Associations between serum carotenoid levels and the risk of non-Hodgkin lymphoma: a case-control study.

Limited studies have investigated the effects of serum carotenoids on the risk of non-Hodgkin lymphoma (NHL), and the findings have been inconclusive. This study aims to assess the association between serum total or specific carotenoid levels and NHL risk. This 1:1 matched, hospital-based case-control study enrolled 512 newly diagnosed (within 1 month) NHL patients and 512 healthy controls who were matched by age (±5 years) and sex in Urumqi, China. Serum carotenoid levels were measured by HPLC. Conditional logistic regression showed that higher serum total carotenoid levels and their subtypes (e.g. α-carotene, ß-carotene, ß-cryptoxanthin and lycopene) were dose-dependently associated with decreased NHL risk. The multivariable-adjusted OR and their 95 % CI for NHL risk for quartile 4 (v. quartile 1) were 0·31 (95 % CI 0·22, 0·48; Pfor trend < 0·001) for total carotenoids, 0·52 (95 % CI 0·33, 0·79; Pfor trend: 0·003) for α-carotene, 0·63 (95 % CI 0·42, 0·94; Pfor trend: 0·031) for ß-carotene, 0·73 (95 % CI 0·49, 1·05; Pfor trend: 0·034) for ß-cryptoxanthin and 0·51 (95 % CI 0·34, 0·75; Pfor trend: 0·001) for lycopene. A null association was observed between serum lutein + zeaxanthin and NHL risk (OR 0·89, 95 % CI 0·57, 1·38; Pfor trend: 0·556). Significant interactions were observed after stratifying according to smoking status, and inverse associations were more evident among current smokers than past or never smokers for total carotenoids, α-carotene and lycopene (Pfor heterogeneity: 0·047, 0·042 and 0·046). This study indicates that higher serum carotenoid levels might be inversely associated with NHL risk, especially among current smokers.

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

Circulating vitamin C and carotenoids are used as biomarkers of fruit and vegetable intake in research, but their comparative validity has never been meta-analysed. PubMed, EMBASE, CENTRAL, CINAHL and Web of Science were systematically searched up to December 2013 for randomised trials of different amounts of fruit and vegetable provision on changes in blood concentrations of carotenoids or vitamin C. Reporting followed PRISMA guidelines. Evidence quality was assessed using the GRADE system. Random effects meta-analysis combined estimates and meta-regression tested for sub-group differences. In all, nineteen fruit and vegetable trials (n 1382) measured at least one biomarker, of which nine (n 667) included five common carotenoids and vitamin C. Evidence quality was low and between-trial heterogeneity (I 2) ranged from 74% for vitamin C to 94 % for α-carotene. Groups provided with more fruit and vegetables had increased blood concentrations of vitamin C, α-carotene, ß-carotene, ß-cryptoxanthin and lutein but not lycopene. However, no clear dose-response effect was observed. Vitamin C showed the largest between-group difference in standardised mean change from the pre-intervention to the post-intervention period (smd 0·94; 95% CI 0·66, 1·22), followed by lutein (smd 0·70; 95% CI 0·37, 1·03) and α-carotene (smd 0·63; 95% CI 0·25, 1·01), but all CI were overlapping, suggesting that none of the biomarkers responded more than the others. Therefore, until further evidence identifies a particular biomarker to be superior, group-level compliance to fruit and vegetable interventions can be indicated equally well by vitamin C or a range of carotenoids. High heterogeneity and a lack of dose-response suggest that individual-level biomarker responses to fruit and vegetables are highly variable.

High serum carotenoids associated with lower risk for the metabolic syndrome and its components among Japanese subjects: Mikkabi cohort study.

