A prospective study of carotenoid and vitamin A intakes and risk of cataract extraction in US women

The influence of the macular carotenoids on women's eye and brain health

Introduction: The mortality-morbidity paradox refers to the inconsistency in survival and disease between males and females: females live longer but tend to suffer greater age-related disease and disability. Many aspects of the latter can be targeted by lifestyle interventions, such as changes in dietary behavior.Methods: The relevant literature is reviewed.Conclusion: Dietary intake of the pigmented carotenoids appears to be particularly important for issues such as visual and cognitive loss. This may be due to the highly selective presence of a fraction of carotenoids, namely lutein (L) and zeaxanthin (Z), in specific tissues of the eye and brain. At those sites, L and Z have been shown to directly improve function and prevent central nervous system degeneration. On the palliative side, retinal LZ reduce glare disability, discomfort and photostress, improve chromatic contrast and visual range (e.g., the ability to see through blue atmospheric haze). These effects on input reflect changes in neural output such as improved visual processing speed, problem solving, memory and executive function (presumably due, also, to local effects in areas such as the hippocampus and frontal cortex). These effects on function throughout the central nervous system are mirrored by effects on disease progression. As potent antioxidants/anti-inflammatory agents, and "blue-blockers" within the retina, the pigments prevent loss that precedes neurodegenerative diseases such as age-related macular degeneration and some forms of dementia.

Nutritional Properties of Ogi Powder and Sensory Perception of Ogi Porridge Made From Synthetic Provitamin: A Maize Genotype

Provitamin-A maize (PVA) with increased carotenoid content obtained through conventional breeding techniques has been largely successful in sub-Saharan Africa. This resulted in a need to evaluate their susceptibility, retention, and nutritional content during processing into local foods. This study evaluated the chemical, carotenoid composition, and retention of PVA, the phytic acid content in ogi powder, and the sensory perception of ogi porridge produced traditionally from the three novel PVA maize genotypes (PVA SYN HGAC0 Maize 1; PVA SYN HGBC0 Maize 2; and PVA SYN HGBC1 Maize 3) and one yellow maize variety (control). Chemical composition analyses showed significant differences (p < 0.05) in all parameters. The PVA ranged from 5.96 to 8.43 μg/g in Maize 2 and 3 before processing while the true percentage retention after processing into ogi powder ranged from 20.25 to 37.54% in Maize 1 and 2, respectively. In addition, there was a reduction in the phytate content of ogi powder, and Maize 2 contained the lowest (2.78 mg/g from 4.09 mg/g). Maize 2 genotype had the highest vitamin A contribution; it can meet 18.3% of the vitamin A requirements in children while in adult males and females (>19 years), 6.2 and 7.7%, respectively. Sensory evaluation showed that the ogi 3 porridge (Maize 3) was the most acceptable, followed by Maize 2. In conclusion, Maize 2 had the highest PVA, true retention of carotenoid, vitamin A contributions, and the second most acceptable ogi porridge with the lowest phytate content.

A Mechanistic Review of β-Carotene, Lutein, and Zeaxanthin in Eye Health and Disease

Carotenoids are natural lipid-soluble antioxidants abundantly found as colorful pigments in fruits and vegetables. At least 600 carotenoids occur naturally, although about 20 of them, including β-carotene, α-carotene, lycopene, lutein, zeaxanthin, meso-zeaxanthin, and cryptoxanthin, are detectable in the human blood. They have distinct physiological and pathophysiological functions ranging from fetal development to adult homeostasis. β-carotene is a precursor of vitamin A that essentially functions in many biological processes including vision. The human macula lutea and eye lens are rich in lutein, zeaxanthin, and meso-zeaxanthin, collectively known as macular xanthophylls, which help maintain eye health and prevent ophthalmic diseases. Ocular carotenoids absorb light from the visible region (400-500 nm wavelength), enabling them to protect the retina and lens from potential photochemical damage induced by light exposure. These natural antioxidants also aid in quenching free radicals produced by complex physiological reactions and, consequently, protect the eye from oxidative stress, apoptosis, mitochondrial dysfunction, and inflammation. This review discusses the protective mechanisms of macular xanthophylls in preventing eye diseases such as cataract, age-related macular degeneration, and diabetic retinopathy. Moreover, some preclinical animal studies and some clinical trials are discussed briefly to understand carotenoid safety and efficacy.

Construction of a pathway to C50-ε-carotene

Substrate tolerance of bacterial cyclases has been demonstrated in various contexts, but little is known about that of plant cyclases. Here, we tested two plant ε-cyclases to convert C₅₀-lycopene, which we previously established by rounds of directed evolution. Unlike bacterial β-cyclases, two-end cyclase from lettuce exhibited complete specificity against this molecule, indicating that this enzyme has some mechanism that exerts size-specificity. Arabidopsis one-end cyclase At-y2 showed detectable activity to C₅₀-lycopene. Interestingly, we found that it functions as a two-end cyclase in a C₅₀ context. Based on this observation, a possible model for substrate discrimination of this enzyme is proposed.

