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PubMed2002

Serum status of carotenoids and tocopherols in patients with age-related cataracts: a case-control study.

BACKGROUND: Cataract is an important health problem that increase with age, causes decreased visual acuity and constitute a major cause of disability in the elderly. Epidemiological studies have shown that elevated serum levels and / or intake of several antioxidants, such as carotenoids, vitamin E and ascorbic acid, are associated with a diminished risk for cataracts. OBJECTIVE: To assess the serum fat-soluble antioxidant status in patients with cataracts and its relationship with visual function. METHODS: One hundred thirty eight patients with senile cataracts, classified according to visual acuity, and 110 age and sex-matched controls were studied for individual carotenoids and tocopherols in serum by a quality-controlled HPLC method. One-way ANOVA analysis and logistic regression analysis were applied. RESULTS: Higher serum levels of lutein and zeaxanthin were associated as risk factors for cataract while b-cryptoxanthin and g-tocopherol appeared as protective variables. Higher levels of zeaxanthin and lower concentrations of b-cryptoxanthin were associated with cataracts in people < 61y whereas only lower levels of g-tocopherol were shown in subjects >61y. No significant correlations (adjusted for sex and age) were found between visual acuity and serum concentrations of carotenoids or tocopherols. CONCLUSION: Although the relation between carotenoids and cataracts is biologically plausible, serum carotenoid levels are highly dependent on dietary intake and thus may not be clinically relevant biomakers for cataracts risk.

Age Factors↗
PubMed2003

The association between lung and prostate cancer risk, and serum micronutrients: results and lessons learned from beta-carotene and retinol efficacy trial.

beta-Carotene and Retinol Efficacy Trial is a nationwide chemoprevention trial that recruited 18,314 high-risk individuals to test the effect of supplemental beta-carotene and retinol on lung cancer incidence. In this report, we conducted a prospective nested case-control study of the association between serum carotenoids, retinoids, and tocopherols on both lung and prostate cancer incidence. Prerandomization serum samples were selected from 278 lung cancer cases and 205 prostate cancer cases, and 483 controls matched by high-risk population, study center location, age, sex (lung cancer only), smoking status, and year of randomization. Carotenoids, retinoids, and tocopherols were analyzed by high-performance liquid chromatography. Endpoints were confirmed by pathology review (lung cancer) or review of the pathology report (prostate cancer). In the control-only population, there was a significant association between tobacco use and serum micronutrient concentration. Current smokers compared with former smokers had lower mean levels of all of the micronutrients tested with zeaxanthin, beta-cryptoxanthin, alpha-carotene, alpha-tocopherol, retinol, and retinyl palmitate reaching statistical significance at P = 0.05. In the overall population, the mean serum concentrations of all of the micronutrients except gamma-tocopherol were lower for lung cancer cases than controls. Statistically significant trends across quartiles were observed in lutein (P = 0.02), zeaxanthin (P = 0.02), and alpha-tocopherol (P = 0.03). The carotenoid findings in the overall population were because of the strong inverse association between serum micronutrients and lung cancer in females. Statistically significant odds ratios (ORs) comparing 4(th) to 1st quartiles in the female population were seen in lutein [OR, 0.31; confidence interval (CI), 0.13-0.75], zeaxanthin (OR, 0.31; CI, 0.12-0.77), and beta-cryptoxanthin (OR, 0.34; CI, 0.14-0.81). For prostate cancer, mean serum concentrations were lower in cases for all of the nutrients except alpha-carotene. Only for alpha-tocopherol (P(trend) = 0.04) were the findings statistically significant. There was no statistically significant association between serum carotenoids and prostate cancer. Our findings provide additional support for the association between physiological levels of dietary micronutrients and cancer incidence.

Aged↗
PubMed2003

[Effects of light on carotenoid biosynthesis and color formation of citrus fruit peel].

