in food-related decisions and preparations.

Conclusions

Persons with WS had a less-favorable dietary pattern when compared to persons with PWS. A larger proportion of persons living in communities frequently consumed precooked meals and showed a tendency of high-frequency soft drink consumption. Otherwise, their intake frequencies of the investigated foods were similar to those living with relatives, but they participated more frequently in decisions and preparations of foods.

An Evidence-Based Systematic Review of Lutein by the Natural Standard Research Collaboration

An evidence-based systematic review of lutein by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

A dietary biomarker approach captures compliance and cardiometabolic effects of a healthy Nordic diet in individuals with metabolic syndrome

Assessment of compliance with dietary interventions is necessary to understand the observed magnitude of the health effects of the diet per se. To avoid reporting bias, different dietary biomarkers (DBs) could be used instead of self-reported data. However, few studies investigated a combination of DBs to assess compliance and its influence on cardiometabolic risk factors. The objectives of this study were to use a combination of DBs to assess compliance and to investigate how a healthy Nordic diet (ND) influences cardiometabolic risk factors in participants with high apparent compliance compared with the whole study population. From a recently conducted isocaloric randomized trial, SYSDIET (Systems Biology in Controlled Dietary Interventions and Cohort Studies), in 166 individuals with metabolic syndrome, several DBs were assessed to reflect different key components of the ND: canola oil (serum phospholipid α-linolenic acid), fatty fish [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)], vegetables (plasma β-carotene), and whole grains (plasma alkylresorcinols). High-fat dairy intake (expectedly low in the ND) was reflected by serum pentadecanoic acid. All participants with biomarker data (n = 154) were included in the analyses. Biomarkers were combined by using a biomarker rank score (DB score) and principal component analysis (PCA). The DB score was then used to assess compliance. During the intervention, median concentrations of alkylresorcinols, α-linolenic acid, EPA, and DHA were >25% higher in the ND individuals than in the controls (P < 0.05), whereas median concentrations of pentadecanoic acid were 14% higher in controls (P < 0.05). Median DB score was 57% higher in the ND than in controls (P < 0.001) during the intervention, and participants were ranked similarly by DB score and PCA score. Overall, estimates of group difference in cardiometabolic effects generally appeared to be greater among compliant participants than in the whole study population (e.g., estimates of treatment effects on blood pressure and lipoproteins were ∼1.5- to 2-fold greater in the most compliant participants), suggesting that poor compliance attenuated the dietary effects. With adequate consideration of their limitations, DB combinations (e.g., DB score) could be useful for assessing compliance in intervention studies investigating cardiometabolic effects of healthy dietary patterns. The study was registered at clinicaltrials.gov as NCT00992641.

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.

Plasma alkylresorcinols reflect important whole-grain components of a healthy Nordic diet

Biomarkers of dietary intake can be important tools in nutrition research. Our aim was to assess whether plasma alkylresorcinol (AR) and β-carotene concentrations could be used as dietary biomarkers for whole-grain, fruits and vegetables in a healthy Nordic diet (ND). Participants (n = 166), 30-65 y with a body mass index of 27-40 kg/m(2) and two more features of metabolic syndrome (International Diabetes Federation definition, slightly modified), were recruited through six centers in the Nordic countries and randomly assigned to an ND or control diet for 18 or 24 wk, depending on study center. Plasma AR and β-carotene were analyzed and nutrient intake calculated from 4-d food records. Median fiber intake increased in the ND group from 2.5 g/MJ at baseline to 4.1 g/MJ (P < 0.001) at end point (week 18 or 24), and median (IQR) fasting plasma total AR concentration increased from 73 (88) to 106 (108) nmol/L, or 45%, from baseline to end point (P < 0.001). The AR concentration was significantly higher in the ND group (P < 0.001) than in the control group at end point. β-Carotene intake tended to increase in the ND group (P = 0.07), but the plasma β-carotene concentration did not change significantly throughout the study and did not differ between the groups at follow-up. In conclusion, an ND resulted in higher dietary fiber intake and increased plasma total AR concentration compared with the control diet, showing that the total AR concentration might be a valid biomarker for an ND in which whole-grain wheat and rye are important components. No significant difference in plasma β-carotene concentrations was observed between the ND and control groups, suggesting that β-carotene may not be a sensitive enough biomarker of the ND.

