Specific Carotenoids Research Articles

Relation of consumption of vitamin E, vitamin C, and carotenoids to risk for stroke among men in the United States.

Antioxidants increase the resistance of low-density lipoprotein to oxidation and may thereby reduce risk for atherosclerosis. To determine whether intake of vitamin E, vitamin C, or carotenoids predict risk for total or ischemic stroke. Prospective observational study. The Health Professionals Follow-up Study. 43,738 men 40 to 75 years of age who did not have cardiovascular disease or diabetes. Repeated and validated dietary assessments were done by using a self-administered 131-item food-frequency questionnaire, which included questions on dose and duration of vitamin supplement use. The follow-up period was 8 years. A total of 328 strokes occurred: 210 ischemic, 70 hemorrhagic, and 48 unclassified. After adjustment for age, smoking, hypertension, hypercholesterolemia, body mass index, physical activity, parental history of myocardial infarction, alcohol consumption, and total energy intake, the relative risk for ischemic stroke in the top quintile of vitamin E intake (median, 411 IU/d) compared with the bottom quintile (5.4 IU/d) was 1.18 (95% CI, 0.77 to 1.82). The relative risk for ischemic stroke in the top quintile of vitamin C intake (1167 mg/d) compared with the bottom quintile (95 mg/d) was 1.03 (CI, 0.66 to 1.59). Results for total stroke were similar. Associations of vitamin intake with hemorrhagic stroke were also nonsignificant, but the CIs were wide. Neither dose nor duration of vitamin E or vitamin C supplement use was related to risk for total or ischemic stroke. The relative risk for ischemic stroke was 1.16 (CI, 0.81 to 1.67) in men using 250 IU or more of vitamin E supplementation per day compared with men who used no vitamin E supplements and was 0.93 (CI, 0.60 to 1.45) in men using 700 mg or more of vitamin C supplementation per day compared with men who used no vitamin C supplements. A significant inverse relation between lutein intake and risk for ischemic stroke was seen but was not independent of other dietary factors. Vitamin E and vitamin C supplements and specific carotenoids did not seem to substantially reduce risk for stroke in this cohort. Modest effects, however, cannot be excluded.

Chlorophyll and carotenoid patterns in olive fruits, Olea europaea Cv. arbequina.

In olive fruits of the cultivar Arbequina, the chlorophyll pigments decrease significantly throughout ripening, while the carotenoids decrease more gradually and discontinuously. There is no degradation of the carotenoid fraction in stages before complete ripeness. The presence of esterified xanthophylls exclusively in this variety suggests that the chloroplast pigment metabolism is different from that in other olive varieties studied previously. There are increases of specific carotenoids, violaxanthin, neoxanthin, antheraxanthin, lutein epoxide, and esterified xanthophylls between the light green and yellowish green ripening stages. Such increases are related to the detection of precursor carotenoids (phytofluene and xi-carotene) in the yellowish green stage. Chlorophyllides (a and b) and alpha-carotene have also been detected exclusively in this variety. Quantitatively, the drastic change in color between light green and yellowish green ripening stages characteristic of this variety can be explained by the considerable reduction found in the chlorophylls/carotenoids ratio. The study of the pigments present in skin and pulp has shown that the pattern of carotenoid distribution differs depending on the fruit part concerned.

Dietary carotenoids and vitamins A, C, and E and risk of breast cancer.