The effects of shading fruit with opaque paper bag at the late stage of fruit enlargement on the contents of chlorophyll, carotenoid and in "Hongshigan" citrus (C. reticulata x C. sinensis) fruit peel and its color were examined. The results showed that after shading, the chlorophyll content in peel decreased quickly, which resulted in its earlier color shifting. In contrast, the contents of total carotenoids and each carotenoid component did not increase, but decreased significantly. At the stage of fruit riping, both chlorophyll in shaded and unshaded fruit disappeared, and the shaded fruit, owing to its lower level of carotenoids, had a lighter color than the unshaded fruit. The sugar content in peel of shaded fruit did not differ obviously from that of unshaded fruit at the earlier stage, but dropped markedly at the late stage of shading. Removing the enclosing paper bag from shaded fruit at the late stage of shading resulted in the increase of sugar, and correspondingly in the increase of carotenoid, especially of beta-cryptoxanthin accumulation with consequent darkening of fruit color. These results stressed the effect of light on stimulating carotenoid synthesis, especially the accumulation of beta-cryptoxanthin in citrus fruit peel. The light is the enviromental signal essential for carotenoid synthesis in citrus fruit during certain stage of fruit development.

Carbohydrates↗
PubMed2004

Carotenoid, tocopherol, and retinol concentrations in elderly human brain.

BACKGROUND: Antioxidants, such as tocopherols and carotenoids, have been implicated in the prevention of degenerative diseases. Although correlations have been made between diseases and tissue levels of antioxidants, to date there are no reports of individual carotenoid concentrations in human brain. OBJECTIVE: To measure the major carotenoids, tocopherols, and retinol in frontal and occipital regions of human brain. DESIGN: Ten samples of brain tissue from frontal lobe cortex and occipital cortex of five cadavers were examined. Sections were dissected into gray and white matter, extracted with organic solvents, and analyzed by HPLC. RESULTS: At least 16 carotenoids, 3 tocopherols, and retinol were present in human brain. Major carotenoids were identified as lutein, zeaxanthin, anhydrolutein, alpha- cryptoxanthin, beta- cryptoxanthin, alpha-carotene, cis- and trans-betacarotene, and cis- and trans-lycopene. Xanthophylls (oxygenated carotenoids) accounted for 66-77% of total carotenoids in all brain regions examined. Similar to neural retina, the ratio of zeaxanthin to lutein was high and these two xanthophylls were significantly correlated (p <0.0001). The tocopherol isomers occurred in the brain over a wider range of mean concentrations (0.11-17.9 nmol/g) than either retinol (87.8 - 163.3 pmol/g) or the identified carotenoids (1.8-23.0 pmol/g). CONCLUSIONS: The frontal cortex, generally vulnerable in Alzheimer's disease, had higher concentrations of all analytes than the occipital cortex which is generally unaffected. Moreover, frontal lobes, but not occipital lobes, exhibited an age-related decline in retinol, total tocopherols, total xanthophylls and total carotenoids. The importance of these differences and the role(s) of these antioxidants in the brain remain to be determined.

Aged↗
PubMed2004

Prediagnostic levels of serum micronutrients in relation to risk of gastric cancer in Shanghai, China.

Data on blood levels of specific carotenoids and vitamins in relation to gastric cancer are scarce. Little is known about the relationship between prediagnostic serum levels of carotenoids other than beta-carotene and risk of gastric cancer especially in non-Western populations. Prediagnostic serum concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein/zeaxanthin, retinol, alpha-tocopherol, gamma-tocopherol, and vitamin C were determined on 191 cases and 570 matched controls within a cohort of 18,244 middle-aged or older men in Shanghai, China, with a follow-up of 12 years. High serum levels of alpha-carotene, beta-carotene, and lycopene were significantly associated with reduced risk of developing gastric cancer (all Ps for trend </= 0.05); the odds ratios (95% confidence intervals) for the highest versus the lowest quartile of alpha-carotene, beta-carotene, and lycopene were 0.38 (0.13-1.11), 0.54 (0.32-0.89), and 0.55 (0.30-1.00), respectively. Increased serum level of vitamin C was significantly associated with reduced risk of gastric cancer among men who neither smoked cigarettes over lifetime nor consumed >/=3 drinks of alcohol per day; the odds ratios (95% confidence intervals) for the second, third, and fourth quartile categories were 0.69 (0.28-1.70), 0.36 (0.14-0.94), and 0.39 (0.15-0.98), respectively, compared with the lowest quartile of vitamin C (P for trend = 0.02). There were no statistically significant relationships of serum levels of beta-cryptoxanthin, lutein/zeaxanthin, retinol, alpha-tocopherol, and gamma-tocopherol with gastric cancer risk. The present study implicates that dietary carotenes, lycopene, and vitamin C are potential chemopreventive agents for gastric cancer in humans.

