Carotenoid intakes, assessed by food-frequency questionnaires (FFQs), are associated with serum carotenoid concentrations in the Jackson Heart Study: validation of the Jackson Heart Study Delta NIRI Adult FFQs

Biochemical Validation of a Self-Administered Carotenoid Intake Screener to Assess Carotenoid Intake in Nonobese Adults

Background

Epidemiological studies have demonstrated an association between carotenoid intake and health. However, an accurate measurement of carotenoid intake is challenging. FFQ is the most commonly used dietary assessment method and is typically composed of 100-200 items. However, the greater participant burden that accompanies a more detailed FFQ provides only a marginal gain in accuracy. Therefore, a brief validated carotenoid intake screener is needed.

Objectives

To conduct secondary analysis evaluating the validity of a newly developed 44-item carotenoid intake screener from The Juice Study: Sensitivity of Skin Carotenoid Status to Detect Change in Intake (NCT03202043) against corresponding plasma carotenoid concentrations (primary) and skin carotenoids (secondary) in nonobese Midwestern American adults.

Methods

Healthy adults (n = 83; 25 men and 58 women) aged 18-65 y (mean age, 32 ± 12 y) with a BMI (in kg/m2) of 18.5-29.9 (mean BMI, 25 ± 3) were recruited between 25 April 2018 and 28 March 2019. Participants completed the carotenoid intake screener weekly during the 8-wk parent study. Plasma carotenoid concentrations were assessed at weeks 0, 4, and 8 using HPLC. Skin carotenoids were assessed weekly using pressure-mediated reflection spectroscopy (RS). Correlation matrices from mixed models were used to determine the correlation between carotenoid intake and plasma and skin carotenoids over time.

Results

The total carotenoid intake, as determined by the carotenoid intake screener, correlated with both the plasma total carotenoid concentration (r = 0.52; P < 0.0001) and the RS-assessed skin carotenoid concentration (r = 0.43; P < 0.0001). Correlations between reported intake and plasma concentrations of α-carotene (r = 0.40; P = 0.0002), cryptoxanthin (r = 0.28; P = 0.0113), and lycopene (r = 0.33; P = 0.0022) were also observed.

Conclusions

The results of this study demonstrate an acceptable relative validity of the carotenoid intake screener to assess total carotenoid intake in adults classified as those having a healthy body or those with overweight.

Application of a Lifestyle-Based Score to Predict Cardiovascular Risk in African Americans: The Jackson Heart Study

Cardiovascular disease (CVD) primordial prevention tools applicable to diverse populations are scarce. Our aim was to assess the performance of a lifestyle-based tool to estimate CVD risk in an African American population. The Jackson Heart Study is a prospective cohort including 5306 African American participants in Jackson, Mississippi (2000-2004), with a mean follow up of 12 years. The Healthy Heart Score is a lifestyle-based CVD risk prediction model based on nine components: body mass index (BMI), physical activity, smoking, and a 5-component diet score. Gender-specific beta coefficients from its derivation cohorts were used to assess the performance of the Healthy Heart Score. Model discrimination was assessed using Harrell's C-Index for survival data and time dependent Area Under the Curve. Model calibration was evaluated through calibration plots. A total of 189 CVD events occurred. The Healthy Heart Score showed high-moderate discrimination for CVD events (C-statistic 0.75 [95% CI, 0.71-0.78]) but with little improvement over the age-only model. Both the age-only and Healthy Heart Score models had better performance in participants without diabetes at baseline and showed good calibration. In African Americans, the Healthy Heart Score does not improve prediction of mid-life CVD events beyond what is obtained by age alone.

From carotenoid intake to carotenoid blood and tissue concentrations - implications for dietary intake recommendations

There is uncertainty regarding carotenoid intake recommendations, because positive and negative health effects have been found or are correlated with carotenoid intake and tissue levels (including blood, adipose tissue, and the macula), depending on the type of study (epidemiological vs intervention), the dose (physiological vs supraphysiological) and the matrix (foods vs supplements, isolated or used in combination). All these factors, combined with interindividual response variations (eg, depending on age, sex, disease state, genetic makeup), make the relationship between carotenoid intake and their blood/tissue concentrations often unclear and highly variable. Although blood total carotenoid concentrations <1000 nmol/L have been related to increased chronic disease risk, no dietary reference intakes (DRIs) exist. Although high total plasma/serum carotenoid concentrations of up to 7500 nmol/L are achievable after supplementation, a plateauing effect for higher doses and prolonged intake is apparent. In this review and position paper, the current knowledge on carotenoids in serum/plasma and tissues and their relationship to dietary intake and health status is summarized with the aim of proposing suggestions for a "normal," safe, and desirable range of concentrations that presumably are beneficial for health. Existing recommendations are likewise evaluated and practical dietary suggestions are included.

Serum carotenoids and Pediatric Metabolic Index predict insulin sensitivity in Mexican American children

High concentrations of carotenoids are protective against cardiometabolic risk traits (CMTs) in adults and children. We recently showed in non-diabetic Mexican American (MA) children that serum α-carotene and β-carotene are inversely correlated with obesity measures and triglycerides and positively with HDL cholesterol and that they were under strong genetic influences. Additionally, we previously described a Pediatric Metabolic Index (PMI) that helps in the identification of children who are at risk for cardiometabolic diseases. Here, we quantified serum lycopene and β-cryptoxanthin concentrations in approximately 580 children from MA families using an ultraperformance liquid chromatography-photodiode array and determined their heritabilities and correlations with CMTs. Using response surface methodology (RSM), we determined two-way interactions of carotenoids and PMI on Matsuda insulin sensitivity index (ISI). The concentrations of lycopene and β-cryptoxanthin were highly heritable [h2 = 0.98, P = 7 × 10-18 and h2 = 0.58, P = 1 × 10-7]. We found significant (P ≤ 0.05) negative phenotypic correlations between β-cryptoxanthin and five CMTs: body mass index (- 0.22), waist circumference (- 0.25), triglycerides (- 0.18), fat mass (- 0.23), fasting glucose (- 0.09), and positive correlations with HDL cholesterol (0.29). In contrast, lycopene only showed a significant negative correlation with fasting glucose (- 0.08) and a positive correlation with HDL cholesterol (0.18). Importantly, we found that common genetic influences significantly contributed to the observed phenotypic correlations. RSM showed that increased serum concentrations of α- and β-carotenoids rather than that of β-cryptoxanthin or lycopene had maximal effects on ISI. In summary, our findings suggest that the serum carotenoids are under strong additive genetic influences and may have differential effects on susceptibility to CMTs in children.

