Macular pigment optical density and photophobia light threshold

AbstractLight absorption by macular pigment may attenuate visual discomfort, or photophobia, for targets composed of short-wavelength light. Macular pigment optical density (MPOD) and photophobia light thresholds were measured psychophysically in 10 subjects. The energy necessary to induce photophobia for a short-wavelength target relative to a long-wavelength target was linearly related to MPOD, as well as estimates of peak MPOD and integrated macular pigment. In four subjects who consumed lutein supplements, increases in MPOD corresponded to increases in photophobia light thresholds. Light absorption by macular pigment appears to influence the amount of short-wavelength light necessary to elicit photophobia

Vitamin A, carotenoid and vitamin E plasma concentrations in children from Laos in relation to sex and growth failure

BACKGROUND: Deficiencies of vitamin A and its precursors, the carotenoids are common problems in developing countries. Plasma levels of these components are used as biomarkers of their availability. The study was conducted to evaluate whether blood plasma obtained from capillaries can be compared with plasma obtained from venous blood with regard to its levels of retinol, carotenoids and α-tocopherol and secondly to apply this technique to evaluate the levels of these components in children in a region with possible deficiencies. METHODS: The survey was conducted in a region of Laos in 81 children (age 35 to 59 months). Dietary intake was assessed by a questionnaire. Retinol, carotenoids and α-tocopherol were determined by HPLC. Blood plasma was obtained either from capillary blood collected into microcapillaries and for reasons of methodological comparison in 14 adults from venous blood. RESULTS: The comparison between capillary and venous blood revealed that all components except zeaxanthin were 9 – 23 % higher in plasma obtained from capillary blood. Results in Laotian children showed that all investigated components except retinol were significantly lower (P < 0.01) compared to European children of slightly older age. Contrary to children in Europe, most components were significantly lower in boys compared to girls. In children from Laos, lutein was the dominant carotenoid, while in children in Europe, β-carotene was dominant. Within the Laotian children only a few differences were observed between stunted and non-stunted children and between children from lowland areas and high land areas. CONCLUSIONS: Results show that in consideration of slightly lower levels than in venous blood, capillary blood can be used to evaluate retinol, carotenoids and α-tocopherol as biomarkers of intake or status and to evaluate the possible effect of diet on absolute and relative carotenoid composition in children from Europe and Laos. Observed sex related differences might not be related to diet and would need further investigation

Neurodegenerative influence of oxidative stress in the retina of a murine model of diabetes

Aims/hypothesis: Diabetic retinopathy is a progressive neuro-degenerative disease, but the underlying mechanism is still obscure. Here, we focused on oxidative stress in the retina, and analysed its influence on retinal neurodegeneration, using an antioxidant, lutein. Methods: C57BL/6 mice with streptozotocin-induced diabetes were constantly fed either a lutein-supplemented diet or a control diet from the onset of diabetes, and their metabolic data were recorded. In 1-month-diabetic mice, reactive oxygen species (ROS) in the retina were measured using dihydroethidium and visual function was evaluated by electroretinograms. Levels of activated extracellular signal-regulated kinase (ERK), synaptophysin and brain-derived neurotrophic factor (BDNF) were also measured by immunoblotting in the retina of 1-month-diabetic mice. In the retinal sections of 4-month-diabetic mice, histological changes, cleaved caspase-3 and TUNEL staining were analysed. Results: Lutein did not affect the metabolic status of the diabetic mice, but it prevented ROS generation in the retina and the visual impairment induced by diabetes. ERK activation, the subsequent synaptophysin reduction, and the BDNF depletion in the diabetic retina were all prevented by lutein. Later, in 4-month-diabetic mice, a decrease in the thickness of the inner plexiform and nuclear layers, and ganglion cell number, together with increase in cleaved caspase-3- and TUNEL-positive cells, were avoided in the retina of lutein-fed mice. Conclusions/interpretation: The results indicated that local oxidative stress that has a neurodegenerative influence in the diabetic retina is prevented by constant intake of a lutein-supplemented diet. The antioxidant, lutein may be a potential therapeutic approach to protect visual function in diabetes

Genetic Variability for Lutein Concentrations in Leafy Vegetable Crops Can Influence Serum Carotenoid Levels and Macular Pigment Optical Density in Human Subjects

Leafy vegetables are important sources of dietary carotenoids and rank highest for reported lutein concentrations. We have shown previously that lutein concentrations can range from 4.8 to 13.4 mg/100 g fresh weight (FW) for kale (Brassica oleracea L.), from 6.5 to 13.0 mg/100 g FW for spinach (Spinacia oleracea L.), and from 4.1 to 8.3 mg/100 g FW for basil (Ocimum basilicum L.) cultigens. Lutein and zeaxanthin are typically the only carotenoids present in the eye, where they are responsible for the yellow pigmentation referred to as macular pigment. Macular pigment conveys antioxidant and photo-protective functions that help prevent the onset of aging eye diseases. Increasing intakes of carotenoid-rich foods can increase serum carotenoids and macular pigment in some, but not all individuals. Our main objective was to assess the dietary impact of lutein after consumption of spinach differing in tissue lutein concentrations (8.4 vs. 12.1 mg lutein/100 g FW). Research compared blood serum carotenoid profiles and macular pigment optical densities (MPOD) in human subjects consuming the different spinach products. Heterochromatic flicker photometry determined MPOD responses. Average blood serum lutein concentrations increased significantly from the baseline to the end of a 12-week intervention in subjects consuming the high-lutein spinach. Average MPOD did not change for the no-spinach (control) or low-lutein spinach group. The high-lutein spinach group demonstrated increases in MPOD at 30’ eccentricity between the baseline and 12-weeks. Results emphasize the role of cultigen selection among vegetable crops in determining phytochemical effects on human health