Data on intake of specific carotenoids and breast cancer risk are limited. Furthermore, studies of vitamins A, C, and E in relation to breast cancer risk are inconclusive. We have conducted a large, prospective study to evaluate long-term intakes of these nutrients and breast cancer risk. We examined, by use of multivariate analysis, associations between intakes of specific carotenoids, vitamins A, C, and E , consumption of fruits and vegetables, and breast cancer risk in a cohort of 83234 women (aged 33-60 years in 1980) who were participating in the Nurses' Health Study. Through 1994, we identified 2697 incident cases of invasive breast cancer (784 premenopausal and 1913 postmenopausal). Intakes of beta-carotene from food and supplements, lutein/zeaxanthin, and vitamin A from foods were weakly inversely associated with breast cancer risk in premenopausal women. Strong inverse associations were found for increasing quintiles of alpha-carotene, beta-carotene, lutein/zeaxanthin, total vitamin C from foods, and total vitamin A among premenopausal women with a positive family history of breast cancer. An inverse association was also found for increasing quintiles of beta-carotene among premenopausal women who consumed 15 g or more of alcohol per day. Premenopausal women who consumed five or more servings per day of fruits and vegetables had modestly lower risk of breast cancer than those who had less than two servings per day (relative risk [RR] = 0.77; 95% confidence interval [CI] = 0.58-1.02); this association was stronger among premenopausal women who had a positive family history of breast cancer (RR = 0.29; 95% CI = 0.13-0.62) or those who consumed 15 g or more of alcohol per day (RR = 0.53; 95% CI = 0.27-1.04). Consumption of fruits and vegetables high in specific carotenoids and vitamins may reduce premenopausal breast cancer risk.

Ancient blue‐green blooms

Recent decades have seen a large increase in surface scums (blooms) of cyanophytes (blue‐green algae and blue‐green bacteria) in inland waters. These are potentially toxic to mammals, including humans, and have caused considerable public concern in Europe, Australasia, and North America. They are often associated with eutrophication, and much has been invested in their control. Not all blooms, however, are necessarily the results of human interference with lakes. Scattered paleolimnological evidence indicates that some blooms may be associated with pristine conditions, though this message has largely been ignored. Evidence is given here of a long history of blooms in Whitemere, U.K., from extraction and identification of specific carotenoids from dated sediment cores. Whitemere is representative of a large group of lakes in the West Midlands of the U.K. and is likely to be representative also of those similar postglacial kettle hole lakes in North America and Eurasia, which are groundwater fed with long retention times and thermally stratified. Blue‐green blooms may thus be a normal feature of such lakes and not necessarily a pathology to be controlled.

Intake of specific carotenoids and flavonoids and the risk of gastric cancer in Spain.

To investigate the relationship between gastric cancer and the intake of specific carotenoids (alpha-carotene, beta-carotene, lutein, and lycopene) and flavonoids (quercetin, kaempferol, myricetin, and luteolin) using new data on their concentration in foods. Case-control study carried out in Spain that included 354 cases of gastric cancer and 354 controls, matched by age, gender, area of residence and hospital. Usual food intake was assessed using a dietary history questionnaire. In a multivariate model adjusted for several dietary factors, no association was found between intake of any of the studied carotenoids and the risk of gastric cancer. The adjusted OR of gastric cancer for the highest quartile of total flavonoid intake versus the lowest quartile was 0.44 (95 percent confidence interval [CI] = 0.25-0.78; P for trend = 0.003). Kaempferol intake was found to be protective (OR = 0.48; CI = 0.26-0.88; P for trend = 0.04) comparing the highest versus the lowest quartile of intake. A trend toward lower risk of stomach cancer with higher intake of quercetin was also found. The results of this study support the hypothesis that the well-established protective effect of fruit and vegetables against gastric cancer could, in part, be due to the presence of flavonoids.

Food selection by calanoid copepods in the euphotic layer of the Gotland Sea (Baltic Proper) during mass occurrence of N2-fixing cyanobacteria

