Vitamin E and risk of age-related cataract: a meta-analysis

Smoking, dietary factors and major age-related eye disorders: an umbrella review of systematic reviews and meta-analyses

BACKGROUND

There is accumulating evidence of the associations between age-related eye diseases (AREDs) and smoking or dietary factors. We aimed to provide an umbrella review of the published literature pertaining to smoking or dietary intake as risk factors for major AREDs including cataract, glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy.

METHODS

We searched for pertinent systematic reviews or meta-analyses in PubMed and Web of Science until 16 April 2022. We reperformed the meta-analysis of each association using random effects models. The heterogeneity and 95% prediction interval were calculated. The presence of small-study effect or excess significance bias was also assessed.

RESULTS

In total, 64 associations from 25 meta-analyses and 41 associations from 10 qualitative systematic reviews were evaluated. There was convincing (class I) evidence for only one association, namely current smoking and cataract. Two factors had highly suggestive (class II) evidence, namely ever smoking associated with cataract and fish consumption associated with AMD. We also found suggestive (class III) evidence for associations between the dietary intake of omega-3 polyunsaturated fatty acid, lutein, zeaxanthin, vitamin C and the risk of cataract.

CONCLUSIONS

Smoking as a risk factor for cataract was the most robust association we identified. We also identified several dietary elements associated with AREDs. Large prospective studies are warranted to further examine the associations discussed in this review.

PROSPERO REGISTRATION NUMBER

CRD42022339082.

Oxidative stress in the eye and its role in the pathophysiology of ocular diseases

Oxidative stress occurs through an imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defense mechanisms of cells. The eye is particularly exposed to oxidative stress because of its permanent exposure to light and due to several structures having high metabolic activities. The anterior part of the eye is highly exposed to ultraviolet (UV) radiation and possesses a complex antioxidant defense system to protect the retina from UV radiation. The posterior part of the eye exhibits high metabolic rates and oxygen consumption leading subsequently to a high production rate of ROS. Furthermore, inflammation, aging, genetic factors, and environmental pollution, are all elements promoting ROS generation and impairing antioxidant defense mechanisms and thereby representing risk factors leading to oxidative stress. An abnormal redox status was shown to be involved in the pathophysiology of various ocular diseases in the anterior and posterior segment of the eye. In this review, we aim to summarize the mechanisms of oxidative stress in ocular diseases to provide an updated understanding on the pathogenesis of common diseases affecting the ocular surface, the lens, the retina, and the optic nerve. Moreover, we discuss potential therapeutic approaches aimed at reducing oxidative stress in this context.

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.

Vitamin E - a scoping review for Nordic Nutrition Recommendations 2023

Current evidence suggests that dietary vitamin E (as α-tocopherol) intake has a beneficial role in preventing certain chronic diseases. In contrast, there is no clear evidence for the benefit of α-tocopherol supplements in a generally healthy population. Deficiency symptoms are rare and mainly occur due to genetic or other factors affecting α-tocopherol absorption and/or metabolism, rather than a low α-tocopherol intake. No qualified systematic review was identified by the NNR2023 project for updating the dietary reference values (DRV).

Vitamin E and Multiple Health Outcomes: An Umbrella Review of Meta-Analyses

The relationship between vitamin E intake or circulating α-tocopherol and various health outcomes is still debatable and uncertain. We conducted an umbrella review to identify the relationships between vitamin E intake or circulating tocopherol and health outcomes by merging and recalculating earlier meta-analyses. The connections that were found to be statistically significant were then classified into different evidence levels based on p values, between-study heterogeneity, prediction intervals, and small study effects. We finally included 32 eligible meta-analyses with four vitamin E sources and 64 unique health outcomes. Only the association between circulating α-tocopherol and wheeze or asthma in children was substantiated by consistent evidence. Suggestive evidence was suggested for seven results on endothelial function (supplemental vitamin E): serum C-reactive protein (CRP) concentrations (supplemental vitamin E), cervical cancer (dietary vitamin E), esophageal cancer (dietary vitamin E), cervical intraepithelial neoplasia (CIN, dietary vitamin E), pancreatic cancer (total vitamin E intake), and colorectal cancer (circulating α-tocopherol levels); all of these showed a protective effect consistent with the vitamin E source. In conclusion, our work has indicated that vitamin E is protective for several particular health outcomes. Further prospective studies are required when other factors that may contribute to bias are considered.

Is Cataract in Patients under 60 Years Associated with Oxidative Stress?

