Demographic, dietary and lifestyle factors differentially explain variability in serum carotenoids and fat-soluble vitamins: baseline results from the sentinel site of the Olestra Post-Marketing Surveillance Study

The development of knee osteoarthritis and serum carotenoid levels among community-dwelling people in Japan

OBJECTIVES

Carotenoids are plant pigments found in many vegetables, functioning as antioxidants scavenging singlet molecular oxygen and peroxyl radicals. No longitudinal study exists on the relationship between carotenoids and knee osteoarthritis (KOA) development. We aimed to determine the incidence of KOA development for 10 years in community-dwelling people in Japan and assess its association with serum carotenoids.

METHODS

Data of 440 participants (174 men, 266 women) with health-screening records for at least 10 years were analysed. We defined KOA development as advancing from K/L grade 0/1 at the initial check-up to grade ≥2 in a unilateral knee during a 10-year follow-up period. Serum carotenoid levels were measured using high-performance liquid chromatography. We used the Cox hazard model for multivariate analysis and investigated each carotenoid's impact on KOA development.

RESULTS

KOA developed in 33.4% of patients; the annual KOA development rate was significantly higher among women than among men (p < .01; 3.4% vs. 1.6%). Among the carotenoids measured, only retinol was associated with KOA development in women using multivariable analysis. KOA development was not associated with any carotenoids in men.

CONCLUSION

The annual rate of KOA development was higher in women, and retinol was associated with KOA development in women.

Impact of Recent Job Loss on Sleep, Energy Consumption and Diet

To examine how sleep quality and sleep duration affect caloric intake among those experiencing involuntary job loss.

Methods

Adequate sleep and self reported dietary recall data from the Assessing Daily Activity Patterns through Occupational Transitions (ADAPT) study was analysed. Primary sleep indices used were total sleep time, time spent in bed after final awakening, and sleep quality as measured by the Daily Sleep Diary (DSD). Mean Energy consumption (MEC) was the primary nutritional index. Secondary indices included diet quality using the Health Eating Index 2015 (HEI), and self-reported intake of protein, carbohydrates and fats.

Results

The study participants were comprised mainly of women (61%) and non-Hispanic white. The participants had at least 2 years of college education and mean body mass index of 30.2±8.08 (kg/m ²). The average time in bed was 541.8 (9.0 hrs) ±77.55 minutes and total sleep time was 461.1 (7.6 hrs) ±56.49 minutes. Mean sleep efficiency was 91±6%, self-reported sleep quality was 2.40±0.57 (0-4 scale, 4 = very good), and minutes earlier than planned morning awakening were 14.36±24.15. Mean HEI score was 47.41±10.92. Although the MEC was below national average for both men and women, male sex was associated with higher MEC. In a fully adjusted model sleep quality was positively associated with MEC.

Conclusion

Daily overall assessments of sleep quality among recently unemployed persons were positively associated with mean energy consumption. Additionally, the diet quality of unemployed persons was found to be unhealthier than the average American and consistent with the relationship between poor socioeconomic status and lower diet quality.

Simulated manned Mars exploration: effects of dietary and diurnal cycle variations on the gut microbiome of crew members in a controlled ecological life support system

BACKGROUND

Changes in gut microbiome are closely related to dietary and environment variations, and diurnal circle interventions impact on human metabolism and the microbiome. Changes in human gut microbiome and serum biochemical parameters during long-term isolation in a controlled ecological life support system (CELSS) are of great significance for maintaining the health of crewmembers. The Green Star 180 project performed an integrated study involving a four-person, 180-day duration assessment in a CELSS, during which variations in gut microbiome and the concentration of serum 25-hydroxyvitamin D, α-tocopherol, retinol and folic acid from the crewmembers were determined.

RESULTS

Energy intake and body mass index decreased during the experiment. A trade-off between Firmicutes and Bacteroidetes during the study period was observed. Dynamic variations in the two dominant genus Bacteroides and Prevotella indicated a variation of enterotypes. Both the evenness and richness of the fecal microbiome decreased during the isolation in the CELSS. Transition of diurnal circle from Earth to Mars increased the abundance of Fusobacteria phylum and decreased alpha diversity of the fecal microbiome. The levels of serum 25-hydroxyvitamin D in the CELSS were significantly lower than those outside the CELSS.

CONCLUSIONS

The unique isolation process in the CELSS led to a loss of alpha diversity and a transition of enterotypes between Bacteroides and Prevotella. Attention should therefore be paid to the transition of the diurnal circle and its effects on the gut microbiome during manned Mars explorations. In particular, serum 25-hydroxyvitamin D levels require monitoring under artificial light environments and during long-term space flight. Large-scale studies are required to further consolidate our findings.

Pro-oxidant effects of a high α-tocopherol dose on kidney antioxidant biomarkers and histopathological aspects

The aim of this study is to evaluate the effect of α-tocopherol supplementation at two doses (600 and 1200 mg × kg^-1) on kidney antioxidant status and the histopathological changes in Wistar rats after 12 weeks of exposure at different diets. Forty rats has been divided into 4 groups of 10 rats each, the control group received basal diet with 5 % fresh sunflower oil (FSO), the second group: 5 % oxidized sunflower oil (OSO), the third group: 5 % OSO supplemented with 600 mg × kg^-1 α-tocopherol and the fourth group: 5 % OSO supplemented with 1200 mg × kg^-1 α-tocopherol. In OSO groups, the results showed highly significant increases of LPO (from 31.3 ± 0.9 to 53.8 ± 1.2 nmol of MDA formed/min/mg protein, p < 0.0001) with a significant decrease (p < = 0.001) of the antioxidant enzymatic activities (CAT, SOD, GPX, GR and G6PDH), body weight (339 ± 9 to 290 ± 3 g) and α-tocopherol levels (13.6 ± 0.6 to 6.5 ± 0.4 μg/mg protein). In OSO groups with 600 mg × kg^-1 α-tocopherol, an antioxidant effect was found, reflected by a return of the parameters to values similar to those of the control group. However, higher doses of α-tocopherol (1200 mg × kg^-1) induced a depletion of antioxidant status, α-tocopherol levels (6.0 ± 0.3 μg/mg protein, p < 0.001) and a very highly significant rise (p < 0.0001) of LPO content (54.86 ± 0.01 nmol of MDA formed/min/mg protein). The kidney tissues also showed changes in glomerular, severe inflammatory cells infiltration, and formation of novel vessels. So, we can conclude that the oxidative stress is attenuated by a moderate administration of 600 mg × kg^-1 α-tocopherol, while a pro-oxidant effect occurs at 1200 mg × kg^-1 α-tocopherol.

Serum carotenoids and colorectal cancer risk: A case-control study in Guangdong, China

SCOPE

Previous epidemiological studies on the association between circulating carotenoids and the risk of colorectal cancer drew inconclusive conclusions. This study aimed to examine serum carotenoids in relation to colorectal cancer risk in a Chinese population.

METHODS AND RESULTS

One case-control study beginning from July 2010, consecutively recruited 538 eligible colorectal cancer cases and 564 age (5-year interval) and sex frequency-matched controls. Serum levels of α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin were detected by HPLC. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence internal (CI) after adjusting for various confounders. Serum levels of α-carotene, β-cryptoxanthin and lycopene were found to be inversely associated with colorectal cancer risk. The adjusted ORs of the highest quartile relative to the lowest quartile serum level were 0.49 (95% CIs 0.33-0.72) for α-carotene, 0.44 (95% CIs 0.29-0.66) for β-cryptoxanthin, and 0.36 (95% CIs 0.24-0.54) for lycopene, respectively. The association between serum β-carotene, lutein/zeaxanthin and colorectal cancer risk was not statistically significant.

CONCLUSION

The results indicated that the incidence of colorectal cancer was associated with lower serum levels of α-carotene, β-cryptoxanthin and lycopene among Chinese population residing in Guangdong.

Vitamin A deficiency and determinants of vitamin A status in Bangladeshi children and women: findings of a national survey

OBJECTIVE

Using data from the national micronutrients survey 2011-2012, the present study explored the status of subclinical vitamin A nutrition and the underlying determinants in the Bangladeshi population.

DESIGN

A nationwide cross-sectional study. Settings The survey covered 150 clusters; fifty in each of rural, urban and slum strata.

SUBJECTS

Three population groups: (i) pre-school age children (6-59 months; PSAC); (ii) school age children (6-14 years; SAC); and (iii) non-pregnant non-lactating women (15-49 years; NPNLW).

RESULTS

National prevalence of subclinical vitamin A deficiency was 20·5, 20·8 and 5·3 % in PSAC, SAC and NPNLW, respectively. Slum populations had higher prevalence compared with urban (PSAC: 38·1 v. 21·2 %, P0·05 for differences in β between <3 months v. 3-6 months, 6-9 months and 9-12 months).

CONCLUSIONS

Prevalence of subclinical vitamin A deficiency was high in children in Bangladesh. Intakes of animal-source foods and leafy vegetables were associated with higher and lower retinol status, respectively. Increased food diversity through animal-source foods is required.

