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Clinical Studies
References
Lutein (and also Zeaxanthin) is an antioxidant in the carotenoid family (a group of naturally occurring fat-soluble pigments found in plants). It may be beneficial in macular degeneration and cataracts, and may offer protection against cancer and degeneration of the eyes and skin by sunlight.
Published Clinical Studiesclin
Serum vitamins and the subsequent risk of bladder cancer.1
Nomura AM, Lee J, Stemmermann GN, Franke AA.
Japan-Hawaii Cancer Study, Kuakini Medical Center, Honolulu, USA.
PURPOSE: We determined whether serum vitamins are inversely related to bladder cancer risk. MATERIALS AND METHODS: A cohort of 9,345 Japanese-American men was examined from 1971 to 1977. At examination a blood specimen was obtained and the serum was frozen. After a surveillance period of more than 20 years 111 tissue confirmed incident cases of bladder cancer were identified. Stored serum and that of 111 age matched controls were tested by high pressure liquid chromatography for certain micronutrients, including lutein, zeaxanthin, anhydrolutein, alpha-cryptoxanthin, beta-cryptoxanthin, lycopene, dihydrolycopene, alpha-carotene, beta-carotene, total carotenoids, retinol, alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol and total tocopherols. RESULTS: Based on quartiles of serum micronutrient levels the ORs for bladder cancer were determined using the general estimating equations approach. There were statistically significant inverse linear trends in risk for alpha-carotene (p <0.01), beta-carotene (p = 0.03), lutein plus zeaxanthin (p = 0.03), beta-cryptoxanthin (p = 0.04) and total carotenoids (p = 0.02). However, after adjustment for pack-years of cigarette smoking none of the inverse trends remained significant. CONCLUSIONS: These results suggest that cigarette smoking, which is a strong risk factor for bladder cancer, may explain the apparent protective effect of individual and total carotenoids against this common cancer.
PMID: 14501712 [PubMed - indexed for MEDLINE]
Dietary carotenoid intake as a predictor of bone mineral density.2
Wattanapenpaiboon N, Lukito W, Wahlqvist ML, Strauss BJ.
Asia Pacific Health and Nutrition Centre, Monash Asia Institute, Monash University, Melbourne, VIC, Australia. tikky.w@adm.monash.edu.au
Our understanding of the influence of nutrition on bone health is limited because most studies concentrate on the role of calcium and protein, while other nutrients receive less attention. Recent evidence shows a positive link between fruit and vegetable consumption and bone health. In the present study, the relationships of dietary intakes of preformed retinol and carotenoids, one group of phytonutrients abundant in fruit and vegetables, were examined in an Anglo-Celtic Australian population of 68 men and 137 women. Bone mass of total body and lumbar spine were positively related to lycopene intake in men, and to lycopene and lutein/zeaxanthin intake in premenopausal women. In addition, a positive association of lumbar spine bone mass with dietary beta-carotene intake was observed in postmenopausal women. No relationship was found between dietary retinol intake and bone mineral status. The finding of the present study suggests a beneficial effect of fruit and vegetable consumption, as indicated by dietary carotenoid intake, on bone health, possibly via an antioxidant mechanism.
PMID: 14672872 [PubMed - in process]
3
Progression of Carotid Intima-Media Thickness and Plasma Antioxidants: The Los Angeles Atherosclerosis Study.
Dwyer JH, Paul-Labrador MJ, Fan J, Shircore AM, Merz CN, Dwyer KM.
Keck School of Medicine of the University of Southern California, Department of Preventive Medicine, Los Angeles, CA; Division of Cardiology, Department of Preventive Medicine, Cedars-Sinai Research Institute, Cedars-Sinai Medical Center and University of California at Los Angeles, CA.
OBJECTIVE: Recent epidemiologic and animal model data suggest that oxygenated carotenoids are protective against early atherosclerosis. We assessed the association between atherosclerotic progression, measured by carotid intima-media thickness (IMT), and plasma levels of oxygenated and hydrocarbon carotenoids, tocopherols, retinol, and ascorbic acid. METHODS AND RESULTS: Participants were from an occupational cohort of 573 middle-aged women and men who were free of symptomatic cardiovascular disease at baseline. Ultrasound examination of the common carotid arteries, lipid level determination, and risk factor assessment were performed at baseline and 18-month follow-up. Plasma levels of antioxidants were determined at baseline only. Change in IMT was related to baseline plasma antioxidant levels in regression models controlling for co-variates. In models adjusted for age, sex, and smoking status, 18-month change in IMT was significantly inversely related to the 3 measured oxygenated carotenoids (lutein, beta-cryptoxanthin, zeaxanthin; P<0.02 for all) and one hydrocarbon carotenoid, alpha-carotene (P=0.003). After adjusting for additional cardiac risk factors and potential confounders, including high-sensitivity C-reactive protein, these associations remained significant (P<0.05). CONCLUSIONS: These findings suggest that higher levels of plasma oxygenated carotenoids (lutein, zeaxanthin, beta-cryptoxanthin) and alpha-carotene may be protective against early atherosclerosis.