Food selection by 2 dominant calanoid copepods, Acartia sp. and Temora longicornis, was studied during mass occurrence of N 2 -fixing cyanobacteria in June/July 1993 and 1994 in the Gotland Sea (Baltic Proper). The aim of this study was to assess the importance of N 2 -fixing cyanobacteria in the diet of calanoid copepods. Two different methods were used: firstly the analysis of marker carotenoids by HPLC (high-performance liquid chromatography), and secondly the analysis of δ 15 N signals of copepods by mass spectrometry. The first method provides a 'snapshot' of autotrophic material ingested; the second method summarises a longer period, and gives evidence that a certain food source is not only ingested but also assimilated. In 1994, mass occurrence of cyanobacteria showed a higher concentration in the euphotic layer than 1993 (97 μg C l -1 in 1994, 57 μg C l -1 in 1993), which was reflected in higher food uptake of N 2 -fixing cyanobacteria in 1994. The average relative amount of myxoxanthophyll, the specific carotenoid of N 2 -fixing cyanobacteria, in the copepod guts showed high values in 1994 (Acartia sp. 37 %, T. longicornis 41%) and low values in 1993 (1% for both copepods). The low δ 15 N values of both Acartia sp. and T longicornis in 1994 (9‰) compared to those in 1993 (10.5‰) support the results of HPLC analyses, because N 2 -fixing cyanobacteria have a lower δ 15 N (average 0.7‰) than eukaryotic phytoplankton (average 12‰). The low δ 15 N values in 1994 indicate that N 2 -fixing cyanobacteria were not only ingested but also assimilated by the copepods to a higher extent in 1994 than 1993.

Oxidative stress status and antioxidant status are apparently not related to carotenoid status in healthy subjects

Several lines of evidence suggest that carotenoids may have a beneficial effect on health as a result of their antioxidant properties. In addition to β-carotene, five other carotenoids are recovered in noticeable amounts from human plasma and tissues. Although the effect of β-carotene on in vivo lipid peroxidation has been documented, few data are available on the effects of the other carotenoids. We evaluated the ability of the main human carotenoids to reduce lipid peroxidation by determining the correlations between plasma carotenoid concentration and plasma antioxidant capacity (in 79 healthy volunteers) and between carotenoid status and breath pentane excretion (in a subgroup of 24 subjects). Carotenoid intake was assessed by means of a 3-day food recall. Carotenoid status was evaluated by measurement of β-carotene, lycopene, lutein/zeaxanthin, and α-carotene in plasma and buccal mucosal cells. Antioxidant status was evaluated by measurement of the total antioxidant capacity of the plasma. Oxidative stress status was evaluated by breath pentane measurements. Food recall data and the carotenoid concentrations in plasma and buccal mucosal cells showed that the subjects had normal carotenoid intake and normal carotenoid status. The total antioxidant capacity of the plasma was not related to the concentration of any specific carotenoid. The level of expired air pentane was not related to the carotenoid status of the subjects. These results show that normal concentrations of carotenoids in plasma and tissues are not correlated with these clinical markers of antioxidant and oxidative stress status.

Use of Chlorella vulgaris as a carotenoid source for rainbow trout: effect of dietary lipid content on pigmentation, digestibility and retention in the muscle tissue

Apparent digestibility, deposition and retention of carotenoids in the muscle of rainbow trout, Oncorhynchus mykiss, were investigated comparing the feeding of pigments from Chlorella vulgaris against commercially available pigments at two different total lipid contents (15% and 20% lipid). Algal biomass (ALG) was included in rainbow trout diets and muscle pigmentation was compared to that obtained in trout fed diets containing a 5:3 mixture of canthaxanthin and astaxanthin (MIX) (reflecting the relative concentrations of these carotenoids in the dry alga) or those fed a diet containing astaxanthin only (AST). Apparent digestibilities of pigments and nutrients were determined by the indirect method, using Cr2 O3 as indicator, and the colour intensity and pigment concentration were assessed in the muscle, using the Roche colour card for salmonids and UV-vis spectrophotometry. After 6 weeks feeding, colour intensity was similar for the various pigment sources, achieving levels 12 to 13, yet significantly higher in fish fed the diet with the higher lipid content (≈ 20%) (p<0.05). Pigment concentration in the muscle was also higher in the fish fed the high-fat diet. Muscle pigment concentrations were similar for fish fed diets ALG and MIX, and over 1.5 times higher than for diet AST (p<0.05) after 6 weeks. Apparent digestibility of dry matter, crude protein, lipid, total energy and specific carotenoid concentrations were also measured. Increased dietary fat content was shown to increase the deposition and the retention of carotenoids in muscle, and the difference increased with time (deposition increase of 10–20% at week 3 and 30–40% at week 6 and retention increase of 10–15% at week 3 and 30% at week 6). Pigment digestibility also apparently increases (10–20%) under those conditions despite the fact that no significant effects in terms of apparent digestibility increase were found for dry matter, protein, lipids or energy. © Rapid Science Ltd. 1998