Health Benefits of Polyphenols and Carotenoids in Age-Related Eye Diseases

Oxidative stress and inflammation play a critical role in the initiation and progression of age-related ocular abnormalities as cataract, glaucoma, diabetic retinopathy, and macular degeneration. Therefore, phytochemicals with proven antioxidant and anti-inflammatory activities, such as carotenoids and polyphenols, could be of benefit in these diseases. We searched PubMed and Web of Science databases for original studies investigating the benefits of different carotenoids and polyphenols in age-related ophthalmic diseases. Our results showed that several polyphenols (such as anthocyanins, Ginkgo biloba, quercetin, and resveratrol) and carotenoids (such as lutein, zeaxanthin, and mezoxanthin) have shown significant preventive and therapeutic benefits against the aforementioned conditions. The involved mechanisms in these findings include mitigating the production of reactive oxygen species, inhibiting the tumor necrosis factor-α and vascular endothelial growth factor pathways, suppressing p53-dependent apoptosis, and suppressing the production of inflammatory markers, such as interleukin- (IL-) 8, IL-6, IL-1a, and endothelial leucocyte adhesion molecule-1. Consumption of products containing these phytochemicals may be protective against these diseases; however, adequate human data are lacking. This review discusses the role and mechanisms of polyphenols and carotenoids and their possible synergistic effects on the prevention and treatment of age-related eye diseases that are induced or augmented by oxidative stress and inflammation.

Coffee brew intake can prevent the reduction of lens glutathione and ascorbic acid levels in HFD-fed animals

The lens has high concentrations of glutathione (GSH) and ascorbic acid (AsA) to maintain redox activity and prevent cataract formation, which is the leading cause of visual impairment worldwide. Metabolic syndrome is reported to be linked with a higher risk of age-associated cataract. As it was demonstrated previously that coffee consumption improved high-fat diet (HFD) -induced metabolic symptoms, it was hypothesized that coffee intake could delay the onset of obesity related-cataract; however, the effect of coffee consumption on this type of cataract remains unknown. Four-week-old male C57BL/6JJms SLC mice were divided into two groups and were provided ad libitum access to either a control diet (control groups) or a HFD (HFD groups). The control groups and HFD groups were further divided into three or four subgroups for each experiment. Coffee intake markedly reduced the increase in body weight in a roasting-time and concentration-dependent manner. Coffee consumption also prevented the HFD-induced decrease in the concentration of GSH and AsA, and treatment with pyrocatechol or caffeine also restored the reduction of antioxidant compounds. Plasma cholesterol and triglycerides were significantly higher in HFD groups; however, coffee brew or coffee constituent treatment in the HFD-fed mice group prevented elevation of these levels. Caffeine is a major coffee component and pyrocatechol is generated thought the roasting process. These results revealed that caffeine and pyrocatechol in coffee brew may be the key constituents responsible for preventing the reduction of lens GSH and AsA in HFD-fed animals.

Dietary vitamin and carotenoid intake and risk of age-related cataract

Background

Existing studies suggest that dietary vitamins and carotenoids might be associated with a reduced risk of age-related cataract (ARC), although a quantitative summary of these associations is lacking.

Objectives

The aim of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) and cohort studies of dietary vitamin and carotenoid intake and ARC risk.

Methods

The MEDLINE, EMBASE, ISI Web of Science, and Cochrane Library databases were searched from inception to June 2018. The adjusted RRs and corresponding 95% CIs for the associations of interest in each study were extracted to calculate pooled estimates. Dose-response relations were assessed with the use of generalized least-squares trend estimation.

Results

We included 8 RCTs and 12 cohort studies in the meta-analysis. Most vitamins and carotenoids were significantly associated with reduced risk of ARC in the cohort studies, including vitamin A (RR: 0.81; 95% CI: 0.71, 0.92; P = 0.001), vitamin C (RR: 0.80; 95% CI: 0.72, 0.88; P < 0.001), vitamin E (RR: 0.90; 95% CI: 0.80, 1.00; P = 0.049), β-carotene (RR: 0.90; 95% CI: 0.83, 0.99; P = 0.023), and lutein or zeaxanthin (RR: 0.81; 95% CI: 0.75, 0.89; P < 0.001). In RCTs, vitamin E (RR: 0.97; 95% CI: 0.91, 1.03; P = 0.262) or β-carotene (RR: 0.99; 95% CI: 0.92, 1.07; P = 0.820) intervention did not reduce the risk of ARC significantly compared with the placebo group. Further dose-response analysis indicated that in cohort studies the risk of ARC significantly decreased by 26% for every 10-mg/d increase in lutein or zeaxanthin intake (RR: 0.74; 95% CI: 0.67, 0.80; P < 0.001), by 18% for each 500-mg/d increase in vitamin C intake (RR: 0.82; 95% CI: 0.74, 0.91; P < 0.001), by 8% for each 5-mg/d increase in β-carotene intake (RR: 0.92; 95% CI: 0.88, 0.96; P < 0.001), and by 6% for every 5 mg/d increase in vitamin A intake (RR: 0.94; 95% CI: 0.90, 0.98; P < 0.001).

