Association of vitamin C with the risk of age-related cataract: a meta-analysis

Influence of Diet, Dietary Products and Vitamins on Age-Related Cataract Incidence: A Systematic Review

Cataract, defined as the opacification of the lens that prevents clear vision, is a leading cause of vision loss and impairment worldwide. Elderly people comprise the highest proportion of those suffering from this eye disease. According to the National Institute of Health (NIH), the risk of developing aged-related cataract (ARC) increases with every decade of life, starting from the age of 40. Despite progress in surgical treatment methods, life-style modifications may be beneficial in prevention or slowing down the progression of ARC. This systematic review aims to summarize studies on the significance of specific nutritional patterns, dietary products, vitamins, minerals, and carotenoids intake in the onset or progression of ARC. In this context, the presented paper thoroughly analyzes 24 articles, following the PRISMA guidelines. The results indicate significant protective effects of various dietary patterns, including the Korean balanced diet, vegetarian diet, "dairy products and vegetables", "traditional", "antioxidant", and "omega-3" patterns. Additionally, the consumption of fruits, vegetables, legumes, nuts, skimmed yoghurt, fish, coffee, and vitamins has shown positive effects on cataract incidence. Therefore, further research seems to be essential to gain a better understanding of these associations and to create uniform dietary recommendations for both the vulnerable population and ARC patients.

A cross-sectional study to evaluate hypovitaminosis C prevalence and risk factors in an acute geriatric unit in Lyon, France: the HYPO-VIT-C protocol

INTRODUCTION

Vitamin C is an essential micronutrient playing crucial roles in human biology. Hypovitaminosis C is defined by a plasmatic ascorbemia below 23 µmol/L and is associated with numerous outcomes such as cardiovascular diseases, cancers or neurocognitive disorders. Numerous risk factors are common among older adults making them particularly susceptible to hypovitaminosis C. These risk factors include reduced vitamin intakes, higher vitamin metabolism related to polypathology, and iatrogeny because of polypharmacy. However, the precise prevalence of hypovitaminosis C and its risk factors are poorly documented within the geriatric population.A better knowledge of hypovitaminosis C prevalence and risk factor may lead to improving the vitamin C status among older people and prevent its consequences.

METHOD AND ANALYSIS

To answer these questions, we designed a monocentric cross-sectional study in a population of older hospitalised patients in Lyon, France. A sample size of 385 patients was needed to estimate hypovitaminosis C prevalence. The study was proposed to all eligible patient aged more than 75 years old entering the participating acute geriatric unit. The plasmatic vitamin C status was systematically assessed for participating patients, and variables part of the medical and geriatric evaluation were collected. For patients with severe vitamin C depletion, an oral supplementation and a follow-up phone call were organised to ensure treatment completion and tolerance.

ETHICS AND DISSEMINATION

The protocol has been approved by an independent national ethics committee and meets the methodological requirements. Final outcomes will be published in a peer-reviewed journal and disseminated through conferences.

TRIAL REGISTRATION NUMBER

NCT05668663.

Ultraviolet B radiation induces oxidative stress and apoptosis in human lens epithelium cells by activating NF-κB signaling to down-regulate sodium vitamin C transporter 2 (SVCT2) expression

Ultraviolet B (UVB) exposure is reported to cause cataract formation by inducing excessive reactive oxygen species (ROS) and apoptosis in human lens epithelial cells (HLECs). Sodium-dependent Vitamin C transports-2 (SVCT2) is a ascorbic acid (AsA) transporter for that can protect cells and tissues from oxidative stress. Here, we focus on the functional characterization and mechanism analysis of SVCT2 in UVB-treated HLECs. The results showed a significant reduction of SVCT2 expression in HLECs treated with UVB. SVCT2 abated apoptosis and Bax expression and increased Bcl-2 expression. Moreover, SVCT2 decreased ROS accumulation and MDA level, but increased the activities of antioxidant enzymes (SOD and GSH-PX). NF-κB inhibitor (PDTC) alleviated ROS production and apoptosis, and promoted SVCT2 expression in UVB-treated HLECs. Additionally, ROS inhibitor (NAC) suppressed oxidative stress, apoptosis, and induced SVCT2 expression in UVB-treated HLECs, while these effects were significantly abated due to the activation of NF-κB signaling. Furthermore, SVCT2 facilitated 14C-AsA absorption in UVB-treated HLECs. Together, our findings demonstrated that UVB exposure-induced ROS generation, which further activated NF-κB signaling to down-regulate SVCT2 expression in HLECs. Then, downregulated SVCT2 promoted ROS accumulation and induced apoptosis by decreasing AsA uptake. Our data reveal a novel NF-κB/SVCT2/AsA regulatory pathway and suggest the therapeutic potential of SVCT2 in UVB-induced cataract.