Serum 25-hydroxyvitamin D concentrations and risk of prostate cancer: results from the Prostate Cancer Prevention Trial

BACKGROUND

Epidemiologic studies have reported inconsistent associations of vitamin D and prostate cancer risk; however, few have adequately controlled for detection bias related to prostate-specific antigen (PSA) screening, and the results of many studies may be affected by occult prostate cancers among controls.

METHODS

Data for this nested case-control analysis (n = 1,695 cases/1,682 controls) are from the Prostate Cancer Prevention Trial. Baseline serum was analyzed for 25-hydroxyvitamin D [25(OH)D]. The presence or absence of cancer was subsequently determined by prostate biopsy. Polytomous logistic regression models were used to estimate associations of 25(OH)D with risk of total, Gleason 2-6, Gleason 7, and Gleason 8-10 prostate cancer. Results are presented for placebo and finasteride arms separately and combined.

RESULTS

There were no associations of serum 25(OH)D with total prostate cancer risk. For Gleason 2-6 cancers, results were inconsistent across treatment arms with a suggestion of increased risk in the placebo arm only; however, there was no dose-response relationship. For Gleason 8-10 prostate cancers, 25(OH)D concentrations were associated with a linear decrease in risk among combined treatment arms [quartile 4 vs. 1: OR, 0.55; 95% confidence interval (CI), 0.32-0.94; P(trend) = 0.04]. These findings were somewhat stronger among men ≥65 versus 55-64 years at baseline (quartile 4 vs. 1: OR, 0.40; 95% CI, 0.18-0.88 vs. OR, 0.73; 95% CI, 0.35-1.52, respectively; P(interaction) = 0.52).

CONCLUSIONS

Higher serum 25(OH)D may modestly increase risk of Gleason 2-6 disease and more substantially reduce risk of Gleason 8-10 prostate cancer.

IMPACT

Vitamin D may have different effects for different stages of prostate cancers.

Longitudinal association of measures of adiposity with serum antioxidant concentrations in postmenopausal women

BACKGROUND/OBJECTIVES

The relationship between obesity and circulating levels of antioxidants is poorly understood. Most studies that have examined the association of adiposity with blood or tissue concentrations of antioxidant micronutrients have been cross-sectional, and few have compared the associations for indices of overall obesity and central obesity. Our aim was to prospectively examine the longitudinal association of body mass index (BMI), waist circumference (WC), waist circumference-height ratio (WCHtR) and waist-hip ratio (WHR) with major serum antioxidants in a population of postmenopausal women.

SUBJECTS/METHODS

We used a subsample of participants in the Women's Health Initiative aged 50-79 years at entry with available fasting blood samples and anthropometric measurements obtained at multiple time points over 12.8 years of follow-up (N=2672). Blood samples were used to measure α-carotene, β-carotene, β-cryptoxanthin, lutein+zeaxanthin, α-tocopherol, γ-tocopherol and retinol at baseline, and at years 1, 3 and 6. We used mixed-effects linear regression analyses to examine associations between anthropometric measures and serum antioxidants at baseline and over time, controlling for covariates.

RESULTS

In longitudinal analyses, carotenoids, and particularly β-carotene, were strongly and inversely associated with BMI, WC and WCHtR and less so with WHR. α-Tocopherol showed a strong positive association with WHR but not with other anthropometric measures, whereas γ-tocopherol was positively and strongly associated with BMI, WC, WCHtR and less so with WHR. Retinol was positively associated with WHR. The inverse association of several carotenoids with anthropometric measures was stronger in never and former smokers compared with current smokers and in women without the metabolic syndrome. The inverse association of carotenoids with obesity measures may reflect reduced micronutrient concentrations owing to inflammation associated with obesity.

CONCLUSIONS

In the present study, the strongest observed associations between anthropometric variables and micronutrients were an inverse association of WC with serum β-carotene and a positive association of WC with γ-tocopherol.

Relationship of serum carotenoid concentrations with allostatic load as a measure of chronic stress among middle-aged adults in the USA

OBJECTIVE

Chronic stress and repeated physiological attempts at stress adaptation may result in 'fatigue' and suboptimal performance of multiple physiological systems, i.e. allostatic load (AL). Although carotenoids have been linked with individual cardiovascular, metabolic and inflammatory biomarkers, little is known about the relationship of carotenoids with the multi-system biomarker measure of stress, AL. The present study examined the association of serum concentrations of carotenoids with AL among middle-aged adults.

DESIGN

Cross-sectional. AL score was calculated based on nine risk-rated indicators (systolic and diastolic blood pressure, pulse rate, total and HDL-cholesterol, glycosylated Hb, sex-specific waist-to-hip ratio, albumin and C-reactive protein).

SUBJECTS

Middle-aged (45-64 years, n 3387) men and women participants in the Third National Health and Nutrition Examination Survey, NHANES III (1988-1994).

RESULTS

Serum β-carotene concentration was inversely associated with high AL after adjusting for age, education, race/ethnicity, serum cotinine, alcohol consumption, physical activity and other carotenoids (α-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin). Females in the lowest β-carotene quartile were 2·94 (95 % CI 1·74, 4·94) times and males 2·90 (95 % CI 1·43, 5·89) times as likely to have high AL, compared with peers in the highest quartile (P for linear trend 0·001 and 0·018 for females and males, respectively). Mean serum β-carotene concentrations were also inversely associated with the number of 'high-risk' AL components (P for linear trend <0·001 and 0·004 for females and males, respectively).

CONCLUSIONS

Our study adds to evidence linking low β-carotene levels with unfavourable health outcomes.

Correlates of 25-hydroxyvitamin D and breast cancer stage in the Women's Healthy Eating and Living Study

Inverse associations between circulating 25-hydroxyvitamin D [25(OH)D] and breast cancer stage have been reported, thus it is critical to understand the variables that contribute to 25(OH)D levels among women with breast cancer. Among 904 women in the Women's Healthy Eating and Living Study, plasma 25(OH)D concentrations were measured and data on demographic characteristics, diet, physical activity, and tumor characteristics were collected at study entry. Statistically significant associations with 25(OH)D concentrations were observed for body mass index (BMI), body surface area (BSA), height, smoking, total vitamin D intake, physical activity, and race or ethnicity. Of the correlates of 25(OH)D, BMI, BSA, height, physical activity, and study site were associated with stage of breast cancer; however, concentrations of 25(OH)D were not significantly related to stage. In fully adjusted logistic regression models, the ORs (95% CIs) for the association between vitamin D deficiency and Stage II and III cancers were 0.85 (0.59-1.22) and 1.23 (0.71-2.15), respectively (P trend = 0.59), compared to Stage I. This study confirms previous work regarding the correlates of 25(OH)D concentrations but does not provide support for an association between vitamin D status and breast cancer stage.

A systematic review of vitamin D status in populations worldwide

Vitamin D deficiency is associated with osteoporosis and is thought to increase the risk of cancer and CVD. Despite these numerous potential health effects, data on vitamin D status at the population level and within key subgroups are limited. The aims of the present study were to examine patterns of 25-hydroxyvitamin D (25(OH)D) levels worldwide and to assess differences by age, sex and region. In a systematic literature review using the Medline and EMBASE databases, we identified 195 studies conducted in forty-four countries involving more than 168 000 participants. Mean population-level 25(OH)D values varied considerably across the studies (range 4·9-136·2 nmol/l), with 37·3 % of the studies reporting mean values below 50 nmol/l. The highest 25(OH)D values were observed in North America. Although age-related differences were observed in the Asia/Pacific and Middle East/Africa regions, they were not observed elsewhere and sex-related differences were not observed in any region. Substantial heterogeneity between the studies precluded drawing conclusions on overall vitamin D status at the population level. Exploratory analyses, however, suggested that newborns and institutionalised elderly from several regions worldwide appeared to be at a generally higher risk of exhibiting lower 25(OH)D values. Substantial details on worldwide patterns of vitamin D status at the population level and within key subgroups are needed to inform public health policy development to reduce risk for potential health consequences of an inadequate vitamin D status.

Comparison and validation of 2 analytical methods for measurement of urinary sucrose and fructose excretion

Urinary sugars excretion has been proposed as a potential biomarker for intake of sugars. In this study, we compared 2 analytical methods (gas chromatography [GC] and enzymatic reactions-UV absorption) for quantifying urinary fructose and sucrose using 24-hour urine samples from a randomized crossover controlled feeding study. All samples were successfully quantified by the GC method; however, 21% and 1.9% of samples were below the detection limit of the enzymatic method for sucrose and fructose, respectively. Although the correlation between the 2 methods was good for fructose (Pearson correlation, 0.71), the correlation was weak for sucrose (Pearson correlation, 0.27). We favor the GC method because of its better sensitivity, simplicity, and the ability to quantify fructose and sucrose directly in the same run. Of the 106 samples from 53 participants with complete urine collection after 2 study diets, 24-hour urinary fructose excretion was significantly associated with fructose intake. The sum of 24-hour urinary fructose and sucrose was significantly associated with total sugars consumption. However, variation in intakes of sugars explained only a modest amount of variation in urinary sugars excretion. In the unadjusted models, fructose intake explained 24.3% of urinary fructose excretion, and intake of total sugars explained 16.3% of the sum of urinary fructose and sucrose. The adjusted models explained 44.3% of urinary fructose excretion and 41.7% of the sum of urinary fructose and sucrose. Therefore, we caution using these biomarkers to predict sugars consumption before other factors that determine urinary sugars excretion are understood.