Conclusions

Higher consumption of certain vitamins and carotenoids was associated with a significant decreased risk of ARC in cohort studies, but evidence from RCTs is less clear.

Cysteine/Glutathione Deficiency: A Significant and Treatable Corollary of Disease

Glutathione (GSH) deficiency may play a pivotal role in a variety of apparently unrelated clinical conditions and diseases. Orally administered N-acetylcysteine (NAC), which replenishes the cysteine required for GSH synthesis, has been tested in a large number of randomized placebo-controlled trials involving these diseases and conditions. This chapter focused on developing a base of evidence suggesting that NAC administration improves disease by increasing cysteine and/or GSH in a variety of diseases, thereby implying a significant role for GSH deficiency in the clinical basis of many diseases. To develop this base of evidence, we systematically selected studies which considered the hypothesis that the therapeutic efficacy for NAC is an indication that cysteine and/or GSH deficiency is a pathophysiological part of the diseases studied. In this manner we focus this chapter on explaining the biological mechanisms of NAC therapy in a wide variety of disorders and demonstrate its ubiquitous role in improving disease that involves disrupted GSH and/or cysteine metabolism.

The Effect of Lutein on Eye and Extra-Eye Health

Lutein is a carotenoid with reported anti-inflammatory properties. A large body of evidence shows that lutein has several beneficial effects, especially on eye health. In particular, lutein is known to improve or even prevent age-related macular disease which is the leading cause of blindness and vision impairment. Furthermore, many studies have reported that lutein may also have positive effects in different clinical conditions, thus ameliorating cognitive function, decreasing the risk of cancer, and improving measures of cardiovascular health. At present, the available data have been obtained from both observational studies investigating lutein intake with food, and a few intervention trials assessing the efficacy of lutein supplementation. In general, sustained lutein consumption, either through diet or supplementation, may contribute to reducing the burden of several chronic diseases. However, there are also conflicting data concerning lutein efficacy in inducing favorable effects on human health and there are no univocal data concerning the most appropriate dosage for daily lutein supplementation. Therefore, based on the most recent findings, this review will focus on lutein properties, dietary sources, usual intake, efficacy in human health, and toxicity.

In vitro studies on nobiletin isolated from citrus plants and the bioactive metabolites, inhibitory action against gelatinase enzymatic activity and the molecular mechanisms in human retinal Müller cell line

Diabetic retinopathy (DR) is the most common cause of vision loss in patients with diabetes mellitus. Despite the presence of effective therapy, DR is still a significant health burden. A recent research suggests that matrix metalloproteinases (MMPs) could be promising targets, which exert multiple actions on early- and late-stage pathogenesis of DR. Among the MMP family, gelatinases (MMP-2 and MMP-9) act as potent proinflammatory, proangiogenic, and pro-apoptotic factors. Therefore, the pharmacological inhibitory effect of gelatinases on retinal MMP-producing cells may be useful in the treatment or prevention of DR. Nobiletin isolated from citrus plants is a multi-functional polymethoxylated flavone, which exerts biological effects including inhibitory action against MMP activity in several cancer cells. In the present study, we demonstrated that nobiletin isolated from citrus plants attenuated MMP-9 enzymatic activity through the suppression of transcription for MMP-9 gene expression and augmentation of TIMP-1 production in retinal Müller cells. Nobiletin regulated MMP-9 gene expression and TIMP-1 by inhibiting the PI3K/Akt signaling pathway. In addition, we observed the augmentation of inhibitory action against MMP-9 enzymatic activity by 4'-demethylated nobiletin, which is a major metabolite of nobiletin. We believe that the enhancement of inhibitory action against MMP-9 enzymatic activity by 4'-demethylated nobiletin is through the dual inhibition on Erk1/2 and Akt phosphorylation. The structure-activity relationship analysis revealed that, for the enhancement of inhibitory action against MMP-9 enzymatic activity, demethylation at position 4' in B-ring was a key structural modification in Müller cells, which are an important source of MMPs found in vitreous fluid and retinal tissues in retinal proliferative diseases. These results suggested that nobiletin, derived from a natural source, may serve as a novel MMP inhibitor with minimal side effects, and lead compound for the design of more efficacious drugs.

