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.     

Dietary carotenoids,serum beta-carotene,and retinol and risk of lung cancer in the alpha-tocopherol,beta-carotene cohort study

Findings from several beta-carotene supplementation trials were unexpected and conflicted with most observational studies. Carotenoids other than beta-carotene are found in a variety of fruits and vegetables and may play a role in this important malignancy, but previous findings regarding the five major carotenoids are inconsistent. The authors analyzed the associations between dietary beta-carotene, beta-carotene, lutein/zeaxanthin, lycopene, beta-cryptoxanthin, vitamin A, serum beta-carotene, and serum retinol and the lung cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort of male smokers conducted in southwestern Finland between 1985 and 1993. Of the 27,084 male smokers aged 50-69 years who completed the 276-food item dietary questionnaire at baseline, 1,644 developed lung cancer during up to 14 years of follow-up. Cox proportional hazards models were used to estimate relative risks and 95% confidence intervals. Consumption of fruits and vegetables was associated with a lower lung cancer risk (relative risk = 0.73, 95% confidence interval: 0.62, 0.86, highest vs. lowest quintile). Lower risks of lung cancer were observed for the highest versus the lowest quintiles of lycopene (28%), lutein/zeaxanthin (17%), beta-cryptoxanthin (15%), total carotenoids (16%), serum beta-carotene (19%), and serum retinol (27%). These findings suggest that high fruit and vegetable consumption, particularly a diet rich in carotenoids, tomatoes, and tomato-based products, may reduce the risk of lung cancer.     

Neighborhood Deprivation is associated with lower levels of serum carotenoids among adults participating in the Third National Health and Nutrition Examination Survey

OBJECTIVE: This study tested the hypothesis that neighborhood deprivation will be associated with lower levels of serum carotenoids in comparison with wealthy residential areas. DESIGN: Cross-sectional, nationally representative survey data were used to assess the relationship between neighborhood level socioeconomic status and serum carotenoids. SUBJECTS: Seventeen thousand two participants aged 17 years and older from the Third National Health and Nutrition Examination Survey were linked with 1990 census data. MAIN OUTCOME MEASURES: Serum levels of lycopene, beta-carotene, alpha-carotene, lutein/zeaxanthin, and beta-cryptoxanthin. STATISTICAL ANALYSIS: Multivariate linear regression was used to model the association of serum carotenoids and neighborhood deprivation, which is a summary index of 11 indicators for tract level socioeconomic status. Adjustments are made for individual level age, sex, years of education, household income, employment, race/ethnicity, body mass index, serum cotinine, alcohol use, physical activity, and serum cholesterol. RESULTS: Multivariate analysis revealed a negative and statistically significant association between high levels of neighborhood deprivation and beta-carotene (beta=-2.98 microg/dL [-0.06 micromol/L], P=0.00), alpha-carotene (beta=-1.28 microg/dL [-0.02 micromol/L], P=<0.0001), lutein/zeaxanthin (-1.69 microg/dL [-0.03 micromol/L], P=0.00, beta-cryptoxanthin (beta=-1.34 microg/dL [-0.02 micromol/L], P<0.0001), and total carotenoids (beta=-8.20 microg/dL, P=<0.0001). Lycopene was not related to neighborhood deprivation. Adjusted mean levels of carotenoids for high deprivation neighborhoods were lower than neighborhoods with low deprivation: beta-carotene=8.72 microg/dL [0.16 micromol/L] vs 20.64 microg/dL [0.38 micromol/L], alpha-carotene=0.44 microg/dL [0.008 micromol/L] vs 5.56 microg/dL [0.10 micromol/L], lutein/zeaxanthin=13.79 microg/dL [0.24 micromol/L] vs 20.55 microg/dL [0.36 micromol/L], beta-cryptoxanthin=4.57 microg/dL [0.08 micromol/L] vs 9.93 microg/dL [0.18 micromol/L], lycopene=22.07 microg/dL [0.41 micromol/L] vs 25.63 microg/dL [0.48 micromol/L], and total=49.56 microg/dL vs 82.36 microg/dL. CONCLUSIONS: Neighborhood deprivation was associated with lower serum levels of carotenoids. There was a substantial disparity between low deprivation and high deprivation residential areas with respect to fruit and vegetable intake.     