Alcohol Drinking↗
PubMed2005

Identification of carotenoids in ovarian tissue in women.

Epidemiological and clinical studies have revealed that vitamin A and its derivatives (carotenoids and retinoids) can reduce the risk of ovarian tumours and may have a role in the metabolism of patients with ovarian cancer. The aim of the study was identification and quantitative assessment of carotenoids found in nature, mainly of provitamin A group, in the tissue material obtained from patients with different lesions of the ovaries. Material for analysis was obtained from 100 women, aged 16-74, operated on for ovarian tumours in the Department of Gynaecology. Carotenoid pigments were separated using column chromatography, thin-layer chromatography and high-performance liquid chromatography. In the tissue material subjected to analysis, 14 carotenoids were identified, including provitamin A carotenoids; beta-carotene, beta-cryptoxanthin, echinenone and hydroxyechinenone. alpha-carotene was not found. In the whole group of pathological lesions, the total carotenoid content was relatively low (mean 1.717 microg/g tissue) and the mean content of provitamin A carotenoids was 17.28%. These results are similar to results obtained in the group of normal ovarian tissue. In the group of benign mucinous tumours (1.042 microg/g tissue) and tumours in the thecoma-fibroma group (1.328 microg/g tissue) and dysgerminoma group (1.279 microg/g tissue), the total carotenoid content was lower. Only in the endometriosis group was this value higher (2.185 microg/g tissue). Epoxy carotenoids; lutein epoxide, violaxanthin and mutatoxanthin were predominant (in %). Irrespective of histological classification, beta-carotene, beta-cryptoxanthin, lutein, lutein epoxide, violaxanthin and mutatoxanthin were identified in all tissue examined. Antheraxanthin was isolated in all tissue except for normal ovarian tissue, serous malignant and mucinous benign and malignant tumours, endometrioid malignant tumours, dermoid cysts, corpus luteum cysts and simple cysts. Hydroxyechinenone was isolated sporadically. Only in one case was capsanthin isolated. Carotenoids act as chemopreventive agents, irrespective of whether they are finally transformed into vitamin A, and may represent a potentially powerful alternative to present chemotherapeutic approaches to the treatment of ovarian cancer.

Adolescent↗
PubMedDate not supplied

Nonaqueous reverse phase liquid chromatographic system for separation and quantitation of provitamins A.

A reverse phase liquid chromatographic (LC) system has been developed for separating the main naturally occurring carotenoids that have provitamin A activity. The system produces baseline separation of beta-carotene, alpha-carotene, and beta-cryptoxanthin (beta, beta-carotene-3-ol, 472-70-8) from biologically inactive zeinoxanthin (beta, epsilon-carotene-3-ol, 24480-38-4) and from a pigment believed to be alpha-cryptoxanthin (beta, epsilon-carotene-3'-ol). Some cis-isomers are also separated. These separations are obtained on a C-18 column, isocratically, with methanol-chloroform eluant. For quantitation, peak areas from detection at 475 nm are compared with that of an internal standard, 1-(phenylazo)-2-naphthalenol (842-07-9), which elutes prior to the provitamins. Provitamin amounts are calculated from absorbance ratios. Prior to LC, esters are saponified, and interfering pigments are removed from ester-free extracts by adsorption on magnesia.

Carotenoids↗
PubMed1977

Carotenoids in fish. XVIII--carotenoids in the brain of some fishes.