Plasma carotenoids, tocopherols and retinol - Association with age in the Berlin Aging Study II

Regular consumption of fruits and vegetables, which is related to high plasma levels of lipid-soluble micronutrients such as carotenoids and tocopherols, is linked to lower incidences of various age-related diseases. Differences in lipid-soluble micronutrient blood concentrations seem to be associated with age. Our retrospective analysis included men and women aged 22-37 and 60-85 years from the Berlin Aging Study II. Participants with simultaneously available plasma samples and dietary data were included (n = 1973). Differences between young and old groups were found for plasma lycopene, α-carotene, α-tocopherol, β-cryptoxanthin (only in women), and γ-tocopherol (only in men). β-Carotene, retinol and lutein/zeaxanthin did not differ between young and old participants regardless of the sex. We found significant associations for lycopene, α-carotene (both inverse), α-tocopherol, γ-tocopherol, and β-carotene (all positive) with age. Adjusting for BMI, smoking status, season, cholesterol and dietary intake confirmed these associations, except for β-carotene. These micronutrients are important antioxidants and associated with lower incidence of age-related diseases, therefore it is important to understand the underlying mechanisms in order to implement dietary strategies for the prevention of age-related diseases. To explain the lower lycopene and α-carotene concentration in older subjects, bioavailability studies in older participants are necessary.

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

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

PARTICIPANTS/SETTING

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

MAIN OUTCOME MEASURES

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

STATISTICAL ANALYSIS

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

RESULTS

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

CONCLUSIONS

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

Influence of individual life course and neighbourhood socioeconomic position on dietary intake in African Americans: the Jackson Heart Study

OBJECTIVE

African Americans, especially those in the Southeastern USA, have different dietary behaviours from the general US population, and have the highest prevalence, incidence and mortality of diet-related disease outcomes, such as cardiovascular disease. However, there are scant data regarding factors such as socioeconomic position (SEP) across the life course that influence dietary behaviours in this high-risk population. Our aim was to examine the impact of life course and neighbourhood SEPs on dietary intake among African Americans.

PARTICIPANTS AND SETTING

Data for this cross-sectional analysis came from the community-based Jackson Heart Study (JHS). We analysed a total of 3948 JHS participants (mean age: 55.4±12.5; 63.9% women), who had complete dietary intake and covariate information.

METHODS

We examined the associations of childhood SEP (CSEP), adulthood SEP (ASEP) and neighbourhood SEP (NSEP) with 10 selected dietary intake measures, using multilevel log-gamma generalised linear regression models.

OUTCOME MEASURES

Dietary intake measures include daily saturated fat, sodium, protein, fibre, fruits and vegetables, whole grains, sugar-sweetened beverage, nuts, fish and processed meat.

RESULTS

In age, sex and total energy intake adjusted models, most dietary intakes were associated with these three SEP measures. After additional adjustment for other SEP measures, most of the significant associations with CSEP and NSEP were attenuated, except for the associations of fibre with CSEP (relative rate [RR] [95% CI] 1.05 [1.00-1.10]) and whole grains with NSEP (RR [95% CI] 1.28 [1.02-1.61]). The associations (shown as RR [95% CI]) between ASEP and sugar-sweetened beverage: 0.70 (0.59-0.83), processed meat: 0.75 (0.63-0.90), sodium: 0.99 (0.94-1.00), fibre: 1.10 (1.03-1.16), protein: 1.05 (1.01-1.09), fruits and vegetables: 1.21 (1.11-1.32), nuts: 2.13 (1.59-2.87), and fish: 1.57 (1.27-1.95) generally persisted after additional adjustment for both CSEP and NSEP. However, the association between ASEP and whole grains was attenuated.

CONCLUSIONS

High ASEP may have a more beneficial influence on dietary practices in African Americans than CSEP or NSEP.

Dietary Phosphorus and Ambulatory Blood Pressure in African Americans: The Jackson Heart Study

BACKGROUND

Higher dietary phosphorus is associated with left ventricular hypertrophy and mortality, which are blood pressure (BP)-related outcomes. For this reason, we hypothesized that dietary phosphorus may be associated with adverse clinic and ambulatory BP patterns.

METHODS

Our study included 973 African American adults enrolled in the Jackson Heart Study (2000-2004) with 24-hour ambulatory BP monitoring (ABPM) data at baseline. We quantified dietary phosphorus from a validated Food Frequency Questionnaire as follows: (i) absolute daily intake, (ii) ratio of phosphorus-to-protein intake, (iii) phosphorus density, and (iv) energy-adjusted phosphorus intake. Using multivariable linear regression, we determined associations between dietary phosphorus intake and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure in clinic and over daytime, nighttime, and 24-hour periods from ABPM. Extent of nocturnal BP dipping was also assessed. Using logistic regression, we modeled relationships between dietary phosphorus intake and clinically relevant qualitative BP phenotypes, such as masked, sustained, or white-coat hypertension and normotension.

RESULTS

There were no statistically significant associations between phosphorus intake and SBP or pulse pressure in adjusted models. Most metrics of higher phosphorus intake were associated with lower daytime, nighttime, and clinic DBP. Higher phosphorus intake was not associated with clinic or ABPM-defined hypertension overall, but most metrics of higher phosphorus intake were associated with lower odds of sustained hypertension compared to sustained normotension, white-coat hypertension, and masked hypertension. There were no associations between dietary phosphorus and nocturnal BP dipping.

CONCLUSIONS

These data do not support a role for higher phosphorus intake and higher BP in African Americans.

A global perspective on carotenoids: Metabolism, biotechnology, and benefits for nutrition and health

Carotenoids are lipophilic isoprenoid compounds synthesized by all photosynthetic organisms and some non-photosynthetic prokaryotes and fungi. With some notable exceptions, animals (including humans) do not produce carotenoids de novo but take them in their diets. In photosynthetic systems carotenoids are essential for photoprotection against excess light and contribute to light harvesting, but perhaps they are best known for their properties as natural pigments in the yellow to red range. Carotenoids can be associated to fatty acids, sugars, proteins, or other compounds that can change their physical and chemical properties and influence their biological roles. Furthermore, oxidative cleavage of carotenoids produces smaller molecules such as apocarotenoids, some of which are important pigments and volatile (aroma) compounds. Enzymatic breakage of carotenoids can also produce biologically active molecules in both plants (hormones, retrograde signals) and animals (retinoids). Both carotenoids and their enzymatic cleavage products are associated with other processes positively impacting human health. Carotenoids are widely used in the industry as food ingredients, feed additives, and supplements. This review, contributed by scientists of complementary disciplines related to carotenoid research, covers recent advances and provides a perspective on future directions on the subjects of carotenoid metabolism, biotechnology, and nutritional and health benefits.

Serum carotenoid and retinol levels in African-Caribbean Tobagonian men with high prostate cancer risk in comparison with African-American men

Black men are known to have a higher risk for prostate cancer (PC). Carotenoids and retinol, linked to PC, have not been compared in different black populations at risk. We examined serum carotenoid and retinol levels between PC-free African-Caribbean (AC) Tobagonian men with a high PC risk (high-grade prostatic intraepithelial neoplasia, atypical foci or repeated abnormal PC screenings) and African-American (AA) men with elevated serum prostate-specific antigen (PSA) levels (≥4 ng/ml). AC men who participated in the 2003 lycopene clinical trial and AA men who participated in the 2001-2006 National Health and Nutrition Examination Survey were compared. Serum specimens were analysed for carotenoid (β-carotene, α-carotene, β-cryptoxanthin, lutein/zeaxanthin and lycopene) and retinol levels by isocratic HPLC. Quantile regression was used to examine the association between serum carotenoid and retinol levels and black ethnicity, overall and among men with elevated serum PSA. There were sixty-nine AC men and sixty-five AA men, aged 41-79 years, included. AC men were associated with lower serum lycopene and retinol levels, and higher serum α- and β-carotenes and lutein/zeaxanthin levels compared with AA men, after adjusting for age, BMI, ever smoked cigarettes, education and hypertension (P≤0·03). Among men with elevated PSA, serum retinol was no longer statistically significant with ethnicity (P=0·06). Possible differences may be attributed to dietary intake, genetics and/or factors that influence bioavailability of these micronutrients. Prospective studies are warranted that investigate whether these differences in micronutrients between AC Tobagonian and AA men influence PC risk.