The Oxygen Paradox, the French Paradox, and age-related diseases

A paradox is a seemingly absurd or impossible concept, proposition, or theory that is often difficult to understand or explain, sometimes apparently self-contradictory, and yet ultimately correct or true. How is it possible, for example, that oxygen "a toxic environmental poison" could be also indispensable for life (Beckman and Ames Physiol Rev 78(2):547-81, 1998; Stadtman and Berlett Chem Res Toxicol 10(5):485-94, 1997)?: the so-called Oxygen Paradox (Davies and Ursini 1995; Davies Biochem Soc Symp 61:1-31, 1995). How can French people apparently disregard the rule that high dietary intakes of cholesterol and saturated fats (e.g., cheese and paté) will result in an early death from cardiovascular diseases (Renaud and de Lorgeril Lancet 339(8808):1523-6, 1992; Catalgol et al. Front Pharmacol 3:141, 2012; Eisenberg et al. Nat Med 22(12):1428-1438, 2016)?: the so-called, French Paradox. Doubtless, the truth is not a duality and epistemological bias probably generates apparently self-contradictory conclusions. Perhaps nowhere in biology are there so many apparently contradictory views, and even experimental results, affecting human physiology and pathology as in the fields of free radicals and oxidative stress, antioxidants, foods and drinks, and dietary recommendations; this is particularly true when issues such as disease-susceptibility or avoidance, "healthspan," "lifespan," and ageing are involved. Consider, for example, the apparently paradoxical observation that treatment with low doses of a substance that is toxic at high concentrations may actually induce transient adaptations that protect against a subsequent exposure to the same (or similar) toxin. This particular paradox is now mechanistically explained as "Adaptive Homeostasis" (Davies Mol Asp Med 49:1-7, 2016; Pomatto et al. 2017a; Lomeli et al. Clin Sci (Lond) 131(21):2573-2599, 2017; Pomatto and Davies 2017); the non-damaging process by which an apparent toxicant can activate biological signal transduction pathways to increase expression of protective genes, by mechanisms that are completely different from those by which the same agent induces toxicity at high concentrations. In this review, we explore the influences and effects of paradoxes such as the Oxygen Paradox and the French Paradox on the etiology, progression, and outcomes of many of the major human age-related diseases, as well as the basic biological phenomenon of ageing itself.

Lutein, Zeaxanthin, and meso-Zeaxanthin in the Clinical Management of Eye Disease

Lutein, zeaxanthin, and meso-zeaxanthin are xanthophyll carotenoids found within the retina and throughout the visual system. The retina is one of the most metabolically active tissues in the body. The highest concentration of xanthophylls is found within the retina, and this selective presence has generated many theories regarding their role in supporting retinal function. Subsequently, the effect of xanthophylls in the prevention and treatment of various eye diseases has been examined through epidemiological studies, animal studies, and clinical trials. This paper attempts to review the epidemiological studies and clinical trials investigating the effects of xanthophylls on the incidence and progression of various eye diseases. Observational studies have reported that increased dietary intake and higher serum levels of lutein and zeaxanthin are associated with lower risk of age-related macular degeneration (AMD), especially late AMD. Randomized, placebo-controlled clinical trials have demonstrated that xanthophyll supplementation increases macular pigment levels, improves visual function, and decreases the risk of progression to late AMD, especially neovascular AMD. Current publications on the preventive and therapeutic effects of lutein and zeaxanthin on cataracts, diabetic retinopathy, and retinopathy of prematurity have reported encouraging results.

Associations between antioxidant vitamins and the risk of invasive cervical cancer in Chinese women: A case-control study

Previous studies on the associations between dietary antioxidant vitamins and the risk of cervical cancer remain inconsistent, and little evidence is available for serum antioxidant vitamins, which provide more accurate measurements of these nutrients. We conducted a case-control study of 458 incident cases with invasive cervical cancer and 742 controls to assess the effects of diet or serum antioxidant vitamins. Higher serum antioxidant vitamins were associated with a lower risk of cervical cancer after adjusting for potential confounders. The odds ratios (ORs) for the highest (vs. lowest) quartile were 0.66 (95% confidence interval [CI] = 0.46–0.93; P = 0.024) for α-carotene, 0.63 (95% CI = 0.45–0.90; P = 0.006) for β-carotene, 0.53 (95% CI = 0.37–0.74; P < 0.001) for vitamin E, and 0.48 (95% CI = 0.33–0.69; P < 0.001) for vitamin C. Dietary intakes of vitamins E and C were inversely associated with the risk of cervical cancer. Risk of cervical cancer from serum antioxidant vitamins was more evident in passive smokers than non-passive smokers. These findings indicated that antioxidant vitamins (mainly α-carotene, β-carotene, and vitamins E and C) might be beneficial in reducing the risk of invasive cervical cancer in Chinese women, especially in passive smokers.

Hypercholesterolemia-induced ocular disorder: Ameliorating role of phytotherapy

The ocular region is a complex structure that allows conscious light perception and vision. It is of ecto-mesodermal origin. Cholesterol and polyunsaturated fatty acids are involved in retinal cell function; however, hypercholesterolemia and diabetes impair its function. Retinal damage, neovascularization, and cataracts are the main complications of cholesterol overload. Dietary supplementation of selected plant products can lead to the scavenging of free reactive oxygen species, thereby protecting the ocular regions from the damage of hypercholesterolemia. This review illustrates the dramatic effects of increased cholesterol levels on the ocular regions. The effect of phytotherapy is discussed in relation to the different regions of the eye, including the retina, cornea, and lens.

