Carotenoid intakes, assessed by dietary questionnaire, are associated with plasma carotenoid concentrations in an elderly population

High intakes of fruits and vegetables and of carotenoids are associated with a lower risk for a variety of chronic diseases. It is therefore important to test the validity of dietary questionnaires that assess these intakes. We compared intakes of five carotenoids, as calculated from responses to the Willett 126-item food-frequency questionnaire, with corresponding biochemical measures. Subjects included 346 women and 201 men, aged 67-93 y, in the Framingham Heart Study. Unadjusted correlations were higher among women than men as follows: alpha-carotene 0.33 and 0.18, beta-carotene, 0.36 and 0.25; beta-cryptoxanthin, 0.44 and 0.32; lycopene, 0.35 and 0.21; and lutein + zeaxanthin, 0.27 and 0.10, respectively. Adjustment for age, energy intake, body mass index (BMI, kg/m2), plasma cholesterol concentrations and smoking reduced the gender differences, respectively, to the following: alpha-carotene 0.30 and 0.28; beta-carotene, 0.34 and 0.31; beta-cryptoxanthin, 0.45 and 0.36; lycopene, 0.36 and 0.31; and lutein + zeaxanthin, 0.24 and 0.14. Plots of adjusted mean plasma carotenoid concentration by quintile of respective carotenoid intake show apparent greater responsiveness among women, compared with men, to dietary intake of alpha- and beta-carotene and beta-cryptoxanthin, but similar blood-diet relationships for lycopene and lutein + zeaxanthin. Reported daily intake of fruits and vegetables correlated most strongly with plasma beta-cryptoxanthin and beta-carotene among women and with plasma alpha- and beta-carotene among men. With the exception of lutein + zeaxanthin, this dietary questionnaire does provide reasonable rankings of carotenoid status among elderly subjects, with the strongest correlations for beta-cryptoxanthin. Appropriate adjustment of confounders is necessary to clarify these associations among men.     

Serum carotenoid concentrations in US children and adolescents

BACKGROUND: Carotenoids, a class of phytochemicals, may affect the risk of several chronic conditions. OBJECTIVE: Our objective was to describe the distributions and correlates of serum carotenoid concentrations in US children and adolescents. DESIGN: Using data from the third National Health and Nutrition Examination Survey (1988-1994), a cross-sectional study, we examined the distributions of serum concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein and zeaxanthin, and lycopene among 4231 persons aged 6-16 y. RESULTS: After adjustment for age, sex, race or ethnicity, poverty-income ratio, body mass index status, HDL- and non-HDL-cholesterol concentrations, C-reactive protein concentration, and cotinine concentration, only HDL-cholesterol (P < 0.001) and non-HDL-cholesterol (P < 0.001) concentrations were directly related to all carotenoid concentrations. Age (P < 0.001) and body mass index status (P < 0.001) were inversely related to all carotenoid concentrations except those of lycopene. Young males had slightly higher carotenoid concentrations than did young females, but the differences were significant only for lycopene concentrations (P = 0.029). African American children and adolescents had significantly higher beta-cryptoxanthin (P < 0.001), lutein and zeaxanthin (P < 0.001), and lycopene (P = 0.006) concentrations but lower alpha-carotene (P < 0.001) concentrations than did white children and adolescents. Mexican American children and adolescents had higher alpha-carotene (P < 0.001), beta-cryptoxanthin (P < 0.001), and lutein and zeaxanthin (P < 0.001) concentrations but lower lycopene (P = 0.001) concentrations than did white children and adolescents. C-reactive protein concentrations were inversely related to beta-carotene (P < 0.001), lutein and zeaxanthin (P < 0.001), and lycopene (P = 0.023) concentrations. Cotinine concentrations were inversely related to alpha-carotene (P = 0.002), beta-carotene (P < 0.001), and beta-cryptoxanthin (P < 0.001) concentrations. CONCLUSION: These data show significant variations in serum carotenoid concentrations among US children and adolescents and may be valuable as reference ranges for this population.     