Carotenoid dietary intakes and plasma concentrations are associated with heel bone ultrasound attenuation and osteoporotic fracture risk in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort

Carotenoids are found in abundance in fruit and vegetables, and may be involved in the positive association of these foods with bone health. This study aimed to explore the associations of dietary carotenoid intakes and plasma concentrations with bone density status and osteoporotic fracture risk in a European population. Cross-sectional analyses (n 14 803) of bone density status, using calcaneal broadband ultrasound attenuation (BUA) and longitudinal analyses (n 25 439) of fracture cases were conducted on data from the prospective European Prospective Investigation into Cancer and Nutrition-Norfolk cohort of middle-aged and older men and women. Health and lifestyle questionnaires were completed, and dietary nutrient intakes were derived from 7-d food diaries. Multiple regression demonstrated significant positive trends in BUA for women across quintiles of dietary α-carotene intake (P=0·029), β-carotene intake (P=0·003), β-cryptoxanthin intake (P=0·031), combined lutein and zeaxanthin intake (P=0·010) and lycopene intake (P=0·005). No significant trends across plasma carotenoid concentration quintiles were apparent (n 4570). The Prentice-weighted Cox regression showed no trends in fracture risk across dietary carotenoid intake quintiles (mean follow-up time 12·5 years), except for a lower risk for wrist fracture in women with higher lutein and zeaxanthin intake (P=0·022); nevertheless, inter-quintile differences in fracture risk were found for both sexes. Analysis of plasma carotenoid data (mean follow-up time 11·9 years) showed lower hip fracture risk in men across higher plasma α-carotene (P=0·026) and β-carotene (P=0·027) quintiles. This study provides novel evidence that dietary carotenoid intake is relevant to bone health in men and women, demonstrating that associations with bone density status and fracture risk exist for dietary intake of specific carotenoids and their plasma concentrations.

Biomarkers of Dietary Intake Are Correlated with Corresponding Measures from Repeated Dietary Recalls and Food-Frequency Questionnaires in the Adventist Health Study-2

BACKGROUND

Accurate assessment of diet in study populations is still a challenge. Some statistical strategies that use biomarkers of dietary intake attempt to compensate for the biasing effects of reporting errors.

OBJECTIVE

The objective was to correlate biomarkers of dietary intake with 2 direct measures of dietary intake.

METHODS

Subjects provided repeated 24-h dietary recalls and 2 food-frequency questionnaires (FFQs) separated by ∼3 y. Correlations between biomarkers and reported dietary intakes as measured by the recalls and FFQs were de-attenuated for within-person variability. The Adventist Health Study-2 (AHS-2) has a large database of biomarkers of dietary intake (blood, urine, adipose tissue) from a calibration study (909 analytic subjects) representing the cohort. Participants were black and non-black Adventists in the United States and Canada.

RESULTS

Dietary items with higher-valued de-attenuated correlations (≥0.50) between biomarkers and recalls included some fatty acids (FAs), the non-fish meats, fruit (non-black subjects), some carotenoids, vitamin B-12 (non-black subjects), and vitamin E. Moderately valued correlations (0.30-0.49) were found for very long chain ω-3 (n-3) FAs, some carotenoids, folate, isoflavones, cruciferous vegetables, fruit (black subjects), and calcium. The highest correlation values in non-black and black subjects were 0.69 (urinary 1-methyl-histidine and meat consumption) and 0.72 (adipose and dietary 18:2 ω-6), respectively. Correlations comparing biomarkers with recalls were generally similar for black and non-black subjects, but correlations between biomarkers and the FFQ were slightly lower than corresponding recall correlations. Correlations between biomarkers and a single FFQ estimate (the usual cohort situation) were generally much lower.

CONCLUSIONS

Many biomarkers that have relatively high-valued correlations with dietary intake were identified and were usually of similar value in black and non-black subjects. These may be used to correct effects of dietary measurement errors in the AHS-2 cohort, and in some cases they also provide evidence supporting the validity of the dietary data.

Absorption, metabolism, and functions of β-cryptoxanthin

β-Cryptoxanthin, a carotenoid found in fruits and vegetables such as tangerines, red peppers, and pumpkin, has several functions important for human health. Most evidence from observational, in vitro, animal model, and human studies suggests that β-cryptoxanthin has relatively high bioavailability from its common food sources, to the extent that some β-cryptoxanthin-rich foods might be equivalent to β-carotene-rich foods as sources of retinol. β-Cryptoxanthin is an antioxidant in vitro and appears to be associated with decreased risk of some cancers and degenerative diseases. In addition, many in vitro, animal model, and human studies suggest that β-cryptoxanthin-rich foods may have an anabolic effect on bone and, thus, may help delay osteoporosis.

Beta-cryptoxanthin as a source of vitamin A

Beta-cryptoxanthin is a common carotenoid that is found in fruit, and in human blood and tissues. Foods that are rich in beta-cryptoxanthin include tangerines, persimmons and oranges. Beta-cryptoxanthin has several functions that are important for human health, including roles in antioxidant defense and cell-to-cell communication. Most importantly, beta-cryptoxanthin is a precursor of vitamin A, which is an essential nutrient needed for eyesight, growth, development and immune response. We evaluate the evidence for beta-cryptoxanthin as a vitamin A-forming carotenoid in this paper. Observational, in vitro, animal model and human studies suggest that beta-cryptoxanthin has greater bioavailability from its common food sources than do alpha- and beta-carotene from theirs. Although beta-cryptoxanthin appears to be a poorer substrate for beta-carotene 15,15' oxygenase than is beta-carotene, animal model and human studies suggest that the comparatively high bioavailability of beta-cryptoxanthin from foods makes beta-cryptoxanthin-rich foods equivalent to beta-carotene-rich foods as sources of vitamin A. These results mean that beta-cryptoxanthin-rich foods are probably better sources of vitamin A, and more important for human health in general, than previously assumed.

Prevalence and changes over time of ideal cardiovascular health metrics among African-Americans: the Jackson Heart Study

OBJECTIVES

The aim of this study is to assess the prevalence and changes over time of ideal Life's Simple Seven (LSS) in African-Americans.

METHODS

Prospective cohort of 5301 African-Americans from the Jackson Heart Study (JHS) from 2000 to 2013. Each of the LSS metrics was categorized as poor, intermediate, or ideal.