The Association of Dietary Lutein plus Zeaxanthin and B Vitamins with Cataracts in the Age-Related Eye Disease Study: AREDS Report No. 37

PURPOSE

To evaluate whether dietary intake of luteiin/zeaxanthin and B vitamins is associated with cataract prevalence and incidence.

DESIGN

Clinic-based, baseline cross-sectional and prospective cohort study designs.

PARTICIPANTS

Three thousand one hundred fifteen patients (6129 eyes) enrolled in the Age-Related Eye Disease Study 55 to 80 years of age followed up for mean of 9.6 years.

METHODS

Participants completed baseline food frequency questionnaires. Baseline and annual lens photographs were graded centrally. Multivariate models controlling for previously identified risk factors for cataracts tested for the association of cataracts with reported dietary intake, using the lowest quintile as reference.

MAIN OUTCOME MEASURES

Cataract surgery, cataract status (type and severity) at baseline, and development of cataracts.

RESULTS

At baseline, increased dietary riboflavin and B12 were associated inversely with nuclear and cortical lens opacities. In comparisons of persons with and without cataract, persons with the highest riboflavin intake versus those with the lowest intake had the following associations: mild nuclear cataract: odds ratio (OR), 0.78; 95% confidence interval (CI), 0.63-0.97; moderate nuclear cataract: OR, 0.62; 95% CI, 0.43-0.90; and mild cortical cataract: OR, 0.80; 95% CI, 0.65-0.99. For B12, the results were: mild nuclear cataract: OR, 0.78; 95% CI, 0.63-0.96; moderate nuclear cataract: OR, 0.62; 95% CI, 0.43-0.88; and mild cortical cataract: OR, 0.77; 95% CI, 0.63-0.95. Highest dietary B6 intake was associated with a decreased risk of moderate nuclear lens opacity developing compared with the lowest quintile (OR, 0.67; 95% CI, 0.45-0.99). Highest dietary intake levels of niacin and B12 were associated with a decreased risk of development of mild nuclear or mild cortical cataracts in participants not taking Centrum (Pfizer, New York, NY) multivitamins. For participants taking multivitamins during the study, the highest intake of dietary folate was associated with an increased risk of mild posterior subcapsular lens opacity development. No statistically significant associations were found between lutein plus zeaxanthin intake and presence at baseline or development of nuclear or cortical lens opacity outcomes.

CONCLUSIONS

These findings are consistent with earlier studies suggesting that dietary intake of B vitamins may affect the occurrence of age-related lens opacities. Further investigations are warranted.

An Evidence-Based Systematic Review of Lutein by the Natural Standard Research Collaboration

An evidence-based systematic review of lutein by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

The gender-differentiated antioxidant effects of a lutein-containing supplement in the aqueous humor of patients with senile cataracts

Antioxidant supplements are expected to decrease oxidative damage and prevent ocular diseases. In this study, changes in the anti-oxidative ability and oxidative status in the aqueous humor before and after intake of a lutein-containing supplement were measured. Forty patients who all had identical grades of cataracts in both eyes were included. The aqueous humor was collected as pre-intake samples during cataract surgery. Ocuvite + Lutein(Ⓡ), an antioxidant supplement, was administered orally beginning the day after surgery. Six weeks later, the aqueous humor was collected as a post-intake sample during cataract surgery of the opposite eye. To determine the anti-oxidative ability, the levels of superoxide (O2(*-)) scavenging activity were measured. To determine the oxidative status, the levels of hydrogen peroxide (H2O2) and total amount of hydroperoxides (TH, including H2O2 and peroxides of lipids, proteins, and nucleic acids) were measured. In post-intake samples, the O2(*-) scavenging activities were significantly higher in both genders (p < 0.05). The levels of H2O2 were significantly higher (p < 0.01) while the levels of TH were significantly lower (p < 0.01) only in females. The level of H2O2 was significantly negatively correlated to the TH in the post-intake samples of both genders (r = -0.50 and p < 0.05 for males; r = -0.59 and p < 0.01 for females) while the level of H2O2 was significantly positively correlated to the O2(*-) scavenging activity in both pre- and post-intake aqueous humor in females only (r = 0.66 and p < 0.01 for pre-intake samples, r = 0.71 and p < 0.01 for post-intake samples). After the introduction of the antioxidant supplement, O2(*-) scavenging activity increased while H2O2 levels remained the same in males, suggesting that scavenging rates are proportional. In postmenopausal females, the superoxide scavenging activity also increased, however unlike in males, the H2O2 levels also increased meaning H2O2 was not completely scavenged. H2O2 is a non-free radical and can be excreted from the aqueous humor to prevent further oxidation of lipids, proteins, and nucleic acids, which was confirmed by the low levels of TH in post-intake samples. Antioxidant supplements are suggested to be effective in reducing oxidation in the aqueous humor by different mechanisms in both genders.