Serum carotenoid levels vary by marital status

This study examined differences in serum carotenoid levels by marital status. The design was a cross-sectional, nationally representative survey of 16,597 participants ages 18 years and older from the Third National Health and Nutrition Examination Survey. 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 marital status by sex and age with adjustments made for age, race/ethnicity, years of education, household income, body mass index, alcohol use, physical activity, serum cotinine, serum cholesterol, and vitamin/mineral supplement use. Among men, never married marital status was associated with lower total carotenoid levels (mean 66.16 microg/dL, P=0.05), lutein/zeaxanthin (mean 15.57 microg/dL [0.27 micromol/L], P=0.01), and lycopene (mean 24.28 microg/dL [0.45 micromol/L], P=0.00) compared to married marital status among men. Divorced marital status was associated with lower lycopene levels (mean 24.23 microg/dL [0.45 micromol/L], P=0.00) compared to married men. Compared to married men, widowed marital status was associated with lower alpha-carotene (mean 2.47 microg/dL [0.05 micromol/L], P=0.02), beta-carotene (mean 11.52 microg/dL [0.21 micromol/L], P=0.04), and lycopene levels (mean 25.15 microg/dL [0.47 micromol/L], P=0.04). Among women, widowed marital status was associated with lower levels of total carotenoids (mean 62.72 microg/dL, P=0.01), alpha-carotene (mean 1.85 microg/dL [0.03 micromol/L], P=0.01), beta-carotene (mean 11.57 microg/dL [0.22 micromol/L], P=0.03), and lutein/zeaxanthin (mean 17.50 microg/dL [0.31 micromol/L], P=0.05) compared to married women. Our conclusion is that serum carotenoid levels varied by marital status, and widowed men and women were at the greatest risk of low carotenoid levels.     

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.     

Vitamin A, retinol, and carotenoids and the risk of gastric cancer: a prospective cohort study

BACKGROUND: Vitamin A may influence gastric carcinogenesis through its essential role in controlling cell proliferation and differentiation. However, epidemiologic studies of vitamin A, retinol (preformed vitamin A), and provitamin A carotenoids in relation to the risk of gastric cancer have documented inconsistent results. OBJECTIVE: The objective of the study was to examine the associations between intakes of vitamin A, retinol, and specific carotenoids and the risk of gastric cancer in a prospective population-based cohort study of Swedish adults. DESIGN: The study cohort consisted of 82 002 Swedish adults aged 45-83 y who had completed a food-frequency questionnaire in 1997. The participants were followed through June 2005. RESULTS: During a mean 7.2-y follow-up, 139 incident cases of gastric cancer were diagnosed. High intakes of vitamin A and retinol from foods only (dietary intake) and from foods and supplements combined (total intake) and of dietary alpha-carotene and beta-carotene were associated with a lower risk of gastric cancer. The multivariate relative risks for the highest versus lowest quartiles of intake were 0.53 (95% CI: 0.32, 0.89; P for trend = 0.02) for total vitamin A, 0.56 (95% CI: 0.33, 0.95; P for trend = 0.05) for total retinol, 0.50 (95% CI: 0.30, 0.83; P for trend = 0.03) for alpha-carotene, and 0.55 (95% CI: 0.32, 0.94; P for trend = 0.07) for beta-carotene. No significant associations were found for beta-cryptoxanthin, lutein and zeaxanthin, or lycopene intake. CONCLUSION: High intakes of vitamin A, retinol, and provitamin A carotenoids may reduce the risk of gastric cancer.     

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.     

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.     

Serum concentrations of retinol, alpha-tocopherol and the carotenoids are influenced by diet, race and obesity in a sample of healthy adolescents

An important part of understanding the functions of vitamin A, vitamin E and the carotenoids in nutritional status assessment, health promotion and disease prevention is knowledge of factors that influence their distribution in human tissues. Our objective was to examine serum concentrations of these nutrients and compounds in a sample of 285 healthy participants, 12-17 y old, from three U. S. cities. Pearson correlations between diet measured with a food frequency questionnaire and serum nutrient concentrations among these adolescents (adjusted for total serum cholesterol, age, sex, race and body mass index) were as follows: retinol, 0.23; alpha-tocopherol, 0.16; alpha-carotene, 0.31; beta-carotene, 0.15; beta-cryptoxanthin, 0.38; lycopene, 0.08; and lutein + zeaxanthin, 0.25. Multivariate linear regression modeled associations of demographic, dietary and physiologic variables with serum concentrations of these nutrients. African-American participants had significantly lower concentrations of serum retinol (P < 0.001), alpha-tocopherol (P < 0.01) and alpha-carotene (P < 0.02), but higher concentrations of lutein + zeaxanthin (P = 0.001) compared with Caucasians. Obese participants had serum nutrient concentrations that were 2-10% (P < 0.05) lower than normal weight participants. Dietary intake was a significant predictor of all serum analytes (P < 0.01) except lycopene. These models explained 20% of the variability in serum retinol, 28% of the variability in serum alpha-tocopherol, and 14-24% of the variability in serum carotenoids.     

