A Mediterranean Diet May Be Protective in the Development of Diabetic Retinopathy

Mediterranean diet and diabetic microvascular complications: a systematic review and meta-analysis

BACKGROUND

Diabetic microvascular complications, including diabetic retinopathy (DR), diabetic nephropathy (DN), and diabetic peripheral neuropathy (DPN), contribute significantly to morbidity and healthcare burdens among individuals with diabetes. The Mediterranean diet (MD) has been associated with improved metabolic health, but its role in mitigating microvascular complications remains unclear. This systematic review and meta-analysis aimed to assess the impact of MD adherence on the risk and progression of these complications.

METHODS

A comprehensive search of PubMed, Web of Science, Embase, and Scopus was conducted through February 12, 2025 to identify studies evaluating MD adherence and diabetic microvascular complications. Meta-analysis was performed where possible, with effect sizes reported as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Fourteen studies, encompassing 138 to 71,392 participants, were included. Meta-analysis indicated a significant reduction in DR risk among individuals adhering to the MD (HR: 0.69, 95% CI: 0.49-0.97, p = 0.03; OR: 0.32, 95% CI: 0.12-0.82, p = 0.02). A lower likelihood of DN development was observed (HR: 0.85, 95% CI: 0.73-0.99, p = 0.04; OR: 0.49, 95% CI: 0.25-0.96, p = 0.04). However, results for diabetic neuropathy were inconclusive due to study heterogeneity. Sensitivity analyses revealed notable heterogeneity and publication bias was detected in some analyses.

CONCLUSION

Adherence to the Mediterranean diet is associated with a reduced risk of diabetic nephropathy and retinopathy, supporting its potential as a dietary intervention for diabetes management. However, the evidence for neuropathy remains inconclusive. Future well-controlled randomized trials are needed to strengthen causal inferences and refine clinical recommendations for MD-based interventions in diabetic microvascular complications.

Prevalence and associated factors of epiretinal membrane using spectralis OCT in Fujian Eye Study

We aimed to determine the prevalence and risk factors of epiretinal membrane in a population-based study of residents aged 50 years and older in Fujian Province, Southeast China. The Fujian Eye Study is a population-based cross-sectional eye study in Fujian province, Southeast China. Residents aged 50 years and older were enrolled and did the questionnaire (educational background, income, blood type, disease history, medication history, smoking, drinking and tea consumption, et al.), physical and ophthalmological examinations with height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), refraction, intraocular pressure (IOP), slit lamp, nonmydriatic fundus photograph and spectralis optical coherence tomography (OCT) imaging. Nonmydriatic fundus photograph and Spectralis OCT were used to assess ERM according to a standardised protocol. A total of 8173 residents were included in this study. Among them, 8.42% (95% CI 0.0782-0.0902) had ERM in at least one eye. Multiple logistic regression showed the presence of ERM was only associated with urbanization and geographic location, but not with age, sex, refractive error, IOP, SBP, DBP, HR, BMI, hypertension, diabetic mellitus, hyperlipidemia, education, income, smoking, alcohol and tea consumption. ERM is common among Chinese with 8.42% in at least one eye. Urbanization and geographic location are the only associated factors for ERM in Fujian Eye Study.

Oxidative stress and retinopathy: evidence from epidemiological studies

BACKGROUND

Previous studies have suggested oxidative stress may play a key role in the pathogenesis of retinopathy, while evidence from observational studies directly linking oxidative biomarkers to clinically relevant outcomes has been limited. This study aims to investigate the association between oxidative balance score (OBS) and prevalence of retinopathy in a nationally representative sample of U.S. adults, including both those with and without diabetes.

METHODS

Data were obtained from the NHANES 2005-2008, including 3,287 participants. OBS was calculated from 16 dietary and 4 lifestyle components and categorized into tertiles. Weighted logistic regression was used to assess the association between OBS and retinopathy in the overall, diabetic, and non-diabetic populations, and Cox proportional hazards models evaluated the link between OBS and all-cause mortality in those with retinopathy. Restricted cubic spline (RCS) analysis explored the dose-response relationship between OBS and retinopathy. Subgroup analyses and interaction tests were conducted based on age, sex, race, BMI, education level, and diabetes status.

RESULTS

Participants in the highest OBS tertile had a 28% lower risk of retinopathy compared to those in the lowest tertile (OR 0.72, 95% CI 0.54-0.95, P = 0.023). RCS analysis showed a significant overall association between higher OBS and reduced retinopathy risk, without a nonlinear pattern. In participants with retinopathy, higher OBS was linked to a 60% reduction in all-cause mortality (HR 0.40, 95% CI 0.24-0.66, P < 0.001). Subgroup analysis revealed stronger inverse associations between OBS and retinopathy in younger individuals and those with higher education, with a significant interaction between OBS and age (P for interaction < 0.05).

CONCLUSION

Our study provides evidence that higher cumulative antioxidant exposure assessed by OBS is associated with a reduced risk and severity of retinopathy and lower all-cause mortality in U.S. adults with retinopathy, highlighting the importance of maintaining a favorable oxidative balance in retinal health.

