Being overweight or obese could be a risk factor for age-related macular degeneration (AMD), according to a new study.

Canadian researchers from the University of Montreal recently reported the findings of their study on the link between obesity and AMD in the journal Science.

They conducted a study involving mice and found that a history of obesity caused by a high-fat diet led to persistent changes in immunity even after losing the extra weight and returning to normal metabolism.

Some epigenetic changes exacerbated the inflammatory response to experimentally induced eye injuries during the mice experiments. This led the team to surmise that in humans, the same changes would translate to a predisposition to AMD among obese people.

"We wanted to know why some people with a genetic predisposition develop AMD while others are spared," study lead and ophthalmology professor Przemyslaw (Mike) Sapieha said in a news release.

Sapieha continued, "Although considerable effort has been invested in understanding the genes responsible for AMD, variations and mutations in susceptibility genes only increase the risk of developing the disease but do not cause it."

The team said their study demonstrated how life stressors such as obesity could alter immune cells and make them destructive to the eyes, causing vision problems later in life.

AMD is considered the major cause of irreversible blindness worldwide. In 2020, approximately 196 million people were diagnosed with this condition, according to Science Daily.

"This observation suggests that we must gain a better understanding of how other factors such as environment and lifestyle contribute to disease development,” Sapieha said.

For Dr. Masayuki Hata, who authored the study when he was still a postdoctoral fellow, their findings could help lead to better treatment options for AMD.

"Our findings provide important information about the biology of the immune cells that cause AMD and will allow for the development of more tailored treatments in the future," Hata, who is now an ophthalmology professor at Kyoto University in Japan, said.

The researchers noted that they hope their work could inspire other scientists to broaden the efforts in further understanding obesity-related health issues and diseases, such as Alzheimer’s disease and multiple sclerosis.