The Journal of Nutrition Nutrient Requirements and Optimal Nutrition A 12-Wk Egg Intervention Increases Serum Zeaxanthin and Macular Pigment Optical Density in Women 1

Abstract Two carotenoids found in egg yolk, lutein and zeaxanthin, accumulate in the macular retina where they may reduce photostress. Increases in serum lutein and zeaxanthin were observed in previous egg interventions, but no study measured macular carotenoids. The objective of this project was to determine whether increased consumption of eggs would increase retinal lutein and zeaxanthin, or macular pigment. Twenty-four females, between 24 and 59 y, were assigned to a pill treatment (PILL) or 1 of 2 egg treatments for 12 wk. Individuals in the PILL treatment consumed 1 sugar-filled capsule/ d. Individuals in the egg treatments consumed 6 eggs/wk, containing either 331mg (EGG 1) or 964 mg (EGG 2) of lutein and zeaxanthin/yolk. Serum cholesterol, serum carotenoids, and macular pigment OD (MPOD) were measured at baseline and after 4, 8, and 12 wk of intervention. Serum cholesterol concentrations did not change in either egg treatment group, but total cholesterol (P ¼ 0.04) and triglycerides (P ¼ 0.02) increased in the PILL group. Serum zeaxanthin, but not serum lutein, increased in both the EGG 1 (P ¼ 0.04) and EGG 2 (P ¼ 0.01) groups. Likewise, MPOD increased in both the EGG 1 (P ¼ 0.001) and EGG 2 (P ¼ 0.049) groups. Although the aggregate concentration of carotenoid in 1 egg yolk may be modest relative to other sources, such as spinach, their bioavailability to the retina appears to be high. Increasing egg consumption to 6 eggs/wk may be an effective method to increase MPOD

Spinach Cultigen Variation for Tissue Carotenoid Concentrations Influences Human Serum Carotenoid Levels and Macular Pigment Optical Density Following a 12-Week Dietary Intervention

Increasing intakes of carotenoid-rich plant foods can increase serum carotenoid concentrations and macular pigment optical density (MPOD) in most, but not all, individuals. Research objectives for this study were to (1) characterize tissue lutein (L) and β-carotene (BC) concentrations in carotenoid-rich spinach (Spinacia oleracea L.) cultigens and (2) determine serum carotenoid and MPOD responses in human subjects consuming spinach cultigens differing in tissue L and BC concentrations. Thirteen spinach cultigens were evaluated for carotenoid accumulations over two consecutive growing seasons. ‘Springer\u27 (8.4 and 6.5 mg/100 g of fresh mass for L and BC, respectively) and ‘Spinner\u27 (12.1 and 9.2 mg/100 g of fresh mass for L and BC, respectively) spinach cultigens were selected for a dietary intervention study and represented low- and high-L concentrations. The high-L (‘Spinner\u27) and low-L (‘Springer\u27) spinach treatment groups consisted of 10 subject volunteers ingesting five 50-g spinach servings/week during a 12-week intervention. Average serum L concentrations increased by 22% (P = 0.07) from baseline (0.233 μmol/L) to 12 weeks (0.297 μmol/L) for subjects consuming low-L spinach. Subjects consuming high-L spinach showed increases of 33% (P = 0.04) in serum L from baseline (0.202 μmol/L) to 12 weeks (0.300 μmol/L). Average MPOD did not change for the low-L treatment group; however, subjects in the high-L group demonstrated increases (P = 0.02) in MPOD at the 30‘ eccentricity between baseline (0.343) and 12 weeks (0.374). This study demonstrates that serum carotenoid and MPOD are determined by L concentrations present in the spinach matrix. Results emphasize the role of cultigen selection among vegetable crops in determining phytochemical effects on human health

Dietary intake and serum concentrations of lutein and zeaxanthin, but not macular pigment optical density, are related in spouses

Lutein and zeaxanthin, 2 carotenoids obtained from the diet, accumulate in the central retina where they are collectively called macular pigment. Although dietary intake of these carotenoids is directly related to tissue concentration, several factors, such as body mass index, appear to indirectly affect macular pigment concentrations. Individuals who consume similar diets and share factors that affect macular pigment, such as married couples, may have similar macular pigment levels. The purpose of this study was to investigate the relatedness of dietary, serum, and retinal concentrations of lutein and zeaxanthin in married couples. Fifty participants, 25 male-female married couples, between 29 and 70 years of age participated in the study. Fruit and vegetable consumption as well as dietary intakes of macronutrients and carotenoids were assessed by a dietary questionnaire. Cholesterol concentrations were measured with reflectance photometry, and serum carotenoid concentrations were determined with high-performance liquid chromatography. Retinal carotenoids, defined as macular pigment optical density (MPOD), were measured by heterochromatic flicker photometry at 4 retinal loci. Dietary intake of lutein and zeaxanthin in the sample was related to serum lutein and zeaxanthin concentrations (P =.01). Both dietary intake (P =.04) and serum concentrations (P =.003) of lutein and zeaxanthin were significantly related to MPOD at 30 \u27 eccentricity. Wives\u27 dietary intake (P =.016) and serum concentrations (P \u3c.001) of lutein and zeaxanthin were linearly related with the husbands\u27. Married couples\u27 MPOD, however, was not related at any retinal locus. Despite similar dietary intakes and serum concentrations of lutein and zeaxanthin, husbands and wives, unexpectedly, did not have similar MPOD. Factors such as lipoprotein concentrations and genes, which are not shared by spouses, appear to influence MPOD more than factors such as diet and body mass index, which are concordant in spouses. (c) 2007 Elsevier Inc. All rights reserved