Using column and thin-layer chromatography the occurrence of various carotenoids was studied in the brain of some (11) fishes. In result of the analyses the presence of the following carotenoids has been established: beta-zeacarotene, canthaxanthin, cryptoxanthin, alpha-cryptoxanthin, isocryptoxanthin, lutein, lutein-5,6-epoxide, zeaxanthin, isozeaxanthin, tunaxanthin, flavoxanthin, astaxanthin ester, 4-hydroxy-alpha-carotene, 4-keto-alpha-carotene and unknown xanthophylls.

Animals↗
PubMedDate not supplied

Questionnaire assessment of intake of specific carotenoids.

We determined whether estimation of intake of specific carotenoids with a standard food-frequency questionnaire (FFQ) could be improved by collection of additional data on the intake of carotenoid-rich food items. The foods included on an addendum to the standard FFQ were potentially important dietary contributors of alpha- and beta-carotene, beta-cryptoxanthin, lutein, zeaxanthin, or lycopene. Participants (n = 215), ages 50-74 years, provided fasting blood samples and completed the FFQ and the addendum. The participants were enrolled in a prepaid health plan and had undergone screening sigmoidoscopy for detection of colorectal polyps. Addendum foods were identified that accounted for variation in blood levels of specific carotenoids, conditional on intake of foods on the standard FFQ. Estimated carotenoid intakes from the standard FFQ, and from the modified FFQ with the selected addendum foods, were examined in relation to plasma carotenoid levels. The correlation coefficient between estimated carotenoid intake and plasma levels (adjusted for age, sex, serum cholesterol, alcohol intake, smoking status, and energy intake) were essentially the same for the standard and modified FFQs. The adjusted correlations for the standard FFQ only were 0.26 for alpha-carotene, 0.22 for beta-carotene, 0.36 for beta-cryptoxanthin, 0.32 for lutein+zeaxanthin, and 0.34 for lycopene. Adding carotenoid-rich foods to the FFQ did not improve estimation of intake for the carotenoids examined in this population. We conclude that assessment of intake of specific carotenoids with the FFQs currently in use may not necessarily be improved by a modified list of carotenoid-rich foods.

Adenomatous Polyps↗
PubMed1993

[Main carotenoids in pressed seeds (Cucurbitae semen) of oil pumpkin (Cucurbita pepo convar. pepo var. styriaca)].

Various use of the oil-pumpkin offers reason for the phytochemical analysis of seed-meal's carotene pigments. Column chromatography was performed on the adsorbents MgO, Celite and CaCO3 with hexane and benzene as eluents. HPLC separation of different pigments was carried out on a 6 microns reverse phase packing with a ternary gradient elution method using a diode-array detector. The main components of the press-residue were lutein [3,3'-dihydroxy-alpha-carotene = (3R,3'R,6'R)-beta,epsilon-carotene-3,3'-diol; 52.5%] and beta-carotene (beta,epsilon-carotene; 10.1%). In addition to the above-mentioned pigments it was successful to reveal the presence of violaxanthin, luteoxanthin, auroxanthin epimers, lutein epoxide, flavoxanthin, chrysanthemaxanthin, 9(9')-cis-lutein, 13(13')-cis-lutein, 15-cis-lutein (central-cis)-lutein, alpha-cryptoxanthin, beta-cryptoxanthin and alpha-carotene (beta,epsilon-carotene) in small quantities.

Carotenoids↗
PubMed1977

High performance liquid chromatographic determination of provitamin A in orange juice.

A quantitative method has been developed for the determination of alpha- and beta-carotenes and beta-cryptoxanthin, the provitamin A carotenoids in orange juice. The carotenoids were separated by high performance liquid chromatography on a single column in approximately 30 min. The procedure may also be used to measure zeta-carotene and alpha-cryptoxanthin.

Beverages↗
PubMed1996

Major fruit and vegetable contributors to the main serum carotenoids in the Spanish diet.