Race-ethnicity is a strong correlate of circulating fat-soluble nutrient concentrations in a representative sample of the U.S. population

Sociodemographic and lifestyle factors exert important influences on nutritional status; however, information on their association with biomarkers of fat-soluble nutrients is limited, particularly in a representative sample of adults. Serum or plasma concentrations of vitamin A, vitamin E, carotenes, xanthophylls, 25-hydroxyvitamin D [25(OH)D], SFAs, MUFAs, PUFAs, and total fatty acids (tFAs) were measured in adults (aged ≥ 20 y) during all or part of NHANES 2003-2006. Simple and multiple linear regression models were used to assess 5 sociodemographic variables (age, sex, race-ethnicity, education, and income) and 5 lifestyle behaviors (smoking, alcohol consumption, BMI, physical activity, and supplement use) and their relation to biomarker concentrations. Adjustment for total serum cholesterol and lipid-altering drug use was added to the full regression model. Adjustment for latitude and season was added to the full model for 25(OH)D. Based on simple linear regression, race-ethnicity, BMI, and supplement use were significantly related to all fat-soluble biomarkers. Sociodemographic variables as a group explained 5-17% of biomarker variability, whereas together, sociodemographic and lifestyle variables explained 22-23% [25(OH)D, vitamin E, xanthophylls], 17% (vitamin A), 15% (MUFAs), 10-11% (SFAs, carotenes, tFAs), and 6% (PUFAs) of biomarker variability. Although lipid adjustment explained additional variability for all biomarkers except for 25(OH)D, it appeared to be largely independent of sociodemographic and lifestyle variables. After adjusting for sociodemographic, lifestyle, and lipid-related variables, major differences in biomarkers were associated with race-ethnicity (from -44 to 57%), smoking (up to -25%), supplement use (up to 21%), and BMI (up to -15%). Latitude and season attenuated some race-ethnicity differences. Of the sociodemographic and lifestyle variables examined, with or without lipid adjustment, most fat-soluble nutrient biomarkers were significantly associated with race-ethnicity.

Development and validation of a vitamin D status prediction model in Danish pregnant women: a study of the Danish National Birth Cohort

Vitamin D has been hypothesized to reduce risk of pregnancy complications such as preeclampsia, gestational diabetes mellitus, and preterm delivery. However, many of these outcomes are rare and require a large sample size to study, representing a challenge for cohorts with a limited number of preserved samples. The aims of this study were to (1) identify predictors of serum 25-hydroxy-vitamin D (25(OH)D) among pregnant women in a subsample (N = 1494) of the Danish National Birth Cohort (DNBC) and (2) develop and validate a score predicting 25(OH)D-status in order to explore associations between vitamin D and maternal and offspring health outcomes in the DNBC. In our study sample, 42.3% of the population had deficient levels of vitamin D (<50 nmol/L 25(OH)D) and average levels of 25(OH)D-status were 56.7(s.d. 24.6) nmol/L. A prediction model consisting of intake of vitamin D from diet and supplements, outdoor physical activity, tanning bed use, smoking, and month of blood draw explained 40.1% of the variance in 25(OH)D and mean measured 25(OH)D-level increased linearly by decile of predicted 25(OH)D-score. In total 32.2% of the women were placed in the same quintile by both measured and predicted 25(OH)D-values and 69.9% were placed in the same or adjacent quintile by both methods. Cohen's weighted kappa coefficient (Κ = 0.3) reflected fair agreement between measured 25(OH)D-levels and predicted 25(OH)D-score. These results are comparable to other settings in which vitamin D scores have shown similar associations with disease outcomes as measured 25(OH)D-levels. Our findings suggest that predicted 25(OH)D-scores may be a useful alternative to measured 25(OH)D for examining associations between vitamin D and disease outcomes in the DNBC cohort, but cannot substitute for measured 25(OH)D-levels for estimates of prevalence.

Weight loss is associated with increased serum 25-hydroxyvitamin D in overweight or obese women

Low circulating concentrations of vitamin D metabolites have been associated with increased risk for several diseases and clinical conditions. Large observational studies and surveys have shown that obesity is independently associated with lower serum 25-hydroxyvitamin D (25(OH)D) concentration. Few studies have examined the effect of weight loss on serum 25(OH)D concentration. The purpose of this study was to prospectively examine the effect of weight loss on serum 25(OH)D concentration. Data were collected from 383 overweight or obese women who participated in a 2-year clinical trial of a weight-loss program, in which 51% (N = 195) lost at least 5% of baseline weight by 24 months, 18% (N = 67) lost 5-10%, and 33% (N = 128) lost >10%. Women who did not lose weight at 24 months had an increase in serum 25(OH)D of 1.9 (9.7) ng/ml (mean (SD)); 25(OH)D increased by 2.7 (9.1) ng/ml for those who lost 5-10% of baseline weight; and 25(OH)D increased by 5.0 (9.2) ng/ml for those who lost >10% of baseline weight (P = 0.014). At baseline, 51% (N = 197) of participants met or exceeded the recommended serum concentration of 20 ng/ml. By study end, 64% (N = 230) of overweight or obese women met this goal, as well as 83% (N = 20) of those whose weight loss achieved a normal BMI. These findings suggest that weight loss, presumably associated with a reduction in body fat, is associated with increased serum 25(OH)D concentration in overweight or obese women.

A single measurement of serum phylloquinone is an adequate indicator of long-term phylloquinone exposure in healthy older adults

Assessment of long-term phylloquinone exposure is challenging in studies investigating vitamin K in health. Data are equivocal as to whether a single measurement of circulating phylloquinone would be adequate. The primary purpose of the present study was to validate the use of a single measurement of serum phylloquinone as a surrogate for long-term phylloquinone exposure in healthy older adults. Using data from the Québec Longitudinal Study on Nutrition and Successful Aging, the objectives were to: 1) determine the reproducibility of circulating phylloquinone over 2 y (n = 234); 2) calculate how a single measurement would rank or classify individuals and attenuate the regression coefficient between circulating phylloquinone and a health outcome; and 3) investigate the association of a single measurement of serum phylloquinone with long-term phylloquinone intakes assessed over the year prior to the blood draw (n = 228). The variance analysis based on 2 blood samples showed a fair to good reproducibility for serum phylloquinone (intra-class correlation = 0.49). The correlation coefficient between the ranking of individuals based on a single measurement of circulating phylloquinone and the "true" ranking would be 0.70. The multiple regression analysis showed that long-term phylloquinone intake was the strongest predictor of serum phylloquinone (t = 4.94; P < 0.001). The partial correlation coefficient (r = 0.32) was comparable with those reported in studies where blood sampling and diet recording were juxtaposed and/or multiple blood samples were used. The present study provides evidence that the use of a single measurement of circulating phylloquinone is adequate for assessing long-term phylloquinone exposure in healthy older adults.

Vitamin D, obesity, and obesity-related chronic disease among ethnic minorities: a systematic review

OBJECTIVE

To assess the association between 25-hydroxyvitamin D (25[OH]D) status and obesity, cardiovascular diseases (CVDs), the metabolic syndrome, and type 2 diabetes mellitus (T2DM) in ethnic minorities.

METHODS

Databases searched were CINHAL with full text, Global Health, MEDLINE with full text, and PsycINFO from 1980 through 2010 (February). Studies were included if they 1) targeted immigrants from low- to high-income countries or ethnic minorities, 2) focused primarily on 25(OH)D and its relation to obesity, T2DM, and/or CVDs, and 3) were published in peer-reviewed journals. The influences of key confounders such as age, gender, and ethnicity on any observed relations were also assessed. Due to the heterogeneity of study characteristics, only a narrative synthesis was undertaken.

RESULTS

Ethnic minorities had significantly higher rates of vitamin D insufficiency (25[OH]D <50 nmol/L; children 43.6-48.7% versus 10%; adults 30.3-53% versus 13.7-26%) than their white counterparts. None of the studies reported a prevalence of obesity stratified by ethnicity. There was evidence supporting links between vitamin D deficiency and obesity-related chronic diseases, with 14 of 14 studies reporting a statistically significant result with a measurement of obesity, four of five for T2DM, four of five for CVDs, and one of one for the metabolic syndrome. However, the strength of the association varied across ethnic groups depending on the index used to measure adiposity, T2DM, and CVDs. Because most of the included studies were cross-sectional and there were variations in outcome measurements, it was not possible to determine the relative contributions of obesity or vitamin D insufficiency to CVD risk and risk of T2DM or which is the initial driver It is possible both have a role to play.

CONCLUSION

Further research specific to migrant populations using randomized controlled trials are required to establish whether causal links between 25(OH)D and obesity-related chronic disease exist, and whether vitamin D supplementation could be valuable in the prevention or treatment of obesity-related diseases.