Non-pro-vitamin A and pro-vitamin A carotenoids in atopy development

Carotenoids are important derivatives of the human diet and occur in high concentrations in the human organism. Various carotenoids are also present in human breast milk and are transferred to breast-fed children. The alternative to breastfeeding is supplementation with an infant milk formula, but these formulas contain only a limited variety of carotenoids. Our question is: 'What is the function of various carotenoids in human nutrition with a special emphasis on child development and the development of atopy?' In this review, the mechanisms of action of the most important non-pro-vitamin A and pro-vitamin A carotenoids: α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene and retinoids are discussed. In summary, the combination of carotenoids, especially lycopene, seems to be of great importance, and exclusive usage of β-carotene in infant formula may yield in an increased atopy prevalence mediated in various target organs like the skin, lungs and immune competent cells. We conclude that the determination of novel bioactive metabolites of various carotenoids, at various stages in different organs during atopy development, might be the key to understanding the potential importance of carotenoids on atopy development.

Molecular nutrition research: the modern way of performing nutritional science

In spite of amazing progress in food supply and nutritional science, and a striking increase in life expectancy of approximately 2.5 months per year in many countries during the previous 150 years, modern nutritional research has a great potential of still contributing to improved health for future generations, granted that the revolutions in molecular and systems technologies are applied to nutritional questions. Descriptive and mechanistic studies using state of the art epidemiology, food intake registration, genomics with single nucleotide polymorphisms (SNPs) and epigenomics, transcriptomics, proteomics, metabolomics, advanced biostatistics, imaging, calorimetry, cell biology, challenge tests (meals, exercise, etc.), and integration of all data by systems biology, will provide insight on a much higher level than today in a field we may name molecular nutrition research. To take advantage of all the new technologies scientists should develop international collaboration and gather data in large open access databases like the suggested Nutritional Phenotype database (dbNP). This collaboration will promote standardization of procedures (SOP), and provide a possibility to use collected data in future research projects. The ultimate goals of future nutritional research are to understand the detailed mechanisms of action for how nutrients/foods interact with the body and thereby enhance health and treat diet-related diseases.

Increasing the vegetable intake dose is associated with a rise in plasma carotenoids without modifying oxidative stress or inflammation in overweight or obese postmenopausal women

The optimal amount of vegetable consumption required to reduce chronic disease risk is widely debated. Intervention trials evaluating biological activity of vegetables at various doses are limited. We conducted a 3-dose, crossover feeding trial to test the hypothesis that vegetable intake is associated in a dose-dependent manner with increased plasma carotenoids and subsequently reduced oxidative stress and inflammation in 49 overweight, postmenopausal women. Participants were assigned in random order to 2 (130 g), 5 (287 g), and 10 (614 g) daily servings of fresh, greenhouse-grown vegetables for 3-wk intervals with a 4-wk washout period between treatments. Plasma total carotenoids significantly increased from 1.63 to 2.07 μmol/L with a dose of 2 vegetable servings, from 1.49 to 2.84 μmol/L with a dose of 5 vegetable servings, and from 1.40 to 4.42 μmol/L with a dose of 10 vegetable servings (pre-post paired ttests, all P < 0.001). The change during each feeding period increased with each dose level (P < 0.001). Urine concentrations of 8-isoprostane F2α, hexanoyl lysine, and serum high sensitivity C-reactive protein were not affected by any administered vegetable dose. In this variable-dose vegetable study, a dose-response for plasma carotenoids was demonstrated without significant change in oxidative stress and inflammation in overweight, postmenopausal women.

Fruit and vegetable intakes in relation to plasma nutrient concentrations in women in Shanghai, China

OBJECTIVE

To evaluate the validity of fruit and vegetable intakes as it relates to plasma carotenoid and vitamin C concentrations in Chinese women, using three classification schemes.

DESIGN

Intakes were calculated using an interviewer-administered FFQ. Fruits and vegetables, botanical groups and high-nutrient groups were evaluated. These three classification schemes were compared with plasma carotenoid and vitamin C concentrations from blood samples collected within 1 week of questionnaire completion.

SETTING

Shanghai, China.