Plasma concentrations of carotenoids and vitamin C are better correlated with dietary intake in normal weight than overweight and obese elderly subjects

Carotenoid and vitamin C intakes, assessed by FFQ, have been positively associated with plasma concentrations in different populations. However, the influence of BMI on these associations has not been explored in detail. We explored in a cross-sectional study the relation between dietary carotenoid and vitamin C intakes, using a 135-item FFQ, with their plasma concentrations by BMI categories in 252 men and 293 women, 65 years and older. For men and women combined, significant (P < 0.05) Pearson correlations were observed between energy-adjusted dietary intakes and plasma concentrations (carotenoids adjusted for cholesterol) for: alpha-carotene 0.21, beta-carotene 0.19, lycopene 0.18, beta-cryptoxanthin 0.20 and vitamin C 0.36. Multiple linear regression analyses showed that the intake of carotenoids and vitamin C were significant predictors of their respective plasma concentration (P<0.01), and that BMI was inversely associated with plasma concentration of carotenoids (P< or =0.01) but not with plasma vitamin C. In addition, we observed significant interactions between BMI and the intakes of alpha-carotene and lutein + zeaxanthin, and to a lower extent beta-carotene, suggesting that these intakes in subjects with high BMI were not good predictors of their plasma concentration. The present data suggest that plasma carotenoids and vitamin C may be good markers of dietary intake in elderly subjects, but not so for alpha-carotene, beta-carotene and lutein + zeaxanthin in obese subjects.     

Circulating levels of retinol, tocopherol and carotenoid in Nepali pregnant and postpartum women following long-term beta-carotene and vitamin A supplementation

OBJECTIVE: To characterize circulating carotenoid and tocopherol levels in Nepali women during pregnancy and post-partum and to determine the effects of beta-carotene and vitamin A supplementation on their concentration in serum. DESIGN: Randomized community supplementation trial. SETTING: The study was carried out from 1994 to 1997 in the Southern, rural plains District of Sarlahi, Nepal. SUBJECTS: A total of 1431 married women had an ascertained pregnancy, of whom 1186 (83%) provided an analyzable serum sample during pregnancy; 1098 (77%) provided an analyzable 3-4 months post-partum serum sample. INTERVENTIONS: Women received a weekly dose of vitamin A (7000 microg RE), beta-carotene (42 mg) or placebo before, during and after pregnancy. Serum was analyzed for retinol, alpha-tocopherol, gamma-tocopherol, beta-carotene, alpha-carotene, lycopene, lutein + zeaxanthin, and beta-cryptoxanthin concentrations during mid-pregnancy and at approximately 3 months post-partum. RESULTS: Compared to placebo, serum retinol, beta-carotene, gamma-tocopherol, beta-cryptoxanthin and lutein + zeaxanthin concentrations were higher among beta-carotene recipients during pregnancy and, except for beta-cryptoxanthin, at postpartum. In the vitamin A group, serum retinol and beta-cryptoxanthin were higher during pregnancy, and retinol and gamma-tocopherol higher at postpartum. Lutein + zeaxanthin was the dominant carotenoid, regardless of treatment group, followed by serum beta-carotene. Serum lycopene level was lowest, and very low compared to the US population. Serum retinol was higher, and carotenoid and alpha-tocopherol lower, at postpartum than during pregnancy in all groups. CONCLUSIONS: Pregnant and lactating Nepali women have lower serum carotenoid and tocopherol levels than well-nourished populations. beta-carotene supplementation appeared to increase levels of tocopherol and other carotenoids in this population.     

