This finding is consistent with a report that both supine and standing HRs were significantly increased 1h and 3h after a 790 kcal meal in the morning after an overnight fast. However, the calorie content in mango and white bread in this current study was only 298 kcal. Studies regarding the consumption of fruits and postprandial BP and HR are scarce. Future research is encouraged to investigate whether fruit intake will induce similar hemodynamics as meals. In study I, the 2h change in blood glucose was not different between mango or no mango intake, despite the difference in sugar intake from the fruit. This observation was reinforced further in study II, where the blood glucose was significantly increased 1h after white bread intake but not after eating an isocalorically-matched amount of mango. The insulin level was also significantly increased 1h after white bread intake compared to 1h after no mango or mango intake. In addition, although the 2h change in blood glucose after eating white bread returned to a level similar to baseline values, the 2h change of insulin was still significantly elevated compared to the 2h value seen in the no mango group. These data are consistent with other reports regarding mango consumption and glucose regulation. For example, in obesity-prone mice fed a high-fat diet, dutch bucket hydroponic the fasting blood glucose, insulin, and homeostatic model assessment for insulin resistance score were significantly decreased after 10 weeks of mango fruit powder intake ateach of three levels .

In obese male C57BL/6J mice consuming a high-fat diet, daily supplementation freeze-dried mango at either 1% or 10% of the weight of the diet significantly reduced body fat compared to those consuming a non-supplemented control diet. Curiously, only the 1% mango group showed significantly decreased fasting blood glucose and postprandial blood glucose responses after tolerance tests, but no difference was noted for insulin or HOMA-IR, compared to those consuming the 10% supplementation or control diets.30 In overweight and obese humans, plasma insulin was significantly increased 45 min after consuming 100 kcal of mango , compared to their baseline levels, but did not increase as much as when the participants consumed an to isocaloric low-fat cookie. The same study also noted that capillary blood glucose levels were significantly elevated 30 min after mango intake compared to their baseline values, while returning to the baseline range at 60, 90, or 120 min after intake, whereas intake of the low-fat cookie showed significantly increased blood glucose at both 30 and 60 min, which is consistent with trends from our study. However, the above study measured insulin at baseline and 45 min after food intake, so the postprandial insulin levels cannot be compared directly with our study. Future research may consider assessing the association between postprandial BP, glucose, and insulin resistance at multiple time points. This study has several limitations. The Ataulfo mangos were not analyzed for nutrients or phenolic contents. Different mango cultivars vary in macronutrients, micronutrients, as well as phytonutrient content.

Among commonly consumed mango cultivars, Ataufo mango pulp contains the highest concentration of β-carotene, ascorbic acid, total phenolics, gallotannins, and mangiferin, in comparison to Haden, Keitt, Kent, and Tommy Atkins. The high concentrations were used in the selection of Ataulfo. The amount of white bread as an isocaloric control was calculated based on the USDA food database, which does not identify the cultivar or cultivars that were tested. Finally, the postprandial blood glucose and insulin responses in study II were not measured at 30 min, which may have missed the possible peak levels. Future studies may take the measurements at more frequent time points, as well as insulin resistance indicators, such as HOMA-IR, to better understand the role of mango in blood glucose management. In conclusion, two weeks of daily mango intake was associated with a decrease in SBP and PP. The glucose and insulin responses after mango intake were also moderated, compared to ingesting of an isocaloric amount of white bread. While the effects of mango intake on microvascular function were not as significant as the response from other whole foods, other measures of cardiovascular health, as well as glucoregulatory benefits, warrant further study.Epidemiological studies suggest that diets rich in carotenoids can be beneficial for vision, heart, bone health, cognitive performance, and cancer prevention. The current review focuses on the potential role of the xanthophyll carotenoids lutein and zeaxanthin in eye health, specifically their potential role in reducing risk of age-related macular degeneration .

