A Vegetarian Diet Is Associated with a Lower Risk of Cataract, Particularly Among Individuals with Overweight: A Prospective Study

Are organics more nutritious than conventional foods? A comprehensive systematic review

The growing consumer interest fueled by the belief in the superiority of organic foods raises questions about their actual nutritional superiority over conventional ones. This assumption remains a controversial issue. The present study addresses scientific evidence to clarify this controversy and provide relevant insights for informed decision-making regarding dietary choices. We collected 147 scientific articles containing 656 comparative analyses based on 1779 samples of 68 vegetable, fruit, and other (cereals, pulses, etc.) foods, 22 nutritional properties, and nine residues. Results show that in 191 (29.1%) comparisons, there were significant differences between organic and conventional foods. In a similar quantity of cases (190; 29.0%), there were divergences in the results since some studies reported significant differences while others did not. Finally, most of the comparative analyses (275; 41.9%) showed no significant difference between organic and conventional foods. Therefore, the results herein show no generalizable superiority of organic over conventional foods. Claims for nutritious advantages would eventually be applied to specific comparisons, depending on the food type and nutritional parameter.

Diet and odor hedonic ratings: comparative study between vegetarians, flexitarians, and omnivores

OBJECTIVES

Odor hedonic perception is well known to exhibit great variability and to depend on several parameters, i.e. stimulus, context, and subject characteristics. As hedonic perception (pleasant/unpleasant character) of food odors is considered one of the most prominent dimensions in eating behavior, the question of hedonic variability in this context arises. Thus, the aim of the present study was to compare odor hedonic ratings in three populations with regard to diet (i.e. omnivore, vegetarian, and flexitarian diets).

METHODS

Four categories of odors were compared: meat, vegetable, other food, and non-food odors.

RESULTS

The results showed that vegetarian and flexitarian individuals rated meat odors as more unpleasant than omnivores, while no significant difference was found for other categories of odors.

DISCUSSION

The question of whether the diet influences the hedonic perception or/and inversely is discussed, regarding several aspects of food consumption such as eating disorders, food education, … and could further serve to manage eating behaviors.

PRACTICAL APPLICATIONS

This study evidenced that vegetarians and flexitarians specifically rated meat odors as being more unpleasant than those of omnivores. Because of the growing number of vegetarians and flexitarians in the general population, it could be suggested to take into account the odor hedonic perception (especially regarding food odors) in studies related to diets. Besides, the present results could further serve research in several aspects of food consumption such as eating disorders (anorexia, bulimia … etc.) or food education as well as the management of eating behaviors, especially in an elderly population.

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.

Fruit and vegetable intake and the risk of cataract: insights from the UK Biobank study

PURPOSE

A prospective cohort study to investigate the association between fruit and vegetable (F&V) intake and the risk of cataract.

METHODS

We included 72,160 participants who were free of cataract at baseline from the UK Biobank. Frequency and type of F&V intake were assessed using a web-based 24 h dietary questionnaire from 2009 to 2012. Development of cataract during the follow-up was defined by self-report or hospital inpatient records up to 2021. Cox proportional regression models were used to estimate the association between F&V intake and incident cataract.

RESULTS

During a mean follow-up of 9.1 years, 5753 participants developed cataract with a corresponding incidence of 8.0%. After adjusting for multiple demographic, medical and lifestyle covariates, higher intake of F&V were associated with a lower risk of cataract (≥6.5 vs. <2 servings/week: hazards ratio [HR]: 0.82, 95% CI: 0.76 to 0.89; P < 0.0001). Regarding specific types, significant reduced risk of cataract was found for higher intake of legumes (P = 0.0016), tomatoes (≥5.2 vs. <1.8 servings/week: HR: 0.94, 95% CI: 0.88 to 1.00), and apple and pear (>7 vs. <3.5 servings/week: 0.89, 95% CI: 0.83 to 0.94; P < 0.0001), but not for cruciferous vegetables, green leafy vegetables, berry, citrus fruit or melon. Smokers were found to benefit more from F&V intake than former and never smokers. Men also could benefit more from higher vegetable intake than women.

CONCLUSIONS

More F&V intake, especially legumes, tomatoes, apple, and pear, was associated with a lower risk of cataract in this UK Biobank cohort.

The relationship between dietary patterns and ophthalmic disease

PURPOSE OF REVIEW

There is a rising interest in the impact of diet on the pathogenesis of common ophthalmic conditions. The purpose of this review is to summarize the potential preventive and therapeutic power of dietary interventions described in recent basic science and epidemiological literature.

