Harvard Medical School and Brigham and Women’s Hospital conducted two major medical studies with more than 100,000 men and women over a period of twenty-eight years. All the subjects were aged 40 and over and none of them had glaucoma at the commencement of the study.
During the period of research everyone received eye checks every two years. A total of 1,483 people developed primary open angle glaucoma (POAG), the most common form of glaucoma. When researchers studied the diets of those involved they found a marked similarity amongst those who did not develop POAG.
These people ate more leafy greens in their diets, such as spinach and kale. In fact it was established that the people who ate a lot of leafy vegetables had a 40 to 50% lower chance of developing POAG.
It is thought that glaucoma impairs the blood flow to the optic nerve while nitric oxide helps regulate the flow. Leafy greens contain high levels of nitrates so eating them may help the blood flow.
As to just how much you should eat, the subjects were found to have consumed an average of 1.5 servings per day, about one and a half cups.
Now I am not suggesting that eating spinach is a cure for glaucoma but it seems as though it may help with prevention.