SUBJECTS

Participants (n 2031) comprised women who had participated in a case-control study of diet and breast-related diseases nested within a randomized trial of breast self-examination among textile workers (n 266 064)

RESULTS

Fruit intake was significantly (P < 0·05) and positively associated with plasma concentrations of α-tocopherol, β-cryptoxanthin, lycopene, α-carotene, β-carotene, retinyl palmitate and vitamin C. Fruit intake was inversely associated with γ-tocopherol and lutein + zeaxanthin concentrations. Vegetable consumption was significantly and positively associated with γ-tocopherol and β-cryptoxanthin concentrations. Each botanical and high-nutrient group was also significantly associated with particular plasma nutrient concentrations. Fruit and vegetable intakes and most plasma nutrient concentrations were significantly associated with season of interview.

CONCLUSIONS

These results suggest that the manner in which fruits and vegetables are grouped leads to different plasma nutrient exposure information, which may be an important consideration when testing and generating hypotheses regarding disease risk in relation to diet. Interview season should be considered when evaluating the associations of reported intake and plasma nutrients with disease outcomes.

Compliance, tolerability and safety of two antioxidant-rich diets: a randomised controlled trial in male smokers

It has been suggested that antioxidants attenuate oxidative stress and prevent oxidative stress-related diseases. Paradoxically, randomised controlled trials (RCT) using pharmacological doses of antioxidant supplements have demonstrated harmful effects in smokers. The aim of the present study was to test the compliance, tolerability and safety of two food-based antioxidant-rich diets in smokers. One of the diets provided antioxidants at levels similar to that used in RCT using supplements which previously have generated harmful effects. The present study followed a randomised, parallel-arm dietary intervention for 8 weeks (n102) in male smokers (age ≥ 45 years). Participants were randomised to either antioxidant-rich diet, kiwi fruit or control groups. The antioxidant-rich foods provided about 300 mmol antioxidants/week from a wide range of plant-based food items. The kiwi fruit group consumed three kiwi fruits/d. Compliance to both diets was good. Only mild, undesirable events were reported by a minority of the participants. The safety of both diets was demonstrated as no potentially harmful or pro-oxidative effects were observed. In the antioxidant-rich diet group, the mean intake of antioxidants increased from 30 mmol/d at baseline to 62 mmol/d during the intervention. In conclusion, we have demonstrated that male smokers can comply with two food-based antioxidant-rich diets. Furthermore, the present study is the first to demonstrate the tolerability and safety of dietary antioxidants at levels similar to dosages provided in RCT using supplements. Such diets may be useful in future studies investigating whether dietary antioxidants may reduce oxidative stress and related diseases.

Effects of organic and conventional growth systems on the content of carotenoids in carrot roots, and on intake and plasma status of carotenoids in humans

BACKGROUND

The demand for organic food products has increased during the last decades due to their probable health effects, among others. A higher content of secondary metabolites such as carotenoids in organic food products has been claimed, though not documented, to contribute to increased health effects of organic foods. The aim was to study the impact of organic and conventional agricultural systems on the content of carotenoids in carrots and human diets. In addition, a human cross-over study was performed, measuring the plasma status of carotenoids in humans consuming diets made from crops from these agricultural systems.

RESULTS

The content of carotenoids in carrot roots and human diets was not significantly affected by the agricultural production system or year, despite differences in fertilisation strategy and levels. The plasma status of carotenoids increased significantly after consumption of the organic and conventional diets, but no systematic differences between the agricultural production systems were observed.

CONCLUSION

The expected higher content of presumed health-promoting carotenoids in organic food products was not documented in this study.

Relative validity of fruit and vegetable intake estimated from an FFQ, using carotenoid and flavonoid biomarkers and the method of triads

The aim of the present study was to validate the intakes of fruit, juice and vegetables from an FFQ. In sub-study I (n 147), intakes from the FFQ were evaluated against 7 d weighed food records (WR) and plasma carotenoid concentrations, whereas in sub-study II (n 85), the intakes were evaluated against plasma carotenoid concentrations and amounts of flavonoids in 24 h urine samples. Relative validity was evaluated by comparing median intakes, estimating correlation coefficients and validity coefficients using the method of triads. In sub-study I, we observed no significant difference in daily median fruit intake between the FFQ and the WR, whereas the intake of vegetables was higher from the FFQ than from the WR. The correlations between intakes from the FFQ and the WR ranged from 0·31 to 0·58. In sub-study II, the intakes of fruit and vegetables correlated significantly with plasma carotenoid concentrations and urinary flavonoids. The validity coefficients for the intakes of fruit and vegetables from the FFQ ranged from 0·61 to 0·88 in sub-study I and from 0·60 to 0·94 in sub-study II. In summary, based on the associations observed between intakes from the FFQ and the biomarkers and the FFQ validity coefficients, the FFQ was found valid and suitable for ranking individuals according to their usual intake of fruit, juice and vegetables.

