You've heard it all before from your mom: Those leafy greens are good for you. You already know they're an excellent source of fiber, folate, and carotenoids. They also contain huge amounts of vitamins C and K and the minerals iron and calcium, not to mention they act as great antioxidants.
But do you know they're also good for your eyes?
Recent studies show that leafy green vegetables can also help reduce the risk of glaucoma. "We found those consuming the most green leafy vegetables had a 20 to 30 percent lower risk of glaucoma," says Jae Kang, the lead author of the study and an assistant professor of medicine at Brigham and Women's Hospital and Harvard Medical School in Boston.
"In glaucoma, we think there is an impairment of blood flow to the optic nerve; and an important factor that regulates blood flow to the eye is the substance called nitric oxide. When you consume the higher amount of green leafy vegetables, you have greater levels of nitric oxide in your body," the professor explains.
The research involved 3,893 women and 41,094 men. Of this number, scientists surveyed those aged 40 and above, and who were considered to be of good health. They also showed no signs of primary open-angle glaucoma, or POAG. This disease is common among people aged over 50.
The study aimed to find a viable link between the consumption of green leafy veggies and glaucoma. The researchers also concentrated on the amount of nitrate included in the volunteers' diet to get a more quantifiable outcome.
Aside from root vegetables like beet and spinach, dietary nitrate can also be found in leafy greens such as celery and rucola.
The result?
Upon evaluating the dietary intake of the participants, the researchers found a 20 to 30 percent lowered risk for glaucoma for those who consumed around a cup and a half of green leafy vegetables per day, thus maximizing their nitrate intake.
Every 2 years for a total span of 25 years, the participants submit themselves for an eye examination. Out of the total number, 1,483 participants acquired the disease.
Furthermore, the scientists also discovered that leafy greens also decreased likelihood by 40 to 50 percent for paracentral visual field loss, a specific kind of glaucoma that disrupts blood flow autoregulation.
As with most studies, the scientists said the research needs further investigation to determine the underlying relationship between a nitrate-rich diet and glaucoma.
The American Academy of Ophthalmology also encourages people aged 40 and above to have annual screenings for glaucoma, and other eye diseases such as diabetic retinopathy and cataract.
The complete study was published by the JAMA Ophthalmology journal.