Recent epidemiological studies show the association of carotenoids with the metabolic syndrome (MetS), but thorough longitudinal cohort studies regarding this association have not been well conducted. The objective of this study was to investigate longitudinally whether serum carotenoids are associated with the risk of developing the MetS and its components in Japanese subjects. We conducted a follow-up study on 1073 men and women aged 30-79 years at the baseline from the Mikkabi prospective cohort study. Those who participated in the baseline and completed follow-up surveys were examined longitudinally. Over the 10-year period, 910 subjects (295 men and 615 women) took part in the follow-up survey at least once. Over a mean follow-up period of 7·8 (sd 2·9) years, thirty-six men and thirty-one women developed new MetS. After adjustments for confounders, the hazard ratio (HR) for the MetS in the highest tertile of serum ß-carotene against the lowest tertile was 0·47 (95 % CI 0·23, 0·95). On the other hand, significantly lower risks for dyslipidaemia were observed in the highest tertiles of serum α- and ß-carotene and ß-cryptoxanthin (HR 0·66; 95 % CI 0·46, 0·96; HR, 0·54; 95 % CI 0·37, 0·79; and HR 0·66; 95 % CI 0·44, 0·99, respectively). Other significant associations between the risks for obesity, high blood pressure and hyperglycaemia with serum carotenoids were not observed. Our results further support the hypothesis that eating a diet rich in carotenoids might help prevent the development of the MetS and its complications in Japanese subjects.

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

Fruit and vegetable consumption produces changes in several biomarkers in blood. The present study aimed to examine the dose-response curve between fruit and vegetable consumption and carotenoid (α-carotene, ß-carotene, ß-cryptoxanthin, lycopene, lutein and zeaxanthin), folate and vitamin C concentrations. Furthermore, a prediction model of fruit and vegetable intake based on these biomarkers and subject characteristics (i.e. age, sex, BMI and smoking status) was established. Data from twelve diet-controlled intervention studies were obtained to develop a prediction model for fruit and vegetable intake (including and excluding fruit and vegetable juices). The study population in the present individual participant data meta-analysis consisted of 526 men and women. Carotenoid, folate and vitamin C concentrations showed a positive relationship with fruit and vegetable intake. Measures of performance for the prediction model were calculated using cross-validation. For the prediction model of fruit, vegetable and juice intake, the root mean squared error (RMSE) was 258.0 g, the correlation between observed and predicted intake was 0.78 and the mean difference between observed and predicted intake was - 1.7 g (limits of agreement: - 466.3, 462.8 g). For the prediction of fruit and vegetable intake (excluding juices), the RMSE was 201.1 g, the correlation was 0.65 and the mean bias was 2.4 g (limits of agreement: -368.2, 373.0 g). The prediction models which include the biomarkers and subject characteristics may be used to estimate average intake at the group level and to investigate the ranking of individuals with regard to their intake of fruit and vegetables when validating questionnaires that measure intake.

Plasma carotenoids and retinol and overall and breast cancer risk: a nested case-control study.

Experimental studies suggest that carotenoids and retinol may play a role in carcinogenesis, but epidemiological evidence is lacking. We investigated the prospective associations between plasma concentrations of major carotenoids and retinol, and overall and breast cancer risk. A nested case-control study included all first incident cancer cases diagnosed in the SU.VI.MAX cohort between 1994 and 2002 (n = 159 cases, 1 matched control/case). Baseline plasma concentrations of carotenoids and retinol were measured by high-performance liquid chromatography. Conditional logistic regression was used to assess odds ratios for an increase of 0.1 µmol/L [odds ratio (OR)] and 95% confidence intervals (CI). Plasma ß-carotene (OR = 0.95, 95% CI = 0.90-0.99, Ptrend = 0.04) and ß-cryptoxanthin concentrations (OR = 0.89, 95% CI = 0.81-0.99, Ptrend = 0.03) were inversely associated with overall cancer risk. Plasma ß-cryptoxanthin concentration was inversely associated with breast cancer risk (OR = 0.83, 95% CI = 0.71-0.96, Ptrend = 0.02). The OR between plasma lycopene concentration and overall cancer risk was 1.07 (0.99-1.15), Ptrend = 0.06. This association turned significant (Ptrend = 0.01) when excluding cancer cases diagnosed during the first year of follow-up. This prospective study suggests an inverse association between plasma concentrations of ß-cryptoxanthin and both overall and breast cancer risk, and an inverse association between ß-carotene and overall cancer risk. The direct association between lycopene concentration and cancer risk deserves further investigation.

