High sugar intake depletes vitamins, causes myopia

While extensive near work and insufficient time outdoors are well-known risk factors for myopia, experts say high sugar consumption may also be a significant lifestyle hazard.

The link between sugar and myopia has recently drawn widespread attention online, with related hashtags becoming one of the hottest topics on the Chinese social media platform Weibo.

Li Ying, a physician in the ophthalmology department at Peking Union Medical College Hospital, said the sclera — the eye's white outer wall — requires substantial vitamins, particularly vitamin B, to develop and maintain its strength.

Heavy consumption of sugary foods and drinks can deplete the body's vitamin reserves, she wrote on her personal Weibo account. That deficiency can lead to a softening of the sclera, making it more prone to elongation, which in turn promotes the development of nearsightedness.

Li recommends that individuals with a family history of myopia, or those whose eyesight is rapidly worsening, reduce their sugar intake.

For those who still wish to indulge occasionally, she suggests they increase their daily vitamin intake, especially vitamin B.

A white paper released by the National Health Commission in 2020 showed that about 90 percent of Chinese college students were myopic, and more than half of all children and adolescents were affected.

China has intensified its myopia-control efforts in recent years. Shen Haiping, head of the commission's maternal and child health department, said the coverage rate of eye care and vision checkups for children aged 6 and under has reached 95.4 percent nationwide.

Shen added that the overall myopia rate among children and adolescents is trending downward, with rates declining to varying degrees among 6-year-olds, primary school students and middle school students.

According to an official guideline released last year, key risk factors for myopia include prolonged near work such as reading, insufficient outdoor activity, poor reading posture, inadequate lighting and genetic predisposition. Additional environmental contributors include excessive and unscientific use of electronic devices, insufficient sleep and nutritional imbalances.

The average daily intake of added sugar in China is about 30 grams per person. Among children and adolescents aged 3 to 17 who regularly consume sugary drinks, the added sugar from beverages alone accounts for more than 5 percent of their total energy intake.

The World Health Organization recommends that daily added sugar intake be limited to less than 10 percent of total energy intake. It further advises that reducing intake to below 5 percent, or about 25 grams per day, provides additional health benefits.