Addition of lutein, lycopene, or β-carotene to LDL or serum in vitro: Effects on carotenoid distribution, LDL composition, and LDL oxidation

Carotenoids are dietary antioxidants transported with plasma lipoproteins, primarily low-density lipoprotein (LDL). In this study in vitro methods were used to increase the amounts of specific, individual carotenoids in LDL. By addition of carotenoid to isolated LDL or to serum, followed by (re)isolation of the lipoproteins, samples of LDL were enriched 4- to 150-fold with lutein, 2- to 15-fold with lycopene, or 3- to 25-fold with β-carotene. Enrichment with specific carotenoids was achieved without affecting the electrophoretic mobility of the lipoprotein, its cholesterol to protein ratio, or the levels of other cartenoids or α-tocopherol. The distributions among lipoproteins of carotenoid added to serum were similar, but not identical, to the distributions of the endogenous carotenoids. In particular, for added lutein, a greater proportion was found in HDL, and for added β-carotene, more was found in very low-density lipoprotein (VLDL). We then studied the effect of enriching LDL with specific carotenoids on its susceptibility to oxidation by copper ions. Lutein, β-cryptoxanthin, lycopene, and β-carotene, the four major plasma carotenoids, and α-tocopherol were destroyed before the formation of lipid peroxidation products. The rates of destruction of the individual carotenoids differed; lycopene was destroyed most rapidly and lutein most slowly. Upon oxidation of β-carotene-enriched LDL, the rates of destruction of β-carotene, lycopene, and lutein were slowed and the lag times before the initiation of lipid peroxidation increased from 19 to 65 min. Neither effect was observed in LDL enriched with lutein or lycopene. Thus, β-carotene was unique among the carotenoids studied in having a small, but significant effect on LDL oxidation in vitro.

Measurement of retinoids and carotenoids in breast adipose tissue and a comparison of concentrations in breast cancer cases and control subjects

A case-control study of the associations of retinoids and specific carotenoids with breast cancer using concentrations of these nutrients in breast adipose tissue was conducted among women attending a breast clinic in the Boston area in 1989-1992. Breast adipose tissue was collected during breast biopsy. Cases (n = 46) were women whose biopsies revealed invasive or in situ breast cancer; control subjects (n = 63) were women whose biopsies revealed benign disease. We observed inverse associations between breast adipose concentrations of retinoids and carotenoids and risk of breast cancer, although not all were statistically significant. The multivariate-adjusted odds ratio comparing women above the median value of the control group for retinol with those below or equal to the median was 0.71 (95% CI: 0.26, 1.93; NS); corresponding odds ratios were 0.61 (95% CI: 0.23, 1.64; NS) for retinyl palmitate, 0.30 (95% CI: 0.11, 0.85) for beta-carotene, 0.32 (95% CI: 0.11, 0.94) for lycopene, and 0.68 (95% CI: 0.27, 1.73; NS) for lutein/zeaxanthin. There was a nonsignificant positive correlation (r = 0.23, P = 0.15) between breast adipose tissue concentrations of retinol and dietary intake of preformed vitamin A, including supplements measured by using a food-frequency questionnaire. No correlation was found between breast adipose concentrations of carotenoids and intake of dietary carotenoids. These data suggest that higher breast adipose concentrations of retinoids and some carotenoids may be associated with decreased risk of breast cancer and that further examination of these relations is warranted.

