Plasma carotenoids, retinol, and tocopherols and risk of breast cancer

The roles of carotenoids, retinol, and tocopherols in breast cancer etiology have been inconclusive. The authors prospectively assessed the relations between plasma alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein/zeaxanthin, retinol, alpha-tocopherol, and gamma-tocopherol and breast cancer risk by conducting a nested case-control study using plasma collected from women enrolled in the Nurses' Health Study. A total of 969 cases of breast cancer diagnosed after blood draw and prior to June 1, 1998, were individually matched to controls. The multivariate risk of breast cancer was 25-35% less for women with the highest quintile compared with that for women with the lowest quintile of alpha-carotene (odds ratio (OR) = 0.64, 95% confidence interval (CI): 0.47, 0.88; p(trend) = 0.01), beta-carotene (OR = 0.73, 95% CI: 0.53, 1.02; p(trend) = 0.01), lutein/zeaxanthin (OR = 0.74, 95% CI: 0.55, 1.01; p(trend) = 0.04), and total carotenoids (OR = 0.76, 95% CI: 0.55, 1.05; p(trend) = 0.05). The inverse association observed with alpha-carotene and breast cancer was greater for invasive cancers with nodal metastasis. The authors conclude that some carotenoids are inversely associated with breast cancer. Although the association was strongest for alpha-carotene, the high degree of collinearity among plasma carotenoids limits our ability to conclude that this association is specific to any individual carotenoid.     

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.     

Carotenoid composition of human milk during the first month postpartum and the response to beta-carotene supplementation

BACKGROUND: Information is lacking regarding normal changes in milk carotenoid concentrations in healthy, well-nourished women during the first month of lactation. OBJECTIVES: This study investigated milk carotenoid concentrations during days 4-32 postpartum and assessed the effects of maternal beta-carotene supplementation. DESIGN: Subjects (n = 21; aged 19-39 y) were randomly assigned to receive beta-carotene (30 mg/d) or placebo from days 4 to 32 postpartum. Each subject provided 8 diet records and 8 milk samples during the study. Diet records were analyzed for energy, macronutrients, vitamins A and E, and carotenoids. Milk samples were analyzed with HPLC for concentrations of carotenoids, retinol, and alpha-tocopherol. Data were analyzed by using repeated-measures analysis and orthogonal contrasts. RESULTS: No significant differences in average dietary intakes, body mass index, age, or parity were found between groups at baseline or after supplementation. Milk carotenoid concentrations decreased over time (P < 0.01), as did retinol and alpha-tocopherol concentrations (P < 0.003). Concentrations of most carotenoids decreased to those reported for mature milk by day 32 postpartum. Milk lutein concentrations remained elevated throughout the study compared with values reported for mature milk, whereas plasma lutein concentrations decreased significantly over time. beta-carotene supplementation did not significantly change the milk concentrations of beta-carotene, the other carotenoids, retinol, or alpha-tocopherol. CONCLUSIONS: The lack of increase in milk beta-carotene despite supplementation suggests that transitional milk may be already nearly saturated with beta-carotene. The elevated milk lutein concentration and simultaneous decrease in plasma lutein suggest that lutein metabolism may be altered during early lactation.     

Plasma concentrations of carotenoids, retinol, and tocopherols in preeclamptic and normotensive pregnant women

This case-control study was conducted in Lima, Peru, from June 1997 through January 1998 to assess whether plasma concentrations of carotenoids (alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin), retinol, and tocopherols (alpha-tocopherol and gamma-tocopherol) are decreased in women with preeclampsia. A total of 125 pregnant women with preeclampsia and 179 normotensive pregnant women were included. Plasma concentrations of antioxidants were determined using high performance liquid chromatography. After adjusting for maternal demographic, behavioral, and reproductive characteristics and total plasma lipid concentrations, the authors found a linear increase in risk of preeclampsia with increasing concentrations of alpha-tocopherol (odds ratio of the highest quartile = 3.13; 95% confidence interval: 1.06, 9.23, with the lowest quartile as the reference group; p value of the test of linear trend = 0.040). The risk of preeclampsia decreased across increasing quartiles of concentrations for retinol (odds ratio of the highest quartile = 0.32; 95% confidence interval: 0.15, 0.69, with the lowest quartile as the reference group; p value of the test of linear trend = 0.001). Some of these results are inconsistent with the prevailing hypothesis that preeclampsia is an antioxidant-deficient state. Preliminary findings confirm an earlier observation of increased plasma concentrations of alpha-tocopherol among women with preeclampsia as compared with normotensive pregnant women.     

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.     

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.     

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.     

Effect of beta-carotene supplementation on the concentrations and distribution of carotenoids,vitamin E,vitamin A,and cholesterol in plasma lipoprotein and non-lipoprotein fractions in healthy older women.

