A new study involving Moorfields Eye Hospital has found people who consume alcohol moderately have a lower chance of developing cataracts that require surgery, especially if they consume wine.
Antioxidants in red wine are thought to contribute to the strongest protective effect of all alcoholic drinks, with wine drinkers demonstrating a 23% lower the cataract surgery risk in one group.
The new research was published last week in Ophthalmology, the journal of the American Academy of Ophthalmology, and was conducted by researchers from NIHR Moorfields Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology.
Previous studies on cataracts and alcohol consumption have been limited in their design and offered mixed results – ranging from an increased risk from heavy drinking, to reduced risk from low to moderate drinking to no link at all between.
To understand the association further, the study – the largest of its kind – tracked 490,000 volunteers in the UK. They were enrolled in two different study groups and answered a detailed questionnaire.
After taking into account factors already known to affect cataracts such as age, sex, ethnicity, social deprivation, weight, smoking and diabetes, the researchers found that people who consumed about 6.5 standard glasses of wine per week (which is within the current guidelines for safe alcohol intake in both the US and UK) were less likely to undergo cataract surgery.
However, people who drank daily or nearly daily had about a 6% higher risk of cataract surgery compared with people who consumed alcohol moderately.
According to the study, wine drinkers benefited the most compared with those who abstained or drank other types of alcohol, showing a 23% reduction in cataract surgery in one study group and a 14% in the other. However, the researchers note their study does not establish causation, only a strong association between alcohol consumption and cataracts.
“There was evidence for reducing the chance of requiring future cataract surgery with progressively higher alcohol intake, but only up to moderate levels within current guidelines,” lead researcher Dr Anthony Khawaja said.
“This does support a direct role of alcohol in the development of cataract, but further studies are needed to investigate this.”
In other findings, the researchers observed that compared with participants who drank one to three times or less per month, those who drank one to two and three to four times per week had 7% and 6% lower risk of cataract surgery, respectively.
Moderate white wine/champagne drinkers had a 10% lower risk than those who abstained, while for beer and spirits the risk reduced by 13% and 14%, respectively.
The researchers said the study’s findings were consistent with what has previously been established with red wine and the benefits of diets rich in antioxidants that may prevent the onset of cataracts.
Grape skin is said to be loaded with healthful antioxidants, resveratrol, and flavonoids. These plant compounds and antioxidants are found in higher concentrations in red wine than in white. And both red and white wine have more than beer.
“Cataract development may be due to gradual damage from oxidative stress during ageing,” Dr Sharon Chua, lead author, said.
“The fact that our findings were particularly evident in wine drinkers may suggest a protective role of polyphenol antioxidants, which are especially abundant in red wine.”