Status of carotenoids, vitamin A, and vitamin E in the mother-infant dyad and anthropometric status of infants in Malawi

This prospective study was carried out during February 2000-April 2003 to characterize the relationship between the status of carotenoids, vitamin E, and retinol and anthropometric status in apparently healthy infants and their mothers in Blantyre, Malawi. Anthropometric status of infants and concentrations of carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, zeaxanthin, and lycopene), retinol, and alpha-tocopherol in plasma were measured in 173 infants at 12 months of age, and concentrations of carotenoids, retinol, and a-tocopherol in plasma were measured in their mothers two weeks postpartum. In multivariate analyses, concentrations of retinol, total carotenoids, non-provitamin A carotenoids, and alpha-tocopherol in infants were associated with under-weight (p = 0.05). Concentrations of a-tocopherol were associated with wasting (p = 0.04). Concentrations in mothers and infants were all correlated (correlation coefficients from 0.230 to 0.502, p < 0.003). The findings suggest that poor status of carotenoids, retinol, and alpha-tocopherol in infants is associated with their poor anthropometric status, and status of carotenoids, retinol, and alpha-tocopherol in mothers and infants has a low-to-moderate association in the mother-infant dyad.     

Intake of vitamin A and carotenoids from the Italian population--results of an Italian total diet study

The present study focused on vitamin A and carotenoids (alpha-and beta-carotene, lutein and zeaxanthin, beta-cryptoxanthin, lycopene) daily intake from the Italian total diet. The input of some food groups (cereals, vegetables, fruits, milk and dairy, meat and meat products, fish) most responsible for major and minor contributions to the daily intake of these molecules was evaluated. Furthermore the contribution to the dietary intake of beta-carotene and lutein of the most consumed vegetables in the market basket of the Italian total diet (beets, brassica vegetables, carrots, chicory, courgette (zucchini), green beans, lettuce, peas, pepper, spinach, tomatoes) was also investigated. Vitamin A daily intake was 855 mg/person/day. The vegetables food group made the greatest contribution (37%), followed by the meat and meat products food group (23%). The Italian total diet provided 14.3 mg/person/day of carotenoids; lycopene was the highest (7.4 mg/day), followed by lutein + zeaxanthin (4 mg/day), beta-carotene (2.6 mg/day), alpha-carotene (0.15 mg/day), and beta-cryptoxanthin (0.17 mg/day). Carrots and tomatoes were the main sources of beta-carotene in the diet, otherwise the daily consumption of leafy vegetables (spinach, beets, lettuce) made the main contribution to lutein + zeaxanthin daily intake.     

Carotenoid and tocopherol estimates from the NCI diet history questionnaire are valid compared with multiple recalls and serum biomarkers

To improve the measurement of usual dietary intake, the National Cancer Institute developed a cognitively based Diet History Questionnaire (DHQ), which has been validated against four 24-h dietary recalls (4 24-HR) for energy, macronutrients, and several vitamins and minerals. This analysis used data from The Eating at America's Table Study (EATS) to determine the validity of estimates for carotenoids and tocopherols from the DHQ. Over the course of a year, 163 participants provided 1 or 2 blood samples and completed the DHQ and 4 24-HR. For both the DHQ and the 4 24-HR, crude correlations between serum and diet were modest to strong for the provitamin A carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin), low to modest for lycopene, and very low for lutein. The individual dietary tocopherols were weakly correlated with the serum tocopherols, but vitamin E from food and dietary supplements was strongly and positively correlated with serum alpha-tocopherol and strongly and inversely correlated with serum gamma-tocopherol for both instruments. Adjustment for energy, BMI, smoking status, serum total cholesterol, and serum triacylglycerol did not appreciably change the correlations. Using the method of triads, validity coefficients for the DHQ were comparable to the 4 24-HR and were especially strong for alpha-carotene, beta-cryptoxanthin, lutein + zeaxanthin, and total vitamin E in men and gamma-tocopherol and total vitamin E in women. In this study, there was no advantage of 2 blood samples over 1, suggesting reasonably stable ranking of individuals for these biomarkers, which is important for large epidemiologic studies that typically obtain only 1 blood sample for biomarker status.     

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.     

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.     

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.     