Plasma carotenoids are associated with socioeconomic status in an urban Indigenous population: an observational study

Background

Indigenous Australians experience poorer health than other Australians. Poor diet may contribute to this, and be related to their generally lower socioeconomic status (SES). Even within Indigenous populations, SES may be important. Our aim was to identify factors associated with plasma carotenoids as a marker of fruit and vegetable intake among urban dwelling Indigenous Australians, with a particular focus on SES.

Methods

Cross sectional study in urban dwelling Indigenous Australians participating in the DRUID (Darwin Region Urban Indigenous Diabetes) Study. An SES score, based on education, employment, household size, home ownership and income was computed and plasma carotenoids measured by high performance liquid chromatography in 897 men and women aged 15 - 81 years (mean 36, standard deviation 15). Linear regression analysis was used to determine the relationship between SES and plasma carotenoids, adjusting for demographic, health and lifestyle variables, including frequency of intakes of food groups (fruit, vegetables, takeaway foods, snacks and fruit/vegetable juice).

Results

SES was positively associated with plasma concentrations of lutein/zeaxanthin (p trend <0.001), lycopene (p trend = 0.001), α- and ß-carotene (p trend = 0.019 and 0.026 respectively), after adjusting for age, sex, glucose tolerance status, smoking, alcohol use, hypercholesterolemia, dyslipidemia, self-reported health, waist to hip ratio and body mass index. These associations remained after adjustment for self-reported frequency of intake of fruit, vegetables, takeaway foods and fruit juice, which all showed some association with plasma carotenoids. Even in the highest SES quintile, concentrations of all carotenoids (except lycopene) were lower than the mean concentrations in a non-Indigenous population.

Conclusions

Even within urban Indigenous Australians, higher SES was associated with higher concentrations of plasma carotenoids. Low plasma carotenoids have been linked with poor health outcomes; increasing accessibility of fruit and vegetables, as well as reducing smoking rates could increase concentrations and otherwise improve health, but our results suggest there may be additional factors contributing to lower carotenoid concentrations in Indigenous Australians.

Noninvasive assessment of dermal carotenoids as a biomarker of fruit and vegetable intake

BACKGROUND

Resonance Raman spectroscopy (RRS) has been suggested as a feasible method for noninvasive carotenoid measurement of human skin. However, before RRS measures of dermal carotenoids can be used as a biomarker, data on intra- and intersubject variability and validity are needed.

OBJECTIVE

The purpose of this study was to evaluate the reproducibility and validity of RRS measures of dermal total carotenoids and lycopene in humans.

DESIGN

In study 1, 74 men and women with diverse skin pigmentation were recruited. RRS measures of the palm, inner arm, and outer arm were obtained at baseline, 1 wk, 2 wk, 1 mo, 3 mo, and 6 mo (to maximize seasonal variation). The RRS device used visible light at 488 nm to estimate total carotenoids and at 514 nm to estimate lycopene. Reproducibility was assessed by intraclass correlation coefficients (ICCs). In study 2, we recruited 28 subjects and assessed dietary carotenoid intake, obtained blood for HPLC analyses, performed RRS measures of dermal carotenoid status, and performed dermal biopsies (3-mm punch biopsy) with dermal carotenoids assessed by HPLC.

RESULTS

ICCs for total carotenoids across time were 0.97 (palm), 0.95 (inner arm), and 0.93 (outer arm). Total dermal carotenoids assessed by RRS were significantly correlated with total dermal carotenoids assessed by HPLC of dermal biopsies (r = 0.66, P = 0.0001). Similarly, lycopene assessed by RRS was significantly correlated with lycopene assessed by HPLC of dermal biopsies (r = 0.74, P < 0.0001).

CONCLUSION

RRS is a feasible and valid method for noninvasively assessing dermal carotenoids as a biomarker for studies of nutrition and health.

Correlates of circulating 25-hydroxyvitamin D: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Low vitamin D status is common globally and is associated with multiple disease outcomes. Understanding the correlates of vitamin D status will help guide clinical practice, research, and interpretation of studies. Correlates of circulating 25-hydroxyvitamin D (25(OH)D) concentrations measured in a single laboratory were examined in 4,723 cancer-free men and women from 10 cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers, which covers a worldwide geographic area. Demographic and lifestyle characteristics were examined in relation to 25(OH)D using stepwise linear regression and polytomous logistic regression. The prevalence of 25(OH)D concentrations less than 25 nmol/L ranged from 3% to 36% across cohorts, and the prevalence of 25(OH)D concentrations less than 50 nmol/L ranged from 29% to 82%. Seasonal differences in circulating 25(OH)D were most marked among whites from northern latitudes. Statistically significant positive correlates of 25(OH)D included male sex, summer blood draw, vigorous physical activity, vitamin D intake, fish intake, multivitamin use, and calcium supplement use. Significant inverse correlates were body mass index, winter and spring blood draw, history of diabetes, sedentary behavior, smoking, and black race/ethnicity. Correlates varied somewhat within season, race/ethnicity, and sex. These findings help identify persons at risk for low vitamin D status for both clinical and research purposes.

Vitamin D and multiple sclerosis

The hypothesis that adequate vitamin D nutrition can contribute to the prevention of multiple sclerosis (MS) was originally proposed to explain the geographical distribution of MS, but only recently has the relation between various measures of vitamin D (eg, sun exposure, dietary sources, and serum concentrations of 25-hydroxyvitamin D) and risk of developing MS been rigorously investigated. Overall, the results of these studies support a protective effect of vitamin D, but there are uncertainties and many unanswered questions, including how vitamin D exerts a protective effect, how genetic variations modify the effect, and whether vitamin D can influence the course of MS progression.

Predictors of serum 25-hydroxyvitamin D concentrations among postmenopausal women: the Women's Health Initiative Calcium plus Vitamin D clinical trial

BACKGROUND

It is unclear how well surrogate markers for vitamin D exposure (eg, oral intake of vitamin D and estimates of sunlight exposure), with and without consideration of other potential predictors of 25-hydroxyvitamin D [25(OH)D] concentrations, similarly rank individuals with respect to 25(OH)D blood concentrations.

OBJECTIVE

The objective was to determine how much variation in serum 25(OH)D concentrations (nmol/L) could be explained by a predictive model with the use of different vitamin D surrogate markers (latitude of residence, mean annual regional solar irradiance estimates, and oral sources) and other individual characteristics that might influence vitamin D status.

DESIGN

A random sample of 3055 postmenopausal women (aged 50-70 y) participating in 3 nested case-control studies of the Women's Health Initiative Calcium plus Vitamin D Clinical Trial was used. Serum 25(OH)D values, assessed at year 1 (1995-2000), and potential predictors of 25(OH)D concentrations, assessed at year 1 or Women's Health Initiative baseline (1993-1998), were used.

RESULTS

More than half of the women (57.1%) had deficient (<50 nmol/L) concentrations of 25(OH)D. Distributions of 25(OH)D concentrations by level of latitude of residence, mean annual regional solar irradiance, and intake of vitamin D varied considerably. The predictive model for 25(OH)D explained 21% of the variation in 25(OH)D concentrations. After adjustment for month of blood draw, breast cancer status, colorectal cancer status, fracture status, participation in the hormone therapy trial, and randomization to the dietary modification trial, the predictive model included total vitamin D intake from foods and supplements, waist circumference, recreational physical activity, race-ethnicity, regional solar irradiance, and age.

CONCLUSIONS

Surrogate markers for 25(OH)D concentrations, although somewhat correlated, do not adequately reflect serum vitamin D measures. These markers and predictive models of blood 25(OH)D concentrations should not be given as much weight in epidemiologic studies of cancer risk.

Determinants of serum 25 hydroxyvitamin D levels in a nationwide cohort of blacks and non-Hispanic whites

OBJECTIVE

To develop algorithms predicting serum 25 hydroxyvitamin D [s25(OH)D] for a large epidemiological study whose subjects come from large geographic areas, are racially diverse and have a wide range in age, skin types, and month of blood sample collection. This will allow a regression calibration approach to determine s25(OH)D levels replacing the more costly method of collection and analysis of blood samples.

STUDY DESIGN AND SETTING

Questionnaire data from a subsample of 236 non-Hispanic whites (whites) and 209 blacks from the widely dispersed Adventist Health Study-2 (n = 96,000) were used to develop prediction algorithms for races separately and combined. A single blood sample was collected from each subject, at different times throughout the year.

RESULTS

Models with independent variables age, sex, BMI, skin type, UV season, erythemal zone, total dietary vitamin D intake, and sun exposure factor explained 22 and 31% of the variance of s25(OH)D levels in white and black populations, respectively (42% when combined). UV season and erythemal zone determined from measured UV radiation produced models with higher R (2) than season and latitude.

CONCLUSION

Combining races with a term for race and using variables with measured UV radiation capture the variance in s25(OH)D levels better than analyzing races separately.