Oxidative balance score and oxidative stress biomarkers in a study of Whites, African Americans, and African immigrants.

CONTEXT: Oxidative balance score (OBS) is a composite measure of multiple pro- and antioxidant exposures. OBJECTIVE: To investigate associations of OBS with F2-isoprostanes (FIP), mitochondrial DNA copy number (mtDNA), and fluorescent oxidative products (FOP), and assess inter-relationships among the biomarkers. METHODS: In a cross-sectional study, associations of a thirteen-component OBS with biomarker levels were assessed using multivariable regression models. RESULTS: Association of OBS with FIP, but not with FOP, was in the hypothesized direction. The results for mtDNA were unstable and analysis-dependent. The three biomarkers were not inter-correlated. CONCLUSIONS: Different biomarkers of oxidative stress may reflect different biological processes.

Gene polymorphisms and gene scores linked to low serum carotenoid status and their associations with metabolic disturbance and depressive symptoms in African-American adults.

Gene polymorphisms provide a means to obtain unconfounded associations between carotenoids and various health outcomes. In the present study, we tested whether gene polymorphisms and gene scores linked to low serum carotenoid status are related to metabolic disturbance and depressive symptoms in African-American adults residing in Baltimore city, MD, using cross-sectional data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study (age range 30-64 years, n 873-994). We examined twenty-four SNP of various gene loci that were previously shown to be associated with low serum carotenoid status (SNPlcar). Gene risk scores were created: five low specific-carotenoid risk scores (LSCRS: α-carotene, ß-carotene, lutein+zeaxanthin, ß-cryptoxanthin and lycopene) and one low total-carotenoid risk score (LTCRS: total carotenoids). SNPlcar, LSCRS and LTCRS were entered as predictors for a number of health outcomes. These included obesity, National Cholesterol Education Program Adult Treatment Panel III metabolic syndrome and its components, elevated homeostatic model assessment of insulin resistance, C-reactive protein, hyperuricaemia and elevated depressive symptoms (EDS, Center for Epidemiologic Studies-Depression score ≥ 16). Among the key findings, SNPlcar were not associated with the main outcomes after correction for multiple testing. However, an inverse association was found between the LTCRS and HDL-cholesterol (HDL-C) dyslipidaemia. Specifically, the α-carotene and ß-cryptoxanthin LSCRS were associated with a lower odds of HDL-C dyslipidaemia. However, the ß-cryptoxanthin LSCRS was linked to a higher odds of EDS, with a linear dose-response relationship. In summary, gene risk scores linked to low serum carotenoids had mixed effects on HDL-C dyslipidaemia and EDS. Further studies using larger African-American population samples are needed.

Higher serum carotenoid concentrations associated with a lower prevalence of the metabolic syndrome in middle-aged and elderly Chinese adults.

The association between serum carotenoids and the metabolic syndrome (MetS) remains uncertain, and little is known about this relationship in the Chinese population. The present study examined the association between serum carotenoid concentrations and the MetS in Chinese adults. We conducted a community-based cross-sectional study in which 2148 subjects (1547 women and 601 men) aged 50-75 years were recruited in urban Guangzhou, China. Dietary data and other covariates were collected during face-to-face interviews. Blood pressure, waist circumference, blood lipids, glucose and serum carotenoids (α-, ß-carotene, ß-cryptoxanthin, lycopene and lutein/zeaxanthin) were examined. We found dose-response inverse relationships between individual serum carotenoid concentrations and total carotenoids and the prevalence of the MetS after adjusting for potential confounders (P for trend < 0.001). The OR of the MetS for the highest (v. lowest) quartile were 0.31 (95% CI 0.20, 0.47) for α-carotene, 0.23 (95% CI 0.15, 0.36) for ß-carotene, 0.44 (95% CI 0.29, 0.67) for ß-cryptoxanthin, 0.39 (95% CI 0.26, 0.58) for lycopene, 0.28 (95% CI 0.18, 0.44) for lutein+zeaxanthin and 0.19 (95% CI 0.12, 0.30) for total carotenoids. Higher concentrations of each individual carotenoid and total carotenoids were significantly associated with a decrease in the number of abnormal MetS components (P for trend < 0.001-0.023). Higher serum carotenoid levels were associated with a lower prevalence of the MetS and fewer abnormal MetS components in middle-aged and elderly Chinese adults.

