Learn about exciting new research that suggests there may be some foods that may lower your risk of being diagnosed with glaucoma, such as green leafy vegetables. Read on to know the details.
A new study on glaucoma and green leafy vegetables
A recent study published in January 2016 in JAMA Ophthalmology, examined the relationship between dietary nitrate consumption, derived primarily from green leafy vegetables, and primary open-angle glaucoma. The researchers were interested in dietary nitrate intake because it is an important source of nitric oxide, which can be beneficial for blood circulation and potentially for glaucoma.
The study used data from two studies that collectively included more than 100,000 people. Researchers assessed the association between dietary nitrate intake (reported by participants) and whether these study participants were diagnosed with glaucoma during the 25-year study.
The study looked at four food groups:
· Leafy greens (iceberg lettuce, romaine lettuce, kale, mustard orchard, cooked spinach, raw spinach)
· Cruciferous vegetables (kale, mustard orchard, broccoli, cauliflower, Brussels sprouts)
· Root vegetables (beets, potatoes, onions, carrots, sweet potatoes, sweet potatoes) and
· Tomato-based foods (tomatoes, tomato sauce, tomato juice)
The study found that, compared to the group with the lowest dietary nitrate intake (approximately 80 milligrams / day), the group with the highest dietary intake (240 milligrams / day) was associated with a 21 percent lower risk of glaucoma and a 44 percent lower risk of a type of glaucoma in which early visual field loss near the center of vision is more common.
What the glaucoma study doesn't reveal
While this research is certainly exciting, it unfortunately does not provide information on whether dietary nitrate intake, in the form of green leafy vegetables, helps if one already has glaucoma.
Other Diet, Glaucoma, and Eye Health Studies
The good news is that this is not the only study that has identified the importance of green leafy vegetables in lowering the risk of a glaucoma diagnosis. As part of a large study (Osteoporotic Fracture Study), women who ate at least one serving per month of collard greens and kale had a 69 percent lower risk of glaucoma compared to women who ate less than one serving per month. Other foods that seemed protective of the glaucoma diagnosis included carrots and canned or dried peaches.
This group of researchers also completed a follow-up study that examined food consumption and glaucoma risk among African American women. Women who ate more than 1 serving per week compared to less than 1 serving per month of sprouts and kale (kale) lowered their chances of diagnosing glaucoma by 57 percent.
Other foods that were protective included increased consumption of fruit or fruit juices, fresh oranges, and fresh peaches. Intake of foods with higher amounts of vitamin A, vitamin C, and carotenoids was also considered protective of glaucoma diagnosis in older African-American women. However, once again, this research does not answer the question of whether eating green leafy vegetables helps someone who already has a diagnosis of glaucoma.
Well-balanced diet of green vegetables and fruits
Although we don't have complete answers, eating your veggies likely has very few drawbacks, and is important to your ov
erall health and well-being. Overdoing any item in the diet (for example, eating a diet high in arugula only) may actually exceed the recommended daily limits for nitrate intake. Therefore, a good recommendation is to simply eat a variety of green and other colored fruits and vegetables for a well-balanced diet.
So, eat those green leafy greens, and be aware that even vegetables in the low nitrate group contain nutrients that are important to your health.
Vegetables classified by nitrate content:
· Very high: Celery, watercress, chervil, lettuce, red beets, spinach and arugula. Other leafy vegetables with high nitrate concentrations include butter lettuce, mixed greens, and kale.
· High: Celery, Chinese cabbage, endive, fennel, kohlrabi, leek and parsley.
· Moderate: Cabbage, dill, turnip and green cabbage or desavoy.
· Low: Broccoli, carrot, cauliflower, cucumber, pumpkin, and chicory.
· Very low: Artichoke, asparagus, lima beans, eggplant, garlic, onion, green beans, mushrooms, peas, bell peppers, potatoes, squash, sweet potato, and tomato.
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