top Clinical Studies References
The macular pigment of the eye is rich in carotenoids, primarily Lutein and Zeaxanthin. In fact macular pigment is mostly Lutein and Zeaxanthin, two substances that act as antioxidants. This means that they fight free radicals. By increasing dietary intake of Zeaxanthin combined with Lutein you may minimize the risk of developing age-related macular degeneration. It seems that adding these specific nutrients to your meals may not only sidestep macular damage by free radicals, but also strengthen macular tissue.
Published Clinical Studiesclin
1 Plasma antioxidants are similarly depleted in mild cognitive impairment and in Alzheimer's disease.
Rinaldi P, Polidori MC, Metastasio A, Mariani E, Mattioli P, Cherubini A, Catani M, Cecchetti R, Senin U, Mecocci P.
Department of Gerontology and Geriatrics, University of Perugia, Policlinico Monteluce-Pad. E, Via Brunamonti 51, 06126 Perugia, Italy.
In order to assess peripheral levels and activities of a broad spectrum of non-enzymatic and enzymatic antioxidants in elderly subjects with mild cognitive impairment (MCI) and Alzheimer's disease (AD), plasma levels of water-soluble (Vitamin C and uric acid) and of lipophilic (Vitamin A, Vitamin E and carotenoids including lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha- and beta-carotene) antioxidant micronutrients as well as activities of plasma and red blood cell (RBC) superoxide dismutase (SOD) and of plasma glutathione peroxidase (GPx) were measured in 25 patients with MCI, 63 AD patients and 53 controls. Peripheral levels and activities of antioxidants were similarly lower in MCI and AD patients as compared to controls. As MCI may represent a prodromal stage of AD, and oxidative damage appears to occur as one of the earliest pathophysiological events in AD, an increased intake of antioxidants in patients with MCI could be helpful in lowering the risk of conversion to dementia.
Publication Types:
PMID: 12928050 [PubMed - indexed for MEDLINE]
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Lutein and zeaxanthin status and risk of age-related macular degeneration.2
Gale CR, Hall NF, Phillips DI, Martyn CN.
Medical Research Council Environmental Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, United Kingdom. crg@mrc.soton.ac.uk
PURPOSE: To investigate the relation between plasma concentrations of lutein and zeaxanthin and age-related macular degeneration in a group of elderly men and women. METHODS: The Wisconsin Age-Related Maculopathy Grading System was used to grade features of early and late macular degeneration in 380 men and women, aged 66 to 75 years, from Sheffield, United Kingdom. Fasting blood samples were taken to assess plasma concentrations of lutein and zeaxanthin. RESULTS: Risk of age-related macular degeneration (early or late) was significantly higher in people with lower plasma concentrations of zeaxanthin. Compared with those whose plasma concentrations of zeaxanthin were in the highest third of the distribution, people whose plasma concentration was in the lowest third had an odds ratio for risk of age-related macular degeneration of 2.0 (95% confidence interval [CI] 1.0-4.1), after adjustment for age and other risk factors. Risk of age-related macular degeneration was increased in people with the lowest plasma concentrations of lutein plus zeaxanthin (odds ratio [OR] 1.9, 95% CI 0.9-3.5) and in those with the lowest concentrations of lutein (OR 1.7, 95% CI 0.9-3.3), but neither of these relations was statistically significant. CONCLUSIONS: These findings provide support for the view that zeaxanthin may protect against age-related macular degeneration.
PMID: 12766044 [PubMed - indexed for MEDLINE]
Are lutein and zeaxanthin conditionally essential nutrients for eye health?3
Semba RD, Dagnelie G.
Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. rdsemba@jhmi.edu
The carotenoids lutein and zeaxanthin are found in the macula in high concentrations and may play a role in the pathogenesis of age-related macular degeneration (ARMD). Lutein and zeaxanthin may protect the macula and photoreceptor outer segments throughout the retina from oxidative stress and play a role in an antioxidant cascade that safely disarms the energy of reactive oxygen species. Although lutein and zeaxanthin are not essential nutrients, studies are beginning to suggest that they fit the criteria for conditionally essential nutrients. Low plasma lutein and zeaxanthin concentrations or dietary intake are associated with low macular pigment density and increased risk of ARMD. Dietary deprivation of lutein and zeaxanthin in primates causes pathological changes in the macula. Should controlled clinical trials show lutein and/or zeaxanthin supplementation protects against the development or progression of ARMD and other eye diseases, then lutein and zeaxanthin could be considered as conditionally essential nutrients for humans.
PMID: 13679014 [PubMed - in process]
Serum vitamins and the subsequent risk of bladder cancer.4
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.5
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]
6 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]
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