Potential Properties of Natural Nutraceuticals and Antioxidants in Age-Related Eye Disorders

Eye health is crucial, and the onset of diseases can reduce vision and affect the quality of life of patients. The main causes of progressive and irreversible vision loss include various pathologies, such as cataracts, ocular atrophy, corneal opacity, age-related macular degeneration, uncorrected refractive error, posterior capsular opacification, uveitis, glaucoma, diabetic retinopathy, retinal detachment, undetermined disease and other disorders involving oxidative stress and inflammation. The eyes are constantly exposed to the external environment and, for this reason, must be protected from damage from the outside. Many drugs, including cortisonics and antinflammatory drugs have widely been used to counteract eye disorders. However, recent advances have been obtained via supplementation with natural antioxidants and nutraceuticals for patients. In particular, evidence has accumulated that polyphenols (mostly deriving from Citrus Bergamia) represent a reliable source of antioxidants able to counteract oxidative stress accompanying early stages of eye diseases. Luteolin in particular has been found to protect photoreceptors, thereby improving vision in many disease states. Moreover, a consistent anti-inflammatory response was found to occur when curcumin is used alone or in combination with other nutraceuticals. Additionally, Coenzyme Q10 has been demonstrated to produce a consistent effect in reducing ocular pressure, thereby leading to protection in patients undergoing glaucoma. Finally, both grape seed extract, rich in anthocyanosides, and polynsatured fatty acids seem to contribute to the prevention of retinal disorders. Thus, a combination of nutraceuticals and antioxidants may represent the right solution for a multi-action activity in eye protection, in association with current drug therapies, and this will be of potential interest in early stages of eye disorders.

Nutraceuticals: A Promising Therapeutic Approach in Ophthalmology

Oxidative stress represents one of the main factors driving the pathophysiology of multiple ophthalmic conditions including presbyopia, cataracts, dry eye disease (DED), glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). Currently, different studies have demonstrated the role of orally administered nutraceuticals in these diseases. For instance, they have demonstrated to improve lens accommodation in presbyopia, reduce protein aggregation in cataracts, ameliorate tear film stability, break up time, and tear production in dry eye, and participate in the avoidance of retinal neuronal damage and a decrease in intraocular pressure in glaucoma, contribute to the delayed progression of AMD, or in the prevention or treatment of neuronal death in diabetic retinopathy. In this review, we summarized the nutraceuticals which have presented a positive impact in ocular disorders, emphasizing the clinical assays. The characteristics of the different types of nutraceuticals are specified along with the nutraceutical concentration used to achieve a therapeutic outcome in ocular diseases.

Changes in Aqueous Humor Lutein Levels of Patients with Cataracts after a 6-Week Course of Lutein-Containing Antioxidant Supplementation

PURPOSE

Oxidative damage is known to be an important cause of age-related cataracts and it has been suggested that administration of antioxidants, such as lutein, may delay the onset and progression of cataracts. Our previous investigation of human aqueous humor after the intake of a lutein-containing supplement demonstrated decreases in peroxidative products. This study evaluated the transportation of lutein into aqueous humor which is an important factor when measuring the antioxidant effects of lutein on the lens.

METHODS

This study enrolled 155 patients with binocular cataracts of the same grade. Serum and aqueous humor samples were collected during cataract surgery before (as pre-intake samples) and after 6 weeks of oral intake of Ocuvite + Lutein^® (as post-intake samples). Lutein levels were measured with high-performance liquid chromatography.

RESULTS

Lutein levels in both the serum and aqueous humor were significantly higher in the post-intake than the pre-intake samples. There were significant increases in the lutein levels in patients with lower pre-intake lutein serum levels. There was also a tendency for greater increases in patients with lower pre-intake aqueous humor lutein levels.

CONCLUSIONS

These results demonstrate that oral lutein supplementation increases lutein levels, which further induce decreases in peroxidation in the aqueous humor. Furthermore, lutein supplementation may be more effective in patients with lower serum lutein levels.

