Diet and Glaucoma by DR NILANJANA DEB
- December 19, 2018
- Win Vision
Glaucoma is a disease of multifactorial origin. Currently, lowering the intraocular pressure is the only modifiable risk factor that has been shown to slow the optic nerve damage associated with glaucoma. Patients frequently enquire about dietary and lifestyle modifications necessary to stabilise the disease. Although there is no concrete evidence to relate diet with glaucoma, certain associations have been documented in literature.
It has been noted that significant caffeine intake over a short period of time can cause transient increase in eye pressure lasting couple of hours. Hence glaucoma patients should restrict their intake of coffee and caffeinated beverages to no more than two cups a day. Similar effect is seen after ingestion of high volume of water (500ml to 1l) over a short span of 15 minutes. On the contrary, catechins i.e. powerful antioxidants present in green tea have been shown to have a beneficial role by virtue of their ability to fight free radicals and oxidative stress, a major risk factor for development of cataracts, glaucoma and retinopathy. Alcohol though initially may lower intraocular pressure, daily intake is associated with increase in eye pressure. Cigarette consumption has not been associated with increased risk of glaucoma but, overall, cigarette smoking has a negative impact on eye health.
Carrots once thought to be good for the eye because of its beta-carotene content may not actually be so because its composition is not the same as what is necessary for the eye. On the other hand, green leafy vegetables (spinach, broccoli) and egg yolk is rich in antioxidants like lutein and zeaxanthin which are vital for the good health of the eye. Common dietary sources of antioxidants include vitamins A, C and E, selenium, polyphenols (found in red wine, pomegranate, acai berries, cranberries, dark chocolate, and black and green tea), anthocyanins (found in bilberry), lycopene (tomato), lutein (dark green leafy vegetables like kale and spinach); and lignan (flax seeds, flaxseed oils and some grains).
Another natural way to reduce eye pressure is by reducing the intake of carbohydrate rich foods like bread, pasta, sugar, rice and cereals which cause surge in the insulin secretion, thereby leading to increased blood and eye pressure. Insulin levels can also be lowered through a regular exercise program consisting of aerobics, short-burst exercises, sprint and strength training and can reduce eye pressure. A recently published study mentions about increased risk of glaucoma associated with diet with high omega 3:6 ratio intake, and thus low in omega 6 fatty acids (present in poultry, nuts, vegetable oils). But whether consuming food low in omega 3 fatty acids (present in kale, vegetable oils, flaxseed, salmon fish) is justified remains to be seen since this also plays a vital role in cardiovascular health.
Last but not the least, another frequently asked question is whether any supplements should be taken to prevent or treat glaucoma. In the absence of any convincing data regarding beneficial role of supplements, a well balanced healthy diet combined with regular exercise lends credence to what Hippocrates, father of modern medicine said hundreds of years ago “let your food be thy medicine”.