The effect of multivitamin/mineral supplements on age-related cataracts: a systematic review and meta-analysis

Antioxidant vitamins supplements have been suggested as a strategy to decrease the risk of age-related cataract development. However, the results from observational studies and interventional trials of associations between antioxidant vitamins A, C, and E and cataract development have been inconsistent. We aim to evaluate the effectiveness of multivitamin/mineral supplements for decreasing the risk of age-related cataracts by conducting a systematic review and meta-analysis. In September 2013, we searched multiple databases to identify relevant studies including both cohort studies and randomized controlled trials (RCTs). A random-effects model was used to calculate the pooled relative risks (RR) with a 95% confidence interval (CI). Twelve prospective cohort studies and two RCTs were included. Pooled results from the cohort studies indicated that multivitamin/mineral supplements have a significant beneficial effect in decreasing the risk of nuclear cataracts (RR: 0.73; 95% CI: 0.64-0.82), cortical cataracts (RR: 0.81; 95% CI: 0.68-0.94), and any cataracts (RR: 0.66; 95% CI: 0.39-0.93). In addition, there were no decreases in the risk of posterior capsular cataracts (RR: 0.96; 95% CI: 0.72-1.20) or cataract surgery (RR: 1.00; 95% CI: 0.92-1.08). The two RCTs demonstrated that multivitamin/mineral supplements could decrease the risk of nuclear cataracts. There is sufficient evidence to support the role of dietary multivitamin/mineral supplements for the decreasing the risk of age-related cataracts.

Nutritional modulation of cataract

Lens opacification or cataract reduces vision in over 80 million people worldwide and blinds 18 million. These numbers will increase dramatically as both the size of the elderly demographic and the number of those with carbohydrate metabolism-related problems increase. Preventative measures for cataract are critical because the availability of cataract surgery in much of the world is insufficient. Epidemiologic literature suggests that the risk of cataract can be diminished by diets that are optimized for vitamin C, lutein/zeaxanthin, B vitamins, omega-3 fatty acids, multivitamins, and carbohydrates: recommended levels of micronutrients are salutary. The limited data from intervention trials provide some support for observational studies with regard to nuclear - but not other types of - cataracts. Presented here are the beneficial levels of nutrients in diets or blood and the total number of participants surveyed in epidemiologic studies since a previous review in 2007.

Effects of multivitamin supplement on cataract and age-related macular degeneration in a randomized trial of male physicians

PURPOSE

To test whether long-term multivitamin supplementation affects the incidence of cataract or age-related macular degeneration (AMD) in a large cohort of men.

DESIGN

Randomized, double-blind, placebo-controlled trial.

PARTICIPANTS

A total of 14,641 US male physicians aged ≥ 50 years.

INTERVENTION

Daily multivitamin or placebo.

MAIN OUTCOME MEASURES

Incident cataract and visually significant AMD responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-reports confirmed by medical record review.

RESULTS

During an average of 11.2 years of treatment and follow-up, a total of 1817 cases of cataract and 281 cases of visually significant AMD were confirmed. There were 872 cataracts in the multivitamin group and 945 cataracts in the placebo group (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.83-0.99; P = 0.04). For visually significant AMD, there were 152 cases in the multivitamin group and 129 cases in the placebo group (HR, 1.19; 95% CI, 0.94-1.50; P = 0.15).

CONCLUSIONS

These randomized trial data from a large cohort of middle-aged and older US male physicians indicate that long-term daily multivitamin use modestly and significantly decreased the risk of cataract but had no significant effect on visually significant AMD.

Self-nanoemulsifying drug delivery system of lutein: physicochemical properties and effect on bioavailability of warfarin

Objective of present study was to prepare and characterize self-nanoemulsifying drug delivery system (SNEDDS) of lutein and to evaluate its effect on bioavailability of warfarin. The SNEDDS was prepared using an oil, a surfactant, and co-surfactants with optimal composition based on pseudo-ternary phase diagram. Effect of the SNEDDS on the bioavailability of warfarin was performed using Sprague Dawley rats. Lutein was successfully formulated as SNEDDS for immediate self-emulsification and dissolution by using combination of Peceol as oil, Labrasol as surfactant, and Transcutol-HP or Lutrol-E400 as co-surfactant. Almost complete dissolution was achieved after 15 min while lutein was not detectable from the lutein powder or intra-capsule content of a commercial formulation. SNEDDS formulation of lutein affected bioavailability of warfarin, showing about 10% increase in C_max and AUC of the drug in rats while lutein as non-SNEDDS did not alter these parameters. Although exact mechanism is not yet elucidated, it appears that surfactant and co-surfactant used for SNEDDS formulation caused disturbance in the anatomy of small intestinal microvilli, leading to permeability change of the mucosal membrane. Based on this finding, it is suggested that drugs with narrow therapeutic range such as warfarin be administered with caution to avoid undesirable drug interaction due to large amount of surfactants contained in SNEDDS.