Vitamin C intake and multiple health outcomes: an umbrella review of systematic reviews and meta-analyses

The purpose of this article was to assess the existing systematic reviews and meta-analyses for the association between vitamin C intake and multiple health outcomes. A total of 76 meta-analyses (51 papers) of randomised controlled trials and observational studies with 63 unique health outcomes were identified. Dose-response analysis showed that vitamin C intake was associated with reduced risk of all-cause mortality, cardiovascular disease (CVD), oesophageal cancer, gastric cancer, cervical cancer and lung cancer with an increment of 50-100 mg per day. Beneficial associations were also identified for respiratory, neurological, ophthalmologic, musculoskeletal, renal and dental outcomes. Harmful associations were found for breast cancer and kidney stones for vitamin C supplement intake. The benefits of vitamin C intake outweigh the disadvantages for a range of health outcomes. However, the recommendation of vitamin C supplements needs to be cautious. More prospective studies and well-designed randomised controlled trials (RCTs) are needed.

Biological Protection in Deep Space Missions

During deep space missions, astronauts are exposed to highly ionizing radiation, incl. neutrons, protons and heavy ions from galactic cosmic rays (GCR), solar wind (SW) and solar energetic particles (SEP). This increase the risks for cancerogenisis, damages in central nervous system (CNS), cardiovascular diseases, etc. Large SEP events can even cause acute radiation syndrome (ARS). Long term manned deep space missions will therefor require unique radiation protection strategies. Since it has been shown that physical shielding alone is not sufficient, this paper propose pre-flight screening of the aspirants for evaluation of their level of adaptive responses. Methods for boosting their immune system, should also be further investigated, and the possibility of using radiation effect modulators are discussed. In this paper, especially, the use of vitamin C as a promising non-toxic, cost-effective, easily available radiation mitigator (which can be used hours after irradiation), is described. Although it has previously been shown that vitamin C can decrease radiation-induced chromosomal damage in rodents, it must be further investigated before any conclusions about its radiation mitigating properties in humans can be concluded.

Effects of Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) Laser Capsulotomy on Visual Outcomes From a Lower-Middle Income Country

Objective

Neodymium-doped yttrium aluminium garnet (Nd: YAG) laser is a non-invasive and effective means to deal with posterior capsule opacification. Although it is safe, it may have some complications. The purpose of this study was to evaluate the efficacy of Nd: YAG laser capsulotomy in terms of visual outcomes.

Methodology

This retrospective study was carried out at the eye department of Shaheed Mohtarma Benazir Bhutto Medical College, Lyari and Sindh Government Lyari General Hospital, Karachi, by using a convenient sampling technique. The duration of the study was six months from 1^st January 2020 to 30^th June 2020. 50 eyes of patients older than 20 years of age of either gender with posterior capsule opacification after cataract surgery for more than 6 months of duration, capsular fibrosis, and visual distortion due to wrinkling were included in the study. 

Results

Our results show that in a total of 50 patients, the mean age was 59.08±5.84 years, of which, 20 (40%) were males. Out of 50 patients, 22 right while 28 left eyes were selected for Nd: YAG laser capsulotomy. None of the patients showed elevated intraocular pressure (IOP) after the 1^st week. Mean IOP was 16.84±3.63 mm of Hg on the 1^st day and mean IOP after 1^st week was 12.48±2.01 mm of Hg. Iritis was observed in 5 (10.0%) patients on the 1^st day and 4 (8.0%) patients on the 1^st week. Raised IOP was observed in 10 (20.0%) cases whereas cystoid macular edema was observed in only 1 (2%) patients on the 1^st day and 1^st week after laser therapy.

Conclusion

The study predicted that Nd: Yag laser posterior capsulotomy gives excellent results in terms of visual acuity. Complications that were associated with the Nd: Yag laser capsulotomy was a rise in intraocular pressure, cystoid macular edema, iritis, and IOL pitting.

Hallmarks of lens aging and cataractogenesis

Lens homeostasis and transparency are dependent on the function and intercellular communication of its epithelia. While the lens epithelium is uniquely equipped with functional repair systems to withstand reactive oxygen species (ROS)-mediated oxidative insult, ROS are not necessarily detrimental to lens cells. Lens aging, and the onset of pathogenesis leading to cataract share an underlying theme; a progressive breakdown of oxidative stress repair systems driving a pro-oxidant shift in the intracellular environment, with cumulative ROS-induced damage to lens cell biomolecules leading to cellular dysfunction and pathology. Here we provide an overview of our current understanding of the sources and essential functions of lens ROS, antioxidative defenses, and changes in the major regulatory systems that serve to maintain the finely tuned balance of oxidative signaling vs. oxidative stress in lens cells. Age-related breakdown of these redox homeostasis systems in the lens leads to the onset of cataractogenesis. We propose eight candidate hallmarks that represent common denominators of aging and cataractogenesis in the mammalian lens: oxidative stress, altered cell signaling, loss of proteostasis, mitochondrial dysfunction, dysregulated ion homeostasis, cell senescence, genomic instability and intrinsic apoptotic cell death.