Synergistic interaction of cigarette smoking and alcohol drinking with serum carotenoid concentrations: findings from a middle-aged Japanese population

Previous studies have indicated low serum carotenoid concentrations among cigarette smokers and/or alcohol drinkers, but little is known about the interaction of smoking and drinking with serum carotenoids. We tested the hypothesis that smoking and drinking reduce serum carotenoid concentrations synergistically. A total of 1073 subjects (357 male and 716 female) who had received health examinations in the town of Mikkabi, Shizuoka Prefecture, Japan, participated in the study. The subjects were divided into six groups according to alcohol intake (non-drinkers, < 1 g/d; light drinkers, > or = 1, < 25 g/d; moderate-to-heavy drinkers, > or = 25 g/d) and smoking status (non-smokers and current smokers). The dietary intakes and serum concentrations of six carotenoids (lycopene, alpha-carotene, beta-carotene, lutein, beta-cryptoxanthin and zeaxanthin) within each group were evaluated cross-sectionally. The dietary intakes of all carotenoids did not differ in the six groups after adjusting for age and sex. The multivariate-adjusted means of the serum carotenoid concentrations in non-drinkers did not differ between non-smokers and current smokers. In contrast, the adjusted means of serum alpha-carotene, beta-carotene and beta-cryptoxanthin were significantly lower than those with increased alcohol intake, and these lower serum carotenoids among alcohol drinkers were more evident in current smokers than in non-smokers. Serum lycopene of moderate-to-heavy drinkers was significantly lower than that of non-drinkers, but it was not influenced by smoking. Neither smoking nor drinking was associated with the serum concentrations of lutein and zeaxanthin. These results suggest that smoking and drinking may reduce the serum alpha-carotene, beta-carotene and beta-cryptoxanthin concentrations in a synergistic manner.

Serum lycopene and the risk of cancer: the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study

PURPOSE

Lycopene is thought to decrease the risk of cancers, although previous epidemiologic studies have produced inconsistent results. The aim of the present study was to evaluate the protective effect of lycopene against the risk of cancer.

METHODS

The study population consisted of 997 middle-aged Finnish men in the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) cohort. During the mean follow-up time of 12.6 years, a total of 141 cancer cases appeared, of which 55 were prostate cancers. The association between the serum concentrations of lycopene and the risk of cancer was studied using the Cox proportional hazard models.

RESULTS

An inverse association was observed between serum lycopene and overall cancer incidence. The adjusted risk ratio (RR) in the highest tertile of serum lycopene was 0.55 (95% confidence interval [CI], 0.34-0.89; p=0.015) compared with the lowest serum lycopene group. No association was observed between the lycopene concentrations and a prostate cancer risk. RR for other cancers was 0.43 (95% CI, 0.23-0.79; p=0.007).

CONCLUSIONS

These findings suggest that in middle-aged men, the higher circulating concentrations of lycopene may contribute to the lower risk of cancer, with the exception of prostate cancer.

Vitamin D insufficiency in a multiethnic cohort of breast cancer survivors

BACKGROUND

Little is known about vitamin D status in breast cancer survivors. This issue is important because vitamin D influences pathways related to carcinogenesis.

OBJECTIVE

The objective of this report was to describe and understand vitamin D status in a breast cancer survivor cohort.

DESIGN

Data are from the Health, Eating, Activity, and Lifestyle study. With the use of a cross-sectional design, we examined serum concentrations of 25-hydroxyvitamin D [25(OH)D] in 790 breast cancer survivors from western Washington state, New Mexico, and Los Angeles County. Cancer treatment data were obtained from Surveillance, Epidemiology, and End Results registries and medical records. Fasting blood, anthropometry, and lifestyle habits were collected after diagnosis and treatment. We examined distributions of 25(OH)D by race-ethnicity, season, geography, and clinical characteristics. Multivariate regression tested associations between 25(OH)D and stage of disease.

RESULTS

Five hundred ninety-seven (75.6%) of the women had low serum 25(OH)D, suggesting vitamin D insufficiency or frank deficiency. The overall mean (+/-SD) was 24.8 +/- 10.4 ng/mL, but it was lower for African Americans (18.1 +/- 8.7 ng/mL) and Hispanics (22.1 +/- 9.2 ng/mL). Women with localized (n = 424) or regional (n = 182) breast cancer had lower serum 25(OH)D than did women with in situ disease (n = 184) (P = 0.05 and P = 0.03, respectively). Multivariate regression models controlled for age, body mass index (in kg/m(2)), race-ethnicity, geography, season, physical activity, diet, and cancer treatments showed that stage of disease independently predicted serum 25(OH)D (P = 0.02).

CONCLUSIONS

In these breast cancer survivors, the prevalence of vitamin D insufficiency was high. Clinicians might consider monitoring vitamin D status in breast cancer patients, together with appropriate treatments, if necessary.

Preditores sócio-demográficos, de estilo de vida e gineco-obstétricos das concentrações séricas ou plasmáticas de homocisteína, ácido fólico e vitaminas B12 e B6 em mulheres de baixa renda de São Paulo, Brasil

O presente estudo investigou fatores sócio-demográficos, de estilo de vida e gineco-obstétricos associados às concentrações séricas ou plasmáticas de homocisteína, ácido fólico, vitaminas B12 e B6 em mulheres de baixa renda de São Paulo, Brasil. Concentrações séricas de ácido fólico e vitamina B12 foram analisadas por fluoroimunoensaio; concentrações plasmáticas de homocisteína e vitamina B6, por cromatografia líquida de alta performance em fase reversa. Variáveis independentes foram inicialmente selecionadas segundo pressupostos teóricos, correlação de Pearson ou teste Kruskal-Wallis (p < 0,20). Concentrações alteradas segundo pontos de corte para homocisteína, ácido fólico, vitaminas B12 e B6 foram observadas em 20%, 6%, 11% e 67% das participantes, respectivamente. Idade foi positivamente correlacionada à vitamina B6 e homocisteína plasmáticas (p < 0,001). Índice de massa corporal foi positivamente correlacionado à vitamina B6 plasmática (p < 0,001). Modelos de regressão linear múltiplos explicaram 10,2%, 5,8%, 14,4% e 9,4% das concentrações de ácido fólico, vitamina B12, vitamina B6 e homocisteína, respectivamente. No presente estudo, variáveis sócio-demográficas, de estilo de vida e gineco-obstétricas apresentaram contribuição importante na variação das concentrações dos indicadores bioquímicos avaliados.

Vitamin A deficiency and child feeding in Beijing and Guizhou, China

BACKGROUND

Vitamin A deficiency (VAD) is one of the three major micronutrient deficiencies in the world. In order to investigate the status of VAD and child feeding in China, we conducted the survey in Beijing city and Guizhou province.

METHODS

We included a high socioeconomic area (Beijing) and a low socioeconomic area (Guizhou province) in China in our study. Participants included 1236 randomly selected children aged 0-71 months from stratified clusters (628 in Beijing and 608 in Guizhou), 409 from urban and 827 from rural areas. A food intake frequency questionnaire was used for dietary assessment. Fluorescence microanalysis was carried out to measure serum retinol concentrations. Serum retinol cut-off values of less than 20 microg/dl and 30 microg/dl were defined as sub-clinical VAD and suspected sub-clinical VAD, respectively.

RESULTS

No xerophthalmia or night blindness was found. The mean concentration of serum retinol was 31.5 microg/dl in the high socioeconomic group, and 26.5 microg/dl in the low socioeconomic group. Rural infants had lower concentrations of serum retinol compared with the urban ones (26.9+/-8.1 microg/dl vs 31.8+/-7.3 microg/dl). The prevalence of sub-clinical VAD among all the children was 7.8%, and increased to 15.7% in children from the low socioeconomic group. In infants from the high socioeconomic area, the prevalence of suspected subclinical VAD was 38.0%, increasing to 59.5% in infants from the low socioeconomic area. The children from the low socioeconomic area had significantly lower fequency of intake of meat than the children in other groups. The prevalence of suspected sub-clinical VAD was higher in the children with lower consumption frequency of vitamin A rich foods than the children with higher consumption frequency of vitamin A rich foods.

CONCLUSIONS

VAD appears to be a moderate public health problem in certain areas of China. In areas with low socioeconomic status, VAD in childrean is more severe, and infants may be the group at the highest risk for VAD. Inadequate intake of vitamin A rich foods may result in VAD. A comprehensive long-term national strategy needs to be fostered in China for the treatment and prevention of the deficiency.

Determinants and correlates of serum undercarboxylated osteocalcin

BACKGROUND/AIMS

To assess dietary and nondietary determinants of serum undercarboxylated osteocalcin (ucOC) as a measure of vitamin K status.

METHODS

UcOC and total intact osteocalcin (iOC) concentrations were determined by specific ELISA tests in serum samples of 231 male and 320 female participants (18-81 years) of the representative, cross-sectional Bavarian Food Consumption Survey II. Determinants of ucOC were investigated by analysis of variance, Spearman's rank correlation coefficients and logistic regression models.

RESULTS

Mean ucOC serum concentration was 2.46 ng/ml in men and 2.34 ng/ml in women. Corresponding means of the ratio of ucOC to iOC (ucOC/iOC) were 0.28 and 0.29. Concentrations of ucOC and iOC, as well as the ratio of ucOC/iOC, strongly depended on the participant's age. UcOC was influenced by smoking status, sports activity, and the season when blood was collected. Dietary intake of the dominant vitamin K sources, green leafy vegetables and dairy products, as well as the plasma concentration of the carotenoid lutein were inversely associated with serum ucOC values.