Plasma carotenoids of monkeys (Macaca fascicularis and Saimiri sciureus) fed a nonpurified diet

The major carotenoid pigments in the plasma and in a common, nonpurified diet of two species of monkeys (Macaca fascicularis and Saimiri sciureus) were measured. The xanthophylls, lutein, zeaxanthin, alpha-cryptoxanthin, and beta-cryptoxanthin, were the principal carotenoids in both the diet and the plasma. Lutein and zeaxanthin were abundant in the all-trans, the 9-cis, and the 13-cis geometrical isomers in the diet, but the 9-cis form was rarely measurable in plasma. However, the 13-cis isomers of lutein and zeaxanthin were found in higher proportions in plasma than in the diet. For both the monohydroxy-xanthophylls, alpha-cryptoxanthin and beta-cryptoxanthin, and the dihydroxy-xanthophylls, lutein and zeaxanthin, the beta, beta structural isomer (beta-cryptoxanthin or zeaxanthin) is less abundant than the beta, epsilon isomer in plasma than in the diet. These results indicate substantial specificity in the absorption or retention of closely related carotenoid isomers in primates. The proportions of different geometrical isomers of lutein and zeaxanthin in the plasma of both species of monkeys were nearly identical and were similar to human values. The hydrocarbon carotenoids, alpha-carotene, beta-carotene and lycopene were usually undetectable in monkey plasma. The monkeys appear to be like humans in their utilization of lutein and zeaxanthin but distinctly different in some other aspects of carotenoid utilization.     

A survey of serum and dietary carotenoids in captive wild animals

Accumulation of carotenoids varies greatly among animal species and is not fully characterized. Circulating carotenoid concentration data in captive wild animals are limited and may be useful for their management. Serum carotenoid concentrations and dietary intakes were surveyed and the extent of accumulation categorized for 76 species of captive wild animals at Brookfield Zoo. Blood samples were obtained opportunistically from 275 individual animals immobilized for a variety of reasons; serum was analyzed for alpha- and beta-carotene, lutein + zeaxanthin, lycopene, beta-cryptoxanthin and canthaxanthin. Total carotenoid content of diets was calculated from tables and chemical analyses of commonly consumed dietary components. Diets were categorized as low, moderate or high in carotenoid content as were total serum carotenoid concentrations. Animals were classified as unknown, high, moderate or low (non-) accumulators of dietary cartenoids. Nonaccumulators had total serum carotenoid concentrations of 0-101 nmol/L, whereas accumulators had concentrations that ranged widely, from 225 to 35,351 nmol/L. Primates were uniquely distinguished by the widest range of type and concentration of carotenoids in their sera. Most were classified as high to moderate accumulators. Felids had high accumulation of beta-carotene regardless of dietary intake, whereas a wide range of exotic birds accumulated only the xanthophylls, lutein + zeaxanthin, canthaxanthin or cryptoxanthin. The exotic ungulates, with the exception of the bovids, had negligible or nondetectable carotenoid serum concentrations despite moderate intakes. Bovids accumulated only beta-carotene despite moderately high lutein + zeaxanthin intakes. Wild captive species demonstrated a wide variety of carotenoid accumulation patterns, which could be exploited to answer remaining questions concerning carotenoid metabolism and function.     

Plasma carotenoids and prostate cancer: a population-based case-control study in Arkansas

Carotenoids possess antioxidant properties and thus may protect against prostate cancer. Epidemiological studies of dietary carotenoids and this malignancy were inconsistent, partially due to dietary assessment error. In this study, we aimed to investigate the relation between plasma concentrations of carotenoids and the risk of prostate cancer in a population-based case-control study in Arkansas. Cases (n = 193) were men with prostate cancer diagnosed in 3 major hospitals, and controls (n = 197) were matched to cases by age, race, and county of residence. After adjustment for confounders, plasma levels of lycopene, lutein/zeaxanthin, and beta-cryptoxanthin were inversely associated with prostate cancer risk. Subjects in the highest quartile of plasma lycopene (513.7 microg/l) had a 55% lower risk of prostate cancer than those in the lowest quartile (140.5 microg/l; P trend = 0.042). No apparent association was observed for plasma alpha-carotene and beta-carotene. Further adjustment for the other 4 carotenoids did not materially alter the risk estimates for plasma lycopene, lutein/zeaxanthin, and beta-cryptoxanthin but appeared to result in an elevated risk with high levels of plasma alpha-carotene and beta-carotene. The results of all analyses did not vary substantially by age, race, and smoking status. This study added to the emerging evidence that high circulating levels of lycopene, lutein/zeaxanthin, and beta-cryptoxanthin are associated with a low risk of prostate cancer.     