RESULTS

Among men, the prevalence of having 0, 1, 2, 3, 4, 5, 6, and 7 ideal LSS was 3.3%, 23.0%, 33.5%, 24.7%, 11.6%, 3.6%, 0.3%, and 0%, respectively. Corresponding values for women were 1.7%, 26.3%, 33.1%, 22.8%, 11.9%, 3.7%, 0.6%, and 0%. Prevalence of ideal diet was 0.9%. The proportions of those meeting LSS ideal recommendations for cholesterol and fasting glucose declined from the first through third JHS visits across all age groups, whereas prevalence of ideal BMI declined only in participants <40 years at a given visit. Prevalence of ideal blood pressure did not change over time and being ideal on physical activity improved from the first [18.3% (95% CI: 17.3% to 19.3%)] to third visit [24.8% (95% CI: 23.3% to 26.3%)].

CONCLUSIONS

Our data show a low prevalence of ideal LSS (especially diet, physical activity, and obesity) in the JHS and a slight improvement in adherence to physical activity recommendations over time.

A church-based pilot study designed to improve dietary quality for rural, lower Mississippi Delta, African American adults

We piloted a 6-month, church-based, behavioral intervention, Delta Body and Soul (DBS), for African American (AA) adults in the Lower Mississippi Delta (LMD). DBS was designed to improve overall dietary quality in LMD AA adults. The intervention included six once monthly group-based educational sessions implemented by trained church members. Program implementation, session attendance, congregational feedback, and baseline and post-intervention, demographic, health, behavioral, and clinical parameters were assessed. Participants were predominately AA, female, and overweight or obese. Retention rate was 79 %. High adherence, defined as attendance at four or more educational sessions, was associated with dietary quality improvement and reduced blood glucose. Implementation of the DBS pilot intervention was feasible and may result in dietary quality and clinical improvements.

Biosynthetic routes of hydroxylated carotenoids (xanthophylls) in Marchantia polymorpha, and production of novel and rare xanthophylls through pathway engineering in Escherichia coli

MpBHY codes for a carotene β-ring 3(,3')-hydroxylase responsible for both zeaxanthin and lutein biosynthesis in liverwort. MpCYP97C functions as an ε-ring hydroxylase (zeinoxanthin 3'-hydroxylase) to produce lutein in liverwort. Xanthophylls are oxygenated or hydroxylated carotenes that are most abundant in the light-harvesting complexes of plants. The plant-type xanthophylls consist of α-xanthophyll (lutein) and β-xanthophylls (zeaxanthin, antheraxanthin, violaxanthin and neoxanthin). The α-xanthophyll and β-xanthophylls are derived from α-carotene and β-carotene by carotene hydroxylase activities, respectively. β-Ring 3,3'-hydroxylase that mediates the route of zeaxanthin from β-carotene via β-cryptoxanthin is present in higher plants and is encoded by the BHY (BCH) gene. On the other hand, CYP97A (or BHY) and CYP97C genes are responsible for β-ring 3-hydroxylation and ε-ring 3'-hydroxylation, respectively, in routes from α-carotene to lutein. To elucidate the evolution of the biosynthetic routes of such hydroxylated carotenoids from carotenes in land plants, we identified and functionally analyzed carotenoid hydroxylase genes of liverwort Marchantia polymorpha L. Three genes homologous to higher plants, BHY, CYP97A, and CYP97C, were isolated and named MpBHY, MpCYP97A, and MpCYP97C, respectively. MpBHY was found to code for β-ring hydroxylase, which is responsible for both routes starting from β-carotene and α-carotene. MpCYP97C functioned as an ε-ring hydroxylase not for α-carotene but for zeinoxanthin, while MpCYP97A showed no hydroxylation activity for β-carotene or α-carotene. These findings suggest the original functions of the hydroxylation enzymes of carotenes in land plants, which are thought to diversify in higher plants. In addition, we generated recombinant Escherichia coli cells, which produced rare and novel carotenoids such as α-echinenone and 4-ketozeinoxanthin, through pathway engineering using bacterial carotenogenic genes that include crtW, in addition to the liverwort MpLCYb, MpLCYe and MpBHY genes.

Biochemical validation of the older Australian's food frequency questionnaire using carotenoids and vitamin E

BACKGROUND

Validation of a food frequency questionnaire (FFQ) is important, as inaccurate and imprecise information may affect the association between dietary exposure and health outcomes.

OBJECTIVE

This study assessed the validity of the Older Australian's FFQ against plasma carotenoids and Vitamin E.

METHODS

A random subsample (n = 150) of 2420 participants in the Hunter Community Study, aged 55-85 years, were included. Correlations between crude and energy-adjusted FFQ estimates of carotenoids, Vitamin E, and fruit and vegetables with corresponding biomarkers were determined. Percentages of participants correctly classified in the same quartile, and in the same ± 1 quartile, by the two methods were calculated.

RESULTS

Significant correlations (P < 0.05) were observed for α-carotene (r = 0.26-0.28), β-carotene (r = 0.21-0.25), and β-cryptoxanthin (r = 0.21-0.23). Intakes of fruits and vegetables also showed similar correlations with these plasma carotenoids. Lycopene was only significantly correlated with fruit and vegetable intakes (r = 0.19-0.23). Weak correlations were observed for lutein + zeaxanthin (r = 0.12-0.16). For Vitamin E, significant correlation was observed for energy-adjusted FFQ estimate and biomarker (r = 0.20). More than 68% of individuals were correctly classified within the same or adjacent quartile, except for lutein + zeaxanthin.

CONCLUSION

With the exception of lutein + zeaxanthin, the Older Australian's FFQ provides reasonable rankings for individuals according to their carotenoids, Vitamin E, fruit and vegetable intakes.

Construction of transplastomic lettuce (Lactuca sativa) dominantly producing astaxanthin fatty acid esters and detailed chemical analysis of generated carotenoids

The plastid genome of lettuce (Lactuca sativa L.) cv. Berkeley was site-specifically modified with the addition of three transgenes, which encoded β,β-carotenoid 3,3'-hydroxylase (CrtZ) and β,β-carotenoid 4,4'-ketolase (4,4'-oxygenase; CrtW) from a marine bacterium Brevundimonas sp. strain SD212, and isopentenyl diphosphate isomerase from a marine bacterium Paracoccus sp. strain N81106. Constructed transplastomic lettuce plants were able to grow on soil at a growth rate similar to that of non-transformed lettuce cv. Berkeley and generate flowers and seeds. The germination ratio of the lettuce transformants (T0) (98.8%) was higher than that of non-transformed lettuce (93.1 %). The transplastomic lettuce (T1) leaves produced the astaxanthin fatty acid (myristate or palmitate) diester (49.2% of total carotenoids), astaxanthin monoester (18.2%), and the free forms of astaxanthin (10.0%) and the other ketocarotenoids (17.5%), which indicated that artificial ketocarotenoids corresponded to 94.9% of total carotenoids (230 μg/g fresh weight). Native carotenoids were there lactucaxanthin (3.8%) and lutein (1.3 %) only. This is the first report to structurally identify the astaxanthin esters biosynthesized in transgenic or transplastomic plants producing astaxanthin. The singlet oxygen-quenching activity of the total carotenoids extracted from the transplastomic leaves was similar to that of astaxanthin (mostly esterified) from the green algae Haematococcus pluvialis.

