A study by a Canadian University has demonstrated how age-related macular degeneration can be more common in and even caused by obesity cases. The study revealed the way that cells in the body’s own immune system can be destructive to the eye as it ages.
As professor Przemyslaw Sapieha has stated:
“Although considerable effort has been invested in understanding the genes responsible for AMD … [these] variations in susceptibility genes only increase the risk of developing the disease, but do not cause it.”
“We must gain a better understanding of how other factors such as environment and lifestyle contribute to disease development.”
The compromised ocular immune system in AMD patients
Something scientists have known for some time is that people who suffer from AMD experience increased aggressiveness in the immune systems of their eyes. This can lead to some degree of collateral damage when infections are encountered, with the body’s immune system damaging its own infrastructure within the eye.
Another instance where cells of the immune system can have their effectiveness reduced is when a person has excess fat cells, such as when someone is obese. If someone is already at risk of developing AMD, the risk can be doubled by the weakening of their immune system associated with obesity.
In the study, the researchers Sapieha and Hata used an accelerated obesity model to exaggerate the difficulties experienced by the body throughout a lifetime of obesity. They then adjusted the model to show that the “body” had “recovered from obesity”. They found that a history of obesity leads to “persistent changes in the DNA architecture within immune cells, making them more susceptible to producing inflammatory molecules”. As we have discussed in the past, increased inflammation is perhaps the most significant risk factor for developing AMD. But the surprising aspect of this was what the researchers referred to as the “reprogramming” of the immune system. The increased inflammatory response of the immune system associated with obesity continued long after a “normal” body environment had returned.
The scientists stated the following in conclusion to their study:
“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”.
While the ultimate cause of AMD is still difficult to understand, the inner-workings of the body and its response to unique environmental conditions shows that progress continues. By understanding as much as they can about the environmental risks associated with this condition scientists may be able to create environments which achieve the opposite effect, with unique therapies recommended to people whose lifestyles play a significant role in the conditions they develop.
- University of Montreal.