CONCLUSIONS

In studies using serum ucOC as a measure of vitamin K supply, determinants, especially age, need to be taken into account.

An overview of interactions between micronutrients and of micronutrients with drugs, genes and immune mechanisms

The objective of the present review is to examine critically the consequences of interactions that micronutrients undergo with nutrients and non-nutrients (mainly prescribed medicines) in diets and lifestyle factors (smoking, tea and alcohol consumption). In addition, the review describes recent work on interactions between nutrients and genes, the influence of gene polymorphisms on micronutrients, the impact of immune responses on micronutrients and specific interactions of antioxidant micronutrients in disease processes to minimise potential pro-oxidant damage.

(n-6) PUFA increase and dairy foods decrease prostate cancer risk in heavy smokers

Previous studies offer suggestive, but not definitive, evidence that total fat or specific fats may increase prostate cancer risk. This study investigates associations of dietary fat, meat, and dairy foods with prostate cancer risk among 12,025 men in the Carotene and Retinol Efficacy Trial (CARET). After 11 y of follow-up, 890 incident prostate cancers were reported and confirmed. Diet was assessed by a biannual FFQ. Cox proportional hazards models were used to estimate multivariate-adjusted hazard ratios (HR) of intake of fat and fat-related foods (meat and dairy) with prostate cancer incidence. Multiplicative interaction terms tested whether associations differed by family history, race, or smoking. Overall, fat was not associated with total, nonaggressive or aggressive prostate cancer. In subgroup analyses the HR for men with a family history of prostate cancer were 2.47 (95%CI = 0.96-6.37) and 2.61 (95% CI = 1.01-6.72) for total polyunsaturated fat (PUFA) and (n-6) PUFA for the 4th vs. 1st quartiles of intake, respectively. Red meat was not associated with total or aggressive prostate cancer. However, higher dairy intake had a statistically significant reduced risk of aggressive prostate cancer than lower dairy intake (HR = 0.59, 95% CI = 0.40-0.85). Dairy foods also protected current, but not former, smokers against aggressive cancer (HR = 0.42, 95% CI = 0.25-0.70). Our findings suggest that associations of dietary fat with prostate cancer risk may vary by type of fat or fat-containing food, and that risk may vary by host factors, including family history and smoking.

Dietary energy density in the treatment of obesity: a year-long trial comparing 2 weight-loss diets

BACKGROUND

Consuming foods low in energy density (kcal/g) decreases energy intake over several days, but the effectiveness of this strategy for weight loss has not been tested.

OBJECTIVE

The effects on weight loss of 2 strategies for reducing the energy density of the diet were compared over 1 y.

DESIGN

Obese women (n = 97) were randomly assigned to groups counseled either to reduce their fat intake (RF group) or to reduce their fat intake and increase their intake of water-rich foods, particularly fruit and vegetables (RF+FV group). No goals for energy or fat intake were assigned; the subjects were instructed to eat ad libitum amounts of food while following the principles of their diet.

RESULTS

After 1 y, study completers (n = 71) in both groups had significant decreases in body weight (P < 0.0001). Subjects in the RF+FV group, however, had a significantly different pattern of weight loss (P = 0.002) than did subjects in the RF group. After 1 y, the RF+FV group lost 7.9 +/- 0.9 kg and the RF group lost 6.4 +/- 0.9 kg. Analysis of all randomly assigned subjects also showed a different pattern of weight loss between groups (P = 0.021). Diet records indicated that both groups had similar reductions in fat intake. The RF+FV group, however, had a lower dietary energy density than did the RF group (P = 0.019) as the result of consuming a greater weight of food (P = 0.025), especially fruit and vegetables (P = 0.037). The RF+FV group also reported less hunger (P = 0.003).

CONCLUSION

Reducing dietary energy density, particularly by combining increased fruit and vegetable intakes with decreased fat intake, is an effective strategy for managing body weight while controlling hunger.

A household food inventory is not a good measure of fruit and vegetable intake among ethnically diverse rural women

Environmental measures of food availability are surrogates of consumption. Such measures may be useful among populations for whom standard dietary assessment is difficult. The objective of this cross-sectional study was to test whether a measure of the household dietary environment would perform as well as or better than a standard fruit and vegetable assessment among ethnically diverse rural women. Participants were 154 non-Hispanic white, 157 Hispanic, and 102 Native American adult women residing in rural Washington state. Participants completed an interviewer-administered household inventory of fruits and vegetables and a standard measure of fruit and vegetable intake used in the 5 A Day for Better Health Program. Pearson correlation coefficients assessed the validity of the measures against biomarkers of fruit and vegetable consumption (serum carotenoids). Pearson correlations were poor to modest between the household inventory and serum carotenoids (r=0.06 to 0.22) and between the 5 A Day responses and serum carotenoids (r=-0.08 to 0.17). There were no differences by ethnic group; both short tools performed poorly compared with the biomarkers across Hispanic, non-Hispanic white, and Native-American participants. In conclusion, both the household inventory and the popular 5 A Day measure were poor indicators of fruit and vegetable intake in this sample of ethnically diverse rural women.

Change in plasma lutein after egg consumption is positively associated with plasma cholesterol and lipoprotein size but negatively correlated with body size in postmenopausal women

We investigated associations between plasma concentrations of cholesterol and lutein after consumption of eggs. Using a crossover design, 22 postmenopausal women (50-77 y) consumed an egg treatment (640 mg/d additional cholesterol and 600 mug/d additional lutein + zeaxanthin) or a baseline treatment (no additional cholesterol or lutein + zeaxanthin) for 30 d, followed by a 3-wk washout period and the alternate diet. The increases in plasma total cholesterol and lutein due to egg consumption were related (r = 0.48, P < 0.05). There was a positive correlation between LDL size (r = 0.45, P < 0.05), HDL size (r = 0.64, P < 0.01), and plasma lutein, but no relation with the number of LDL or HDL particles. The activities of cholesterol ester transfer protein and lecithin cholesterol acyltransferase, although important in the exchange of cholesterol among lipoproteins, were not associated with changes in plasma lutein. Plasma lutein concentrations observed during the baseline period were a strong predictor of the increase in plasma lutein after egg treatment (r = 0.50 P < 0.05). There was a negative association between the change in lutein due to egg consumption and BMI (r = -0.40, P < 0.06) and waist circumference (r = -0.49, P < 0.05). This was particularly evident in individuals with BMI >29. We conclude that the increase in plasma lutein after egg consumption is associated with the change in plasma total cholesterol, but that the effect is diminished by obesity. Lipoprotein size, but not number, also affects plasma response to dietary lutein.

Relationship between diet and anticoagulant response to warfarin: a factor analysis

BACKGROUND

Diet composition is one of the factors that may contribute to intraindividual variability in the anticoagulant response to warfarin.

AIM OF THE STUDY

To determine the associations between food pattern and anticoagulant response to warfarin in a group of Brazilian patients with vascular disease.

METHODS

Recent and usual food intakes were assessed in 115 patients receiving warfarin; and corresponding plasma phylloquinone (vitamin K(1)), serum triglyceride concentrations, prothrombin time (PT), and International Normalized Ratio (INR) were determined. A factor analysis was used to examine the association of specific foods and biochemical variables with anticoagulant data.

RESULTS

Mean age was 59 +/- 15 years. Inadequate anticoagulation, defined as values of INR 2 or 3, was found in 48% of the patients. Soybean oil and kidney beans were the primary food sources of phylloquinone intake. Factor analysis yielded four separate factors, explaining 56.4% of the total variance in the data set. The factor analysis revealed that intakes of kidney beans and soybean oil, 24-h recall of phylloquinone intake, PT and INR loaded significantly on factor 1. Triglycerides, PT, INR, plasma phylloquinone, and duration of anticoagulation therapy loaded on factor 3.

CONCLUSIONS

Fluctuations in phylloquinone intake, particularly from kidney beans, and plasma phylloquinone concentrations were associated with variation in measures of anticoagulation (PT and INR) in a Brazilian group of patients with vascular disease.

Plasma phylloquinone (vitamin K1) concentration and its relationship to intake in a national sample of British elderly people

Plasma phylloquinone (vitamin K1) concentration was examined according to season, socio-demographic and lifestyle factors and phylloquinone intake in a nationally representative sample of British people aged 65 years and over from the 1994–5 National Diet and Nutrition Survey. Values for both plasma phylloquinone concentration and phylloquinone intake were available from 1076 participants (561 men, 515 women). Eight hundred and thirty-four were living in private households, 242 in residential or nursing homes. Weighted geometric mean plasma phylloquinone concentrations were 0·36 (95 % CI 0·06, 2·01) and 0·24 (95 % CI 0·06, 0·96) nmol/l in free-living and institution samples respectively. Plasma phylloquinone concentrations did not generally differ between men and women, although values in free-living people were significantly lower during autumn and winter (October to March). Plasma phylloquinone concentration was not significantly associated with age. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in free-living men and women (r0·18 and 0·30 respectively, bothP<0·001). Stepwise multiple regression analysis found that 11 % of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, season and plasma triacylglycerol concentration. After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (eachP<0·01) with plasma concentrations of triacylglycerol, cholesterol, retinol and 25-hydroxyvitamin D in free-living women but not men, and with plasma concentrations of carotenes, α- and γ-tocopherols and lutein in free-living men and women. The possibility of concurrent low fat-soluble vitamin status in elderly populations may be a cause for concern.