New and rare carotenoids isolated from marine bacteria and their antioxidant activities

Marine bacteria have not been examined as extensively as land bacteria. We screened carotenoids from orange or red pigments-producing marine bacteria belonging to rare or novel species. The new acyclic carotenoids with a C₃₀ aglycone, diapolycopenedioc acid xylosylesters A-C and methyl 5-glucosyl-5,6-dihydro-apo-4,4'-lycopenoate, were isolated from the novel Gram-negative bacterium Rubritalea squalenifaciens, which belongs to phylum Verrucomicrobia, as well as the low-GC Gram-positive bacterium Planococcus maritimus strain iso-3 belonging to the class Bacilli, phylum Firmicutes, respectively. The rare monocyclic C₄₀ carotenoids, (3R)-saproxanthin and (3R,2'S)-myxol, were isolated from novel species of Gram-negative bacteria belonging to the family Flavobacteriaceae, phylum Bacteroidetes. In this review, we report the structures and antioxidant activities of these carotenoids, and consider relationships between bacterial phyla and carotenoid structures.

3-β-Glucosyl-3'-β-quinovosyl zeaxanthin, a novel carotenoid glycoside synthesized by Escherichia coli cells expressing the Pantoea ananatis carotenoid biosynthesis gene cluster

Escherichia coli cells that express the full six carotenoid biosynthesis genes (crtE, crtB, crtI, crtY, crtZ, and crtX) of the bacterium Pantoea ananatis have been shown to biosynthesize zeaxanthin 3,3'-β-D-diglucoside. We found that this recombinant E. coli also produced a novel carotenoid glycoside that contained a rare carbohydrate moiety, quinovose (chinovose; 6-deoxy-D-glucose), which was identified as 3-β-glucosyl-3'-β-quinovosyl zeaxanthin by chromatographic and spectroscopic analyses. The chirality of the aglycone of these zeaxanthin glycosides had been shown to be 3R,3'R, in which the hydroxyl groups were formed with the CrtZ enzyme. It was here demonstrated that zeaxanthin synthesized from β-carotene with CrtR or CYP175A1, the other hydroxylase with similar catalytic function to CrtZ, possessed the same stereochemistry. It was also suggested that the singlet oxygen-quenching activity of zeaxanthin 3,3'-β-D-diglucoside, which has a chemical structure close to the new carotenoid glycoside, was superior to that of zeaxanthin.

Quantifying diet for nutrigenomic studies

The field of nutrigenomics shows tremendous promise for improved understanding of the effects of dietary intake on health. The knowledge that metabolic pathways may be altered in individuals with genetic variants in the presence of certain dietary exposures offers great potential for personalized nutrition advice. However, although considerable resources have gone into improving technology for measurement of the genome and biological systems, dietary intake assessment remains inadequate. Each of the methods currently used has limitations that may be exaggerated in the context of gene × nutrient interaction in large multiethnic studies. Because of the specificity of most gene × nutrient interactions, valid data are needed for nutrient intakes at the individual level. Most statistical adjustment efforts are designed to improve estimates of nutrient intake distributions in populations and are unlikely to solve this problem. An improved method of direct measurement of individual usual dietary intake that is unbiased across populations is urgently needed.

Dietary, anthropometric, and lifestyle correlates of serum carotenoids in postmenopausal women

PURPOSE

Concentration of carotenoids in the serum is a biomarker of mainly vegetable and fruit consumption. However, the levels of carotenoids in humans may decline with age and can also depend on body fat, alcohol consumption, and cigarette smoking.

METHOD

Food intake and characteristics of 159 randomly chosen women aged 56-75 years were obtained by a self-administered questionnaire. Serum concentrations of carotenoids were determined by high-performance liquid chromatography. Estimation of fat mass was carried out by dual energy X-ray absorptiometry.

RESULTS

The estimated total daily intake of carotenoids was 9.75 mg: α-carotene 10.6%; β-carotene 35.6%; lutein/zeaxanthin 27.1%; β-cryptoxanthin 4.7%; and lycopene 22.0%. We observed statistically significant positive correlations between concentrations of serum carotenoids and their estimated intakes (r = 0.11 lycopene to 0.38 β-carotene) and fruit and vegetable intake (r = 0.15 lycopene to 0.30 β-carotene). Concentration of serum carotenoids positively correlated with education (r = 0.17 α-carotene to 0.29 lycopene) and alcohol intake (r = 0.02 α-carotene to r = 0.25 lycopene). Inverse correlations were with the age (r = -0.18 α-carotene to -0.42 lycopene) and fat mass (r = -0.15 lycopene to -0.29 α-, β-carotene).

CONCLUSION

In this population of healthy postmenopausal women, serum concentrations of carotenoids declined with increasing age and body fat mass. The concentrations were increased among women with high vegetable and fruit consumption, moderate alcohol intake, and high level of education.

Are religiosity and spirituality associated with obesity among African Americans in the Southeastern United States (the Jackson Heart Study)?

There are several lines of evidence that suggest religiosity and spirituality are protective factors for both physical and mental health, but the association with obesity is less clear. This study examined the associations between dimensions of religiosity and spirituality (religious attendance, daily spirituality, and private prayer), health behaviors and weight among African Americans in central Mississippi. Jackson Heart Study participants with complete data on religious attendance, private prayer, daily spirituality, caloric intake, physical activity, depression, and social support (n = 2,378) were included. Height, weight, and waist circumference were measured. We observed no significant association between religiosity, spirituality, and weight. The relationship between religiosity/spirituality and obesity was not moderated by demographic variables, psychosocial variables, or health behaviors. However, greater religiosity and spirituality were related to lower energy intake, less alcohol use, and less likelihood of lifetime smoking. Although religious participation and spirituality were not cross-sectionally related to weight among African Americans, religiosity and spirituality might promote certain health behaviors. The association between religion and spirituality and weight gain deserves further investigation in studies with a longitudinal study design.

Both comprehensive and brief self-administered diet history questionnaires satisfactorily rank nutrient intakes in Japanese adults

BACKGROUND

A comprehensive self-administered diet history questionnaire (DHQ: 150-item semi-quantitative questionnaire) and a brief self-administered DHQ (BDHQ: 58-item fixed-portion-type questionnaire) were developed for assessing Japanese diets. We compared the relative validity of nutrient intake derived from DHQ with that from the BDHQ, using semi-weighed 16-day dietary records (DRs) as reference.

METHODS

Ninety-two Japanese women aged 31 to 69 years and 92 Japanese men aged 32 to 76 years completed a 4-nonconsecutive-day DR, a DHQ, and a BDHQ 4 times each (once per season) in 3 areas of Japan (Osaka, Nagano, and Tottori).