Traditional and Dairy Products and Vegetables Dietary Patterns Are Inversely Associated with the Risk of Cataract in the Middle Age and Aged Population: A Case-Control Study

OBJECTIVES

Cataract is one of the most common causes of visual impairment and blindness in the world. In the present study, we have been trying to investigate the relationship between major dietary patterns and cataract.

DESIGN

This was a case-control study.

SETTING

An ophthalmology outpatient clinic of Khatam al-Anbia Hospital, in Shoushtar city.

PARTICIPANTS

336 subjects (168 patients with cataract and 168 healthy ones), from 40 to 80 years old, were recruited.

MEASUREMENTS

A socio-demographic questionnaire was used to record the demographic information. A food frequency questionnaire was used to determine the foods consumed during the last year. The principal component analysis was used to extract major dietary patterns. The possible relationship between the major dietary patterns and cataract was assessed by multivariable logistic regression models.

RESULTS

We tried to eliminate the effect of cofactors. The results showed "dairy products and vegetables" dietary pattern had a negative association with cataract (OR: 0.301, 95%CI =0.137-0.658, P trend =0.002). The fourth quartile of the "traditional" dietary pattern also showed a protective role against the cataract (OR: 0.393, 95%CI =0.184-0.842, P trend = 0.036). The third and fourth quartiles of "carbohydrate and simple sugar" pattern were more related with cataract compared to the first quartile (OR: 3.574, 95%CI =1.665-7.671, and OR: 5.067, 95%CI =2.265-11.335, P trend <0.001 respectively). No significant association was found between «nuts, seeds and simple sugar" dietary pattern and cataract.

CONCLUSION

It seems a dietary pattern rich in proteins and vegetables can decrease the risk of cataract in middle-aged and aged subjects.

Determination of Oxidative Stress Markers in the Aqueous Humor and Corneal Tissues of Patients With Congenital Hereditary Endothelial Dystrophy

PURPOSE

The aim of this study is to determine the presence of oxidative stress markers in the aqueous humor (AH) and corneal tissues of patients with congenital hereditary endothelial dystrophy (CHED).

METHODS

Interventional prospective study was undertaken to quantify levels of ascorbic acid and glutathione in the AH of patients with CHED. AH was collected from patients undergoing keratoplasty and levels of ascorbic acid and glutathione were determined using biochemical assays and measured spectrophotometrically. AH collected from pediatric patients with cataract were used as control. Corneal sections of patients who underwent penetrating keratoplasty were obtained, and presence of glutathione peroxidase 1, catalase, and superoxide dismutase was determined by immunohistochemistry. Tissue sections obtained from cadaveric corneas unsuitable for clinical transplant were used as control.

RESULTS

Significantly increased ascorbic acid levels were determined in patients with CHED (605.6 ± 158.9 μM) compared with those in controls (190.5 ± 74.72 μM). However, a trend toward reduced level of glutathione was detected in patients with CHED compared with that in the controls. Increased glutathione peroxidase 1 staining and reduced expression of catalase was detected in corneal tissues of patients with CHED compared with those in control corneal tissues. There was no apparent changes observed in the expression of superoxide dismutase in the corneal sections obtained from patients with CHED.

CONCLUSIONS

To the best of our knowledge, this is the first study to determine the levels of ascorbic acid and glutathione in AH of patients with CHED. Our data suggest the presence of oxidative stress in CHED that might be responsible for the pathological changes in patients with CHED.

Vitamin C and the Lens: New Insights into Delaying the Onset of Cataract

Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic population, the burden of cataracts will grow. Cataract surgery is an effective way to restore vision; however, alternatives to cataract surgery are required to reduce the looming cataract epidemic. Since it is well established that oxidative damage plays a major role in the etiology of cataracts, antioxidants have been promoted as therapies to delay and/or prevent cataracts. However, many antioxidant interventions including vitamin C have produced mixed results as anti-cataract therapies. Progress has been made towards our understanding of lens physiology and the mechanisms involved in the delivery and uptake of antioxidants to the lens which may guide future studies aimed at addressing some of the inconsistencies seen in previous animal and human studies. Of interest is the potential for vitamin C based supplements in delaying the onset of cataracts post vitrectomy which occurs in up to 80% of patients within two years. These targeted approaches are required to reduce the burden of cataract on hospitals and improve the quality of life of our aging and diabetic population.