Oxidative stress is considered as a possible factor in the genesis of cataract. The study aimed to determine the systemic antioxidant status in cataract patients under 60 years. We studied 28 consecutive cataract patients, mean of 53 years (SD = 9.2), a range of 22-60 and 37 controls. In erythrocytes, activity of antioxidant enzymes was determined: superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), in contrast with plasma concentrations of vitamin A and E. Conjugated dienes (CD) level and protein carbonyls (PC) concentration were also determined in plasma. Malondialdehyde (MDA) concentrations in erythrocytes and plasma were also measured. SOD and GPx activity and vitamin A and E concentrations were lower in cataract patients (p = 0.000511, 0.02, 0.022, and 0.000006, respectively). MDA plasma and erythrocytes concentrations were higher in cataract patients (p = 0.000001 and 0.0000001, respectively). PC concentration was higher in cataract patients than in controls (p = 0.00000013). There were statistically significant correlations between oxidative stress markers both in the cataract patients group as well as in the control group. Cataract incidence in patients under 60 years seems to be accompanied by enhanced lipid peroxidation and protein oxidation, as well as antioxidant defense depletion. Thus, supplementation with antioxidants could be beneficial in this group of patients.

Circ_HIPK3 Inhibits H2O2-Induced Lens Epithelial Cell Injury in Age-Related Cataract Depending on the Regulation of miR-495-3p/HDAC4 Pathway

Age-related cataract (ARC) is one of the most common chronic diseases. Circular RNA (circ)_HIPK3 is reported to be involved in the advancement of ARC, but its molecular mechanism has not been clarified. Our study provides a new perspective on the clinical treatment of ARC. Our data showed that the expression levels of circ_HIPK3 and histone deacetylase 4 (HDAC4) were downregulated, while microRNA (miR)-495-3p level was increased in ARC tissues and H₂O₂-induced SRA01/04 cells. Functional experiments showed that circ_HIPK3 and HDAC4 overexpression could inhibit H₂O₂-induced lens epithelial cell apoptosis and fibrosis. In terms of mechanism, we found that circ_HIPK3 could sponge miR-495-3p, miR-495-3p could target HDAC4. Besides, we confirmed that circ_HIPK3 sponged miR-495-3p to positively regulate HDAC4. Additionally, miR-495-3p overexpression or HDAC4 knockdown reversed the inhibition effect of circ_HIPK3 on H₂O₂-induced lens epithelial cell injury. In conclusion, our data showed that circ_HIPK3 suppressed H₂O₂-induced lens epithelial cell injury by regulating miR-495-3p/HDAC4 axis.

The Pathomechanism, Antioxidant Biomarkers, and Treatment of Oxidative Stress-Related Eye Diseases

Oxidative stress is an important pathomechanism found in numerous ocular degenerative diseases. To provide a better understanding of the mechanism and treatment of oxidant/antioxidant imbalance-induced ocular diseases, this article summarizes and provides updates on the relevant research. We review the oxidative damage (e.g., lipid peroxidation, DNA lesions, autophagy, and apoptosis) that occurs in different areas of the eye (e.g., cornea, anterior chamber, lens, retina, and optic nerve). We then introduce the antioxidant mechanisms present in the eye, as well as the ocular diseases that occur as a result of antioxidant imbalances (e.g., keratoconus, cataracts, age-related macular degeneration, and glaucoma), the relevant antioxidant biomarkers, and the potential of predictive diagnostics. Finally, we discuss natural antioxidant therapies for oxidative stress-related ocular diseases.

Reported evidence of vitamin E protection against cataract and glaucoma

Cataract and glaucoma are the major causes of severe visual loss and blindness in older adults. This review article describes the currently available basic and clinical evidence regarding vitamin E protection against these eye diseases in the chronologic order of the publications. Experimental evidence has suggested both that oxidative stress due to the accumulation of free radicals plays a role in the pathogenesis of cataracts and glaucoma and that the process can be prevented or ameliorated by vitamin E. The results of observational studies have been inconsistent regarding the association between blood vitamin E levels and the risk of age-related cataract or glaucoma. Despite the encouraging effects of vitamin E from case series, case-control studies, and cross-sectional studies in humans, the effects on cataract formation and/or progression have not been consistent among prospective and randomized control studies; few randomized control studies have tested the effects of supplemental vitamin E on glaucoma development or progression. Given the high prevalence of cataract and glaucoma in the elderly population, even a modest reduction in the risk for these eye diseases would potentially have a substantial public health impact; however, the potential benefits of vitamin E on cataract or glaucoma remain inconclusive and need to be carefully considered.