OBJECTIVE: To identify the main sources of serum carotenoids (lutein, zeaxanthin, lycopene, beta-cryptoxanthin, alpha-carotene and beta-carotene) among the fruits and vegetables in the Spanish diet, to be used in the design of food questionnaires and to provide useful information for epidemiological and comparative studies. DESIGN: A Family Budget Survey from the National Institute of Statistics (1990-1991); an open questionnaire dealing with foods consumed over a one-week period; physical amounts consumed annually and during three-month periods. Calculation of the percentage contribution of each food on the basis of a standard portion as well as the carotenoid concentrations previously reported by our laboratory. SETTING: Nationwide (urban and rural). SUBJECTS: Twenty-one thousand, one hundred and fifty-five (21 155) randomly selected, private households throughout Spain (72279 subjects). RESULTS: Nine vegetables (potato, tomato, green bean, green and/or red pepper, carrot, artichoke, spinach, lettuce and beet) and five fruits (orange, tangerine, banana, peach and watermelon) account for more than 96% of the intake of the major six carotenoids in serum, both on a yearly and on a seasonal basis. Fruit and vegetables provide between 3.0mg (in autumn) and 4.3mg (in summer) of these carotenoids per day. CONCLUSIONS: In our population, a small number of fruits and vegetables can provide significant information on carotenoid intake (both annually and seasonally) to be used in the design of questionnaires for epidemiological studies, minimizing misclassification and errors. The marked seasonality of some products causes wide differences in the supply of, above all, beta-cryptoxanthin and lycopene.

Carotenoids↗
PubMed1996

cis-trans lycopene isomers, carotenoids, and retinol in the human prostate.

An evaluation of the Health Professionals Follow-Up Study has detected a lower prostate cancer risk associated with the greater consumption of tomatoes and related food products. Tomatoes are the primary dietary source of lycopene, a non-provitamin A carotenoid with potent antioxidant activity. Our goal was to define the concentrations of lycopene, other carotenoids, and retinol in paired benign and malignant prostate tissue from 25 men, ages 53 to 74, undergoing prostatectomy for localized prostate cancer. The concentrations of specific carotenoids in the benign and malignant prostate tissue from the same subject are highly correlated. Lycopene and all-trans beta-carotene are the predominant carotenoids observed, with means +/- SE of 0.80 +/- 0.08 nmol/g and 0.54 +/- 0.09, respectively. Lycopene concentrations range from 0 to 2.58 nmol/g, and all-trans beta-carotene concentrations range from 0.09 to 1.70 nmol/g. The 9-cis beta-carotene isomer, alpha-carotene, lutein, alpha-cryptoxanthin, zeaxanthin, and beta-cryptoxanthin are consistently detectable in prostate tissue. No significant correlations between the concentration of lycopene and the concentrations of any other carotenoid are observed. In contrast, strong correlations between prostate beta-carotene and alpha-carotene are noted (correlation coefficient, 0.88; P < 0.0001), as are correlations between several other carotenoid pairs, which reflects their similar dietary origins. Mean vitamin A concentration in the prostate is 1.52 nmol/g, with a range of 0.71 to 3.30 nmol/g. We further evaluated tomato-based food products, serum, and prostate tissue for the presence of geometric lycopene isomers using high-performance liquid chromatography with a polymeric C30 reversed phase column. All-trans lycopene accounts for 79 to 91% and cis lycopene isomers for 9 to 21% of total lycopene in tomatoes, tomato paste, and tomato soup. Lycopene concentrations in the serum of men range between 0.60 and 1.9 nmol/ml, with 27 to 42% all-trans lycopene and 58 to 73% cis-isomers distributed among 12 to 13 peaks, depending upon their chromatographic resolution. In striking contrast with foods, all-trans lycopene accounts for only 12 to 21% and cis isomers for 79 to 88% of total lycopene in benign or malignant prostate tissues. cis Isomers of lycopene within the prostate are distributed among 14 to 18 peaks. We conclude that a diverse array of carotenoids are found in the human prostate with significant intra-individual variation. The presence of lycopene in the prostate at concentrations that are biologically active in laboratory studies supports the hypothesis that lycopene may have direct effects within the prostate and contribute to the reduced prostate cancer risk associated with the reduced prostate cancer risk associated with the consumption of tomato-based foods. The future identification and characterization of geometric lycopene isomers may lead to the development of novel agents for chemoprevention studies.