Diet and cataract: a case-control study

We conducted a case-control study to assess the association between diet and risk of cataract in Athens, Greece. Totals of 314 cases and 314 frequency-matched controls of both sexes, aged 45-85 years and attending the ophthalmology department of a major teaching hospital in Athens, Greece, were included in the study. All participants were interviewed using a semi-quantitative food-frequency questionnaire, covering the average frequency of consumption of about 120 food items. Analyses were conducted through multiple logistic regression. The analysis was carried out taking cataract as a general outcome (all types of cataract combined) and repeated by the specific type of cataract. We found significant inverse associations of cataract with dietary consumption of fish (OR = 0.69, p < 0.001), vegetables (OR = 0.47, p < 0.001), fruits (OR = 0.53, p < 0.001), and potatoes (OR = 0.76, p = 0.004), while consumption of meat was positively associated with cataract (OR = 1.46, p = 0.001). High intake of total fat (OR = 2.00, p < 0.001) and cholesterol (OR = 1.65, p < 0.001) increased the risk of cataract. There was a protective association between cataract risk and intake of carbohydrates (OR = 0.39, p < 0.001), carotene (OR = 0.56, p < 0.001), vitamins C and E (OR = 0.50, p < 0.001 and OR = 0.50, p < 0.001 respectively). We identified an association between the risk of cataract and several food groups and nutrients. Diets rich in fruits, vegetables, fish, pulses and starchy foods may protect against cataract. In addition, high intake of vitamins C and E and carotene with reduction of intake in total fat and cholesterol may be beneficial. Dietary advice along these lines may provide adequate public health guidelines for the delay of age-related cataract.

Current evidence on healthy eating

Large nutritional epidemiology studies, with long-term follow-up to assess major clinical end points, coupled with advances in basic science and clinical trials, have led to important improvements in our understanding of nutrition in primary prevention of chronic disease. Although much work remains, sufficient evidence has accrued to provide solid advice on healthy eating. Good data now support the benefits of diets that are rich in plant sources of fats and protein, fish, nuts, whole grains, and fruits and vegetables; that avoid partially hydrogenated fats; and that limit red meat and refined carbohydrates. The simplistic advice to reduce all fat, or all carbohydrates, has not stood the test of science; strong evidence supports the need to consider fat and carbohydrate quality and different protein sources. This article briefly summarizes major findings from recent years bearing on these issues.

A global clinical view on vitamin A and carotenoids

The clinical importance of vitamin A as an essential nutrient has become increasingly clear. Adequate vitamin A is required for normal organogenesis, immune competence, tissue differentiation, and the visual cycle. Deficiency, which is widespread throughout the developing world, is responsible for a million or more instances of unnecessary death and blindness each year. β-Carotene is an important, but insufficient, source of vitamin A among poor populations, which accounts for the widespread nature of vitamin A deficiency. It has only recently become apparent that the bioconversion of traditional dietary sources of β-carotene to vitamin A is much less efficient than previously supposed. The other major carotenoids, particularly lycopene, lutein, and zeaxanthin, have been found to have important biological properties, including antioxidant and photoprotective activity, and high intake has been linked in observational studies with reduced risk of a number of chronic diseases. But, to date, no clinical trials have proven the clinical value of ingested carotenoids individually or in combination, in either physiologic or pharmacologic doses, with the excepton of the provitamin A activity of carotene. Indeed, several trials have suggested an increased risk of lung cancer among high-risk individuals (smokers and asbestos workers) who were given high doses of β-carotene alone or in combination with other antioxidants. Much more evidence is needed before commonly encountered claims of the value of ingesting high doses of non-provitamin A carotenoids are validated.

Determination of carotenoids, total phenolic content, and antioxidant activity of Arazá (Eugenia stipitata McVaugh), an Amazonian fruit

The fruit of Arazá (Eugenia stipitata McVaugh) native to the Colombian Amazon is considered a potentially economically valuable fruit for the Andean economy due to its novel and unique taste. The fruit has an intense yellow color, but its chemical composition and properties have not been well studied. Here we report the identification and quantitation of carotenoids in the ripe fruit using high performance liquid chromatography (HPLC) with photodiode array detector (PDA) and atmospheric pressure chemical ionization (APcI) mass spectrometry (MS/MS). The qualitative carotenoid profile of the fruit according to maturity stage was also observed. Furthermore, antioxidant activity of the peel and pulp were assessed using the ferric reducing ability of plasma (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, in addition to chemical indexes and total phenolic content. Multiple carotenoids were identified in the peel and pulp including four xanthophylls (free and esterified as their mono and diesters) and two carotenes. One of the xanthophylls was tentatively identified as zeinoxanthin, while the others were identified as lutein, zeaxanthin, and β-cryptoxanthin. Carotenes included α-carotene and β-carotene. The total carotenoid content was significantly higher in the peel (2484 ± 421 μg/100 g FW) than in the pulp (806 ± 348 μg/100 g FW) with lutein, β-cryptoxanthin, and zeinoxanthin as the major carotenoid components. The unique carotenoid composition of this fruit can differentiate it from other carotenoid-rich fruits and perhaps be useful in authentication procedures. Overall, results from this study suggest that Colombian Arazá may be a good edible source of carotenoids important in retinal health as well as carotenoids with provitamin A activity. Therefore, Arazá fruit can be used as a nutraceutical ingredient and in production of functional foods in the Colombian diet.

