By Aline Rodrigues
Researchers from Xi’an Jiaotong University and the UniSA (University of South Australia) have found conclusive evidence that regular physical exercise reduces the risk of age-related cataracts, the cause of blindness in an estimated 13 million people worldwide.
The study, published in the ‘International Journal of Ophthalmology’, found a 10% reduction in age-related cataracts among people who engaged in regular physical activity such as walking and cycling. Data from previous studies with more than 170,000 people were analysed.
According to Dr Ming Li, UniSA epidemiologist, physical activity reduces oxidative stress in the eye by inhibiting lipid degradation which results in cell damage.
“We know that exercise increases antioxidant enzyme activity which has all sorts of benefits, including limiting infections and inflammation in the eye,” Dr Li explains.
Exercise also improves insulin resistance and lipid profiles, both of which have been associated with an increased risk of cataract.
“Age-related cataracts are one of the most common causes of vision impairment and blindness in the world and although surgery is an effective option to recover vision, it is very costly,” Dr Li says.
He still underlines that the lens is highly susceptible to oxidative damage because of its high concentration of polyunsaturated fatty acid and its specific biological function.
“Although we don’t completely understand the mechanisms underlying ARC, we do know that ageing and oxidative damage play a crucial role in the development of the disease.”
Besides that, the researchers found that the risk of developing cataracts could potentially decrease by 2% for every hour of cycling or walking per day.
“Considering the fact that 24% of adults are inactive, these findings will hopefully encourage older people to start exercising on a regular basis,” Dr Li says.