Effect of ß-cryptoxanthin plus phytosterols on cardiovascular risk and bone turnover markers in post-menopausal women: a randomized crossover trial.

BACKGROUND AND AIM: Post-menopausal women are at higher risk of cardiovascular disease and bone demineralization. Phytosterols (PS) may be used for hypercholesterolemia in some groups and ß-cryptoxanthin (ß-Cx) displays a unique anabolic effect on bone. Our aim was to assess the changes in cardiovascular and bone turnover markers from the oral intake of ß-Cx and PS in post-menopausal women. METHODS AND RESULTS: A randomized, double-blind, crossover study with ß-Cx (0.75 mg/day) and PS (1.5 g/day), single and combined, was performed in 38 postmenopausal women. Diet was supplemented with 1 × 250 mL milk-based fruit drink/day for 4 weeks with a wash-out period of 4-weeks in between. Serum ß-Cx and PS were determined by UPLC and CG-FID respectively. Outcome variables included markers of bone turnover and cardiovascular risk. Biological effect was assessed by paired t test and generalized estimating equations analysis that included the previous treatment, the order of intervention and the interactions. The intake of beverages containing ß-Cx and PS brought about a significant increase in serum levels of ß-Cx, ß-sitosterol and campesterol. Intervention caused changes in almost all the markers while the order, previous treatment and the interaction did not reach statistical significance. Only the intake of the beverage containing ß-Cx plus PS brought about significant decreases in total cholesterol, c-HDL, c-LDL and bone turnover markers. CONCLUSIONS: ß-Cx improves the cholesterol-lowering effect of PS when supplied simultaneously and this combination may also be beneficial in reducing risk of osteoporosis. CLINICAL TRIAL REGISTRY: ClinicalTrials.gov number NCT01074723.

Comparison of bioavailability between ß-cryptoxanthin and ß-carotene and tissue distribution in its intact form in rats.

The bioavailability of two intact carotenoids in several tissues of ß-cryptoxanthin- and ß-carotene-fed rats (20 mg/kg of diet) was investigated. Although metabolites of provitamin A are not included in our study, ß-cryptoxanthin was found at higher concentrations in majority of the tissues. The results show that the bioavailability of intact ß-cryptoxanthin seemed to be higher than that of ß-carotene.

Do smoking and fruit and vegetable intake mediate the association between socio-economic status and plasma carotenoids?

BACKGROUND: The aim was to study whether the association between educational attainment and antioxidant status is mediated by smoking and fruit and vegetable intake. METHODS: Cross-sectional analyses of the Oslo Youth Study 2006 wave were carried out. Information about education, smoking habits and diet was collected by questionnaire for 261 subjects (142 women and 119 men aged 38-42 years). Blood samples, height and weight measurements were taken by the participants' General Practitioner. Blood were analysed for plasma carotenoids. Linear regression analyses were used to examine whether smoking and fruit and vegetable intake mediate the association between education and plasma carotenoids. RESULTS: Educational level was positively associated with ß-cryptoxanthin, α-carotene and lutein/zeaxanthin, but not with total carotenoids, ß-carotene or lycopene. Education was negatively associated with smoking and positively associated with fruit and vegetable intake. Smoking was negatively associated with ß-cryptoxanthin, and fruit and vegetable intake was positively associated with ß-cryptoxanthin (adjusted for educational level). Moreover, cigarette consumption mediated the association between education and ß-cryptoxanthin by 37%, while fruit and vegetable intake mediated this association by 18%. The total mediation effect was 55%. CONCLUSION: Smoking seemed to be more important as a mediator between education and plasma levels of ß-cryptoxanthin than the intake of fruit and vegetables, but more studies are needed to establish the relative importance of smoking and diet as mediators of the association between education and antioxidant status.