Serum carotenoid depletion follows first-order kinetics in healthy adult women fed naturally low carotenoid diets

Dietary intakes of carotenoids are highly variable in human populations as are serum carotenoid concentrations. However, there are few controlled data relating carotenoid intake to concentration. Most of the data that are available are from measurements of the absorption and decay of large pharmacologic doses of carotenoids, and are therefore of unknown physiologic relevance. Our objective was to determine the half-life (t(1/2)) of the most abundant carotenoids in blood serum from healthy adult women living under controlled conditions. As part of two carotenoid isotopic studies, we measured serum concentrations of beta-carotene, alpha-carotene, lutein, zeaxanthin, beta-cryptoxanthin and lycopene in 19 healthy young adult women that were fed controlled low carotenoid diets for approximately 10 wk. All other nutrients (vitamins A, E and C) were provided at 100-150% of the 1989 U.S. recommended dietary allowance levels. Exercise and activities were controlled throughout the studies to simulate usual activity patterns. Carotenoid concentrations were measured by reversed-phase HPLC. Serum carotenoid concentration decreases during depletion followed first-order kinetics. The half-lives determined in decreasing order were as follows: lutein (76 d) > alpha-carotene (45 d) = beta-cryptoxanthin (39 d) = zeaxanthin (38 d) = beta-carotene (37 d) > lycopene (26 d). Half-lives were unrelated to physical or demographic characteristics such as body mass, body fat, racial background or age in these relatively homogeneous groups. Carotenoids decreased by similar first-order mechanisms, although the rates differed for individual carotenoids.     

Hispanic and non-Hispanic white elders from Massachusetts have different patterns of carotenoid intake and plasma concentrations

Carotenoids have been linked with protective roles against diseases associated with aging, including cancer, cardiovascular disease, cataracts, and age-related macular degeneration. With data from a semiquantitative, validated FFQ, we examined carotenoid intake of 340 Puerto Ricans, 98 Dominicans, and 146 non-Hispanic whites (>60 y old) in Massachusetts. Compared with non-Hispanic white men, Hispanic men reported a higher intake of lycopene and lower intakes of alpha-carotene, lutein + zeaxanthin, beta-carotene (from diet only), and total beta-carotene (diet and supplements) (P < 0.001). Hispanic women reported higher intakes of beta-cryptoxanthin and lycopene but lower intakes of lutein + zeaxanthin (P < 0.001) than non-Hispanic white women. The frequency of consumption of fruit and vegetables was higher among Hispanic women, relative to non-Hispanic white women (P < 0.05). Plasma concentrations of alpha-carotene and lycopene were higher in Hispanic than in non-Hispanic white men and women. For both ethnic groups, higher intakes of carotenoids were associated with higher plasma concentrations of the respective carotenoids, except for lycopene (Hispanics) and lutein + zeaxanthin (non-Hispanic whites). Food sources contributing most to total intakes differed among the groups. The major sources of alpha- and beta-carotene were carrots for non-Hispanic whites and winter squash for Hispanics. The major source of lycopene was cooked tomato products for Hispanics, and pasta dishes for non-Hispanic whites. Traditional foods such as beans and plantains were also important contributors of carotenoids for Hispanics. Because of the potential importance of carotenoids as protective factors against chronic diseases, more attention to food-related practices associated with carotenoid intake in differing population groups is warranted.     

