Green tea to the rescue once again and adding one more health benefit to the ever-growing list of proven and unproven claims. Amongst fighting against Alzheimer’s, cancer and heart disease, the latest preliminary research suggests that green tea is able to prevent the development of glaucoma. The antioxidant effects of catechins found in green tea helps protect against oxidative eye damage caused by glaucoma and possibly other eye diseases such as cataracts and retinal degeneration. Green tea contains vitamin C, minerals, polyphenols and phytochemical compounds amongst others.
Glaucoma is one of the leading causes of blindness and is an irreversible disease. Free radicals overwhelm the body’s ability to neutralize the radicals and the disease develops when the eye’s drainage system becomes clogged and fluid pressure builds up in the eye impairing the optic nerve, which in turn results in loss of vision. It steals sight and as the damage to the optic nerve progresses, side vision starts to fail so that only tunnel vision is left. Eventually, the damage becomes so severe that the individual loses all vision. With glaucoma, everyone is at risk; from babies to the elderly with rarely any symptoms to warn you, as there is no pain linked with increased eye pressure. Glaucoma is hard to pick and the best way is to be tested so treatment can be started early which may preserve vision. However, any damage done before treatment cannot be reversed.
“There are two primary mechanisms for lowering eye pressure: 1) Decrease the amount of aqueous humor coming into the eye i.e. reduce the production of aqueous, and 2) Increase the amount of aqueous leaving the eye i.e. increase the outflow of aqueous.”
The principal constituent of green tea is epigallocatechin-gallate. EGCG has been found to protect the eye’s health in four ways: it protects the retina, lens and aqueous humor; protects retina against UV damage; prevents cataract formation and protects against age related degeneration and glaucoma.
“A study just published in the American Chemical Society’s Journal of Agricultural and Food Chemistry concludes that phytochemicals found in green tea actually penetrate deeply into tissues of the eyes. This is the first report to document how the lens, retina and other parts of the eye absorb the powerful antioxidants and disease-fighting substances found in green tea and it strongly raises the possibility that green tea can prevent glaucoma as well as other eye diseases and conditions.”
Scientist Chi Pui Pang, Ph.D., of the department of ophthalmology and visual sciences at the Chinese University of Hong Kong, stated that green tea contains flavonoids known as catechins that are thought to protect the eye. This statement was under scrutiny as there was doubt that catechins could get to the eye tissue. However, in experiments carried out on laboratory rats, “the scientists showed conclusively that after green tea is consumed, structures in the eye absorb sight-protecting green tea catechins.” The eye tissues of the rats used in the study were analysed and found that significant amounts of catechins had been absorbed by various eye structures. The retina had the highest levels of a catechin known as gallocatechin and the aqueous humor took up the phytochemical epigallocatechin. “Bottom line: green tea catechins reduced harmful oxidative stress in the eyes that is linked to glaucoma and other eye diseases. What’s more, the protective effect lasted up to 20 hours.
A 2007 study conducted by Chosun University College of Medicine in Korea had also discovered that the green tea antioxidant epigallocatechin gallate (EGCG) could protect human retinas against UV damage.
We would need to drink around five cups or more of green tea a day or there is a green tea extract to gain sufficient amounts of antioxidants to ease the damage of free radicals. As glaucoma is irreversible and prevention is cheaper than the cure, start drinking green tea and be tested.