Postradiotherapy plasma lutein, alpha-carotene, and beta-carotene are positively associated with survival in patients with head and neck squamous cell carcinoma

The aim of our study was to compare plasma carotenoids (i.e., biomarkers of fruits and vegetables intake) and tocopherols in 29 head and neck squamous cell carcinoma (HNSCC) patients with 51 healthy controls and to explore the possibility whether these plasma antioxidants could be related to outcome among patients. The patients' blood samples were taken at the end of radiotherapy. We observed that plasma lutein, zeaxanthin, alpha-carotene, beta-carotene, lycopene, and total carotenoids were significantly lower in HNSCC patients than controls. Among the patients, 18 died and 11 were still alive during median follow-up of 55 mo for survivors. We found a significant positive association between postradiotherapy plasma carotenoids (lutein, alpha-carotene, and beta-carotene) and progression-free survival in these patients. This study indicates that increasing postradiotherapy plasma carotenoid concentration may reduce risk of premature death or recurrence of tumor in HNSCC patients. Increasing plasma carotenoid concentration should be done by increasing intake of carotenoid-rich fruits and vegetables, as other studies have shown either no or negative effects due to use of carotenoid supplements.

Plant sterols from rapeseed and tall oils: effects on lipids, fat-soluble vitamins and plant sterol concentrations

BACKGROUND AND AIMS

Data comparing the impact of different sources of plant sterols on CVD risk factors and antioxidant levels is scarce. We evaluated the effects of plant sterols from rapeseed and tall oils on serum lipids, lipoproteins, fat-soluble vitamins and plant sterol concentrations.

METHODS AND RESULTS

This was a double-blinded, randomized, crossover trial in which 59 hypercholesterolemic subjects consumed 25 g/day of margarine for 4 weeks separated by 1 week washout periods. The two experimental margarines provided 2g/day of plant sterols from rapeseed or tall oil. The control margarine had no added plant sterols. The control margarine reduced LDL cholesterol by 4.5% (95% CI 1.4, 7.6%). The tall and rapeseed sterol margarines additionally reduced LDL cholesterol by 9.0% (95% CI 5.5, 12.4%) and 8.2% (95% CI 5.2, 11.4%) and apolipoprotein B by 5.3% (95% CI 1.0, 9.6%) and 6.9% (95% CI 3.6, 10.2%), respectively. Lipid-adjusted beta-carotene concentrations were reduced by both sterol margarines (P<0.017). alpha-Tocopherol concentrations were reduced by the tall sterol compared to the rapeseed sterol margarine (P=0.001). Campesterol concentrations increased more markedly with the rapeseed sterol versus tall sterol margarine (P<0.001). The rapeseed sterol margarine increased while the tall sterol margarine decreased brassicasterol concentrations (P<0.001).

CONCLUSIONS

Plant sterols from tall and rapeseed oils reduce atherogenic lipids and lipoproteins similarly. The rapeseed sterol margarine may have more favorable effects on serum alpha-tocopherol concentrations.

Effect of Spinacia oleraceae L. and Perilla frutescens L. on antioxidants and lipid peroxidation in an intervention study in healthy individuals

Daily consumption of fruits and vegetables is frequently recommended to prevent several diseases. This health-promoting effect is considered to be in part due to the antioxidant content of fruits and vegetables and their ability to decrease oxidative stress. To investigate whether the ingestion of preparations from spinach or perilla, two carotenoid-rich leafy vegetables, is followed by an increase in carotenoid concentration and/or affects parameters of oxidative stress in human blood plasma. 12 healthy volunteers ingested a perilla- or spinach preparation for 10 days (5 mg lutein/d). We quantified antioxidant levels in plasma, kinetics of lipid peroxidation, MDA concentration, and total antioxidative capacity of plasma. We observed a significant increase in lutein content and a moderate increase (n.s.) in beta-carotene content in human blood plasma after consumption of spinach or perilla. The markers of lipid peroxidation tended to decrease, but no influence on antioxidative capacity of plasma could be detected. The high lutein content of perilla caused a more pronounced increase of lutein compared to spinach. Both vegetables seem to be able to influence lipid peroxidation in a beneficial manner.

