New research indicates that leafy greens may be even healthier than we thought. While veggies like spinach, kale and collard greens may not be able to cure glaucoma, eating them regularly may help protect you against ever developing the most common form of the disease, known as primary open angle glaucoma (POAG).
Researchers at Brigham and Women’s Hospital and Harvard Medical School followed more than 100,000 men and women who were enrolled in two major medical studies for a period of more than 28 years. Everyone in these studies was 40 years or older, and none had glaucoma at the start of the study.
The patients received eye exams every two years, and throughout the course of the studies, 1,483 people developed POAG. When the researchers looked at the diets of the study participants, they noted a strong similarity among those who did not develop glaucoma — these people ate more leafy greens. In fact, greater intake of green leafy vegetables was associated with a 20 percent to 30 percent lower risk of POAG.
The association was even stronger for POAG with early paracentral visual field loss, a common subtype of POAG. The research revealed that people who ate a lot of leafy greens had a 40 percent to 50 percent lower risk of acquiring this form of the disease.
The reason these super foods offer such great protection is related to the dietary nitrate they contain. It’s thought that glaucoma impairs blood flow to the optic nerve. Nitric oxide helps regulate this flow. Since leafy greens contain high levels of nitrates, the precursor to nitric oxide, consuming them likely keeps things running more smoothly.
A significant amount of other new research is currently aimed at developing therapeutics that treat glaucoma by way of nitric oxide. In fact, the FDA is reviewing at least one new medication that donates nitric oxide. But thanks to this latest report, far fewer people will need it if they load up on leafy greens before any glaucomatous damage is done.
So just how much roughage do you need to eat to protect yourself from glaucoma? In this study, those who consumed the most leafy greens averaged about 1.5 servings per day, which equates to about one and a half cups.
The study was published in JAMA Ophthalmology this month — A.H.
This article was originally published on the All About Vision website.