Daily intake of multivitamins during long-term intake of olestra in men prevents declines in serum vitamins A and E but not carotenoids

The objective of this study was to determine whether vitamin supplementation during long-term (36 wk) ingestion of olestra supplemented with vitamin E could prevent decreases in vitamin E, vitamin A, and carotenoids. This was a 36-wk study of 37 healthy males randomly assigned to consume a control diet composed of 33% energy from fat, a similar diet in which one third of the energy from fat had been replaced with olestra, or a fat-reduced (25% of energy from fat) diet. Subjects also ingested a daily multivitamin (Centrum). Serum concentrations of alpha-tocopherol, retinol, beta-carotene, lycopene, and lutein + zeaxanthin were analyzed by HPLC. Subjects eating the olestra-containing diet had substantial decreases in serum beta-carotene, lycopene, and lutein + zeaxanthin, which occurred by 12 wk; these changes were found despite correcting for serum total cholesterol or BMI. Serum beta-carotene and lycopene concentrations were below the lower limit of the reference range (<0.186 and <0.298 mumol/L, respectively) at one or more time points. The slight decline in serum alpha-tocopherol concentration, significant at 24 wk, was caused by the decline in serum cholesterol. Retinol concentrations decreased with time in all 3 groups, but were not affected by olestra. We conclude that supplementation with a multivitamin containing vitamins A and E was adequate to prevent olestra-induced decrease in serum alpha-tocopherol and retinol. Olestra-induced decreases in serum beta-carotene, lycopene, and lutein + zeaxanthin were not prevented by the vitamin supplement used in this study.     

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.     

Lung function in relation to intake of carotenoids and other antioxidant vitamins in a population-based study

Accumulating evidence suggests that dietary antioxidant vitamins are positively associated with lung function. No evidence exists regarding whether dietary carotenoids other than beta-carotene are related to pulmonary function. In 1995--1998 the authors studied the association of forced expiratory volume in 1 second and forced vital capacity as the percentage of the predicted value (FEV(1)% and FVC%, respectively) after adjustment for height, age, gender, and race with the intakes of several carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, and lycopene) in a random sample of 1,616 men and women who were residents of western New York State, aged 35--79 years, and free from respiratory disease. They observed significant associations of lutein/zeaxanthin and vitamins C and E with FEV(1)% and FVC% using multiple linear regression after adjustment for total energy intake, smoking, and other covariates. When they analyzed all of these antioxidant vitamins simultaneously, they observed the strongest association of vitamin E with FEV(1)% and of lutein/zeaxanthin with FVC%. The differences in forced expiratory volume in 1 second and forced vital capacity associated with a decrease of 1 standard deviation of dietary vitamin E or lutein/zeaxanthin were equivalent to the influence of approximately 1--2 years of aging. Their findings support the hypothesis that carotenoids, vitamin C, and vitamin E may play a role in respiratory health and that carotenoids other than beta-carotene may be involved.     

山东临沂市254名农村婴幼儿血清视黄醇和类胡萝卜素水平及其与相关膳食因素的关系

目的为了解农村婴幼儿血清维生素A(VA)营养状况和血清类胡萝卜素水平,以及两者关系和相关影响因素而开展本研究。方法采用整群抽样方法,对山东省临沂市某镇辖区内254名6～24月龄健康婴幼儿进行健康体检和喂养状况调查。采集足背静脉血样,用高效液相色谱法测定血清视黄醇和β-胡萝卜素、α-胡萝卜素、β-隐黄素及叶黄素+玉米黄素含量。用膳食频率法回顾性调查婴幼儿最近一个月内的各类食物摄入状况,分析喂养状况与血清视黄醇和类胡萝卜素水平的关系。结果被调查婴幼儿血清视黄醇浓度平均为(0.96±0.55)μmol/L,不同月龄段间没有明显差异(P>0.05);血清VA缺乏率为40.6%,边缘性VA缺乏率为32.6%。血清β-胡萝卜素、α-胡萝卜素、β-隐黄素和叶黄素+玉米黄素浓度的平均值分别为(0.056±0.088)μmol/L、(3.3±12.1)nmol/L、(27.0±45.2)nmol/L和(0.22±0.22)μmol/L。不同月龄段儿童血清叶黄素+玉米黄素浓度存在差异(P<0.05),13～18月龄段低于6～12月龄儿童。母乳喂养和配方奶粉是影响婴幼儿血清视黄醇和β-胡萝卜素水平的主要因素。母乳喂养频率与β-胡萝卜素水平呈负相关(P<0.05),而配方粉喂养频率与血清视黄醇和除α-胡萝卜素以外的类胡萝卜素水平呈正相关(均为P<0.05);水果蔬菜喂养频率则只与血清β-胡萝卜素、α-胡萝卜素和β-隐黄素浓度呈正相关。血清视黄醇与类胡萝卜素各组分,以及类胡萝卜素各组分之间,具有显著正相关关系(均为P<0.001)。结论调查的农村婴幼儿血清VA营养状况较差,血清β-胡萝卜素、α-胡萝卜素、β-隐黄素及叶黄素+玉米黄素浓度与母乳、配方奶粉、水果蔬菜添加等喂养状况关系密切。     

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.