Airway and circulating levels of carotenoids in asthma and healthy controls

BACKGROUND: Elevated oxidative stress and impaired antioxidant defences are increasingly recognised features of asthma. Carotenoids are potent dietary antioxidants that may protect against asthma by reducing oxidative damage. OBJECTIVES: This study aimed firstly, to characterise circulating and airway levels of carotenoids in asthma compared to healthy controls, in relation to dietary intake. Secondly, the study aimed to test whether airway lycopene defences can be improved using oral supplements. METHODS: Induced sputum and peripheral blood samples were collected from subjects with asthma (n = 15) and healthy controls (n = 16). Dietary carotenoid intakes were estimated using the 24-hour recall method and analysed using a modified version of the Foodworks 210 Nutrient Calculation Software. Another group of healthy controls (n = 9) were supplemented with 20 mg/day lycopene for 4 weeks. Carotenoids (beta-carotene, lycopene, alpha-carotene, beta-cryptoxanthin, lutein/zeaxanthin) were measured by HPLC. RESULTS: Despite similar dietary intake, whole blood levels of total carotenoids, lycopene, lutein, beta-cryptoxanthin, alpha-carotene and beta-carotene were significantly lower in asthma than controls. However, there were no differences in plasma or sputum carotenoid levels. Induced sputum carotenoid levels were significantly lower than plasma and whole blood levels, but correlated strongly with plasma levels (r = 0.798, p < 0.001). Although there were no overall increases in either plasma or sputum lycopene levels following supplementation, changes in airway lycopene levels correlated with changes in plasma levels (r = 0.908, p < 0.002). CONCLUSIONS: Whole blood, but not plasma or sputum, carotenoid levels are deficient in asthma. Plasma carotenoid levels reflect airway carotenoid levels and when plasma levels are improved using oral supplements this is reflected in the airways.     

Serum concentrations of carotenoids and vitamins A, E, and C in control subjects from five European countries

High intakes of fruits and vegetables, or high circulating levels of their biomarkers (carotenoids, vitamins C and E), have been associated with a relatively low incidence of cardiovascular disease, cataract and cancer. Exposure to a high fruit and vegetable diet increases antioxidant concentrations in blood and body tissues, and potentially protects against oxidative damage to cells and tissues. This paper describes blood concentrations of carotenoids, tocopherols, ascorbic acid and retinol in well-defined groups of healthy, non-smokers, aged 25-45 years, 175 men and 174 women from five European countries (France, UK (Northern Ireland), Republic of Ireland, The Netherlands and Spain). Analysis was centralised and performed within 18 months. Within-gender, vitamin C showed no significant differences between centres. Females in France, Republic of Ireland and Spain had significantly higher plasma vitamin C concentrations than their male counterparts. Serum retinol and alpha-tocopherol levels were similar between centres, but gamma-tocopherol showed a great variability being the lowest in Spain and France, and the highest in The Netherlands. The provitamin A: non-provitamin A carotenoid ratio was similar among countries, whereas the xanthophylls (lutein, zeaxanthin, beta-cryptoxanthin) to carotenes (alpha-carotene, beta-carotene, lycopene) ratio was double in southern (Spain) compared to the northern areas (Northern Ireland and Republic of Ireland). Serum concentrations of lutein and zeaxanthin were highest in France and Spain; beta-cryptoxanthin was highest in Spain and The Netherlands; trans-lycopene tended to be highest in Irish males and lowest in Spanish males; alpha-carotene and beta-carotene were higher in the French volunteers. Due to the study design, the concentrations of carotenoids and vitamins A, C and E represent physiological ranges achievable by dietary means and may be considered as 'reference values' in serum of healthy, non-smoking middle-aged subjects from five European countries. The results suggest that lutein (and zeaxanthin), beta-cryptoxanthin, total xanthophylls and gamma-tocopherol (and alpha- : gamma-tocopherol) may be important markers related to the healthy or protective effects of the Mediterranean-like diet.     