SERUM VITAMIN D LEVELS IN DIFFERENT MORPHOLOGIC FORMS OF AGE RELATED CATARACT

Purpose

Vitamin D insufficiency and age related cataract (ARC) are public health problems. We evaluated serum vitamin D levels in ARC patients.

Method

A prospective hospital-based cross-sectional study was designed to measure the vitamin D status of patients with ARC. Patients have grouped either presence of any type of posterior subcapsular cataract (PSC) (group 1) or ARC without the PSC component (Group 2). After full ophthalmologic consideration, patients over 40 years of age with no history of ocular trauma, multivitamin supplement ingestion, chronic renal failure, thyroidectomy, parathyroidectomy, skin cancer, and cigarette smoking were included in the study.

Results

Totally, 79 subjects of which 26 (32.9%) subjects in group 1 and 53 (67.1%) subjects in group 2 were included in the study. Group 1 had mean vitamin D levels of 17.31±13.30 ng/mL. Vitamin D levels in Group 2 were 13.34±7.87 ng/mL. Group 1 did not show vitamin D insufficiency (P = 0.31; one-sample t-test). However, Group 2 showed a statistically significantly lower vitamin D level compared to the insufficiency level of 20ng/mL (P= 0.00; one-sample t-test).

Conclusion

Vitamin D may have an important function in lens metabolism. Vitamin D deficiency and cataract development need further extensive researches.

The Association between Dietary Vitamin A and C Intakes and Cataract: Data from Korea National Health and Nutrition Examination Survey 2012

Oxidative stress in eye lens is one of the main causes of the cataract. Dietary antioxidants including vitamin A and C are therefore known to be associated with the risk of the disease. However, evidences are still lacking in Koreans. This study aimed to examine whether dietary vitamin A and C levels are associated with the cataract, using data of Korea National Health and Nutrition Examination Survey 2012. A total of 3,344 individuals (599 cases and 2,745 controls) were analyzed in the study. Dietary data was classified into 3 groups following Dietary Reference Intakes for Koreans 2015: 1) ≤ estimated average requirements (EAR), 2) EAR-recommended nutrient intake (RNI), and 3) ≥ RNI. Findings suggested normal subjects (controls) had better vitamin A and C nutritional status. Vitamin A and C intakes of normal subjects were significantly higher than those of cataract cases (p < 0.001, respectively). Ratio of subjects who consumed vitamin A and C lower than EAR was higher in cataract cases compared to normal subjects (p < 0.001, respectively). These antioxidant intake levels predicted that having lower level of vitamins lower than EAR increased the odd ratios (ORs) for cataract [for vitamin A: OR, 1.89; 95% confidence interval (CI), 1.55–2.31 and for vitamin C: OR, 2.06; 95% CI, 1.69–2.51]. However, such associations were not retained, when the subjects’ demographic and lifestyle factor were adjusted. In conclusion, vitamin A and C showed a protective effect against cataract. However, subjects' life style and demographic factors nullified the association. More studies are required to verify the true association between dietary antioxidants and risk of cataract in Koreans.

Are vitamins relevant to cancer risks? A Mendelian randomization investigation

OBJECTIVE

The relationship between vitamin intake and the occurrence of cancer is controversial. The aim of this study was to examine the genetic associations between vitamins D, E, and B₁₂ and five cancers (i.e., colorectal cancer, breast cancer, prostate cancer, malignant melanoma, and squamous cell carcinoma).

METHODS

This study started from genome-wide association data for three vitamins (N = 11 238) and five cancers (N = 373 316). The study analyzed their associations using Mendelian randomization (MR) methods. Additionally, survival analysis was performed using data from The Cancer Genome Atlas (TCGA) to further evaluate some MR results.

RESULTS

MR analysis indicated that intake of vitamins D, E, and B₁₂ is not relevant to the risk for the five cancers (P_MR > Bonferroni-corrected P = 0.02). Some of the results were supported by epidemiological observations; some were further supported by survival analysis using TCGA data.

CONCLUSION

There is no genetic evidence to support the association between intake of vitamins D, E, and B₁₂ and the risk for colorectal, breast, and prostate cancers, malignant melanoma, and squamous cell carcinoma.

Intake of Vegetables and Fruits and the Risk of Cataract Incidence in a Japanese Population: The Japan Public Health Center-Based Prospective Study

Background

Although the consumption of vegetables and fruits is reported to influence the risk of cataract, no prospective study of this association from Asia has yet appeared. Here, we investigated the association between vegetable and fruit intake and cataract incidence in a large-scale population-based prospective cohort study in Japan.