Aged↗
PubMed1997

Serum micronutrients and prostate cancer in Japanese Americans in Hawaii.

Numerous dietary studies and several serum micronutrient studies have produced equivocal results on the relation of vitamins A and E to prostate cancer risk. To evaluate this association further, we conducted a nested case-control study in a cohort of 6860 Japanese-American men examined from 1971 to 1975. At the time of examination, a single blood specimen was obtained, and the serum was frozen. After a surveillance period of more than 20 years, 142 tissue-confirmed incident cases of prostate cancer were identified. Their stored sera and those of 142 matched controls were measured by high-performance liquid chromatography for the following: total carotenoids, lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha-carotene, beta-carotene, total retinoids, retinol, total tocopherols, alpha-tocopherol, delta-tocopherol, and gamma-tocopherol. Odds ratios for prostate cancer, based on quartiles of serum micronutrient levels, were determined using conditional logistic regression analysis. The odds ratio for the highest quartiles were 1.8 (95% confidence interval, 0.9-3.9) for beta-cryptoxanthin, 1.6 (0.8-3.5) for beta-carotene, 0.8 (0.4-1.5) for retinol, and 0.7 (0.3-1.5) for gamma-tocopherol, but none of the differences was statistically significant. For the other micronutrients, the results were also unremarkable. The findings of this study indicate that none of the micronutrients is strongly associated with prostate cancer risk.

Aged↗
PubMed1997

Antioxidant nutrients: associations with persistent human papillomavirus infection.

Research from the past several years has definitively shown intermediate and high risk-type human papillomavirus (HPV) infection to play a significant role in cervical carcinogenesis. Persistent compared with intermittent infection appears to confer an elevated risk, and cofactors may be necessary to allow the virus to progress to cervical cancer. We explored the association between circulating concentrations of the antioxidant nutrients (alpha- and beta-carotene, lutein, lycopene, beta-cryptoxanthin, alpha-tocopherol, gamma-tocopherol, and ascorbate) and persistent HPV infection among 123 low-income Hispanic women who were all nonsmokers and were not currently using vitamin and mineral supplements. In addition, the association between these nutrients and grade of cervical pathology, independent of HPV status, was assessed. Intermediate and high risk-type HPV infection was assessed by the Digene Hybrid Capture System at two time points, 3 months apart. At the second interview, cytology, colposcopy, and a fasting blood draw were conducted. Mean concentrations of serum and plasma antioxidant nutrients were calculated within categories of HPV status (two times HPV negative, one time HPV positive, and two times HPV positive) and colposcopy. Adjusted mean concentrations of serum beta-carotene, beta-cryptoxanthin, lutein, and alpha- and gamma-tocopherol were on average 24% (P < 0.05) lower among women two times HPV positive compared with either two times HPV negative or one time HPV positive. Independent of HPV status, alpha-tocopherol was significantly inversely associated with grade of cervical dysplasia (normal, 21.57 microM; cervical intraepithelial neoplasia III, 17.27 microM). The results obtained in this study need to be confirmed in larger cohort studies with a longer follow-up period.

Adult↗
PubMedDate not supplied

[Serum status of carotenoids in control subjects and its relation to the diet].

Carotenoids are a group of fat soluble pigments which are present in the human being, both in blood, as in tissues, and which are obtained through the diet, mainly from fruits and vegetables. The interest of these compounds is due not only to the provitamin A activity of some of them, but also due to a whole series of biological activities such as: antioxidant or prooxidant, photo-protective, modulator of the immune response, anti-carcinogen, etc. The best analytical method available for the analysis of carotenoids is high performance liquid chromatography (HPLC), which is used in our study both for serum as for foods, and it is controlled throughout periodic quality controls. In this article we present the preliminary results of the levels of the major serum carotenoids (b-carotene, a-carotene, b-cryptoxanthin, lutein, zeaxanthin, and lycopene) in control subjects from five European countries, as well as indicating the major dietary contributors to the carotenoids intake in the Spanish population. The percentage of each carotenoid to the total of the carotenoids analyzed, varies according to the origin of the studied population. Ireland and the UK show a very similar carotenoids profile. France presents the highest levels of lutein and b-carotene, which are present simultaneously in green vegetables. Spain shows the lowest levels of b-carotene, along with the highest levels of b-cryptoxanthin, which in our country is supplied mainly by oranges and tangerines. The most abundant carotenoid in all countries was lycopene. The average daily intake of these carotenoids (from fresh fruits and vegetables) in our population, is 3.5 mg/day. Through the relationships between the dietary carotenoid contents and serum the identification of "biomarkers" have been proposed, which might be correlated with several pathological situations, and thus contribute to the prevention of certain diseases.