Carotenoids are decreased in biopsies from colorectal adenomas

A lower intake of carotenoids is associated with an increased risk of colorectal cancer. In order to take advantage of the chemopreventive properties of carotenoids, it is necessary to determine carotenoid concentration at the target tissue. As early stages in the adenoma-carcinoma sequence of colorectal cancer might be susceptible to chemoprevention, we sought to determine carotenoid concentrations in biopsies from colorectal adenomas. METHODS: Biopsies from colorectal adenomas and non-involved mucosa were taken from seven patients. For controls, biopsies were obtained from the ascending and descending colon of patients without polyps (n = 5). Concentration of carotenoids (alpha-, beta-carotene, lutein, lycopene, zeaxanthin, beta-cryptoxanthin) were determined by optimizing gradient HPLC-analysis. Results are expressed as pmol/microg DNA. RESULTS: Except for alpha-carotene, all carotenoids could reliably be detected in all specimens. In control patients carotenoid concentrations were highest in the ascending colon, being followed by the descending colon and non-involved mucosa from polyp-carriers. In colorectal adenomas all carotenoids were significantly reduced as compared to-non-involved mucosa (beta-carotene: 0.37 vs 0.19, P<0.03; lycopene: 0.34 vs 0.21, P<0.06, beta-cryptoxanthin: 0.14 vs 0.09, P<0.03, zeaxanthin: 0.18 vs 0.09, P<0.02; lutein: 0.18 vs 0.13,P <0.02). CONCLUSION: All carotenoids investigated are reduced in colorectal adenomas, suggesting that mucosal carotenoids could serve as biomarkers for predisposition to colorectal cancer. Moreover, anti-tumor activity exerted by carotenoids is limited due to mucosal depletion. We speculate that supplementation of a larger array of carotenoids might be beneficial for patients with colorectal adenoma.     

Bioavailability of lutein from vegetables is 5 times higher than that of beta-carotene.

BACKGROUND: To gain more insight into the relation between vegetable consumption and the risk of chronic diseases, it is important to determine the bioavailability of carotenoids from vegetables and the effect of vegetable consumption on selected biomarkers of chronic diseases. OBJECTIVE: To assess the bioavailability of beta-carotene and lutein from vegetables and the effect of increased vegetable consumption on the ex vivo oxidizability of LDL. DESIGN: Over 4 wk, 22 healthy adult subjects consumed a high-vegetable diet (490 g/d), 22 consumed a low-vegetable diet (130 g/d), and 10 consumed a low-vegetable diet supplemented with pure beta-carotene (6 mg/d) and lutein (9 mg/d). RESULTS: Plasma concentrations of vitamin C and carotenoids (ie, alpha-carotene, beta-carotene, lutein, zeaxanthin, and beta-cryptoxanthin) were significantly higher after the high-vegetable diet than after the low-vegetable diet. In addition to an increase in plasma beta-carotene and lutein, the pure carotenoid-supplemented diet induced a significant decrease in plasma lycopene concentration of -0.11 micromol/L (95% CI: -0.21, -0.0061). The responses of plasma beta-carotene and lutein to the high-vegetable diet were 14% and 67%, respectively, of those to the pure carotenoid- supplemented diet. Conversion of beta-carotene to retinol may have attenuated its plasma response compared with that of lutein. There was no significant effect on the resistance of LDL to oxidation ex vivo. CONCLUSIONS: Increased vegetable consumption enhances plasma vitamin C and carotenoid concentrations, but not resistance of LDL to oxidation. The relative bioavailability of lutein from vegetables is higher than that of beta-carotene.     

Plasma carotenoid response to chronic intake of selected foods and beta-carotene supplements in men.

We determined serial changes in four major plasma carotenoid fractions (alpha-carotene, beta-carotene, lutein/zeaxanthin, and lycopene) in 30 men consuming defined daily doses of carotenoids from foods (broccoli, carrots, or tomato juice) or from purified beta-carotene in capsules (12 or 30 mg) for 6 wk while fed a controlled diet. Compared with baseline, beta-carotene increased in the 30- and 12-mg-capsule and carrot groups whereas alpha-carotene increased in the carrot group and lutein increased in the broccoli group. Lower lutein concentrations in recipients of beta-carotene capsules suggested an interaction between these two carotenoids. Lycopene declined in all groups except the tomato-juice group. Total carotenoid concentration changes only reflected the large increases in beta-carotene concentrations and not the smaller changes observed in other individual carotenoids. Overall, purified beta-carotene produced a greater plasma response than did similar quantities of carotenoids from foods sources. However, some foods increased plasma concentrations of certain carotenoids.     