Changes in Carotenoid Intake in the United States: The 1987 and 1992 National Health Interview Surveys

Objectives To assess the changes in carotenoid intake between 1987 and 1992 among US adults by sociodemographic characteristics and high-risk groups for chronic disease; and to identify the dietary sources of specific carotenoid intake. Design A food frequency questionnaire (FFQ) was collected from a representative sample of respondents to the 1987 and 1992 National Health Interview Surveys throughout two calendar quarters. Black and white adults, 18 to 69 years old, participated in 1987 (n=8,161) and 1992 (n=8,341). Method FFQ data were matched and linked to the US Department of Agriculture–National Cancer Institute carotenoid food composition database for analysis. Statistical analysis Mean differences in carotenoid intake over time were compared by sociodemographic characteristics and region of the country, after adjustment for sampling weights in a multiple linear regression model. Results Mean intake of the carotenoid lutein declined among white women (18%), among adults aged 40 to 69 years (16%), among persons with 9 to 12 years of education (11%), among nondrinkers (18%), among drinkers of 1 to 6 alcoholic drinks/week (7%), among smokers (former smokers by 11%, current smokers by 7%, and never smokers by 9%), among income groups (<$20,000 by 7%, ≥$20,000 by 9%), and residents in the south and northeast (by 13% each, respectively). Mean intake of the carotenoid lycopene increased among white men (9%), among adults aged 18 to 39 years and aged 40 to 69 years (by 5% and 6%, respectively), among those with 13 years of education or more (12.5%), among alcohol drinkers (by 10% and 7% for 1 to 6 vs 7 or more drinks/week, respectively), among former and current smokers (by 6% each), among those with incomes >$20,000 (8%), and among residents in the west (16%) and midwest (5%). All differences described were statistically significant ( P<.01). Application The decline in lutein intake (from dark green leafy vegetables), particularly in white women, may have public health implications as a result of the recognized inverse association between carotenoid intake and disease risk.

Carotinoid‐ und Retinolgehalt in Hühnereiern

AbstractDie Bestimmung von acht einzelnen Carotinoiden (α‐,β‐Carotin, Cryptoxanthin, Lutein, Zeaxanthin, Canthaxanthin, Lycopin, β‐Apo‐Carotinsäureethylester) und Vitamin A erfolgte mit der RP‐HPLC‐Methode. Die Untersuchungen von acht verschiedenen Eisorten [sechs handelsübliche Eisorten: Sommer (FS) und Winter Freilandeier (FW), Eier aus der Bodenhaltung (BoH), Vierkorneier (BV), Eier aus der Batteriehaltung (BTT), Docosahexaensäure‐Eier (DHA) und zwei von einem Legehennenversuch der BASF AG gelieferte Eisorten: B4 ‐ mit Fischöl, Bll ‐ mit Leinöl] zeigten große Unterschiede sowohl im Vitamin A‐ als auch im Carotinoidgehalt. Die höchsten Vitamin‐A‐Gehalte wurden in den beiden Freilandeisorten festgestellt. Bei den übrigen Sorten waren die Vitamin‐A‐Werte geringer und zahlenmäßig ausgeglichen. Ähnliche Tendenzen wiesen auch Carotinoide auf. Die größten Spuren von Vitamin‐A‐wirksamen Carotinoiden enthielten Freilandsommereier. Die höchsten Mengen an Nicht‐Provitamin‐A‐Carotinoiden lieferten Lutein und Zeaxanthin. Beide Isomere dominierten wiederum in Freilandsorten. Die Eier aus dem Fütterungsversuch (B4, Bll) zeigten nur etwa 10% der Luteinkonzentration, über die Freilandeisorten verfügten. Zeaxanthin wurde nicht gefunden. Diese beiden Eisorten besaßen noch C30‐Ester und Canthaxanthin, zwei Carotinoide, die dem Futter hinzugefügt wurden. Lycopin wurde in Spuren nur in DHA‐Eiern nachgewiesen. Wie zu erwarten, enthielten Eier nur in Spuren Provitamin‐A‐aktive Carotinoide. Sie erhöhten das Retinoläquivalent um etwa 1,2%. Von nicht‐Provitamin‐A‐wirksamen Carotinoiden tragen Lutein und Zeaxanthin einen wesentlichen Anteil mit etwa 310 ug an der täglichen Carotinoidzufuhr.

Specific and total carotenoid intakes among oral contraceptive and estrogen hormone users in the United States.