Serum Carotenoids Reveal Poor Fruit and Vegetable Intake among Schoolchildren in Burkina Faso.

The health benefits of fruits and vegetables are well-documented. Those rich in provitamin A carotenoids are good sources of vitamin A. This cross-sectional study indirectly assessed fruit and vegetable intakes using serum carotenoids in 193 schoolchildren aged 7 to 12 years in the Western part of Burkina Faso. The mean total serum carotenoid concentration was 0.23 ± 0.29 µmol/L, which included α- and ß-carotene, lutein, and ß-cryptoxanthin, and determined with serum retinol concentrations in a single analysis with high performance liquid chromatography. Serum retinol concentration was 0.80 ± 0.35 µmol/L with 46% of children (n = 88) having low values <0.7 µmol/L. Total serum carotene (the sum of α- and ß-carotene) concentration was 0.13 ± 0.24 µmol/L, well below the reference range of 0.9⁻3.7 µmol carotene/L used to assess habitual intake of fruits and vegetables. Individual carotenoid concentrations were determined for α-carotene (0.01 ± 0.05 µmol/L), ß-carotene (0.17 ± 0.24 µmol/L), ß-cryptoxanthin (0.07 ± 0.06 µmol/L), and lutein (0.06 ± 0.05 µmol/L). These results confirm the previously measured high prevalence of low serum vitamin A concentrations and adds information about low serum carotenoids among schoolchildren suggesting that they have low intakes of provitamin A-rich fruits and vegetables.

Serum Nutrient Levels and Aging Effects on Periodontitis.

Periodontal disease damages tissues as a result of dysregulated host responses against the chronic bacterial biofilm insult and approximately 50% of US adults >30 years old exhibit periodontitis. The association of five blood nutrients and periodontitis were evaluated due to our previous findings regarding a potential protective effect for these nutrients in periodontal disease derived from the US population sampled as part of the National Health and Nutrition Examination Survey (1999⁻2004). Data from over 15,000 subjects was analyzed for blood levels of cis-ß-carotene, ß-cryptoxanthin, folate, vitamin D, and vitamin E, linked with analysis of the presence and severity of periodontitis. Moderate/severe disease patients had lower cis-ß-carotene levels across all racial/ethnic groups and these decreased levels in moderate/severe periodontitis were exacerbated with age. ß-cryptoxanthin demonstrated lower levels in severe disease patients across the entire age range in all racial/ethnic groups. Folate differences were evident across the various age groups with consistently lower levels in periodontitis patients >30 years and most pronounced in females. Lower levels of vitamin D were consistently noted across the entire age range of patients with a greater difference seen in females with periodontitis. Finally, an analytical approach to identify interactions among these nutrients related to age and periodontitis showed interactions of vitamin D in females, and folate with race in the population. These findings suggest that improving specific nutrient intake leading to elevated blood levels of a combination of these protective factors may provide a novel strategy to affect the significant increase in periodontitis that occurs with aging.

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, ß-carotene, ß-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, ß-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 ß-cryptoxanthin, and 0.36 (95% CIs 0.24-0.54) for lycopene, respectively. The association between serum ß-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, ß-cryptoxanthin and lycopene among Chinese population residing in Guangdong.

[ß-Cryptoxanthin and the risk for lifestyle-related disease: findings from recent nutritional epidemiologic studies].