We review the absorption, distribution, and metabolism of L and Z, and the current dietary recommendations for these carotenoids, then speculate about their putative role in maternal and infant health. Lastly, we discuss the potential value of goji berry within the diet as a food with the highest known amount of Z. Carotenoids contribute to the bright red, orange, and yellow color in plants. These fat-soluble phytochemicals are classified into two categories: carotenes, which include only hydrocarbons, and xanthophylls that also contain oxygen. While some dietary carotenoids serve as vitamin A precursors most of the approximately 100 carotenoids found in plants do not. Among the carotenoids devoid of vitamin A activity are L and Z, along with meso-zeaxanthin , a stereoisomeric metabolite of L. Absorption involves enterocyte uptake by CD36, scavenger receptor class B type I , and Niemann-Pick C1-like transporter 1 at the apical membrane. Xanthophylls are then secreted through the basolateral membrane of the enterocyte, mainly by ATP binding cassette A1 and carried by lipoproteins to target tissues. SR-B1, SR-B2, and CD36 transport L and Z into the tissues. Steroidogenic acute regulatory domain protein 3 has been identified as a binding protein for L in the retina, and glutathione S-transferase pi isoform for Z. Lutein, Z, and meso-Z impart a distinctive yellow color to the fovea of primates – the specialized central area of the macular region of the retina that is rich in cone photoreceptors and optimized for high-acuity central color vision. The compounds have a maximal absorbance at a wavelength near 460 nm and are most concentrated in the inner and outer plexiform layers, which consists primarily of axonal connections between the retinal layers. Their combined density is greatest in the center of the macula and decreases with increasing retinal eccentricity. In the central fovea, the concentration of Z and meso-Z is higher than L at a ratio of 2.4:1. Lutein is most abundant in the peripheral macula, with a Z + meso-Z to L ratio of 1:2 when measured by high performance liquid charomatography. However, a newer technique, confocal resonance Raman microscopy suggests that the Z + meso-Z to L ratio is as high as 9:1 at the central fovea.16 Protection from blue light is critical for eye health. Compared to longer wavelengths of visible light, short blue wavelengths are higher in energy and generate reactive oxygen species . Zeaxanthin can provide stronger oxidant defense than L during photooxidation, while lutein has a greater capacity to absorb short wavelength light irradiation in lipid membranes. Compared to other carotenoids , L and Z are more effective in scavenging ROS and can also reduce phospholipid peroxidation. The photoreceptor-retinal pigment epithelium complex in the outer retina is particularly susceptible to ROS damage due to its high polyunsaturated lipid content . Quenching of singlet oxygen appeared best when L, Z, and meso-Z were mixed in equal ratios rather than separately when assessed in an eye tissue model, suggesting some synergy between the these macular pigments in their antioxidant properties. The most common method to quantify xanthophylls in the retina is to assess macular pigment optical density . This parameter is measured through techniques such as heterochromatic flicker photometry , a non-invasive psychophysical technique, fundus reflectometry, resonance Raman spectroscopy, or autofluorescence imaging. The MPOD index is associated with plasma levels of L and Z, and has been used to assess the risk for AMD. However, some studies report no correlation between MPOD and risk of AMD,31 which suggests that other ocular measures may be useful to obtain a more complete profile of AMD risk. In human donor eyes, dutch buckets system the amount of L and Z was inversely associated with AMD. Supplementation of L, Z, and meso-Z have been shown to significantly increase MPOD in both healthy individuals and patients diagnosed with AMD. However, studies using foods rich in L and Z have produced inconsistent results, which may be due to the relatively modest amounts of these carotenoids in foods compared to supplements.

Importantly, the plasma concentration of L and Z has been more strongly associated with MPOD than the correlation between MPOD and dietary intake. Age-related macular degeneration is the third leading cause of blindness worldwide after uncorrected refractive errors and cataracts. An estimated 288 million people worldwide are projected to suffer from AMD by 2040. In the United States, the prevalence of early-stage AMD was 9.1 million in 2010, and this number is projected to increase to 17.8 million by 2050. AMD is characterized by a gradual loss of eyesight from the central visual field. Although the exact etiology of AMD is not clear, common pathologic progress includes oxidative stress, lipofuscin toxicity, lipid accumulation, immune dysregulation, and choroidal hyperperfusion. Age-related processes such as a decrease in retinal neuronal elements, alterations in the size and shape of RPE cells, and thickening of Bruch’s membrane also participate in the pathology of AMD. Damage to mitochondria in RPE cells has also been suggested to play a role. Dry AMD, also termed non-exudative AMD, involves the formation of drusen, which are mainly lipid and protein deposits that accumulate between the RPE and Bruch’s membrane in the macula. In contrast, wet AMD, also termed exudative or neovascular AMD, is a consequence of abnormal blood vessel formation arising from the choroid, known as choroidal neovascularization . Clinically, AMD is classified as early or intermediate stage based on the size and number of drusen, as well as presence of pigmentary changes. The AMD is considered late or advanced stage in the presence of CNV, where fluid accumulation may result in damage to the neurosensory retina and fibrous scarring, or geographic atrophy , where loss of the RPE result in damage to overlying photoreceptors and underlying choriocapillaris causing irreversible vision loss. The main risk factors for AMD are aging and smoking, although some studies have shown no difference in MPOD between healthy older individuals and healthy young. Other risk factors may include race, obesity, previous cataract surgery, presence of cardiovascular disease, and hypertension. According to the U.S. National Institutes of Health, the prevalence of AMD is highest among Caucasians as compared to other races, and higher in females than in males. Genetic factors are also associated with AMD, with several high-risk single-nucleotide polymorphisms identified from genome wide association studies. The strongest risk variants include the Y402H variant of complement factor H gene as well as those in the age-related maculopathy susceptibility 2 locus. Whether the color of the iris or sunlight exposure are related to the risk of AMD is still being explored. Dietary interventions using L- and Z-rich foods have generated inconsistent results regarding the risk of AMD. In a cohort study that assessed dietary carotenoid consumption among individuals without AMD at baseline over more than 20 years, increased predicted plasma carotenoid score of L, Z, β-carotene, α-carotene and β-cryptoxanthin were associated with a lower risk of advanced, but not early or intermediate AMD. Similarly, a meta-analysis of six longitudinal cohort studies found that the dietary intake of L and Z significantly reduced the risk of GA by 26% and CNV by 32%, with no apparent impact on early stages. Another metaanalysis concluded that supplementation with L, Z, and meso-Z significantly increased MPOD levels in both AMD patients and healthy individuals in a dose-response manner. However, whether the improvement in MPOD could be sustained after L and Z supplementation is discontinued remains unclear. The Age-Related Eye Disease Study was a multi-center study that assessed the efficacy of a dietary anti-oxidant supplements on subjects who are 50 to 80 years old, with and without AMD or cataracts, for more than seven years. The initial study used a formula containing 15 mg of β-carotene, 500 mg of vitamin C, 400 IU of vitamin E, with or without 80 mg of zinc and 2 mg of copper. Lutein and Z were not included because the scientific evidence to include these two carotenoids was not yet clear.