Adult↗
PubMed2007

Prospective study of vitamins C, E, and A and carotenoids and risk of oral premalignant lesions in men.

Case-control studies indicate that vitamins C, E, A and carotenoids decrease risk of oral premalignant lesions (OPLs) and oral cancer, but clinical trials have failed to find protective effects of beta-carotene and suggest that vitamin E may increase risk. The authors prospectively evaluated the association between intake of vitamins C, E, A and carotenoids and incidence of OPL. Participants were 42,340 men in the Health Professionals Follow-up Study who provided information on supplement use and diet every 2-4 years by food frequency questionnaire. The authors confirmed 207 clinically or histopathologically diagnosed OPL events occurring between 1986 and 2002 by medical record review. Multivariate-adjusted relative risks (RR) of OPL were calculated with proportional hazards models. Total intake of vitamin C, vitamin A or carotenoids was not significantly associated with OPL risk. Dietary vitamin C was significantly associated with reduced risk (quintile 5 vs. 1, RR = 0.52, 95% CI 0.31-0.85, p(trend) = 0.04), but no association with supplemental vitamin C was observed. Inverse associations were apparent for beta-cryptoxanthin and alpha-carotene intake. No clear relationship emerged with beta-carotene, lycopene or lutein/zeaxanthin. Vitamin E was associated with increased risk (quintile 5 vs. 1, RR = 1.86, 95% CI 1.06-3.19), particularly among current smokers and with supplemental intake (current-smokers, supplement dose tertile 3 vs. 1, RR = 3.07, 95% CI 1.28-7.34, p(trend) = 0.01). For current smokers, beta-carotene also increased risk. Vitamin C from dietary sources, but not supplements, was associated with a reduced risk of OPL. The observed increased risk for current smokers with high vitamin E or beta-carotene intake should be explored further.

Adult↗
PubMed2004

Effects of LDL-immunoapheresis on plasma concentrations of vitamin E and carotenoids in patients with familial hypercholesterolemia.

Recently very potent extracorporeal cholesterol-lowering treatment options have become available for patients with hypercholesterolemia. LDL immunoapheresis treatment selectively removes LDL and lipoprotein(a) from the circulation. Since LDL is the major carrier of lipophilic antioxidants in plasma, the purpose of the present study was to assess the effects of a single LDL apheresis treatment on plasma concentrations of tocopherols (alpha- and gamma-tocopherol) and carotenoids (alpha- and beta-carotene, zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, and retinol). Plasma antioxidant concentrations were determined by HPLC in 7 patients with familial hypercholesterolemia before and after LDL immunoapheresis treatment. Plasma concentrations of both alpha- and gamma-tocopherol and the different carotenoids were significantly reduced by LDL apheresis. However, when standardized for cholesterol to adjust for cholesterol removal, alpha- and gamma-tocopherol, retinol, and the more polar carotenoids lutein and zeaxanthin increased in response to apheresis treatment, while the more unpolar carotenoids such as beta-carotene and lycopene did not change. These data demonstrate that a single LDL immunoapheresis treatment affects tocopherols and individual carotenoids differently. This may be explained by differences in chemical structure and preferential association with different lipoproteins. These results further imply that tocopherols, lutein, zeaxanthin, and retinol, are associated in part with lipoproteins and other carriers such as retinol-binding protein that are not removed during apheresis treatment.

Adult↗