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

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

Frequent intake of tropical fruits that are rich in beta-cryptoxanthin is associated with higher plasma beta-cryptoxanthin concentrations in Costa Rican adolescents

Dietary tocopherols and carotenoids may play a role in preventing cancer and cardiovascular diseases. Because these may begin to develop during adolescence, dietary patterns during this period could influence long-term risk. The objective of this study was to examine the intake and plasma concentrations of the major carotenoids and tocopherols in 159 adolescents (mean +/- SD, 15.5 +/- 2.5 y old) living in Costa Rica. All participants completed a 135-item food-frequency questionnaire and provided a fasting blood sample. Carotenoid and tocopherol intakes were adjusted for total energy and plasma concentrations for total cholesterol. The relative abundance of carotenoids in the diet was similar to their distribution in plasma; lycopene was the most abundant, followed by beta-carotene and lutein + zeaxanthin. gamma-Tocopherol was more abundant than alpha-tocopherol in the diet, but alpha-tocopherol was approximately sevenfold higher in plasma. The highest diet-plasma correlations (adjusted for age, sex and body mass index) were 0.38 for beta-cryptoxanthin, 0.33 for gamma-tocopherol and 0.17 for lutein + zeaxanthin (all P < 0.05). All other correlations were r < 0.15. Papaya intake was the best food predictor of plasma beta-cryptoxanthin concentrations (r = 0.41). Subjects that frequently (> or =3/d) consumed tropical fruits with at least 50 micro g/100 g beta-cryptoxanthin (papaya, tangerine, orange and watermelon) had twofold the plasma beta-cryptoxanthin concentrations of those with intakes of <4/wk (P for trend = 0.0009). In sum, the diet-plasma carotenoid and tocopherol correlations were generally low in Costa Rican adolescents. Intakes of beta-cryptoxanthin and papaya, a tropical fruit frequently consumed in Latin America, were the best predictors of beta-cryptoxanthin concentrations in plasma.     

Antioxidants, oxidative stress, and pulmonary function in individuals diagnosed with asthma or COPD

OBJECTIVE: The objective of this study was to investigate the association between antioxidant nutrients and markers of oxidative stress with pulmonary function in persons with chronic airflow limitation. DESIGN: Cross-sectional study exploring the association of antioxidant nutrients and markers of oxidative stress with forced expiratory volume in the first second (FEV1%) and forced vital capacity (FVC%). SETTING/SUBJECTS: The study data included 218 persons with chronic airflow limitation recruited randomly from the general population of Erie and Niagara counties, New York State, USA. RESULTS: After adjustment for covariates, multiple linear regression analysis showed that serum beta-cryptoxanthin, lutein/zeaxanthin, and retinol, and dietary beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, vitamin C, and lycopene were positively associated with FEV1% (P < 0.05, all associations). Serum vitamins beta-cryptoxanthin, lutein/zeaxanthin, and lycopene, and dietary beta-cryptoxanthin, beta-carotene, vitamin C, and lutein/zeaxanthin were positively associated with FVC% (P < 0.05, all associations). Erythrocytic glutathione was negatively associated with FEV1%, while plasma thiobarbituric acid-reactive substances (TBARS) were negatively associated with FVC% (P < 0.05). CONCLUSION: These results support the hypothesis that an imbalance in antioxidant/oxidant status is associated with chronic airflow limitation, and that dietary habits and/or oxidative stress play contributing roles.     

Comparison of the uptake and secretion of carotene and xanthophyll carotenoids by Caco-2 intestinal cells