Methods

This study included 32,387 men and 39,333 women aged 45–74 years who had no past history of cataract and had completed a dietary questionnaire of the Japan Public Health Center-based Prospective Cohort Study. The incidence of cataract was evaluated after 5-year follow-up. We used multiple logistic regression analyses to estimate the sex-specific odds ratios (ORs), with adjustment for confounding factors.

Results

We identified 1,836 incident cataracts in 594 men and 1,242 women. In men, the OR for cataract was decreased with higher intake of vegetables (OR_{Q5 vs Q1}, 0.77; 95% confidence interval [CI], 0.59–1.01; P_trend across quartile categories = 0.03) and cruciferous vegetables (OR_{Q5 vs Q1}, 0.74; 95% CI, 0.57–0.96; P_trend = 0.02). In contrast, the OR for cataract was increased with higher intake of vegetables among women (OR_{Q5 vs Q1}, 1.28; 95% CI, 1.06–1.53; P_trend = 0.01). Green and yellow vegetable and fruit intake were not associated with cataract in either sex.

Conclusions

This study suggests that vegetables may reduce the risk of cataract in men, but not in women.

Nutritional effect on age-related cataract formation and progression

PURPOSE OF REVIEW

To provide a comprehensive summary of the latest evidence-based data on nutrients linked to the pathogenesis of cataract formation and progression.

RECENT FINDINGS

This summary of peer-reviewed publications emphasizes the ongoing effort to modulate the cataractogenous process through nutrition, and points at an only weak evidence for the contribution of a specific nutrient to this process. Although observational studies successfully demonstrated a positive correlation between specific nutrients intake and age-related cataract, such evidence was usually lacking in following interventional studies. Three metanalyses point towards a beneficial effect of high intake of vitamin C, vitamin E and vitamin A on the risk of age-related cataract. New studies point at a protective effect of a high intake of vitamin K1 and vitamin D but negate the influence of Mediterranean diet or an overall high dairy consumption on the progression of cataract in a subgroup of patients. Sterols are candidate nutrients for future investigation.

SUMMARY

Nutrition rich in fruits and vegetables, and a high dietary intake of vitamins A, C, D, E and K1 may be inversely associated with the risk of age-related cataract. More studies involving patients in a wide range of nutritional status are required to establish the long-term benefit of nutritional supplements.

Risk factors of presenile nuclear cataract in health screening study

Background

To identify risk factors for the development of presenile nuclear cataract in health screening test.

Methods

The cross sectional study included a total of 532 eyes of 266 participants aged 30 to 49 years of Samsung Medical Center from February 2013 to April 2015. Presence of nuclear cataract was defined when the log MAR visual acuity with correction was greater than or equal to 0.2 and one or more of the following were met: Pentacam Nuclear Staging (PNS) grading score ≥ 1, average value of nuclear density ≥ 15%, maximum value of nuclear density ≥ 30%. Possible risk factors were obtained from blood tests and questionnaires of a health screening test of Samsung Medical Center. Association between nuclear cataract and risk factors was investigated using univariate and multivariate logistic regression analysis by generalized estimating equation (GEE) models.

Results

Five factors were significantly associated with presenile nuclear cataract: current smoking [odds ratio (OR) = 2.80, 95% confidence interval (CI), 1.10–7.12, p = 0.0310], non-exercise and high amount of daily physical exercise (OR = 3.99, 95% CI, 1.27–12.52, p = 0.0178; OR = 2.92, 95% CI, 1.38–6.22, p = 0.0053), asthma (OR = 8.93, 95% CI, 1.12–71.15, p = 0.0386), tuberculosis (OR = 4.28, 95% CI, 1.36–13.50, p = 0.0131), and higher total iron binding capacity (OR = 1.01, 95% CI, 1.00–1.02, p = 0.0059).

Conclusions

Presenile nuclear cataract is related to current smoking, non-exercise or high amount of physical exercise, asthma, tuberculosis, and iron deficiency status. The association of non-exercise group and presenile nuclear cataract seems to be related to co-morbidity. Patients with asthma, tuberculosis, or iron deficiency anemia are recommended to receive frequent ophthalmic examination to detect cataract.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0928-6) contains supplementary material, which is available to authorized users.