Plasma phylloquinone (vitamin K1) concentration and its relationship to intake in British adults aged 19-64 years

Plasma phylloquinone (vitamin K1) concentration from non-fasted blood samples was examined by season, smoking status, socio-demographic factors and phylloquinone intake in a nationally representative sample of 1154 British individuals aged 19-64 years from the 2000-1 National Diet and Nutrition Survey. Geometric mean plasma phylloquinone concentration was 0.94 (95% CI 0.88, 1.00) nmol/l, with 95% of values in the range 0.10-8.72 nmol/l. Plasma phylloquinone concentrations of 530 men were significantly higher than those of 624 women (1.13 (95% CI 1.04, 1.22) v. 0.81 (95% CI 0.74, 0.88) nmol/l; P<0.001), independent of other factors. Women aged 19-34 years had significantly lower plasma phylloquinone concentration than their older counterparts. Women were also found to have lower plasma phylloquinone concentrations during summer compared with winter and spring (each P<0.01). In contrast, plasma phylloquinone concentration in men did not vary significantly by season or any of the socio-demographic or lifestyle factors. Plasma phylloquinone concentrations were positively correlated with phylloquinone intake in men and women (r 0.26 and 0.32 respectively; each P<0.001). Overall, forward stepwise multiple regression analysis revealed that 8% of the variation in plasma phylloquinone concentration was explained by phylloquinone intake, with a further 10% of its variation explained by plasma concentrations of gamma-tocopherol (6%) and retinyl palmitate (4%). After adjustment for age and corresponding nutrient intakes, plasma phylloquinone concentration was significantly associated (each P<0.01) with plasma concentrations of total and LDL-cholesterol, alpha- and gamma-tocopherols, retinyl palmitate, beta-carotene, lycopene and lutein plus zeaxanthin in men and women.

Lycopene consumption decreases oxidative stress and bone resorption markers in postmenopausal women

INTRODUCTION

Oxidative stress induced by reactive oxygen species (ROS) is associated with the risk of osteoporosis, and can be reduced by certain dietary antioxidants. Lycopene is an antioxidant known to decrease the risk of age-related chronic diseases, such as cancer. However, the role of lycopene in osteoporosis has not yet been investigated.

MATERIALS AND METHODS

In a cross-sectional study, 33 postmenopausal women aged 50-60 years provided seven-day dietary records and blood samples. Serum samples were used to measure serum lycopene, lipid peroxidation, protein thiols, bone alkaline phosphatase (BAP), and cross-linked N-telopeptides of type I collagen (NTx). The serum lycopene per kilogram body weight of the participants was grouped into quartiles and associated with the above serum parameters using one-way ANOVA and the Newman-Keuls post-test.

RESULTS

The results showed that groups with higher lycopene intake, as determined from the dietary records, had higher serum lycopene (p<0.02). A higher serum lycopene was found to be associated with a low NTx (p<0.005). Similarly, groups with higher serum lycopene had lower protein oxidation (p<0.05).

DISCUSSION

In conclusion, these results suggest that the dietary antioxidant lycopene reduces oxidative stress and the levels of bone turnover markers in postmenopausal women, and may be beneficial in reducing the risk of osteoporosis.

Selected nutritional biomarkers predict diet quality

Objective:

To examine associations of biomarkers of nutrient intake with overall diet quality.

Subjects:

A convenience sample of 102 healthy postmenopausal women in Seattle, Washington (USA).

Design and method:

Participants attended a study centre where they provided fasting blood specimens and completed a 122-item validated food-frequency questionnaire (FFQ). Data from the FFQ were used to calculate Diet Quality Index (DQI) scores and categorise women as having diets of excellent, good, fair or poor quality. The blood specimens were analysed for nine phospholipid fatty acids (as percentage of total) and serum concentrations of vitamin C, α-tocopherol, γ-tocopherol, vitamin B12, folate and six carotenoids. Multivariate linear regression was used to model associations of the nutrient biomarkers with DQI scores.

Results:

Compared with women with poor-quality diets, women with excellent diets, as measured by the DQI, had higher plasma concentrations of vitamin C (Pfor trend = 0.01), α-tocopherol (Pfor trend = 0.02) and β-cryptoxanthin (Pfor trend = 0.03). Women with excellent diets also had lower proportions of plasma phospholipid fatty acids of two potentially atherogenic fatty acids: stearic acid (Pfor trend = 0.01) and behenic acid (Pfor trend = 0.03). A group of six biomarkers explained a moderate proportion of the total variability in DQI scores (36%).

Conclusions:

These objective measures of dietary intake support the use of the DQI as a useful tool to measure dietary patterns.

Evaluating associations between Mediterranean diet adherence indexes and biomarkers of diet and disease

Objective

We examined associations between two Mediterranean diet (MD) adherence indexes (the MD index, MDI, and the MD score, MDS) and several blood biomarkers of diet and disease.

Subjects

We studied 328 individuals from Catalonia (Northeastern Spain), ages 18–75, who provided fasting blood samples, a subset of the 2346 individuals as part of a larger representative and random sample from the 1992–1993 Catalan Nutritional Survey.

Design and method

Diet was measured using 24-h recalls. Biomarkers studied were plasma levels of β-carotene, α-tocopherol, retinol, vitamins B12, C and folates as well as serum total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. Multivariate linear regression was used to analyse associations of the nutrient biomarkers with the dietary pattern indexes, adjusting for potential confounders.

Results and conclusions

Subjects with higher MD adherence, as measured by the two dietary indexes, had significantly higher plasma concentrations of β-carotene, folates, vitamin C, α-tocopherol and HDL cholesterol. The most highly significant relationship was that between folates and the adherence to the MD Pattern, as determined by both indexes.

These research findings suggest the potential usefulness of biomarkers as complementary tools for assessing adherence to a dietary pattern. This type of data not only informs the development of robust dietary adherence indexes, but it also provides specific clues about the potential physiological mechanisms that explain the beneficial effects of the MD pattern on chronic disease risk.

Higher baseline serum concentrations of vitamin E are associated with lower total and cause-specific mortality in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study

BACKGROUND

A meta-analysis of 19 trials suggested a small increase in the risk of all-cause mortality with high-dose vitamin E supplementation. Little is known, however, about the relation between mortality and circulating concentrations of vitamin E resulting from dietary intake, low-dose supplementation, or both.

OBJECTIVE

We examined whether baseline serum alpha-tocopherol concentrations are associated with total and cause-specific mortality.

DESIGN

A prospective cohort study of 29 092 Finnish male smokers aged 50-69 y who participated in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study was carried out. Fasting serum alpha-tocopherol was measured at baseline by using HPLC. Only 10% of participants reported vitamin E supplement use at baseline, and thus serum concentrations of vitamin E mainly reflected dietary intake and other host factors. Risks of total and cause-specific mortality were estimated by using proportional hazards models.

RESULTS

During up to 19 y of follow-up, 13 380 deaths (including 4518 and 5776 due to cancer and cardiovascular disease, respectively) were identified. Men in the higher quintiles of serum alpha-tocopherol had significantly lower risks of total and cause-specific mortality than did those in the lowest quintile [relative risk (RR) = 0.82 (95% CI: 0.78, 0.86) for total mortality and 0.79 (0.72, 0.86), 0.81 (0.75, 0.88), and 0.70 (0.63, 0.79) for deaths due to cancer, cardiovascular disease, and other causes, respectively; P for trend for all < 0.0001]. Cubic regression spline analysis of continuous serum alpha-tocopherol values indicated greater risk reductions with increasing concentrations up to approximately 13-14 mg/L, after which no further benefit was noted.

CONCLUSION

Higher circulating concentrations of alpha-tocopherol within the normal range are associated with significantly lower total and cause-specific mortality in older male smokers.