Cataract: Advances in surgery and whether surgery remains the only treatment in future

Background

Cataract is the world's leading eye disease that causes blindness. The prevalence of cataract aged 40 years and older is approximately 11.8%-18.8%. Currently, surgery is the only way to treat cataracts.

Main Text

From early intracapsular cataract extraction to extracapsular cataract extraction, to current phacoemulsification cataract surgery, the incision ranges from 12 to 3 ​mm, and sometimes to even 1.8 ​mm or less, and the revolution in cataract surgery is ongoing. Cataract surgery has transformed from vision recovery to refractive surgery, leading to the era of refractive cataract surgery, and premium intraocular lenses (IOLs) such as toric IOLs, multifocal IOLs, and extended depth-of-focus IOLs are being increasingly used to meet the individual needs of patients. With its advantages of providing better visual acuity and causing fewer complications, phacoemulsification is currently the mainstream cataract surgery technique worldwide. However, patient expectations for the safety and accuracy of the operation are continually increasing. Femtosecond laser-assisted cataract surgery (FLACS) has entered the public's field of vision. FLACS is a combination of new laser technology and artificial intelligence to replace fine manual clear corneal incision, capsulorhexis, and nuclear pre-fragmentation, providing new alternative technologies for patients and ophthalmologists. As FLACS matures, it is being increasingly applied in complex cases; however, some think it is not cost-effective. Although more than 26 million cataract surgeries are performed each year, there is still a gap in the prevalence of cataracts, especially in developing countries. Although cataract surgery is a nearly ideal procedure and complications are manageable, both patients and doctors dream of using drugs to cure cataracts. Is surgery really the only way to treat cataracts in the future? It has been verified by animal experiments that lanosterol therapy in rabbits and dogs could make cataract severity alleviated and lens transparency partially recovered. Although there is still much to learn about cataract reversal, this groundbreaking work provided a new strategy for the prevention and treatment of cataracts.

Conclusions

Although cataract surgery is nearly ideal, it is still insufficient, we expect the prospects for cataract drugs to be bright.

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.

Major dietary patterns in relation to age-related cataract

BACKGROUND AND AIMS

Dietary pattern (DP) may play an important role in the formation of Age-related cataract (ARC). The objective of the study was to investigate the association between DP and ARC.

METHODS

Participants (120 cases and 240 controls) aged 50-80 years were selected from the ophthalmology clinic of Urmia Imam Khomeini Educational Hospital in the Northwest of Iran by the simple random sampling method between 2017 and 2018. Participants in matched case-control study were free of diabetes, autoimmune diseases and cancer. Factor analysis method was used to identify the major DPs. The association between participants' DPs and ARC were evaluated using logistic regression analysis in SPSS20.

RESULTS

Four major DPs were found and nominated: "Unhealthy", "Healthy", "Salty foods" and "Mixed" patterns. In continues model the Unhealthy pattern was positively associated with the risk of ARC disease (odds ratio in adjusted model was 5.71; 95% CI: 3.68-8.87, P _trend< 0.001). The Healthy pattern was inversely associated with the ARC (odds ratio in adjusted model was 0.48; 95% CI: 0.34-0.67, P_trend = 0.02). The Salty foods pattern was associated with ARC (odds ratio in adjusted model was 1.45; 95% CI; 1.04-2.02, P_trend = 0.03). The association between ARC disease and Mixed patterns was not statistically significant.

CONCLUSION

The results indicate that Unhealthy and Salty foods patterns were associated with increased risk of ARC. Further prospective studies are needed to confirm such an association.

Advances in pharmacotherapy of cataracts

Cataracts, the leading cause of vision impairment worldwide, arise from abnormal aggregation of lens proteins. According to the World Health Organization, cataracts cause more than 40% of blindness cases. As the population ages, the prevalence of cataracts will increase rapidly. Although cataract surgery is regarded as effective, it still suffers from complications and high cost, and could not meet the increasingly surgery demand. Therefore, pharmacological treatment for cataracts is a cheaper and more readily available option for patients, which is also a hot topic for years. Anti-cataract drug screening was previously mainly based on the specific pathogenic factors: oxidative stress, excess of quinoid substances, and aldose reductase (AR) activation. And several anti-cataract drugs have been applied in the clinic, while the effect is still unsatisfied. Makley and Zhao recently identified two kinds of novel pharmacological substances (25-hydroxycholesterol, lanosterol) that can reverse lens opacity by dissolving the aggregation of crystallin proteins, indicating that protein aggregation is not an endpoint and could be reversed with specific small-molecule drugs, significantly boosting the development of the cataract pharmacopeia and being regarded as a new dawn for cataract treatment. Our team built a novel optimized platform and had screened several potential therapeutic agents from a collection of lanosterol derivatives. In this review, we would mainly focus on the advancement of cataract pharmacotherapy based on the targets for anti-cataract drugs.