Association between various types of obesity and macular pigment optical density

PURPOSE

To elucidate the association between macular pigment optical density (MPOD) and various types of obesity in the South-Indian population.

PATIENTS AND METHODS

In total, 300 eyes of 161 healthy volunteers of South-Indian origin were studied. MPOD was measured psychophysically at 0.25°, 0.50°, 1.00°, and 1.75° eccentricities from fovea. Anthropometric measurements included waist circumference (WC) and waist-to-hip ratio (WHR) and body mass index (BMI). Using the WHO Expert Consultation guidelines, obesity was defined based on BMI alone (BMI ≥ 23 kg/m(2)), based on WC alone (WC ≥ 90 cm for men and ≥ 80 cm for women), and based on WHR alone (≥ 0.90 for men and ≥ 0.85 for women). Isolated generalized obesity was defined as increased BMI and normal WC. Isolated abdominal obesity was defined as increased WC and normal BMI. Combined obesity was defined as increased BMI and increased WC.

RESULTS

Mean MPOD at all eccentricities was not significantly different between men and women. Mean MPOD values did not significantly differ in various types of obesity, when compared with the normal subjects. On subgroup analysis, in age group ≥ 60 years, mean MPOD values were significantly higher in subjects with obesity based on BMI (0.61 vs 0.41, P=0.036), obesity based on WHR (0.67 vs 0.41, P=0.007), and isolated generalized obesity (0.66 vs 0.41, P=0.045) in comparison with normal subjects at 0.25° eccentricity.

CONCLUSION

We found lack of an association between MPOD and obesity in the South-Indian population. A similar finding was also noted on age group- and gender-wise analyses.

Dose-response relationship for α-tocopherol prevention of ultraviolet radiation induced cataract in rat

The purpose of this study is to establish the dose response relationship for α-tocopherol protection of ultraviolet radiation (UVR) induced cataract in the rat. Four groups of 20 six-week-old albino Sprague Dawley rats received 5, 25, 50, and 100 IU/day α-tocopherol, whilst another group of 20 rats without any α-tocopherol feeding was the control group. After 4 weeks of feeding, each rat was unilaterally exposed to 8 kJ/m(2) UVR-300 nm for 15 min. At 1 week after exposure, the rats were sacrificed and lens light scattering was measured quantitatively. Lens total reduced (GSH) and oxidized (GSSG) glutathione; glutathione reductase (GR) and peroxidase (GPx) were determined spectrophotometrically. The UVR-exposed lenses in the α-tocopherol fed groups developed superficial cataract, whereas lenses in the control group developed cortical and equatorial opacities. Light scattering in lenses from the α-tocopherol-supplemented rats was lower than in lenses from the control group. The difference of light scattering between the exposed and contralateral non-exposed lens decreased with increasing doses of α-tocopherol to an asymptote level. UVR-exposure caused a significant depletion of lens GSH in rats without or at low α-tocopherol supplementation. The depletion of GSH became less with higher α-tocopherol supplementation. There was no detectable difference in lens GSSG, GR or GPx at any level of α-tocopherol supplementation. Orally administered α-tocopherol dose dependently protects against UVR-induced cataract. The protection is associated with an α-tocopherol dose-dependent GSH depletion secondary to UVR exposure. UVR-induced light scattering only occurs if the GSH depletion exceeds a threshold.

Diet, vegetarianism, and cataract risk

BACKGROUND

Age-related cataract is a major cause of morbidity. Previous studies of diet and cataract risk have focused on specific nutrients or healthy eating indexes but not on identifiable dietary groups such as vegetarians.

OBJECTIVE

We investigated the association between diet and cataract risk in a population that has a wide range of diets and includes a high proportion of vegetarians.

DESIGN

We used Cox proportional hazards regression to study cataract risk in relation to baseline dietary and lifestyle characteristics of 27,670 self-reported nondiabetic participants aged ≥40 y at recruitment in the Oxford (United Kingdom) arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford) by using data from the Hospital Episode Statistics in England and Scottish Morbidity Records.

RESULTS

There was a strong relation between cataract risk and diet group, with a progressive decrease in risk of cataract in high meat eaters to low meat eaters, fish eaters (participants who ate fish but not meat), vegetarians, and vegans. After multivariable adjustment, incidence rate ratios (95% CIs) for moderate meat eaters (50-99 g meat/d), low meat eaters (<50 g meat/d), fish eaters, vegetarians, and vegans compared with high-meat eaters (≥100 g meat/d) were 0.96 (0.84, 1.11), 0.85 (0.72, 0.99), 0.79 (0.65, 0.97), 0.70 (0.58, 0.84), and 0.60 (0.38, 0.96), respectively (P < 0.001 for heterogeneity). Associations between cataract risk and intakes of selected nutrients and foods generally reflected the strong association with diet group.

CONCLUSION

Vegetarians were at lower risk of cataract than were meat eaters in this cohort of health-conscious British residents.