PMID: 14656738 [PubMed - as supplied by publisher]
C-reactive protein concentration and concentrations of blood vitamins, carotenoids, and selenium among United States adults.
Ford ES, Liu S, Mannino DM, Giles WH, Smith SJ.
Division of Environmental Hazards and Health Effects, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA, USA. esf2@cdc.gov
OBJECTIVE: To examine the relationships between circulating concentrations of C-reactive protein and concentrations of retinol, retinyl esters, vitamin C, vitamin E, carotenoids, and selenium. DESIGN: Cross-sectional study using National Health and Nutrition Examination Survey III (1988-1994) data. SETTING: United States population. SUBJECTS: Up to 14 519 US noninstitutionalized civilian men and women aged > or=20 y. RESULTS: C-reactive protein concentration (dichotomized at the sex-specific 85th percentile) was inversely and significantly associated with concentrations of retinol, retinyl esters, vitamin C, alpha-carotene, beta-carotene, cryptoxanthin, lutein/zeaxanthin, lycopene, and selenium after adjustment for age, sex, race or ethnicity, education, cotinine concentration, body mass index, leisure-time physical activity, and aspirin use. CONCLUSIONS: These results suggest that the inflammatory process, through the production of reactive oxygen species, may deplete stores of antioxidants. Whether increased consumption of foods rich in antioxidants or supplementation with antioxidants can provide health benefits to people characterized by elevated C-reactive protein concentrations may be worthy of further study.
PMID: 12947436 [PubMed - in process]
Non-nutritive bioactive constituents of plants: lycopene, lutein and zeaxanthin.5
Sies H, Stahl W.
Institut fur Physiologische Chemie I, Heinrich-Heine-Universitat Dusseldorf, P.O. Box 10 10 07, D-40001 Dusseldorf, Germany. sies@uni-duesseldorf.de
Lycopene, lutein, and zeaxanthin are major carotenoids in human blood and tissues but unlike beta-carotene do not contribute to vitamin A supply. These carotenoids are efficient antioxidants quenching singlet molecular oxygen which is formed in photooxidative processes and thus may contribute to the prevention of light-exposed tissue, skin and eyes, from light-induced damage. Increasing lycopene intake by daily consumption of tomato paste over a period of ten weeks provides protection against erythema formation following UV-irradiation. Lycopene and other carotenoids may be used as oral sun protectants and contribute to the maintenance of skin health. The yellow color of the macula lutea is due to the presence of the carotenoid pigments lutein and zeaxanthin. These macula carotenoids are suggested to play a role in protection against light-dependent damage. Filtering of blue light and scavenging of reactive intermediates generated in photooxidation are considered to be the underlying protective mechanisms. Epidemiological studies provide evidence that an increased consumption of lutein is associated with a lowered risk for age-related macular degeneration, a disease with increasing incidence in the elderly.
Publication Types:
PMID: 12747216 [PubMed - indexed for MEDLINE]
6
Dietary lutein/zeaxanthin decreases ultraviolet B-induced epidermal hyperproliferation and acute inflammation in hairless mice.
Gonzalez S, Astner S, An W, Goukassian D, Pathak MA.
Wellman Laboratories of Photomedicine, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA. sgonzalez3@partners.org
Lutein and zeaxanthin are carotenoids found in green leafy vegetables with interesting antioxidant properties. They are present in high concentrations in the fovea centralis of the human retina and their role in the prevention of age-related macula degeneration has been reported. We have investigated the effect of orally administered lutein and zeaxanthin in the cutaneous response to ultraviolet B irradiation. Female hairless SKh-1 mice receiving 0.4% and 0.04% lutein plus zeaxanthin-enriched diet for 2 wk were exposed to single doses of ultraviolet B radiation. Skin biopsies were taken at 24 and 48 h after irradiation and analyzed for the presence of apoptotic cells, proliferating cells, and expression of proliferating cell nuclear antigen. Our results show a clear ultraviolet-induced dose-dependent inflammatory response. Orally administered 0.4% lutein and zeaxanthin decreased significantly the edematous cutaneous response (p<0.01) as determined by the reduction of the UVB-induced increase of ear bifold thickening. Additionally, dietary carotenoids were efficient in reducing the ultraviolet B-induced increases in the percentage of proliferating cell nuclear antigen (p<0.05), bromodeoxyuridine (p<0.05), and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling-positive cells (p<0.01). These data demonstrate that oral supplementation of lutein and zeaxanthin diminishes the effects of ultraviolet B irradiation by reducing acute inflammatory responses and ultraviolet-induced hyperproliferative rebound.
PMID: 12880433 [PubMed - indexed for MEDLINE]
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