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.

Botany, traditional uses, phytochemistry and biological activities of cardamom [Elettaria cardamomum (L.) Maton] - A critical review

ETHNOPHARMACOLOGICAL RELEVANCE

Small cardamom [Elettaria cardamomum (L.) Maton. (Family: Zingiberaceae)] capsules (fruits) have been used for traditional medicine applications including for the control of asthma, teeth and gum infections, cataracts, nausea, diarrhea, as well as cardiac, digestive and kidney disorders. The versatile use of cardamom capsules has several other beneficial health effects that are relevant in light of traditional and modern pharmaceutical perspectives.

AIM OF THE STUDY

This review aims to provide a critical and comprehensive evaluation of the traditional and current medical uses of E. cardamomum, and compare these applications with modern research studies. This critical review also discusses the botanical distribution, phytochemical constituents and biological activities of cardamom capsule extracts and essential oil.

MATERIALS AND METHODS

An online survey was conducted of the traditional uses, phytochemical composition, and pharmacological applications of cardamom essential oil (CEO) and extracts. Pertinent data were obtained from several electronic scientific databases (Science Direct, Elsevier, Web of Science, PubMed, Springer, ACS publications, Taylor and Francis, Wiley On-line Library and Google Scholar), and additional information was obtained from textbooks and local prints and scripts.

RESULTS

Cardamom fruits (capsules) are used widely as a spice and flavoring ingredient in foods, and are often recognized for their beneficial health properties. They are also used in fragrances. Phytochemical analyses have described important chemical constituents of cardamom including carbohydrates, proteins, minerals, lipids, essential oils, flavonoids, terpenoids and carotenoids. CEO has several biological roles including antioxidant, antidiabetic, antibacterial, anticancer, gastro-protective and insecticidal activities.

CONCLUSION

The widespread availability and recommendation of synthetic compounds for addressing human health have several side effects besides higher costs. Hence, examining natural bioactive compounds is imperative. This review investigates and presents the pertinent information on cardamom and its traditional uses, as well as potential pharmacological properties of CEO and extracts. Additional research studies are needed to understand the mechanism of action of bioactive constituents.

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.

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.

Novel approaches for improving stability of cysteamine formulations

Cystinosis is a genetic disorder that leads to the formation of cystine crystals in many organs in the body including cornea. Ocular manifestation of this disease is treated by eye drops of cysteamine which can easily oxidize into its disulfide cystamine. The rapid oxidation limits the shelf life as well the duration during which the drug can be used after opening the eye drop bottle. We evaluate two approaches of preventing the oxidation of cysteamine with the goal of increasing the time of use after opening the bottle to one month. The first approach integrates antioxidants such as catalase enzyme and vitamins C and E into the aqueous solution. Results show that catalase is the most effective additive as it decreases the oxidation rate by 58%, which on its own is not sufficient to reach targeted one month stability. The second approach focuses on incorporating diffusion barriers to prevent oxygen from reaching the cysteamine solution. This was accomplished by two methods: formulation of a hydrophobic layer which floats on the surface of the aqueous solution and integration of OMAC® oxygen-resistant material into the eye drop bottle. Both methods delay the onset of cysteamine degradation and decrease the rate of degradation. In particular, an eye drop bottle with three layers of OMAC® has less than 10% degradation after one month of opening the bottle and withdrawing a drop each day. By integrating all three methods, we designed a system where >90% of cysteamine remains in the active form for 70 days after opening the bottle. In addition, we examine the use of OMAC® as heat-sealed pouches for storage of cysteamine eye drop bottles during packaging to eliminate the need for the current approach of freezing the formulation during shipping. The results show that such heat-sealed pouches would keep cysteamine stable for over one year at ambient conditions.

