After cataracts glaucoma is a leading cause of blindness around the globe, it is a neurological disorder that leads to deterioration of the optic nerve which connects the eyes to the brain, eventually glaucoma will lead to irreversible blindness.
Approximately 60 million people around the world have glaucoma, with 3 million Americans being affected by it. Those at high risk include those over 60, with a family history of it, diabetics, and those that are severely nearsighted. Light coloured eyes are another risk factor, with gray or blue eyes being more likely to suffer damage compared to hazel or green, and brown eyes are at the least risk.
An increase in intraocular pressure is a major risk factor, poor regulation of blood flow to the optic nerve is another, as well as oxidative damage contributing to the condition. Currently there is no cure for glaucoma available, drug therapies focus on lowering pressure in the eye but that will not always prevent progression of glaucoma.
Various natural substances have been shown in studies to be useful in treating the condition that help to relieve IOP, improve blood flow to the eye, and reduce oxidative stress; results show improving diet can reduce risks for developing glaucoma. Increasing intake of fresh fruits and vegetables high in vitamins A&C and carotenoid content are linked to lowering risks.
An NIH study found that women who ate 3+ servings daily of all fruits and fruit juices decreased their odds of glaucoma by 79% compared to those who ate less.
Those who get the highest levels of vitamin C decreased their risk by 70%, higher intakes of vitamin A cut risks by 63%, and alpha carotene lowers risks by 54%, but not all fruits and vegetables will provide the same protection.
Another NIH study found eating 3+ servings of vegetable per day didn’t have any effect on glaucoma rates, however certain vegetables produced completely different results such as one serving of kale or collard greens per week may cut risks of glaucoma by 57%
A Harvard study suggests that leafy green vegetables with higher nitrate levels may be better at fighting off glaucoma, the nitrates from the greens are a precursor for nitric oxide which promotes blood circulation. Another large Harvard study found getting more nitrates and leafy greens into the diet was linked to a 20-30% lower risk of glaucoma; the link was ever greater for a certain type of glaucoma linked to poor blood flow, in those cases the risk was lowered by 40-50%.
Women who ate 2+ servings of fresh oranges or peaches in an NIH study were found to have decreased their odds of glaucoma by 70% with peaches and 82% with oranges. Juice did not provide the same protection as the fresh fruit did, nor did canned fruit.
Glaucoma patients were found to have lower levels of EPA, DHA, and total omega-3 long chain polyunsaturated fatty acid, it was suggested that EPA and DHA may modulate impaired systemic microcirculation and ocular blood flow as well as optic neuropathy which are associated with the condition. Great sources of DHA and EPA are wild caught salmon, and other fatty cold water fish such as sardines, mackerel, herring and tuna.
Flavonoids are showing promising roles in studies helping to improve vision for patients with glaucoma and high eye pressure, appearing to help improve and slow down the progression of visual field loss. Flavonoids are antioxidants from plants that have been found to have neuroprotective and antioxidant properties which appear to be of benefit to glaucoma patients. Red wine, green tea, and cocoa are the most common flavonoid rich foods.
Black currant anthocyanins have been shown to help slow down visual field deterioration in a randomized placebo controlled double masked 24 month trial, black currants were suggested to help normalize blood flow in the eye.
Goji berries help stop the loss of RGCs and neurodegeneration in the retina found in glaucoma during animal studies; benefits were independent of eye pressure, animal fed goji extracts nearly totally escaped from pressure induced loss of RGCs.
Eggplant helped to reduce intraocular pressure by 25% in another study where male volunteers ate 10 grams of eggplant, the authors suggest eggplant would be of benefit to those suffering from glaucoma.
While there may not be a cure, simple diet changes may help to reduce the risks of glaucoma which may be of benefit to those who are at risk.