To compare carotenoid intakes between hormone users and nonusers in a nationally representative sample of US women by demographic and lifestyle characteristics and to identify those with potentially greater risk for disease. Data from the 1987 National Health Interview Survey's-Epidemiology Supplement food frequency questionnaire were linked to the USDA-NCI Carotenoid database to estimate mean total and specific carotenoid intakes. Women (n = 8,962) were grouped by menopausal status and classified by hormone use into premenopausal oral contraceptive users/nonusers (n = 5,918) and postmenopausal estrogen replacement hormone users/nonusers (n = 3,044). Mean carotenoid intakes and standard errors were weighted using SUDAAN and adjusted for potential confounding factors using multiple linear regression analysis. Statistically significant differences were at p values < 0.01. Compared to nonusers, oral contraceptive users had lower specific carotenoid intakes. Demographic and lifestyle characteristics differed between oral contraceptive users/nonusers and were examined in relation to carotenoid intakes. More oral contraceptive users than nonusers were married, highly educated, drank alcoholic beverages, and smoked. After adjustment for these factors in a multiple linear regression model, the associations between oral contraceptive use and carotenoid intake remained statistically significant. Mean carotenoid intakes were not significantly different among estrogen hormone replacement users versus nonusers. Oral contraceptive users have lower dietary carotenoid intakes than nonusers. Since oral contraceptive users smoke and drink more than nonusers, and both factors are associated with lower carotenoid intakes, oral contraceptive users form a potential high risk group for disease.

Arabidopsis carotenoid mutants demonstrate that lutein is not essential for photosynthesis in higher plants.

Lutein, a dihydroxy beta, epsilon-carotenoid, is the predominant carotenoid in photosynthetic plant tissue and plays a critical role in light-harvesting complex assembly and function. To further understand lutein synthesis and function, we isolated four lutein-deficient mutants of Arabidopsis that define two loci, lut1 and lut2 (for lutein deficient). These loci are required for lutein biosynthesis but not for the biosynthesis of beta, beta-carotenoids. The lut1 mutations are recessive, accumulate high levels of zeinoxanthin, which is the immediate precursor of lutein, and define lut1 as a disruption in epsilon ring hydroxylation. The lut2 mutations are semidominant, and their biochemical phenotype is consistent with a disruption of epsilon ring cyclization. The lut2 locus cosegregates with the recently isolated epsilon cyclase gene, thus, providing additional evidence that the lut2 alleles are mutations in the epsilon cyclase gene. It appears likely that the epsilon cyclase is a key step in regulating lutein levels and the ratio of lutein to beta,beta-carotenoids. Surprisingly, despite the absence of lutein, neither the lut1 nor lut2 mutation causes a visible deleterious phenotype or altered chlorophyll content, but both mutants have significantly higher levels of beta, beta-carotenoids. In particular, there is a stable increase in the xanthophyll cycle pigments (violaxanthin, antheraxanthin, and zeaxanthin) in both lut1 and lut2 mutants as well as an increase in zeinoxanthin in lut1 and beta-carotene in lut2. The accumulation of specific carotenoids is discussed as it pertains to the regulation of carotenoid biosynthesis and incorporation into the photosynthetic apparatus. Presumably, particular beta, beta-carotenoids are able to compensate functionally and structurally for lutein in the photosystems of Arabidopsis.

Effect of alcohol consumption on plasma carotenoid concentrations in premenopausal women: a controlled dietary study

This 6-mo controlled dietary study compared the effect of 30 g alcohol/d for three menstrual cycles with three alcohol-free cycles on plasma carotenoid concentrations in 18 nonsmoking, premenopausal women. Participants were randomly allocated within a crossover design to either phase and consumed approximately 6 mg total carotenoids/d under isoenergetic conditions. Blood was drawn during the third menstrual cycle of each alcohol phase. After adjustment for the mean daily specific carotenoid and energy intakes for each alcohol phase, the paired differences in mean plasma alpha- and beta-carotene concentrations were significantly higher by 19% (P = 0.027) and 13% (P = 0.034), respectively, during the alcohol-intake phase of the study. The paired difference in mean plasma lutein/zeaxanthin concentration was significantly lower by 17% (P = 0.031) when the participants consumed alcohol than when they did not. This is the first reported study in women to document the independent effect of alcohol on plasma carotenoid concentrations without the potential interaction of smoking under controlled dietary conditions.