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 Association of Cataract and Lens Epithelial Cell Apoptosis in Patients with Pseudoexfoliation Syndrome

PURPOSE

The aim of this study was to measure the density of apoptotic lens epithelial cells (LECs) and to determine its association with cataract formation in eyes with pseudoexfoliation syndrome (PEX).

MATERIALS AND METHODS

Twenty-one eyes of 21 patients diagnosed with PEX without glaucoma (Group 1) and 22 eyes of 22 subjects without PEX (Group 2) were enrolled in this study. During cataract surgery, anterior capsule samples were obtained by the 5.5 mm continuous curvilinear capsulorhexis method. Apoptosis was determined with a TUNEL kit (Boster, Wuhan, China) according to the manufacturer's protocol. Four fields in each pathology preparation were chosen randomly under a microscope, and 100 cells were counted in each field to calculate the apoptosis rates.

RESULTS

Forty-three eyes of 43 subjects were enrolled in this study. There were no significant differences in age or sex between the two studied groups (p > 0.05). Under a microscope, the LECs were stained light blue and their nuclei were oval shaped. Positive stained cells were found occasionally in Group 2, while a significant amount of black-brown positively stained LECs with condensed nuclei was found in Group 1. The apoptosis rates were 35.2 ± 2.1% and 14.1 ± 1% in Groups 1 and 2, respectively. The proportion of positively stained LECs was higher in Group 1 (p < 0.001).

CONCLUSION

Our study suggests that apoptosis in LECs is the pathophysiological mechanism for the higher rate of cataracts in PEX patients, in addition to the ocular ischemia hypothesis.

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.

Nutrient patterns and risk of cataract: a case-control study

AIM

To assess the relation between nutrient patterns and cataract risk.

METHODS

This is a hospital-based case-control study with 97 cataract patients and 198 matched controls. Dietary consumption was collected through a valid food frequency questionnaire (FFQ). Nutrient patterns were detected by applying factor analysis. Unconditional logistic regression models were used to estimate odds ratio (ORs) and 95%CIs.

RESULTS

We extracted 5 main nutrient patterns. Factor 1 included niacin, thiamin, carbohydrates, protein, zinc, vitamin B6 and sodium (sodium pattern). Factor 2 was characterized by oleic acid, monounsaturated fats, polyunsaturated fats, linoleic acid, trans fatty acid, linolenic acid, vitamin E and saturated fats (fatty acid pattern). The third factor represented high intake of vitamin B12, vitamin D, cholesterol and calcium (mixed pattern). The 4^th pattern was high in intake of beta and alpha carotene, vitamin A and vitamin C (antioxidant pattern). Finally, the 5^th pattern loaded heavily on docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) (omega-3 pattern). In crude and multivariate analysis, the sodium pattern was associated with increased risk of cataract (OR=1.97, 95%CI: 1.09-3.96). The fatty acid pattern elevated the risk of cataract (OR=1.94, 95%CI: 1.1-3.86). Antioxidant pattern was associated with a significant 79% reduced risk (2^nd category compared with the 1^st). Omega-3 pattern was significantly negatively associated with risk of cataract (P=0.04).

CONCLUSION

These findings imply that nutrient patterns reflecting a combined consumption of nutrients might be important in the etiology of cataract. Additional studies with more efficient designs are warranted to confirm our findings.

Tocopherols and Tocotrienols in Common and Emerging Dietary Sources: Occurrence, Applications, and Health Benefits

Edible oils are the major natural dietary sources of tocopherols and tocotrienols, collectively known as tocols. Plant foods with low lipid content usually have negligible quantities of tocols. However, seeds and other plant food processing by-products may serve as alternative sources of edible oils with considerable contents of tocopherols and tocotrienols. Tocopherols are among the most important lipid-soluble antioxidants in food as well as in human and animal tissues. Tocopherols are found in lipid-rich regions of cells (e.g., mitochondrial membranes), fat depots, and lipoproteins such as low-density lipoprotein cholesterol. Their health benefits may also be explained by regulation of gene expression, signal transduction, and modulation of cell functions. Potential health benefits of tocols include prevention of certain types of cancer, heart disease, and other chronic ailments. Although deficiencies of tocopherol are uncommon, a continuous intake from common and novel dietary sources of tocopherols and tocotrienols is advantageous. Thus, this contribution will focus on the relevant literature on common and emerging edible oils as a source of tocols. Potential application and health effects as well as the impact of new cultivars as sources of edible oils and their processing discards are presented. Future trends and drawbacks are also briefly covered.