Can we use biomarkers in combination with self-reports to strengthen the analysis of nutritional epidemiologic studies?

Identifying diet-disease relationships in nutritional cohort studies is plagued by the measurement error in self-reported intakes.

The authors propose using biomarkers known to be correlated with dietary intake, so as to strengthen analyses of diet-disease hypotheses. The authors consider combining self-reported intakes and biomarker levels using principal components, Howe's method, or a joint statistical test of effects in a bivariate model. They compared the statistical power of these methods with that of conventional univariate analyses of self-reported intake or of biomarker level. They used computer simulation of different disease risk models, with input parameters based on data from the literature on the relationship between lutein intake and age-related macular degeneration.

The results showed that if the dietary effect on disease was fully mediated through the biomarker level, then the univariate analysis of the biomarker was the most powerful approach. However, combination methods, particularly principal components and Howe's method, were not greatly inferior in this situation, and were as good as, or better than, univariate biomarker analysis if mediation was only partial or non-existent. In some circumstances sample size requirements were reduced to 20-50% of those required for conventional analyses of self-reported intake.

The authors conclude that (i) including biomarker data in addition to the usual dietary data in a cohort could greatly strengthen the investigation of diet-disease relationships, and (ii) when the extent of mediation through the biomarker is unknown, use of principal components or Howe's method appears a good strategy.

Carotenoids: actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans

Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: beta-carotene, beta-cryptoxanthin, alpha-carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.

Validation of overweight children's fruit and vegetable intake using plasma carotenoids

Assessing dietary intake in children is difficult and limited validated tools exist. Plasma carotenoids are nutritional biomarkers of fruit and vegetable intake and therefore suitable to validate reported dietary intakes. The aim of this study was to examine the comparative validity of a food frequency questionnaire (FFQ), completed by parents reporting child fruit and vegetable intake compared to plasma carotenoid concentrations. A sample of children aged 5-12 years (n = 93) from a range of weight categories were assessed. Dietary intake was measured using a 137-item semi-quantitative FFQ. Plasma carotenoids were measured using reverse phase high-performance liquid chromatography. Pearson correlation coefficients between reported dietary intake of carotenoids and plasma carotenoid concentrations were strongest after adjustment for BMI (beta-carotene (r = 0.56, P < 0.05), alpha-carotene (r = 0.51, P < 0.001), cryptoxanthin (r = 0.32, P < 0.001)). Significantly lower levels (P < 0.05) of all plasma carotenoids, except lutein, were found among overweight and obese children when compared to healthy weight children. Parental report of children's carotenoid intakes, using a FFQ can be used to provide a relative validation of fruit and vegetable intake. The lower plasma carotenoid concentrations found in overweight and obese children requires further investigation.

Genetic variation in bitter taste and plasma markers of anti-oxidant status in college women

Genetic taste sensitivity to the bitterness of 6-n-propylthiouracil (PROP) is a potential marker for food selection. Compared with non-tasters, PROP tasters, especially super-tasters, are less accepting of cruciferous and other green vegetables, bitter citrus, added fats and chili pepper. If super-tasters avoid these foods, it may be hypothesized that they would have lower plasma antioxidant concentrations. Ninety-three healthy, non-smoking college women who did not use vitamins/supplements were classified by PROP-taster status using the paper disk method. Each participant provided a fasting blood sample that was assayed for vitamin C, beta-carotene, alpha-tocopherol, lycopene, uric acid and total peroxyl-trapping antioxidant capacity. Plasma alpha-tocopherol was lower in super-tasters than in non-tasters (P<0.05), but no other indices differed among the groups. These findings suggest that PROP status does not associate with overall antioxidant status, but may be related to alpha-tocopherol intake derived principally from vegetable oils and green vegetables.

Reliability of plasma carotenoid biomarkers and its relation to study power

BACKGROUND

The reliability of biomarkers profoundly impacts validity of their use in epidemiology and can have serious implications for study power and the ability to find true associations. We assessed reliability of plasma carotenoid levels over time and how it could influence study power through sample size and effect-size.