Crustacyanin, the lobster carapace astaxanthin-protein: effects of modification of tyrosine residues of apocrustacyanin with tetranitromethane on the ability of the protein to reconstitute with astaxanthin

The effects of modification of apocrustacyanin with the tyrosine-specific reagent, tetanitromethane, on the ability of the protein to reconstitute with astaxanthin is investigated. Modification of an average three to six tyrosine residues per apoprotein molecule destroys the specific carotenoid binding responsible for the bathochromic spectral shift of the native carotenoprotein. The reaction is accompanied by intermolecular cross-linking of the protein, giving polymeric, polydisperse material which associates with carotenoid micelles. The loss of the carotenoid binding in this case may be due to general protein unfolding rather than alteration of specific tyrosine residues at the ligand binding sites. At lower levels of tyrosine modification (two to three tyrosine/subunit) intermolecular cross-linking is still evident but the monomeric and cross-linked dimeric apoprotein have reduced affinity for astaxanthin. Treatment of the separate apoprotein, A 2, with low levels of tetranitromethane modifying less than three tyrosine on average/subunit results, partly, in the formation of intermolecular cross-linked dimers and lesser amounts of higher molecular sized oligomers. The remaining apoprotein monomer (and the cross-linked dimers) shows a reduced ability to bind astaxanthin. It is concluded that tyrosine residues may be of importance for the interaction between carotenoid and apoprotein or for maintaining the integrity of the carotenoid binding sites.

Dietary Carotenoids, Vitamins A, C, and E, and Advanced Age-Related Macular Degeneration

<h3>Objective.</h3> —To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults. <h3>Design.</h3> —The multicenter Eye Disease Case-Control Study. <h3>Setting.</h3> —Five ophthalmology centers in the United States. <h3>Patients.</h3> —A total of 356 case subjects who were diagnosed with the advanced stage of AMD within 1 year prior to their enrollment, aged 55 to 80 years, and residing near a participating clinical center. The 520 control subjects were from the same geographic areas as case subjects, had other ocular diseases, and were frequency-matched to cases according to age and sex. <h3>Main Outcome Measures.</h3> —The relative risk for AMD was estimated according to dietary indicators of antioxidant status, controlling for smoking and other risk factors, by using multiple logistic-regression analyses. <h3>Results.</h3> —A higher dietary intake of carotenoids was associated with a lower risk for AMD. Adjusting for other risk factors for AMD, we found that those in the highest quintile of carotenoid intake had a 43% lower risk for AMD compared with those in the lowest quintile (odds ratio, 0.57; 95% confidence interval, 0.35 to 0.92;<i>P</i>for trend=.02). Among the specific carotenoids, lutein and zeaxanthin, which are primarily obtained from dark green, leafy vegetables, were most strongly associated with a reduced risk for AMD (<i>P</i>for trend=.001). Several food items rich in carotenoids were inversely associated with AMD. In particular, a higher frequency of intake of spinach or collard greens was associated with a substantially lower risk for AMD (<i>P</i>for trend&lt;.001). The intake of preformed vitamin A (retinol) was not appreciably related to AMD. Neither vitamin E nor total vitamin C consumption was associated with a statistically significant reduced risk for AMD, although a possibly lower risk for AMD was suggested among those with higher intake of vitamin C, particularly from foods. <h3>Conclusion.</h3> —Increasing the consumption of foods rich in certain carotenoids, in particular dark green, leafy vegetables, may decrease the risk of developing advanced or exudative AMD, the most visually disabling form of macular degeneration among older people. These findings support the need for further studies of this relationship. (<i>JAMA</i>. 1994;272:1413-1420)

Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group

OBJECTIVE--To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults. DESIGN--The multicenter Eye Disease Case-Control Study. SETTING--Five ophthalmology centers in the United States. PATIENTS--A total of 356 case subjects who were diagnosed with the advanced stage of AMD within 1 year prior to their enrollment, aged 55 to 80 years, and residing near a participating clinical center. The 520 control subjects were from the same geographic areas as case subjects, had other ocular diseases, and were frequency-matched to cases according to age and sex. MAIN OUTCOME MEASURES--The relative risk for AMD was estimated according to dietary indicators of antioxidant status, controlling for smoking and other risk factors, by using multiple logistic-regression analyses. RESULTS--A higher dietary intake of carotenoids was associated with a lower risk for AMD. Adjusting for other risk factors for AMD, we found that those in the highest quintile of carotenoid intake had a 43% lower risk for AMD compared with those in the lowest quintile (odds ratio, 0.57; 95% confidence interval, 0.35 to 0.92; P for trend = .02). Among the specific carotenoids, lutein and zeaxanthin, which are primarily obtained from dark green, leafy vegetables, were most strongly associated with a reduced risk for AMD (P for trend = .001). Several food items rich in carotenoids were inversely associated with AMD. In particular, a higher frequency of intake of spinach or collard greens was associated with a substantially lower risk for AMD (P for trend < .001). The intake of preformed vitamin A (retinol) was not appreciably related to AMD. Neither vitamin E nor total vitamin C consumption was associated with a statistically significant reduced risk for AMD, although a possibly lower risk for AMD was suggested among those with higher intake of vitamin C, particularly from foods. CONCLUSION--Increasing the consumption of foods rich in certain carotenoids, in particular dark green, leafy vegetables, may decrease the risk of developing advanced or exudative AMD, the most visually disabling form of macular degeneration among older people. These findings support the need for further studies of this relationship.

A specific carotenoid is required for reconstitution of the Rubrivivaxgelatinosus B875 light harvesting complex from its subunit form B820

The core light-harvesting complex B875 from Rubrivivax gelatinosus has been reconstituted from its subunit form B820 with hydroxyspheroidene, the carotenoid which is bound to native B875 antenna. Other carotenoids which are chemically similar to hydroxyspheroidene (spheroidene, spheroidenone, neurosporene and spirilloxanthin) gave only low levels of partial reconstitution. Absorption and circular dichroism spectra of the hydroxyspheroidene-containing, reconstituted B875 were identical with those of original B875 antenna isolated directly from chromatophores, indicating that the two hydroxyspheroidene molecules bind to their native sites within the (αβ)Bchl 2, subunit during the reconstitution process. These observations point to a structural role for this carotenoid in determining the architecture of Rv. gelatinosus B875 antenna.

Relationship between dietary intake and plasma concentrations of carotenoids in premenopausal women: application of the USDA-NCI carotenoid food-composition database

The diet-plasma relationships for carotenoids were examined in a group of 98 nonsmoking premenopausal women who participated in the cross-sectional phase of the National Cancer Institute (NCI)-US Department of Agriculture (USDA) diet study on alcohol-hormone metabolism, 1988-90. With use of the newly developed USDA-NCI carotenoid food-composition database, the mean daily intakes of carotenoids were significantly higher when estimated from the food-frequency questionnaire (FFQ) than from the 7-d diet records. Lycopene (mean = 0.58 mmol/L), lutein plus zeaxanthin (mean = 0.46 mmol/L), and beta-carotene (mean = 0.34 mmol/L) were the major plasma carotenoids. After adjustment for body mass index, energy and alcohol intakes, and total plasma cholesterol concentration, the following significant correlation (P < 0.05) were observed between the diet record and the FFQ-estimated carotenoid intakes and their respective plasma concentrations: alpha-carotene (r = 0.58 vs 0.49), beta-carotene (r = 0.51 vs 0.49), beta-cryptoxanthin (r = 0.49 vs 0.36), lutein plus zeaxanthin (r = 0.31 vs 0.37), lycopene (r = 0.50 vs 0.26), and total carotenoids (r = 0.57 vs 0.49). These data indicate that plasma carotenoid concentrations are reflective of dietary intake, but the magnitude of the correlation varies depending on the specific carotenoid and on the dietary assessment tool.