RESULTS

No significant differences were seen in estimates of energy-adjusted intakes of 42 selected nutrients (based on the residual method) between the 16-day DRs and the first DHQ (DHQ1) or between the DR and the first BDHQ (BDHQ1) for 18 (43%) and 14 (33%) nutrients, respectively, among women and for 4 (10%) and 21 (50%) nutrients among men. The median (interquartile range) Pearson correlation coefficients with the DR for energy-adjusted intakes of the 42 nutrients were 0.57 (0.50 to 0.64) for the DHQ1 and 0.54 (0.45 to 0.61) for the BDHQ1 in women; in men, the respective values were 0.50 (0.42 to 0.59) and 0.56 (0.41 to 0.63). Similar results were observed for the means of the 4 DHQs and BDHQs.

CONCLUSIONS

The DHQ and BDHQ had satisfactory ranking ability for the energy-adjusted intakes of many nutrients among the present Japanese population, although these instruments were satisfactory in estimating mean values for only a small number of nutrients.

Health literacy is associated with healthy eating index scores and sugar-sweetened beverage intake: findings from the rural Lower Mississippi Delta

BACKGROUND

Although health literacy has been a public health priority area for more than a decade, the relationship between health literacy and dietary quality has not been thoroughly explored.

OBJECTIVE

To evaluate health literacy skills in relation to Healthy Eating Index (HEI) scores and sugar-sweetened beverage (SSB) consumption while accounting for demographic variables.

DESIGN

Cross-sectional survey.

PARTICIPANTS/SETTING

A community-based proportional sample of adults residing in the rural Lower Mississippi Delta.

METHODS

Instruments included a validated 158-item regional food frequency questionnaire and the Newest Vital Sign (scores range 0 to 6) to assess health literacy.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics, analysis of variance, and multivariate linear regression.

RESULTS

Of 376 participants, the majority were African American (67.6%), without a college degree (71.5%), and household income level <$20,000/year (55.0%). Most participants (73.9%) scored in the two lowest health literacy categories. The multivariate linear regression model to predict total HEI scores was significant (R(2)=0.24; F=18.8; P<0.01), such that every 1-point increase in health literacy was associated with a 1.21-point increase in HEI scores, while controlling for all other variables. Other significant predictors of HEI scores included age, sex, and Supplemental Nutrition Assistance Program participation. Health literacy also significantly predicted SSB consumption (R(2)=0.15; F=6.3; P<0.01) while accounting for demographic variables. Every 1 point in health literacy scores was associated with 34 fewer kilocalories per day from SSBs. Age was the only significant covariate in the SSB model.

CONCLUSIONS

Although health literacy has been linked to numerous poor health outcomes, to our knowledge this is the first investigation to establish a relationship between health literacy and HEI scores and SSB consumption. Our study suggests that understanding the causes and consequences of limited health literacy is an important factor in promoting compliance to the Dietary Guidelines for Americans.

Production of caloxanthin 3'-β-D-glucoside, zeaxanthin 3,3'-β-D-diglucoside, and nostoxanthin in a recombinant Escherichia coli expressing system harboring seven carotenoid biosynthesis genes, including crtX and crtG

The aim of this study was to produce rare β-carotene-modified carotenoids possessing 2-O (-H or -glu) and/or 3-O (-H or -glu) functionalities in their β-ionone ring(s) using a recombinant Escherichia coli approach. This involved expressing seven carotenoid biosynthesis genes (crtE, crtB, crtI, crtY, crtZ, crtX and crtG). From the cells of the recombinant E. coli, caloxanthin (β,β-carotene-2,3,2',3'-tetrol)-3'-β-D-glucose, zeaxanthin (β,β-carotene-3,3'-diol) 3,3'-β-D-diglucoside, and nostoxanthin (β,β-carotene-2,3,3'-triol) (rare carotenoids) were isolated and identified. Caloxanthin 3'-β-D-glucose displayed potent (1)O(2) quenching activity (IC(50) 19 μM).

Proline betaine and its biotransformation products in fasting urine samples are potential biomarkers of habitual citrus fruit consumption

The lack of robust measures of dietary exposure hinders a quantitative understanding of causal relationships between diet and health. Non-targeted metabolite fingerprinting was used to explore the relationships between citrus exposure in free-living human subjects, estimated by a FFQ, and the chemical content of urine. Volunteers (study 1, n 12; study 2, n 11) were classified into high-, medium- and low-frequency citrus consumption groups. Overnight and spot fasting urine samples were obtained after exposure to a standardised citrus-free evening meal. The urine samples were analysed by flow injection electrospray-ionisation MS followed by supervised multivariate data classification analysis to discover discriminatory features associated with the level of citrus exposure. Good separation of high and low citrus consumption classes was achieved. Deeper exploration of high-ranked explanatory mass signals revealed several correlated signals derived from proline betaine. Targeted analysis of the relative levels of proline betaine in both fasting and overnight urine samples demonstrated good correlation with FFQ exposure data. Acute exposure of volunteers to orange juice resulted in the appearance of proline betaine and several biotransformed products in postprandial urine samples. Biomarker validation showed sensitivities of 80·8-92·2 % and specificities of 74·2-94·1 % (false discovery rate-adjusted P values < 0·05) for elevated proline betaine in participants who reported high citrus consumption. Proline betaine biotransformation products displayed weaker quantitative relationships with habitual citrus exposure. Targeted screening for the presence of biotransformation products of hesperidin and narirutin, known to be abundant in oranges, revealed that they were relatively poor indicators of citrus exposure.

Racial differences in correlations between reported dietary intakes of carotenoids and their concentration biomarkers

BACKGROUND

The predictive ability of dietary assessment methods to estimate specific circulating plasma carotenoid concentrations has been compared between African Americans and whites in only one study to date.

OBJECTIVE

The predictive abilities of 24-h dietary recalls and a food-frequency questionnaire in reporting dietary carotenoids when measured against concentration biomarkers were assessed in African Americans and compared with the findings in whites.

DESIGN

Data were collected from 250 generally healthy, nonsmoking white and African American participants aged 21-69 y, who completed 8 self-administered online 24-h dietary recalls and one National Cancer Institute diet-history questionnaire in the University of California Los Angeles (UCLA) Energetics Study. Mean intakes from 4-d dietary recalls were correlated with plasma xanthophyll concentrations (lutein + zeaxanthin and β-cryptoxanthin) and hydrocarbon carotenoids (lycopene, α-carotene, and β-carotene).

RESULTS

Adjusted correlations of plasma carotenoids with reported dietary intakes for African Americans in the 24-h dietary recall ranged from 0.03 for β-carotene to 0.40 for β-cryptoxanthin. For whites, the correlations ranged from 0.13 for lycopene to 0.51 for β-cryptoxanthin.

CONCLUSIONS

Despite stronger validity in reported energy intakes for African Americans than for whites in the 24-h dietary recall in the Energetics Study, both recalls and food-frequency dietary assessment methods yielded lower correlations in African Americans than in whites. This finding might be attributable to reporting differences in both dietary sources and food preparation or to racially related genetic variants influencing circulating concentrations. The current findings support the need to account for differences in race, age, sex, and body mass index in regression calibrations of dietary reports and measurement error adjustments.