RECENT FINDINGS

Basic science investigations have elucidated a variety of mechanisms by which diet may impact ophthalmic disease, particularly through its action on chronic oxidative stress, inflammation and macular pigmentation. Epidemiologic investigations have shown the real-world influence of diet on the incidence and progression of a number of ophthalmic diseases, particularly cataract, age-related macular degeneration (AMD) and diabetic retinopathy. A large observational cohort study found a 20% reduction in the incidence of cataract among vegetarians compared with nonvegetarians. Two recent systematic reviews found that higher adherence to Mediterranean dietary patterns was associated with a decreased risk of progression of AMD to later stages. Finally, large meta-analyses found that patients following plant-based and Mediterranean diets had significant reductions of mean haemoglobin A1c scores and incidence of diabetic retinopathy as compared with controls.

SUMMARY

There is a significant and growing body of evidence that Mediterranean diet and plant-based diets - those that maximize fruits, vegetables, legumes, whole grains and nuts; and that minimize animal products and processed foods - help prevent vision loss from cataract, AMD and diabetic retinopathy. These diets may hold benefits for other ophthalmic conditions, as well. Nevertheless, there is a need for further randomized, controlled and longitudinal studies in this area.

Association of MTHFR C667T Polymorphism, Homocysteine, and B Vitamins with Senile Cataract

Senile cataract has become the leading cause of visual impairment and even blindness in the world, but there are few reports on its relationship with methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms. This study is aimed to investigate the correlation between MTHFR gene polymorphisms or its enzyme metabolites and senile cataract. From January 2019 to June 2020, 663 patients with senile cataract at the Mianyang Central Hospital were enrolled as the observation group, and 646 healthy subjects were randomly selected as the control group. MTHFR gene polymorphisms (i.e., CC, CT, or TT genotypes) and serum homocysteine (HCY), folic acid (FOL), vitamin B12 (VitB12), and vitamin B6 (VitB6) levels were detected. The mutation rate of MTHFR C677T and HCY levels in the observation group were significantly higher than those in the control group, whereas FOL, VitB12, and VitB6 were significantly lower. With an increase in the MTHFR C677T mutation, HCY showed an upward trend, whereas FOL and VitB12 showed a decreasing trend in both the observation and control groups. Multiple logistic regression analysis showed that HCY and FOL were associated with senile cataract and MTHFR mutations; VitB12 was only associated with senile cataract. Compared to that with the CC genotype, CT and TT genotypes were associated with an increased senile cataract risk. Monitoring MTHFR gene polymorphisms and changes in serum HCY, FOL, and VitB12 levels could provide references in predicting senile cataract.

Association between Healthy Eating Index-2015 and Age-Related Cataract in American Adults: A Cross-Sectional Study of NHANES 2005-2008

BACKGROUND

Healthy Eating Index-2015 (HEI-2015), a healthy eating pattern proposed by Dietary Guidelines for Americans, is proven to be protective against various diseases. However, whether it is associated with age-related cataracts is unknown.

METHODS

This population-based cross-sectional study included 6395 participants from the National Health and Nutrition Examination Survey (NHANES) in the cycles from 2005 to 2008. HEI-2015 was calculated from 24-h dietary recall interviews, ranging from 0 to 100, and higher HEI-2015 represents better diet quality. Age-related cataract was generated from the questionnaire. The association between HEI-2015 and cataract was assessed with logistic regression models. Propensity score weighting, restricted cubic spline, and subgroup analysis were conducted to further explore the relationship.

RESULTS

6395 participants were included in the study, with a mean [standard deviation (SD)] age of 48.7 (15.3) years and 3115 (48.7%) being male. HEI-2015 was negatively associated with cataracts after adjusting all covariates included, both as a continuous variable [odds ratio (OR): 0.991, 95% confidence interval (CI): 0.984-0.997, p = 0.006] and quartiles with the highest quartile compared to the lowest (OR: 0.739, 95% CI: 0.559-0.980, p = 0.035). After propensity score weighting, the association remained significant. Restricted cubic spline revealed no non-linear relationship (p for non-linearity 0.085). Subgroup analysis showed that there were no interaction effects.

CONCLUSIONS

Adherence to the healthy eating pattern, HEI-2015, was associated with a lower risk of age-related cataracts.

Health sector solutions for promoting sustainable and nutritious diets

Renzo R Guinto and colleagues discuss why the health sector must embrace the planetary health approach and advocate concrete solutions for fixing the food system