Re-Assessing the Role of Platelet Activating Factor and Its Inflammatory Signaling and Inhibitors in Cancer and Anti-Cancer Strategies

Since 2000s, we have outlined the multifaceted role of inflammation in several aspects of cancer, via specific inflammatory mediators, including the platelet activating factor (PAF) and PAF-receptor (PAFR) related signaling, which affect important inflammatory junctions and cellular interactions that are associated with tumor-related inflammatory manifestations. It is now well established that disease-related unresolved chronic inflammatory responses can promote carcinogenesis. At the same time, tumors themselves are able to promote their progression and metastasis, by triggering an inflammation-related vicious cycle, in which PAF and its signaling play crucial role(s), which usually conclude in tumor growth and angiogenesis. In parallel, new evidence suggests that PAF and its signaling also interact with several inflammation-related cancer treatments by inducing an antitumor immune response or, conversely, promoting tumor recurrence. Within this review article, the current knowledge and future perspectives of the implication of PAF and its signaling in all these important aspects of cancer are thoroughly re-assessed. The potential beneficial role of PAF-inhibitors and natural or synthetic modulators of PAF-metabolism against tumors, tumor progression and metastasis are evaluated. Emphasis is given to natural and synthetic molecules with dual anti-PAF and anti-cancer activities (Bio-DAPAC-tives), with proven evidence of their antitumor potency through clinical trials, as well as on metal-based anti-inflammatory mediators that constitute a new class of potent inhibitors. The way these compounds may promote anti-tumor effects and modulate the inflammatory cellular actions and immune responses is also discussed. Limitations and future perspectives on targeting of PAF, its metabolism and receptor, including PAF-related inflammatory signaling, as part(s) of anti-tumor strategies that involve inflammation and immune response(s) for an improved outcome, are also evaluated.

Effect of the Mediterranean Diet (MeDi) on the Progression of Retinal Disease: A Narrative Review

Worldwide, the number of individuals suffering from visual impairment, as well as those affected by blindness, is about 600 million and it will further increase in the coming decades. These diseases also seriously affect the quality of life in working-age individuals. Beyond the characterization of metabolic, genetic, and environmental factors related to ocular pathologies, it is important to verify how lifestyle may participate in the induction of the molecular pathways underlying these diseases. On the other hand, scientific studies are also contributing to investigations as to whether lifestyle could intervene in modulating pathophysiological cellular responses, including the production of metabolites and neurohormonal factors, through the intake of natural compounds capable of interfering with molecular mechanisms that lead to ocular diseases. Nutraceuticals are promising in ameliorating pathophysiological complications of ocular disease such as inflammation and neurodegeneration. Moreover, it is important to characterize the nutritional patterns and/or natural compounds that may be beneficial against certain ocular diseases. The adherence to the Mediterranean diet (MeDi) is proposed as a promising intervention for the prevention and amelioration of several eye diseases. Several characteristic compounds and micronutrients of MeDi, including vitamins, carotenoids, flavonoids, and omega-3 fatty acids, are proposed as adjuvants against several ocular diseases. In this review, we focus on studies that analyze the effects of MeDi in ameliorating diabetic retinopathy, macular degeneration, and glaucoma. The analysis of knowledge in this field is requested in order to provide direction on recommendations for nutritional interventions aimed to prevent and ameliorate ocular diseases.

Adherence to a Mediterranean diet is associated with a lower risk of diabetic kidney disease among individuals with hyperglycemia: a prospective cohort study

BACKGROUND

Type 2 diabetes is associated with a variety of complications, including micro- and macrovascular complications, neurological manifestations and poor wound healing. Adhering to a Mediterranean Diet (MED) is generally considered an effective intervention in individuals at risk for type 2 diabetes mellitus (T2DM). However, little is known about its effect with respect to the different specific manifestations of T2DM. This prompted us to explore the effect of MED on the three most significant microvascular complications of T2DM: diabetic retinopathy (DR), diabetic kidney disease (DKD), and vascular diabetic neuropathies (DN).

METHODS

We examined the association between the MED and the incidence of these microvascular complications in a prospective cohort of 33,441 participants with hyperglycemia free of microvascular complications at baseline, identified in the UK Biobank. For each individual, we calculated the Alternate Mediterranean Diet (AMED) score, which yields a semi-continuous measure of the extent to which an individual's diet can be considered as MED. We used Cox proportional hazard models to analyze hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics, lifestyle factors, medical histories and cardiovascular risk factors.

RESULTS

Over a median of 12.3 years of follow-up, 3,392 cases of microvascular complications occurred, including 1,084 cases of diabetic retinopathy (DR), 2,184 cases of diabetic kidney disease (DKD), and 632 cases of diabetic neuropathies (DN), with some patients having 2 or 3 microvascular complications simultaneously. After adjusting for confounders, we observed that higher AMED scores offer protection against DKD among participants with hyperglycemia (comparing the highest AMED scores to the lowest yielded an HR of 0.79 [95% CIs: 0.67, 0.94]). Additionally, the protective effect of AMED against DKD was more evident in the hyperglycemic participants with T2DM (HR, 0.64; 95% CI: 0.50, 0.83). No such effect, however, was seen for DR or DN.

CONCLUSIONS

In this prospective cohort study, we have demonstrated that higher adherence to a MED is associated with a reduced risk of DKD among individuals with hyperglycemia. Our study emphasizes the necessity for continued research focusing on the benefits of the MED. Such efforts including the ongoing clinical trial will offer further insights into the role of MED in the clinical management of DKD.

Special Issue "The Molecular and Cellular Pathophysiologic Mechanisms Underlying Ocular Diseases and Emerging Therapies"

Visual impairment and ophthalmic diseases represent significant global public health concerns, and their prevalence continues to rise [...].