Monitoring micronutrients in cigarette smokers

Smoking is associated with oxidative stress and increased risks of many chronic diseases that both shorten life and impair its quality. Low concentrations of several micronutrients, especially the antioxidants vitamin C and beta-carotene, are also associated with smoking, and there has been much interest in determining whether deficiencies in micronutrients are involved etiologically in smoking-related diseases. The objective of this review was to bring together reports on dietary intakes, biochemical indicators of micronutrient status, and results of some intervention studies on micronutrients where authors had compared outcomes in smokers and non-smokers. The micronutrients discussed are vitamins A, E, and C; the carotenoids; some of the B-vitamin group; and the minerals selenium, zinc, copper, and iron. The data were then examined to determine whether effects on the biochemical markers of micronutrient status were due to differences in dietary intakes between smokers and non-smokers or to the consequences of inflammatory changes caused by the oxidative stress of smoking. It was concluded that although smoking is associated with reduced dietary intake of vitamin C and carotenoid-containing foods, inflammatory changes increase turnover of these micronutrients so that blood concentrations are still lower in smokers than non-smokers even when there is control for dietary differences. In the case of vitamin E, there is some evidence for increased turnover of this nutrient in smokers, but this has little to no influence on blood concentrations, and there are no differences in dietary intake of vitamin E between smokers and non-smokers. Serum concentrations of vitamin A, folate, and vitamin B12 and B6 markers do not appear to be influenced by smoking, although there is some influence of dietary intake on concentrations of these nutrients in the body. In the case of the minerals examined, the main effects on biochemical markers of mineral status were attributed to inflammation and were therefore greater in heavy or long-term smokers. Serum concentrations of selenium and erythrocyte GPx activity were lower in smokers. Erythrocyte CuZn-SOD activity and serum ceruloplasmin concentrations were elevated, while serum zinc concentrations were depressed only in heavy smokers. Lastly, smoking appears to affect iron homeostasis mainly by changing hemoglobin concentrations, which were in general increased. Serum iron, TfR, and ferritin were mostly unaffected by smoking, except in pregnancy where there is evidence of increased erythropoiesis causing lower saturation of plasma transferrin and some evidence of lowering of iron stores.

Validity and systematic error in measuring carotenoid consumption with dietary self-report instruments

Vegetables and fruits are rich in carotenoids, a group of compounds thought to protect against cancer. Studies of diet-disease associations need valid and reliable instruments for measuring dietary intake. The authors present a measurement error model to estimate the validity (defined as correlation between self-reported intake and "true" intake), systematic error, and reliability of two self-report dietary assessment methods. Carotenoid exposure is measured by repeated 24-hour recalls, a food frequency questionnaire (FFQ), and a plasma marker. The model is applied to 1,013 participants assigned between 1995 and 2000 to the nonintervention arm of the Women's Healthy Eating and Living Study, a randomized trial assessing the impact of a low-fat, high-vegetable/fruit/fiber diet on preventing new breast cancer events. Diagnostics including graphs are used to assess the goodness of fit. The validity of the instruments was 0.44 for the 24-hour recalls and 0.39 for the FFQ. Systematic error accounted for over 22% and 50% of measurement error variance for the 24-hour recalls and FFQ, respectively. The use of either self-report method alone in diet-disease studies could lead to substantial bias and error. Multiple methods of dietary assessment may provide more accurate estimates of true dietary intake.

Longitudinal associations between body mass index and serum carotenoids: the CARDIA study

Cross-sectional studies report an inverse association between BMI and serum carotenoid concentration. The present study examined the prospective association between BMI and the serum concentration of five carotenoids in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Serum carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, zeaxanthin/lutein, lycopene), BMI, dietary intake, physical activity and dietary supplement use were measured at years 0 and 7 in 3071 black and white male and female participants, who were either persistent smokers or non-smokers. Among non-smokers, year 0 BMI predicted year 7 serum carotenoid levels: obese subjects (BMI > or =30 kg/m2) had an average concentration of the sum of four carotenoids (alpha-carotene +beta-carotene + zeaxanthin/lutein+beta-cryptoxanthin) that was 22 % lower than the concentration among subjects with a BMI of less than 22 kg/m2. In contrast, the sum of carotenoids among smokers was only 6 % lower. Relationships between BMI and serum lycopene were weak. The change from year 0 to year 7 in serum carotenoids, except for lycopene, was inversely associated with the change in BMI among non-smokers but not among smokers. Parallel findings were observed for BMI and serum gamma-glutamyl transferase level. In summary, the observation that BMI predicted the evolution of serum carotenoids during a 7-year follow-up among young non-smoking adults is consistent with the hypothesis that carotenoids are decreased in protecting against oxidative stress generated by adipose tissue, while smokers maintain a minimal level of serum carotenoids independent of adiposity. The results for lycopene were, however, discordant from those of the other carotenoids.

Olestra is associated with slight reductions in serum carotenoids but does not markedly influence serum fat-soluble vitamin concentrations

BACKGROUND

The 1996 Food and Drug Administration approval of the fat substitute olestra (sucrose polyester) called for active postmarketing surveillance because preapproval studies showed that olestra may lower circulating concentrations of fat-soluble nutrients such as vitamins and carotenoids.

OBJECTIVE

The objective of the Olestra Post-Marketing Surveillance Study was to examine whether customary consumption of olestra-containing savory snacks was associated with changes in serum fat-soluble vitamin and carotenoid concentrations among free-living persons in geographically and ethnically distinct US cities.

DESIGN

Adults (n = 2535) and their children aged 12-17 y (n = 272) in Baltimore, Minneapolis, and San Diego attended clinic visits during which data were collected on diet, savory snack consumption, lifestyle, and anthropometric indexes. Blood samples were drawn to assay carotenoids and vitamins A, D, E, and K. Data and blood samples were collected both before and after the nationwide introduction of olestra. General estimating equations were used in multivariate-adjusted models that examined olestra's association with the specified serum nutrients.

RESULTS

Compared with no intake, the top 2 tertiles of olestra use in adults were associated with circulating carotenoid concentrations that were modestly but significantly lower (4.3% to 22.4%). There were no significant associations of olestra with any serum nutrients among adolescents.

CONCLUSIONS

This active postmarketing surveillance study of a food additive suggests that small decreases in serum fat-soluble nutrients are attributable to olestra use. Although health outcomes were not measured here, it is unlikely that these small changes in nutrient measures would adversely affect health.

Selenium and vitamins status in Saudi children

BACKGROUND

Selenium is an essential element, and a cofactor required to maintain glutathione peroxidase activity. Its deficiency may induce modification in the cellular antioxidative status and the appearance of different diseases. Previous studies in Al-Kharj reported low selenium levels in the soil and the milk of lactating mothers living in that area.

METHODS

A cross-sectional study was carried out to determine the status of selenium, dl-alpha-tocopherol, and all-trans-retinol in 513 Saudi children living in Al-Kharj district using serum and toenail samples.

RESULTS

The prevalence of children with serum selenium below the threshold limit of clinical importance in coronary and cardiovascular diseases (45 microg/l) was only 1.4%, while 53.4% of the tested children had toenail selenium >0.56 microg/g, which is considered a low level as indicated in a previous study. DL-alpha-tocopherol deficiency (<0.5 mg/dl) was found only in 3.1%. However, none of the children in this study had a severe all-trans-retinol deficiency (<10 microg/dl) and the percentage of children with marginal deficiency <20 microg/dl was 5.5%.

CONCLUSION

It seems that the geographical location of primary health care units (PHCUs) is the most important factor in influencing the selenium status of these children. This implies variations in food habits. Serum and toenail selenium concentrations were significantly related which can both reflect dietary selenium intake. Although our results suggest an adequate vitamin A status, we found interestingly that 10.9% of the children had retinol >50 microg/dl. This suggests that a high dietary intake of vitamin A might have a harmful effect. Further work is necessary to determine whether the hypervitaminosis A in children reflects an excessive dietary intake of retinol. A significant negative association was also found between dl-alpha-tocopherol and all-trans-retinol and malonaldehyde (MDA) levels in the serum of children population. This confirms their role in reducing oxidative stress.

Serum concentrations of beta-carotene, vitamins C and E, zinc and selenium are influenced by sex, age, diet, smoking status, alcohol consumption and corpulence in a general French adult population

OBJECTIVE

To assess relationships between energy, nutrient and food intakes, alcohol consumption, smoking status and body mass index (BMI), and serum concentrations of beta-carotene, alpha-tocopherol, vitamin C, selenium and zinc.

METHODS

Data on health status, alcohol consumption, smoking habits, anthropometric data and biochemical measurements were obtained in 1821 women aged 35-60 y and 1307 men aged 45-60 y, participant to the SU.VI.MAX Study. Data on dietary intake were available on a subsample who reported six 24-h dietary records during the first 18 months of the study.

RESULTS

Women had higher baseline serum beta-carotene and vitamin C concentrations and lower concentration for serum vitamin E, zinc and selenium than men. In women, younger age was associated with lowered mean concentration of serum beta-carotene, vitamin E and selenium. In men, only differences were observed for serum zinc, which was lower in older men. Current smokers of both sexes had significantly lower concentrations of serum beta-carotene, vitamin C and selenium, and, only in women, of vitamin E, than nonsmokers. Alcohol consumers had lower concentrations of serum beta-carotene and higher selenium concentrations. Serum beta-carotene and vitamin C concentrations were lower in obese subjects. There were positive associations of dietary beta-carotene, vitamin C and E with their serum concentrations. Age, nutrient and alcohol intakes, serum cholesterol, BMI and smoking status explained 15.2% of the variance of serum beta-carotene in men and 13.9% in women, and 10.8 and 10.0% for serum vitamin C, and 26.3 and 28.6% for serum vitamin E, respectively.

CONCLUSION

Serum antioxidant nutrient concentrations are primarily influenced by sex, age, obesity, tobacco smoking, alcohol consumption and especially dietary intake of those antioxidant nutrients.