Sight Loss May Be Prevented By Regular Walking, Research Suggests
Sight Loss May Be Prevented By Regular Walking, Research Suggests
PA/The Huffington Post UK
Regular walking may protect the eyes and help prevent age-related vision loss, research has suggested.
Tests on mice showed that moderate exercise slows down the death of light-sensitive retinal cells.
Scientists believe the discovery has important implications for age-related macular degeneration, the leading cause of blindness in the elderly.
Open Image Modal
"This research may lead to tailored exercise regimens or combination therapies in treatments of retinal degenerative diseases," said lead researcher Dr Machelle Pardue, from Emory Eye Centre in Atlanta, Georgia, United States.
"Possibly in the near future, ophthalmologists could be prescribing exercise as a low-cost intervention to delay vision loss."
Macular degeneration is caused by the death of photoreceptors in the retina, the digital "camera" at the back of the eye which turns light signals into nerve impulses.
Story continues below the slideshow:
Preserve Your Eyesight With These 10 Foods
Collard Greens(01 of10)
Open Image Modal
Like all leafy green vegetables, collards are high in the carotenoid nutrient lutein. Eating foods rich in carotenoids, particularly lutein and zeaxanthin, is associated with reduced risk of developing age-related macular degeneration. (credit:Shutterstock)
Zucchini(02 of10)
Open Image Modal
Another food rich in lutein and zeaxanthin. Lutein and zeaxanthin help by protecting the central retina (also known as the macula) from blue and ultraviolet light. Consumption of zeaxanthin, with lutein, has been found in studies to reduce the likehood of developing cataracts. (credit:Shutterstock)
Broccoli (03 of10)
Open Image Modal
Broccoli and broccoli sprouts have been found to protect the retina from free radical damage. This may be due to a compound in broccoli called sulphoraphane which naturally boosts the body's own defense system against free radicals. (credit:Shutterstock)
Eggs(04 of10)
Open Image Modal
Eggs are rich in cysteine and sulphur, two components of glutathione, a protein that acts as an antioxidant for the lens of the eye. This may explain why sulphur-containing compounds have been found to protect from cataract formation. Egg yolks also contain lutein and diets high in lutein lead to reduced risk of developing age-related macular degeneration. (credit:Shutterstock)
Garlic And Onions(05 of10)
Open Image Modal
Sulphur-rich garlic and onions are important for the production of glutathione, an important sulphur containing protein that acts as an antioxidant for the lens of the eye. Raising glutathione levels can be instrumental in both prevention and resolution of visual problems like macular degeneration, glaucoma or cataracts. (credit:Shutterstock)
Tomatoes(06 of10)
Open Image Modal
Tomatoes contain two eye-healthy nutrients -- lycopene and lutein. Both of these phytochemicals are carotenoids, found to be helpful for vision. Lycopene has been well documented as effective in cancer-protection, but its antioxidant capabilities also act to protect the eyes from sun damage. (credit:Shutterstock)
Carrots (07 of10)
Open Image Modal
The old axiom that carrots are good for the eyes is not just a myth. Carrots are rich in betacarotene (precursor to vitamin A, a necessary nutrient for vision), lycopene (a phytonutrient antioxidant protective of UVB radiation in the eye) and lutein (a protective phytonutrient found in high concentrations in the macula which protects it from free radical damage). (credit:Shutterstock)
Blueberries (08 of10)
Open Image Modal
Eating blueberries has been associated with the reduction of eye fatigue. As well as having the eye-healthy carotenoids lutein and zeaxanthin, blueberries contain anthocyanins, eye-nourishing phytonutrients which have been shown to improve night vision. They also contain flavonoids like rutin, resveratrol and quercitin which may have preventative effects on macular degeneration. Blueberries also contain minerals necessary for proper vision including selenium and zinc. (credit:Shutterstock)
Apricots (09 of10)
Open Image Modal
Apricots are rich in both beta-carotene and lycopene, two phytochemicals that promote good vision. Beta-carotene is converted by the body to vitamin A, an important antioxidant that resists oxidative stress damage to the lense of the eye, helping to prevent cataracts and macular degeneration. (credit:Shutterstock)
Fatty Fish(10 of10)
Open Image Modal
Cold-water fish such as salmon, tuna, cod, haddock as well as sardines are rich in the healthy Omega-3 oils. Fish are especially high in EPA and DHA, two Omega-3 fats which are important for cellular health. DHA makes up 30 percent of the fatty acids that comprise the retina. (credit:Shutterstock)
Dr Pardue's team studied mice that ran on a treadmill for two weeks before and after being exposed to bright light to trigger retinal cell loss and mimic the effects of the disease.
Exercised animals ended up with nearly twice as many photoreceptors as mice which spent the same amount of time on stationary treadmill.
Their retinal cells were also more responsive to light.
"One point to emphasise is that the exercise the animals engaged in is really comparable to a brisk walk," Dr Pardue pointed out.
"One previous study that examined the effects of exercise on vision in humans had examined a select group of long distance runners. Our results suggest it's possible to attain these effects with more moderate exercise."
The benefits of exercise to vision partly stem from a growth factor protein called BDNF, the researchers believe.
Mice running in the treadmill had higher levels of BDNF in the blood, brain and retina.
When the protein's activity was chemically blocked, it cancelled out the protective effect.
The team, whose findings are reported in the Journal of Neuroscience, is now looking to see if exercise can also help combat other retinal diseases such as glaucoma and diabetic retinopathy.