We studied the effect of beta-carotene supplementation on the concentrations and distribution in plasma lipoprotein and non-lipoprotein fractions of carotenoids, alpha-tocopherol, retinol, and cholesterol.

Ten women ingested either 90 mg of beta-carotene or placebo daily for 3 weeks while residing in their homes and eating their usual meals. Carotenoids (beta-carotene, lycopene, lutein/zeaxanthin), retinol, alpha-tocopherol, and cholesterol were measured in plasma lipoprotein and non-lipoprotein fractions before and after treatment.

In the beta-carotene-supplemented group, total plasma beta-carotene increased 14-fold from 0.48 +/? 0.13 to 6.83 +/? 2.12 mumol/L (p = 0.04). Although the greatest increase in beta-carotene was in low-density-lipoproteins (LDL), the magnitude of increase was similar in LDL, high-density-lipoproteins (HDL), and very-low-density-lipoproteins (VLDL). Thus, the relative distribution of beta-carotene in lipoproteins was unchanged: approximately 71% was in LDL, approximately 15% in HDL and approximately 12% in VLDL, before and after beta-carotene supplementation. There were no changes in amounts and distribution in lipoproteins of the other carotenoids, alpha-tocopherol, and cholesterol. There was no change in the amount of retinol in lipoprotein-deficient plasma. There were no changes in total plasma triglycerides. Significant positive correlations were found between LDL- or VLDL-cholesterol and alpha-tocopherol in LDL or VLDL, respectively; between LDL- or VLDL-cholesterol and lutein/zeaxanthin in LDL or VLDL, respectively; and between HDL-cholesterol and beta-carotene in HDL.

beta-Carotene supplementation (90 mg/day for 3 weeks) in healthy older women results in an enrichment of all plasma lipoprotein fractions with beta-carotene, but does not alter the relative distribution of beta-carotene in lipoproteins. beta-Carotene supplementation has no effect on the amounts and relative distribution of lycopene, lutein/zeaxanthin, and alpha-tocopherol in lipoproteins, or of retinol in the non-lipoprotein fraction of plasma. Short-term beta-carotene supplementation has no effect on the concentrations of plasma total triglycerides, total cholesterol, HDL-, LDL-, and VLDL-cholesterol.     

Plasma antioxidant vitamins and carotenoids in five Japanese populations with varied mortality from gastric cancer.

To examine the geographic associations between plasma antioxidant levels and gastric cancer risk, we conducted an ecological study in five regions of Japan representing the threefold variation in the disease mortality within the country. Subjects were 634 men aged 40-49 years sampled randomly from the five regions with 72% response rates. Plasma concentrations of five carotenoids (beta-carotene, alpha-carotene, lycopene, lutein, and zeaxanthin), alpha-tocopherol, and ascorbic acid were measured, and the mean levels were correlated with age-adjusted mortality rates from gastric cancer. beta-Carotene and alpha-tocopherol were inversely correlated with gastric cancer rates (r = -0.31 and -0.89, respectively). alpha-Carotene and lycopene showed stronger inverse correlation than did beta-carotene (r = -0.67 and -0.56, respectively), but these relations disappeared after the exclusion of one outlying region in Okinawa with the lowest mortality. In contrast, ascorbic acid revealed a negative correlation with the exclusion of this outlier (r = -0.61). Lutein and zeaxanthin were not inversely associated with risk. The results suggest that plasma levels of beta-carotene and alpha-tocopherol, and possibly alpha-carotene, lycopene, and ascorbic acid, may partly account for the regional difference in gastric cancer mortality in Japan.     

Correlations of vitamin A and E intakes with the plasma concentrations of carotenoids and tocopherols among American men and women.

The authors investigated the association of diet and other factors with the plasma concentrations of carotenoids, retinol and tocopherols in a sample of 121 men and 186 women participating in two prospective investigations of dietary etiologies of chronic diseases. Lycopene (mean concentration, 0.82 mumol/L in men, 0.76 mumol/L in women), beta-carotene (mean 0.46 mumol/L in men, 0.58 mumol/L in women) and lutein (mean 0.28 mumol/L in men, 0.27 mumol/L in women) were the major circulating carotenoids. Among nonsmokers, dietary carotenoid, as typically calculated in epidemiologic studies, was significantly correlated with plasma beta-carotene (r = 0.34 in men, r = 0.30 in women), alpha-carotene (r = 0.52 in men, r = 0.37 in women) and lutein (r = 0.36 in men, r = 0.19 in women), but not with plasma zeaxanthin (r = 0.11 and r = 0.02) or lycopene (r = 0.13 and r = 0.01) after adjusting for plasma cholesterol and triglycerides, body mass index and energy intake. Total vitamin E intake was positively associated with plasma concentrations of alpha-tocopherol (r = 0.51 in men, r = 0.41 in women) and inversely associated with plasma concentrations of gamma-tocopherol (r = -0.51 in men r = -0.42 in women), but this was primarily due to use of vitamin E supplements. Measurements of specific carotenoids can provide independent information beyond the usual calculation of carotene intake in epidemiologic studies.     