Comparison of relative validity of food group intakes estimated by comprehensive and brief-type self-administered diet history questionnaires against 16 d dietary records in Japanese adults

OBJECTIVE

To compare the relative validity of food group intakes derived from a comprehensive self-administered diet history questionnaire (DHQ) and a brief-type DHQ (BDHQ) developed for the assessment of Japanese diets during the previous month using semi-weighed dietary records (DR) as a reference method.

DESIGN

Between November 2002 and September 2003, a 4 d DR (covering four non-consecutive days), a DHQ (150-item semi-quantitative questionnaire) and a BDHQ (fifty-eight-item fixed-portion-type questionnaire) were completed four times (once per season) at 3-month intervals.

SETTING

Three areas in Japan: Osaka, Nagano and Tottori.

SUBJECTS

Ninety-two Japanese women aged 31-69 years and ninety-two Japanese men aged 32-76 years.

RESULTS

Median food group intakes were estimated well for approximately half of the food groups. No statistically significant differences were noted between a 16 d DR and the first DHQ (DHQ1) or between the DR and the first BDHQ (BDHQ1) in fifteen (44 %) and fifteen (52 %) food items for women and in fourteen (41 %) and sixteen (55 %) food items for men, respectively, indicating that both questionnaires estimated median values reasonably well. Median Spearman's correlation coefficients with the DR were 0·43 (range: -0·09 to 0·77) for DHQ1 and 0·44 (range: 0·14 to 0·82) for BDHQ1 in women, with respective values of 0·44 (range: 0·08 to 0·87) and 0·48 (range: 0·22 to 0·83) in men, indicating reasonable ranking ability. Similar results were observed for mean values of the four DHQ and BDHQ.

CONCLUSIONS

In terms of food intake estimates, both the DHQ and the BDHQ showed reasonable validity.

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.

β-Cryptoxanthin- and α-carotene-rich foods have greater apparent bioavailability than β-carotene-rich foods in Western diets

β-Carotene (BC), β-cryptoxanthin (CX) and α-carotene (AC) are common carotenoids that form retinol. The amount of retinol (vitamin A) formed from carotenoid-rich foods should depend chiefly on the bioavailability (absorption and circulation time in the body) of carotenoids from their major food sources and the selectivity and reactivity of carotene cleavage enzymes towards them. The objective of the present study was to estimate the apparent bioavailability of the major sources of provitamin A (AC, BC and CX) from the diet by comparing the concentrations of these carotenoids in blood to their dietary intakes. Dietary intakes were estimated by FFQ (three studies in this laboratory, n 86; apparent bioavailability calculated for six other studies, n 5738) or by food record (two studies in our laboratory, n 59; apparent bioavailability calculated for two other studies, n 54). Carotenoid concentrations were measured by reversed-phase HPLC. Apparent bioavailability was calculated as the ratio of concentration in the blood to carotenoid intake. Then apparent bioavailabilities for AC and CX were compared to BC. Eating comparable amounts of AC-, CX- and BC-rich foods resulted in 53 % greater AC (99 % CI 23, 83) and 725 % greater CX (99 % CI 535, 915) concentrations in the blood. This suggests that the apparent bioavailability of CX from typical diets is greater than that of BC. Thus, CX-rich foods might be better sources of vitamin A than expected.

Dietary, but not supplemental, intakes of carotenoids and vitamin C are associated with decreased odds of lower urinary tract symptoms in men

Lower urinary tract symptoms (LUTS) in men may be related to micronutrients involved in prevention of oxidative damage or cell growth and differentiation. We tested the hypothesis that carotenoid, vitamin A, and vitamin C intake were inversely associated with total LUTS, voiding, and storage symptoms. We conducted a cross-sectional multivariate analysis of 1466 men aged 30-79 y in the Boston Area Community Health survey (2002-2005), a population-based random sample survey. Data were collected by in-person interview and validated FFQ. Moderate-to-severe LUTS were defined using the American Urological Symptom Index and analyzed using multivariate logistic regression. Overall, men consuming greater dietary lycopene, β-carotene, total carotenoid, or vitamin A had ~40-50% decreased odds of LUTS compared with the lowest intake quartiles (e.g. β-carotene and storage symptoms, OR = 0.56, 95% CI = 0.39, 0.82; P-trend = 0.02). Interactions were observed between dietary iron and vitamin C or β-cryptoxanthin, whereby inverse associations with LUTS, particularly voiding symptoms, occurred only among men with moderate-to-high iron intake (P-interaction = 0.001). High-dose supplemental and total vitamin C were positively associated with LUTS (e.g. supplemental vitamin C ≥ 250 mg/d, OR = 1.83, 95% CI = 1.21, 2.77; P-trend = 0.02). An interaction between β-carotene and smoking status (P-interaction = 0.004) indicated greater odds of LUTS with higher β-carotene intake among current smokers. Results suggest that modifying consumption of carotenoids and vitamin C may influence LUTS in men.

Biochemical validation of food frequency questionnaire-estimated carotenoid, alpha-tocopherol, and folate intakes among African Americans and non-Hispanic Whites in the Southern Community Cohort Study

Few food frequency questionnaires (FFQs) have been developed specifically for use among African Americans, and reports of FFQ performance among African Americans or low-income groups assessed using biochemical indicators are scarce. The authors conducted a validation study within the Southern Community Cohort Study to evaluate FFQ-estimated intakes of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, folate, and alpha-tocopherol in relation to blood levels of these nutrients. Included were 255 nonsmoking participants (125 African Americans, 130 non-Hispanic whites) who provided a blood sample at the time of study enrollment and FFQ administration in 2002-2004. Levels of biochemical indicators of each micronutrient (alpha-tocopherol among women only) significantly increased with increasing FFQ-estimated intake (adjusted correlation coefficients: alpha-carotene, 0.35; beta-carotene, 0.28; beta-cryptoxanthin, 0.35; lutein/zeaxanthin, 0.28; lycopene, 0.15; folate, 0.26; alpha-tocopherol, 0.26 among women; all P's < 0.05). Subjects in the top decile of FFQ intake had blood levels that were 27% (lycopene) to 178% (beta-cryptoxanthin) higher than those of subjects in the lowest decile. Satisfactory FFQ performance was noted even for participants with less than a high school education. Some variation was noted in the FFQ's ability to predict blood levels for subgroups defined by race, sex, and other characteristics, but overall the Southern Community Cohort Study FFQ appears to generate useful dietary exposure rankings in the cohort.

Total antioxidant performance is associated with diet and serum antioxidants in participants of the diet and physical activity substudy of the Jackson Heart Study

Total antioxidant performance (TAP) measures antioxidant capacities in both hydrophilic and lipophilic compartments of serum and interactions known to exist between them. Our objective was to assess TAP levels in a subset of Jackson Heart Study (JHS) participants and to examine associations with dietary and total (diet + supplement) intakes of alpha-tocopherol, gamma-tocopherol (diet only), beta-carotene, vitamin C, fruit, vegetables, and nuts, and serum concentrations of alpha-tocopherol, gamma-tocopherol, and beta-carotene. We conducted a cross-sectional analysis of 420 (mean age 61 y; 254 women) African American men and women participating in the Diet and Physical Activity Sub-Study of the JHS in Jackson, Mississippi. In multivariate-adjusted models, we observed positive associations between total alpha-tocopherol, total and dietary beta-carotene, and total vitamin C intakes and TAP levels (P-trend < 0.05). Positive associations were also observed for vegetable, fruit, and total fruit and vegetable intakes (P-trend < 0.05). For serum antioxidant nutrients, alpha-tocopherol but not beta-carotene was associated with serum TAP levels. There were inverse associations for serum gamma-tocopherol and TAP levels. Associations for alpha-tocopherol were seen at intake levels much higher than the current Recommended Dietary Allowance. It may, therefore, be prudent to focus on increasing consumption of fruit, vegetables, nuts, and seeds to increase total antioxidant capacity.