Hidden Hunger: Solutions for America's Aging Populations

The global population, including the United States, is experiencing a demographic shift with the proportion of older adults (aged ≥ 65 years) growing faster than any other age group. This demographic group is at higher risk for developing nutrition-related chronic conditions such as heart disease and diabetes as well as infections such as influenza and pneumonia. As a result, an emphasis on nutrition is instrumental for disease risk reduction. Unfortunately, inadequate nutrient status or deficiency, often termed hidden hunger, disproportionately affects older adults because of systematic healthcare, environmental, and biological challenges. This report summarizes the unique nutrition challenges facing the aging population and identifies strategies, interventions, and policies to address hidden hunger among the older adults, discussed at the scientific symposium "Hidden Hunger: Solutions for America's Aging Population", on March 23, 2018.

Dairy products intake and the risk of incident cataracts surgery in an elderly Mediterranean population: results from the PREDIMED study

PROPOSAL

The aim of this study was to examine the association between the consumption of total and specific types of dairy products and the risk of incident cataracts in an elderly Mediterranean population at high cardiovascular risk.

METHODS

We prospectively analyzed 5860 subjects from the PREvención con DIeta MEDiterránea (PREDIMED) Study. The time to cataract surgery was calculated as the time between recruitment and the date of the surgery, last visit of the follow-up, date of death, or until the end of the study. Dairy products intake was assessed using validated food frequency questionnaires. We used Cox proportional hazard regression to assess the risk of cataract surgery according to average dietary energy-adjusted total dairy products, milk, yogurt and cheese consumption.

RESULTS

We documented a total of 768 new cataract events after a median of 5.6 years of follow-up. Subjects in the second [hazard ratio (HR) 0.62; 95% CI 0.52, 0.74] and third tertile (HR: 0.71; 95% CI 0.60, 0.85) of skimmed yogurt intake had a significantly lower risk of cataracts after adjusting for potential confounders. No significant associations were observed for total dairy products, whole and skimmed milk, whole yogurt and cheese consumption.

CONCLUSION

The intake of skimmed yogurt was associated with a reduced risk of cataracts in an elderly Mediterranean population with high cardiovascular risk. No significant associations were observed for other type of dairy product.

CLINICAL TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005.

The effects of antioxidants on ocular blood flow in patients with glaucoma

PURPOSE

To investigate the effects of an antioxidant dietary supplement that includes Ginkgo biloba, on retinal and retrobulbar blood flow in patients with open-angle glaucoma (OAG).

METHODS

Forty-five patients with confirmed OAG were enroled in a randomized, double blinded, placebo-controlled cross-over study. Baseline and postadministration measurements of intraocular pressure (IOP), ocular perfusion pressure (OPP), retrobulbar blood flow, and retinal capillary blood flow were non-invasively measured (ultrasound and laser Doppler modalities, respectively) before and one month after antioxidant nutraceuticals and placebo administration. Changes in measurements between the active supplement and placebo arms were evaluated using paired t-tests, with p < 0.05 considered statistically significant.

RESULTS

Antioxidant supplementation produced a statistically significant increase in peak systolic and/or end diastolic blood flow velocities in all retrobulbar blood vessels compared to placebo. Vascular resistance was also reduced in central retinal and nasal short posterior ciliary arteries following antioxidant administration. Additionally, antioxidant supplementation increased superior and inferior temporal retinal capillary mean blood flow and the ratio of active to non-active retina capillaries compared to placebo.

CONCLUSION

One-month oral administration of antioxidants produced increases in biomarkers of ocular blood flow within retinal and retrobulbar vascular beds in patients with OAG.

Association of Dietary Vitamin K1 Intake With the Incidence of Cataract Surgery in an Adult Mediterranean Population: A Secondary Analysis of a Randomized Clinical Trial

Importance

Cataract, one of the most frequent causes of blindness in developed countries, is strongly associated with aging. The exact mechanisms underlying cataract formation are still unclear, but growing evidence suggests a potential role of inflammatory and oxidative processes. Therefore, antioxidant and anti-inflammatory factors of the diet, such as vitamin K1, could play a protective role.

Objective

To examine the association between dietary vitamin K1 intake and the risk of incident cataracts in an elderly Mediterranean population.

Design, Setting, and Participants

A prospective analysis was conducted in 5860 participants from the Prevención con Dieta Mediterránea Study, a randomized clinical trial executed between 2003 and 2011. Participants were community-dwelling men (44.2%) and women (55.8%), and the mean (SD) age was 66.3 (6.1) years.

Main Outcomes and Measures

Dietary vitamin K1 intake was evaluated using a validated food frequency questionnaire. The time to the cataract event was calculated as the time between recruitment and the date of the occurrence to cataract surgery, the time to the last visit of the follow-up, date of death, or the end of the study. Hazard ratios and 95% CIs for cataract incidence were estimated with a multivariable Cox proportional hazards model.