Low plasma lycopene concentration is associated with increased mortality in a cohort of patients with prior oral, pharynx or larynx cancers

OBJECTIVE: This analysis was conducted to evaluate the association between plasma beta-carotene, alpha-carotene, lycopene, lutein/zeaxanthin, total carotenoids, retinol, alpha-tocopherol and subsequent mortality. METHODS: Blood samples collected longitudinally from 259 participants in a chemoprevention trial aimed at the prevention of second cancers of the oral cavity, pharynx, or larynx were analyzed by high performance liquid chromatography for selected micronutrients. All-cause mortality (primary outcome) and cause-specific mortality (secondary outcomes) were evaluated in relation to plasma micronutrient concentrations at baseline and longitudinally. RESULTS: A total of 61 deaths occurred over a follow-up time of up to 90 months. Cox proportional hazards models with time-dependent covariates were used for data analyses. In models adjusted for age, plasma cholesterol, time-dependent smoking, treatment arm, study site and gender, only plasma lycopene was significantly inversely associated with total mortality [hazard ratio (HR) above versus below median = 0.53, 95% confidence interval (CI) 0.30-0.93]. Plasma alpha-carotene was inversely associated (HR 0.24, 95% CI 0.08-0.75) while plasma retinol was positively associated (HR 5.12, 95% CI 1.54-17.05) with cardiovascular death. Smoking status modified plasma nutrient associations with total mortality. Lycopene (HR 0.08, 95% CI 0.02-0.36), alpha-carotene (HR 0.25, 95% CI 0.09-0.73) and total carotenoids (HR 0.22, 95% CI 0.07-0.70) were inversely associated with mortality in non-smokers, while plasma retinol (HR = 3.56, 95% CI 1.40-9.09) and alpha-tocopherol (HR = 2.47, 95% CI 1.02-5.98) were positively associated with mortality in smokers. CONCLUSIONS: Only plasma lycopene was significantly associated (inversely) with total mortality in the full study population. Smoking modifies associations between nutrients and mortality.     

Effects of the consumption of cigarettes, alcohol and foods on serum concentrations of carotenoids, retinol and tocopherols in healthy inhabitants living in a rural area of Hokkaido.

The relationship between serum concentrations of carotenoids, tocopherols and retinol and the consumption of cigarettes, alcohol and foods was investigated in 835 healthy inhabitants (aged 35-79 years) of a rural area of Hokkaido. Serum concentrations of beta-carotene (BC), alpha-carotene (AC), lycopene (LY), beta-cryptoxanthin (BX), zeaxanthin (including lutein, ZX), canthaxanthin (CX) and beta-tocopherol (including gamma-tocopherol, BT) were higher in females than in males, while serum retinol (RE) concentrations were lower. Serum alpha-tocopherol (AT) concentrations were the same for both sexes. The serum values of BC, BX, AC, LY and ZX for males were inversely associated with the consumption of cigarettes in multiple-regression analysis. The serum values of BC, AC and BX for males were inversely associated with alcohol consumption, while serum RE values were positively related to alcohol consumption for both sexes. There were significant relations between serum values of BC, AC, and ZX and the intake frequencies of carrots, tomatoes, milk and/or green-leaf vegetables, especially for females, and between serum BX values and the intake of oranges, juices and fruits. Serum RE and AT concentrations were not associated with any food intake, and BT concentrations were associated with the intake of tomatoes and juices for males.     

Concentrations of tocopherols and carotenoids in maternal and cord blood plasma.