Carotenoids have been shown to have potential beneficial effects on human health which has led to an increasing interest in the study of their bioavailability. A Caco-2 cell model, as previously described, was employed to examine the percentage transfer of the carotenoids alpha-carotene, beta-carotene, lycopene, astaxanthin, beta-cryptoxanthin, lutein and zeaxanthin through an intact, highly differentiated Caco-2 cell monolayer at a range of different amounts. Our results show that astaxanthin, a carotenoid with powerful antioxidant capacity, had the highest percentage transfer overall. We examined the cellular uptake and secretion of lutein and zeaxanthin to compare two structurally similar carotenoids. Both were efficiently transported through the monolayer with a range between 5.1 (sem 1.2) % to 20.2 (sem 3.3) % and 5.5 (sem 2.5) % to 13.4 (sem 4) % for lutein and zeaxanthin, respectively. These carotenoids were compared to each other at each added amount and no significant difference was observed between the two xanthophylls. The carotene carotenoids alpha-carotene, beta-carotene and lycopene and the xanthophyll beta-cryptoxanthin were also examined and had lower uptake and secretion values when compared to lutein, zeaxanthin and astaxanthin. The xanthophyll beta-cryptoxanthin was also not significantly different when compared to the carotene carotenoids. Data generated from this study compares well with in vivo bioavailability studies. Furthermore, the model provides comparative data on the relative absorption and transfer of seven different carotenoids. Our data indicate that lower amounts of carotenoids were absorbed and transferred more efficiently than higher amounts suggesting a saturation effect at higher exposure.     

Acculturation in the United States is associated with lower serum carotenoid levels: Third National Health and Nutrition Examination Survey

This study examined the association of acculturation in the United States and serum carotenoid levels. The design was a cross-sectional, nationally representative survey of 16,539 participants, 17 years of age and older, from the Third National Health and Nutrition Examination Survey (NHANES III). The main outcome measures were serum levels of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, lycopene, and total carotenoids. Multivariate linear regression was used to model the association of serum carotenoids and country of birth, language of interview, and years in the United States. Adjustments were made for age, sex, years of education, race/ethnicity, body mass index, alcohol use, physical activity, serum cotinine, serum cholesterol, and vitamin/mineral usage. Individuals born in the United States who speak English had the lowest levels of carotenoids, and individuals born in Mexico had the highest levels of carotenoids, with the exception of lycopene. Years of residence in the United States was associated with lower alpha-carotene (4.18 vs 1.51), beta-carotene (20.21 vs 14.87), beta-cryptoxanthin (12.51 vs 8.95), lutein/zeaxanthin (25.15 vs 18.03), and total carotenoids (88.79 vs 75.44). Years residence in the United States was positively associated with higher lycopene levels (26.69 vs 32.03). Acculturation in the United States was associated with lower fruit and vegetable intake, as measured by serum carotenoid levels.     

Lipid standardization of serum fat-soluble antioxidant concentrations: the YALTA study

BACKGROUND: Blood lipids can influence fat-soluble antioxidant concentrations and confound their interpretation as indicators of antioxidant intake status and disease risk. OBJECTIVES: The objectives were to identify lipoproteins that can confound the interpretation of serum fat-soluble antioxidants, to evaluate the amount of the confounding, and to recommend a method for standardizing blood concentrations of fat-soluble antioxidants. DESIGN: Several methods of lipid standardization of fat-soluble antioxidants were evaluated in a large cohort of young adults with the use of both cross-sectional and longitudinal data analysis. RESULTS: Tocopherol and carotenoid concentrations were associated with plasma total cholesterol and its components, LDL, HDL, and VLDL cholesterol (estimated as plasma total triacylglycerols/5), some of which were independent predictors for all of the fat-soluble antioxidants. Among supplement nonusers, the most amphipathic (polar) of the antioxidants (alpha-tocopherol, gamma-tocopherol, and zeaxanthin plus lutein) and lycopene were associated strongly with these lipid fractions (R(2) = 0.09, 0.40). Consistent with a causal association in which blood antioxidant concentrations change as blood lipid concentrations change, similar relations were found for changes in blood antioxidant and lipid concentrations over a 7-y period. Concentrations of the remaining carotenoids (beta-cryptoxanthin, alpha-carotene, and beta-carotene) had a weaker association with plasma lipoproteins (R(2) < 0.06). Similar relations were found for supplement users. CONCLUSIONS: The simultaneous adjustment of the concentrations of tocopherols, zeaxanthin plus lutein, and lycopene for VLDL, HDL, and LDL cholesterol is recommended. This method is practical and can provide a basis for the standardization of carotenoid and tocopherol concentrations.