  Antioxidant micronutrients, such as vitamins and carotenoids, exist in abundance in fruits and vegetables and have been known to contribute to the body's defense against reactive oxygen species. Numerous recent epidemiologic studies have demonstrated that a high dietary consumption of fruit and vegetables rich in carotenoids or with high serum carotenoid concentrations results in lower risks of certain cancers, diabetes, and cardiovascular disease. These epidemiologic studies have suggested that antioxidant carotenoids may have a protective effect against several lifestyle-related diseases. ß-Cryptoxanthin is a carotenoid pigment found in Japanese mandarin (Citrus unshiu MARC.) fruit, which is mainly produced in Japan. Our nutritional epidemiologic survey, the Mikkabi Study, utilized data derived from health examinations of inhabitants performed in the town of Mikkabi in Shizuoka, Japan. In this survey, we measured serum ß-cryptoxanthin as a specific biomarker to estimate the consumption of Japanese mandarin fruit. From the cross-sectional analyses from the Mikkabi Study, we found inverse associations of serum ß-cryptoxanthin with the risks for atherosclerosis, insulin resistance, liver dysfunction, metabolic syndrome, low bone mineral density, and oxidative stress. In this review, recent epidemiologic studies about the associations between serum ß-cryptoxanthin with the risk for several lifestyle-related diseases were reviewed.

Bioavailability of ß-cryptoxanthin is greater from pasteurized orange juice than from fresh oranges - a randomized cross-over study.

SCOPE: Orange fruits and products thereof represent important dietary sources of carotenoids, particularly ß-cryptoxanthin. Since previous studies reported a positive effect of vegetable processing on carotenoid absorption, our objective was to compare the bioavailability of ß-cryptoxanthin from either fresh navel oranges (Citrus sinensis L. Osbeck) or pasteurized orange juice. METHODS AND RESULTS: The study was designed as a randomized 2-way cross-over study. Twelve volunteers consumed two meals delivering 744 µg of ß-cryptoxanthin from either fresh navel oranges or pasteurized orange juice. Eight blood samples were collected over 9.5 h after test meal consumption and analyzed using HPLC-DAD. Additionally, carotenoid bioaccessibility was assessed after in vitro digestion of the same test foods. ß-cryptoxanthin bioavailability from pasteurized orange juice was 1.8-fold higher than from fresh oranges (P = 0.011). Similarly, mean absorption of the non-dose adjusted carotenoids lutein (P = 0.301), zeaxanthin (P = 0.216), and zeinoxanthin (P = 0.090) were slightly higher from orange juice, although not reaching statistical significance. The in vitro digestion revealed a 5.3-fold higher bioaccessibility of ß-cryptoxanthin from orange juice. Dietary fiber contents in the test foods were inversely associated with carotenoid bioavailability. CONCLUSION: Orange juice represents a more bioavailable source of ß-cryptoxanthin than fresh oranges.

The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet.

Iron deficiency anemia, zinc and vitamin A deficiencies are serious public health problems in Cameroon, as in many developing countries. Local vegetables which are sources of provitamin A carotenoids (PACs) can be used to improve vitamin A intakes. However, traditional meals are often unable to cover zinc and iron needs. The aim of this study was to determine the bioavailability of 3 PACs (α-carotene, ß-carotene, and ß-cryptoxanthin) in young men, who were fed with a vitamin A-free diet and received iron and zinc supplementation. Twelve healthy participants were divided into three groups and were supplemented with elemental iron (20 mg of iron fumarate), 20 mg of zinc sulfate or iron+zinc (20 mg of iron in the morning and 20 mg of zinc in the evening) for 11 d. They were given a vitamin A- and PAC-free diet from the 6th to the 11th day, followed by a test meal containing 0.55 kg of freshly peeled papaya as a source of PACs. Blood samples were collected four times successively on the 11th day (the test meal day), at T0 (just after the test meal), after 2 h (T2), after 4 h (T4) and after 7 h (T7). Ultracentrifugation was used to isolate serum chylomicrons. Retinol appearance and PAC postprandial concentrations were determined. The supplementation with zinc, iron and iron+zinc influenced the chylomicron appearance of retinol and PACs differently as reflected by retention times and maximum absorption peaks. Iron led to highest retinol levels in the chylomicron. Zinc and iron+zinc supplements were best for optimal intact appearance of α-carotene, ß-carotene and ß-cryptoxanthin respectively. Supplementation with iron led to the greatest bioavailability of PACs from papaya and its conversion to retinol.

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), ß-carotene (r = 0.21-0.25), and ß-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.