OBJECTIVES: To determine the levels of tocopherols, retinol and carotenoids in maternal and umbilical cord blood plasma and to investigate the relationships between them. DESIGN: Venous blood plasma concentrations of alpha, gamma and delta-tocopherol, retinol, lutein, lycopene, zeaxanthin, beta-cryptoxanthin, alpha and beta-carotene were determined by HPLC in healthy pregnant women and in pair-matched umbilical cords. Plasma levels of triglycerides and cholesterol were also measured. SUBJECTS: Sixty-six women, between 10 and 20 weeks gestation, were recruited randomly during their first antenatal appointment. From this group, 40 pair-matched umbilical cord blood samples were obtained. RESULTS: Tocopherols, retinol, carotenoids and lipids were present in significantly higher (P < 0.001) concentrations in maternal plasma than in cord plasma. There was a significant correlation (r = 0.45, P < 0.005) between maternal and cord levels of gamma-tocopherol, but not of alpha-tocopherol, retinol or carotenoids. Tocopherols and carotenoids were significantly correlated with each other (P < 0.05) in maternal and cord plasma. CONCLUSIONS: Plasma levels of tocopherols, carotenoids and lipids are substantially lower at birth than in adulthood. There is a clear relationship between gamma-tocopherol levels in maternal and cord plasma. The importance of gamma-tocopherol in human nutrition should be further investigated. There are no significant relationships between plasma alpha-tocopherol and carotenoids in pregnant mothers and cords. More research is needed to elucidate the maternal-foetal transfer of tocopherols and carotenoids, and to examine the impact of maternal antioxidant nutrient status on neonatal antioxidant capacity. It is important to determine if a low level of tocopherols and carotenoids at birth is a normal stage of human development or indicative of deficiency.     

Plasma antioxidant concentrations in a population of elderly women: Findings from the nun study

Low plasma alpha-tocopherol and beta-carotene concentrations have been associated with an increased risk of numerous degenerative diseases, including cancer. Several characteristics that accompany aging, including changes in dietary habits and physiologic capacity, may place elderly populations at a high risk of low plasma antioxidant concentrations. Thus, the present study was undertaken to characterize plasma concentrations of alpha-tocopherol, beta-carotene and several other carotenoids in elderly subjects, to describe the relationship between age and plasma antioxidant concentrations in this population and to compare the concentrations of plasma antioxidants in middle-aged and elderly individuals. The study recruited 94 participants from the Nun Study, a longitudinal study of aging and Alzheimer disease. Women in this population were unique for their advanced age, 77–99 years old, and their comparability across age groups due to the absence of several potential confounders of plasma antioxidant concentrations. The population mean and standard deviation of several plasma carotenoids and alpha-tocopherol concentrations (μg/dl) were as follows: lycopene, 15.0+/− 10.0; beta-carotene, 30.0+/− 19.7; alpha-carotene, 15.0 +/− 9.6; zeaxanthin plus lutein, 22.0+/− 7.4; beta-cryptoxanthin, 14.0 +/− 8.6 and alpha-tocopherol, 980 +/− 310. Concentrations of all analytes, except lycopene, were similar to or higher than those reported for several middle-aged American populations. Lycopene concentrations were significantly lower in the population of sisters as compared with the middle-aged populations and tended to decrease across age groups within the population of sisters. Age appeared to be a relatively minor determinant of plasma alpha-tocopherol and the concentrations of carotenoids, other than lycopene, in this population. Importantly, the plasma concentrations of most carotenoids and alpha-tocopherol in this population of independent elderly women were apparently adequate on the basis of population comparisons. Further studies of this population may define determinants essential for the maintenance of antioxidant status in elderly populations.     

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.     

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.     

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.     

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.     

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.     

The relationship between the acute changes in the systemic inflammatory response, lipid soluble antioxidant vitamins and lipid peroxidation following elective knee arthroplasty

BACKGROUND AND AIMS: The aim of the present study was to examine the time course of the change in the concentrations of plasma retinol, alpha-tocopherol, lutein, lycopene, alpha-carotene, beta-carotene (antioxidant vitamins) and malondialdehyde (lipid peroxidation) in patients following elective knee arthroplasty. METHODS: Patients (n=20) who underwent an elective knee arthroplasty, had venous blood samples withdrawn pre-operatively and at 12, 24, 48, 72 and 168 h after the start of surgery for the analysis of circulating concentrations of C-reactive protein, albumin, cholesterol, triglycerides and malondialdehyde and also the lipid soluble antioxidants vitamins. RESULTS: Over the study period of 0-168 h there was a significant increase in circulating C-reactive protein concentrations (peak 48 h, P<0.001) and a significant fall in albumin, cholesterol and triglyceride concentrations (trough 48 h, P<0.001). Malondialdehyde concentrations fell by approximately 35% (P<0.001) during the study period. However, they did not alter significantly over the study period when adjusted for triglyceride (P=0.309). The plasma concentrations of retinol, alpha-tocopherol, lutein, lycopene, alpha-carotene and beta-carotene all fell (P0.001). When adjusted for cholesterol, the reductions in plasma concentrations of alpha-tocopherol, lutein, lycopene, and beta-carotene in the post-operative period were no longer statistically significant. CONCLUSIONS: The results of the present study indicate that, in apparently healthy subjects undergoing an acute inflammatory insult, circulating lipid soluble vitamin antioxidants are transiently reduced. However, when corrected for lipids the concentrations were similar to those of baseline. In the absence of an increase in lipid peroxidation such falls in plasma concentrations of lipid soluble vitamins are unlikely to be a reliable measure of status.