Results

Participants were community-dwelling men (44.2%; n = 868) and women (55.8%; n = 1086), and the mean (SD) age was 66.3 (6.1) years. After a median of 5.6 years follow-up, we documented a total of 768 new cataracts. Participants in the highest tertile of dietary vitamin K1 intake had a lower risk of cataracts than those in the lowest tertile (hazard ratio, 0.71; 95% CI, 0.58-0.88; P = .002), after adjusting for potential confounders.

Conclusions and Relevance

High intake of dietary vitamin K1 was associated with a reduced risk of cataracts in an elderly Mediterranean population even after adjusting by other potential confounders.

Trial Registration

isrctn.org: ISRCTN35739639.

Ascorbic acid concentrations in aqueous humor after systemic vitamin C supplementation in patients with cataract: pilot study

Background

To measure ascorbic acid concentration in aqueous humor of patients with cataract after oral or intravenous vitamin C supplementation.

Methods

Forty-two eyes of 42 patients with senile cataract who underwent uncomplicated cataract surgery were enrolled. Patients (n = 14 each) were administered oral vitamin C (2 g), intravenous vitamin C (20 g) or no treatment (control group) on the day before surgery. Samples of aqueous humor (0.1 cm³) were obtained by anterior chamber aspiration at the beginning of surgery and stored at −80 °C. Ascorbic acid concentration in aqueous humor was measured by high-pressure liquid chromatography.

Results

The mean age at surgery was 62.5 years, with no difference among the three groups. The mean ± standard deviation concentrations of ascorbic acid in aqueous humor in the control and oral and intravenous vitamin C groups were 1347 ± 331 μmol/L, 1859 ± 408 μmol/L and 2387 ± 445 μmol/L, respectively. Ascorbic acid concentration was significantly lower in the control than in the oral (P < 0.01) and intravenous (P < 0.001) vitamin C groups and was significantly higher in the intravenous than in the oral vitamin C group (P < 0.05).

Conclusions

Ascorbic acid concentration in aqueous humor is increased by systemic vitamin C supplementation, with intravenous administration being more effective than oral administration.

Serum 25-hydroxyvitamin D and Age-Related Cataract

PURPOSE

Cataract and insufficient vitamin D intake are both increasing worldwide concerns, yet little is known about the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and age-related cataract. We performed this study to determine the association between serum 25(OH)D levels and age-related cataract in adults.

METHODS

Study participants comprised 16,086 adults aged 40 years or older who had never been diagnosed with or undergone surgery for cataract using Korean National Health and Nutrition Examination Survey data from 2008 to 2012. Participants were assessed to have cataract when diagnosed with cortical, nuclear, anterior subcapsular, posterior subcapsular, or mixed cataract. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the magnitude and significance of the association between serum 25(OH)D levels and cataract in multivariable logistic regression models.

RESULTS

The OR for nuclear cataract with the highest quintile of serum 25(OH)D levels was 0.86 (95% CI 0.75-0.99) compared to the lowest quintile. A linear trend across quintiles was significant. Natural log-transformed serum 25(OH)D levels were also significantly associated with nuclear cataract (OR 0.84, 95% CI 0.75-0.95). The opulation-attributable fraction of nuclear cataract due to serum 25(OH)D insufficiency (<30 ng/mL) was 8.8% (p = 0.048).

CONCLUSIONS

Serum 25(OH)D levels were inversely associated with the risk of nuclear cataract. Prospective studies investigating the effects of serum 25(OH)D levels on the development of nuclear cataract are needed to confirm our findings.

The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery

BACKGROUND

Cataract is a leading cause of vision impairment worldwide, and surgery is the only available treatment. The process that initiates lens opacification is dependent on the oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet (MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects.

METHODS

We included 5802 men and women (age range: 55-80 years) from the Prevención con Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups: (1) a MedDiet enriched with extra-virgin olive oil (EVOO) (n = 1998); (2) a MedDiet enriched with nuts (n = 1914), and a control group recommended to follow a low-fat diet (n = 1890). The incidence of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses were performed on an intention-to-treat basis. Cox regression analyses were used to assess the relationship between the nutritional intervention and the incidence of cataract surgery.

RESULTS

During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years), 559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence interval [CI]: 0.84-1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and 1.06 (95% CI: 0.86-1.31, p = 0.58) for the control group versus the MedDiet + Nuts group.

CONCLUSIONS

To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary to investigate whether a MedDiet could have a preventive role in cataract surgery.