In the news: Med Diet Lowers AMD Risk; RCT: Meditation Helpful in Glaucoma

Mediterranean Diet May Lower Risk for AMD

Adherence to the Mediterranean diet may contribute to the prevention of age-related macular degeneration (AMD), according to research conducted by a consortium of Spanish, German, Dutch and French researchers. Study participants with better adherence had a 41% reduction in risk of incident advanced AMD versus those with poor adherence (1).

The researchers examined the associations of adhering to the Mediterranean eating pattern with the incidence of advanced AMD in two population-based prospective cohorts, the Rotterdam Study 1 (RS-1) and the Alienor Study. Included in the analysis were 4,446 Dutch participants aged 55 years or older from RS-1 and 550 French subjects aged > 73 years from the Alienor Study with complete ophthalmologic and dietary data available.

Exams were performed every 5 yrs. over a 21-yr. period in RS-1, and every 2 yrs. over a 4-yr. span in the Alienor cohort. Adherence was assessed using a 9-component Med Diet score based on intake of fruits, vegetables, cereals, fish, meat, legumes, dairy, alcohol and a mono-unsaturated (e.g. olive oil) to saturated fat ratio. The main outcome was incidence of advanced AMD evaluated by fundus photographs.

Among the participants, 155 total developed advanced AMD. Pooling data for both cohorts, those with high Med Diet scores (6-9) had a significantly reduced risk for advanced AMD compared to those with low scores (0-3), HR 0.59 and p for trend = 0.04.

These findings, according to the authors, support the role of a diet rich in healthful nutrient-rich foods in preventing AMD. The abundant polyphenols and antioxidant nutrients provided by the Med Diet are thought to target inflammation and oxidative stress – significant drivers of AMD pathobiology.

AMD is a complex disease involving aging and genetics – factors that can’t be modified. However, stopping smoking and adopting a Med style of eating are positive risk-reducing steps that can be taken.

Meditation Complements Glaucoma Treatments

Glaucoma sufferers and their clinicians should take heed of a study just published in Journal of Glaucoma. The study found that 60 minutes of meditation each morning resulted in intraocular pressure (IOP) lowering similar to that typically seen with prostaglandin analogues like latanoprost or β-blockers such as timolol. The best part about these findings is that the meditation techniques are easy to learn and incorporate for most glaucoma patients.

Stress is a key risk factor affecting mechanisms at play in glaucoma including ischemia, oxidative stress, glutamate excitotoxicity, inflammation/glial activation, neurotrophin loss and vascular dysregulation. Knowing that sight-threatening glaucoma causes stress and anxiety in patients, and that stress often leads to elevated blood pressure, the investigators set out to assess the impact of stress reduction on IOP.
 
In the randomized trial (2), 90 POAG patients (180 eyes; age >45) treated with eye drops were assigned to a waitlist control or a mindfulness meditation group led by a yoga instructor and practiced daily for 3 weeks. IOP (the primary endpoint), quality of life (QOL), stress-related serum biomarkers (cortisol, β-endorphins, IL6, TNF-α, BDNF, ROS, TAC) and whole genome expression were measured.

Between group comparisons showed that this short course of meditation therapy lowered IOP by nearly 5 points on average (OD: 18.8 to 12.7, OS 19.0 to 13.1 mm Hg). The mean IOP reduction correlated with a normalization of all the stress biomarkers evaluated (all P values < 0.001). The meditators improved in QQL (p < 0.05). These changes also correlated well with gene-expression profiling. Whether stress reduction will lead to improvements in visual fields is still to be studied. However the findings to date are important and impressive.

References

1. Merle BMJ et al. Mediterranean diet and incidence of advanced age-related macular degeneration: The EYE-RISK Consortium. Ophthalmol. Epub Aug. 13, 2018.
2. Dada T et al. Mindfulness meditation reduces intraocular pressure, lowers stress biomarkers and modulates gene expression in glaucoma: A randomized controlled trial. J Glaucoma. Epub Sept. 25, 2018.