METHODS

Plasma carotenoid levels were measured in a cohort study of 1323 women participating in the control arm of the Women's Healthy Eating and Living Study. We compared mean plasma levels at baseline, year 1, and year 4 of the study for alpha-carotene, beta-carotene, lycopene, lutein, and beta-cryptoxanthin. Reliability of these levels over time was assessed by Spearman correlations and intraclass correlation.

RESULTS

We found limited variation in mean levels between any 2 time points. Variation did not exceed 8% for lycopene, lutein, and beta-cryptoxanthin, 15% for alpha-carotene, and 18% for beta-carotene. Spearman correlations for individual carotenoids over time varied between 0.50 and 0.80, with lycopene having the lowest correlation. Intraclass correlations ranged from 0.47 to 0.66 for carotenoids.

CONCLUSION

Intraclass correlations for plasma carotenoids over a period of several years are acceptable for epidemiologic studies. However, such variation is enough to decrease statistical power and increase the sample size needed to detect a given effect.

Effects of social approval bias on self-reported fruit and vegetable consumption: a randomized controlled trial

Background

Self-reports of dietary intake in the context of nutrition intervention research can be biased by the tendency of respondents to answer consistent with expected norms (social approval bias). The objective of this study was to assess the potential influence of social approval bias on self-reports of fruit and vegetable intake obtained using both food frequency questionnaire (FFQ) and 24-hour recall methods.

Methods

A randomized blinded trial compared reported fruit and vegetable intake among subjects exposed to a potentially biasing prompt to that from control subjects. Subjects included 163 women residing in Colorado between 35 and 65 years of age who were randomly selected and recruited by telephone to complete what they were told would be a future telephone survey about health. Randomly half of the subjects then received a letter prior to the interview describing this as a study of fruit and vegetable intake. The letter included a brief statement of the benefits of fruits and vegetables, a 5-A-Day sticker, and a 5-a-Day refrigerator magnet. The remainder received the same letter, but describing the study purpose only as a more general nutrition survey, with neither the fruit and vegetable message nor the 5-A-Day materials. Subjects were then interviewed on the telephone within 10 days following the letters using an eight-item FFQ and a limited 24-hour recall to estimate fruit and vegetable intake. All interviewers were blinded to the treatment condition.

Results

By the FFQ method, subjects who viewed the potentially biasing prompts reported consuming more fruits and vegetables than did control subjects (5.2 vs. 3.7 servings per day, p < 0.001). By the 24-hour recall method, 61% of the intervention group but only 32% of the control reported eating fruits and vegetables on 3 or more occasions the prior day (p = 0.002). These associations were independent of age, race/ethnicity, education level, self-perceived health status, and time since last medical check-up.

Conclusion

Self-reports of fruit and vegetable intake using either a food frequency questionnaire or a limited 24-hour recall are both susceptible to substantial social approval bias. Valid assessments of intervention effects in nutritional intervention trials may require objective measures of dietary change.

Changes in carotenoid intake from fruit and vegetables in the Spanish population over the period 1964–2004

Objective

To assess changes in carotenoid intake based on the variations in the consumption of fresh fruit and vegetables in the Spanish population over the period 1964–2004.

Design

Consumption data of fresh fruit and vegetables from Family Budget Surveys carried out in 1964, 1980, 1990 and 2004. Consumption data (g per person per day) accounted for >90% of fruit and vegetable consumption at each time point. Quality controlled high-performance liquid chromatography analysis of the carotenoid composition of Spanish fruit and vegetable was used.

Subjects

Randomly selected, private households throughout Spain (20 800 households in 1964, 30 311 households in 1980, 21 155 households in 1990 and 6000 households in 2004). Twelve vegetables and 16 fruits representing 89–96% of the total consumption of fresh fruit and vegetables were used.

Results

Individual consumption of fruit and vegetables has changed over this period, altering the total and individual intake of carotenoids. Total carotenoid intake increased from 2.5 mg per person per day in 1964 to 4.1 mg per person per day in 1990, with a decrease to 3.3 mg per person per day in 2004. These increments are due to an increase in lycopene, α- and β-carotene, while a decrease in lutein and zeaxanthin is observed during the last decade. A continuous and consistent decrease in the relative contribution of lutein in the diet is observed over the period studied.

Conclusion

Although the consumption of fruit and vegetables is still consistent with a Mediterranean-type pattern, modifications in the consumption of individual fruits and vegetables have provoked changes in total and specific carotenoid intake with potential relevance in human health.