Moderate red wine consumption may protect vision, retina specialist says

The protective effects of resveratrol against oxidative stress and angiogenesis might be the key to why moderate red wine drinkers are at a reduced risk of developing AMD.

Issue: January 2011

Paolo Lanzetta

Moderate consumption of red wine might play a protective role against age-related macular degeneration, according to a retina specialist.

The key ingredient is resveratrol, a substance produced naturally by some plants as a defense against pathogens such as bacteria or fungi. Resveratrol is found in the skin of red grapes and is contained in red wine in the quantity of 1.98 mg/L to 7.13 mg/L, compared to 0.005 mg/L to 1.80 mg/L in white wine.

“The mechanism is not fully understood. By activating the SIRT1 and MnSOD enzymes, resveratrol might improve mitochondrial functions and reduce oxidative stress. It also seems to have anti-angiogenic properties,” Paolo Lanzetta, MD, OSN Europe Edition Editorial Board member, said.

Epidemiological studies so far have been conducted with methods that are not completely accurate, he said, but there is some evidence that the incidence of AMD might be reduced in people consuming red wine.

In a large cohort of 3,072 adults aged 45 to 74 years, a statistically significant negative association between wine consumption and AMD was found.

Early study

In vitro experiments have shown that resveratrol reduces oxidation and hyperproliferation of human retinal pigment epithelial cells. By maintaining retinal pigment epithelial cell viability, the formation of drusen associated with aging and macular degeneration might be prevented.

In vivo, in an animal model of laser-induced choroidal neovascularization, resveratrol was shown to inhibit the growth of neovascular membranes.

“There are several points in the oxidative damage cascade where resveratrol might act as a chain breaker,” Dr. Lanzetta said.

Possible benefits

Experimental studies have also shown that resveratrol decreases the incidence of skin cancer and esophageal and colon tumors, reduces the formation of plaques in Alzheimer models, and protects against the progression of inflammatory arthritis and coronary heart disease.

“The regular consumption of red wine might explain the ‘French paradox,’ ie, why the French, in spite of having a diet that is very rich in saturated fats, suffer a much lower incidence of coronary heart disease compared with other populations having a similarly fatty diet,” Dr. Lanzetta said.

“There is a great deal of attention focused on resveratrol and its natural source, red wine. We need further studies, including large population studies conducted in areas of production and regular consumption of red wine,” he said.

Dr. Lanzetta is head of ophthalmology at the University School of Medicine of Udine, situated in a territory in Italy where famous high-quality red wines, such as refosco and cabernet franc, are produced.

“We are getting organized in our clinic to do our own studies on the protective effect of resveratrol against degenerative eye diseases. We will soon start in vitro experiments,” he said. – by Michela Cimberle

References:

Khan AA, Dace DS, Ryazanov AG, Kelly J, Apte RS. Resveratrol regulates pathologic angiogenesis by a eukaryotic elongation factor-2 kinase-regulated pathway. Am J Pathol. 2010;177(1):481-492.

King RE, Kent KD, Bomser JA. Resveratrol reduces oxidation and proliferation of human retinal pigment epithelial cells via extracellular signal-regulated kinase inhibition. Chem Biol Interact. 2005;151(2):143-149.

Obisesan TO, Hirsch R, Kosoko O, Carlson L, Parrott M. Moderate wine consumption is associated with decreased odds of developing age-related macular degeneration in NHANES-1. J Am Geriatr Soc. 1998;46(1):1-7.

Paolo Lanzetta, MD, can reached at University of Udine, Department of Ophthalmology, Piazzale S. Maria della Misericordia; 33100 Udine, Italy; +39-0432-559-905; fax: +39-0432-559-904; e-mail: paolo.lanzetta@uniud.it.