Validity and calibration of food frequency questionnaires used with African-American adults in the Jackson Heart Study

OBJECTIVE

To examine the relative validity of two food frequency questionnaires (FFQs) developed for use in investigating diet and disease relationships within the adult African-American population in the southern United States.

DESIGN

Cross-sectional analyses of dietary nutrient intake data, comparing four 24-hour dietary recalls with an FFQ developed by the Lower Mississippi Delta Nutrition Intervention Research Initiative, and its shorter version adapted for use in the Jackson Heart Study.

SUBJECTS

A representative subset of participants (n=499, aged 35 to 81 years) from the baseline Jackson Heart Study cohort (N=5,302) was selected for this study. Data collection took place between winter 2000 and spring 2004.

STATISTICAL ANALYSES

Pearson's correlation coefficients (energy adjusted and de-attenuated) for 26 nutrients estimates from each of the FFQs, comparing them with the mean of four 24-hour dietary recalls. The ability of the FFQs to rank individuals based on nutrient intakes was compared to that of the mean of four 24-hour dietary recalls and attenuation coefficients were also calculated.

RESULTS

Median nutrient intake estimates tended to be higher on the long and lower on the short FFQ compared to the median for the mean of four 24-hour dietary recalls. Energy adjusted and deattenuated correlations of FFQ intake estimates with recalls ranged from 0.20 for sodium to 0.70 for carbohydrate for the short FFQ and from 0.23 for polyunsaturated fat to 0.75 for dietary fiber and magnesium for the long. Attenuation coefficients for men on average were 0.42 for the short and 0.49 for the long FFQ. For women, these were 0.31 for the short and 0.42 for the long FFQ.

CONCLUSIONS

Both FFQs appear to be reasonably valid for assessment of dietary intake of adult African Americans in the South. The Lower Mississippi Delta Nutrition Intervention Research Initiative FFQ exhibited higher intake estimates and stronger correlations with recalls than the Jackson Heart Study FFQ for most nutrients analyzed, more so for women than men.

Common variation in the beta-carotene 15,15'-monooxygenase 1 gene affects circulating levels of carotenoids: a genome-wide association study

Low plasma levels of carotenoids and tocopherols are associated with increased risk of chronic disease and disability. Because dietary intake of these lipid-soluble antioxidant vitamins is only poorly correlated with plasma levels, we hypothesized that circulating carotenoids (vitamin A-related compounds) and tocopherols (vitamin E-related compounds) are affected by common genetic variation. By conducting a genome-wide association study in a sample of Italians (n = 1190), we identified novel common variants associated with circulating carotenoid levels and known lipid variants associated with alpha-tocopherol levels. Effects were replicated in the Women's Health and Aging Study (n = 615) and in the alpha-Tocopherol, beta-Carotene Cancer Prevention (ATBC) study (n = 2136). In meta-analyses including all three studies, the G allele at rs6564851, near the beta-carotene 15,15'-monooxygenase 1 (BCMO1) gene, was associated with higher beta-carotene (p = 1.6 x 10(-24)) and alpha-carotene (p = 0.0001) levels and lower lycopene (0.003), zeaxanthin (p = 1.3 x 10(-5)), and lutein (p = 7.3 x 10(-15)) levels, with effect sizes ranging from 0.10-0.28 SDs per allele. Interestingly, this genetic variant had no significant effect on plasma retinol (p > 0.05). The SNP rs12272004, in linkage disequilibrium with the S19W variant in the APOA5 gene, was associated with alpha-tocopherol (meta-analysis p = 7.8 x 10(-10)) levels, and this association was substantially weaker when we adjusted for triglyceride levels (p = 0.002). Our findings might shed light on the controversial relationship between lipid-soluble anti-oxidant nutrients and human health.

Serum carotenoid and tocopherol concentrations vary by dietary pattern among African Americans

BACKGROUND

Intakes and biochemical concentrations of carotenoids and tocopherols have been associated with chronic diseases.

OBJECTIVE

To describe dietary patterns in Jackson Heart Study participants and to determine if biochemical measurements of antioxidants differ across these.

DESIGN

Cross-sectional analysis of data for 373 African-American men and women (age 35 to 80 years), participating in the Diet and Physical Activity Substudy of the Jackson Heart Study.

METHODS

Dietary intake was assessed with a region specific food frequency questionnaire. Patterns were defined by cluster analysis of food groups, as percent of energy intake.

RESULTS

Four dietary patterns were identified: fast food, Southern, prudent, and juice. Individuals in the fast-food pattern (n=153) had significantly lower serum concentrations of lutein plus zeaxanthin and beta-cryptoxanthin; those in the Southern cluster (n=99) had significantly lower serum alpha-carotene; and those in the prudent (n=63) and juice (n=58) clusters had significantly higher serum alpha-carotene and beta-cryptoxanthin (P<0.05) relative to those in at least one other cluster (all P<0.05). The juice cluster also had higher serum alpha-tocopherol concentrations relative to the fast-food cluster.

CONCLUSIONS

Diets high in fast foods, snacks, soft drinks, and meat were associated with relatively low concentrations of carotenoids and alpha-tocopherol. This pattern contained the largest number of participants, and could contribute to the extensive health disparities seen in this region.

Personalizing nutrigenomics research through community based participatory research and omics technologies

Personal and public health information are often obtained from studies of large population groups. Risk factors for nutrients, toxins, genetic variation, and more recently, nutrient-gene interactions are statistical estimates of the percentage reduction in disease in the population if the risk were to be avoided or the gene variant were not present. Because individuals differ in genetic makeup, lifestyle, and dietary patterns than those individuals in the study population, these risk factors are valuable guidelines, but may not apply to individuals. Intervention studies are likewise limited by small sample sizes, short time frames to assess physiological changes, and variable experimental designs that often preclude comparative or consensus analyses. A fundamental challenge for nutrigenomics will be to develop a means to sort individuals into metabolic groups, and eventually, develop risk factors for individuals. To reach the goal of personalizing medicine and nutrition, new experimental strategies are needed for human study designs. A promising approach for more complete analyses of the interaction of genetic makeups and environment relies on community-based participatory research (CBPR) methodologies. CBPR's central focus is developing a partnership among researchers and individuals in a community that allows for more in depth lifestyle analyses but also translational research that simultaneously helps improve the health of individuals and communities. The USDA-ARS Delta Nutrition Intervention Research program exemplifies CBPR providing a foundation for expanded personalized nutrition and medicine research for communities and individuals.