The eyes are more than a window to the soul—they might also be a regulator of lifespan. A groundbreaking study has revealed that eye health not only affects vision but could also have a profound impact on aging and longevity. Researchers from the Buck Institute for Research on Aging discovered that eye dysfunction can accelerate aging and shorten lifespan, while maintaining eye health may delay aging and extend life. By studying fruit flies, they uncovered intriguing connections between diet, photoreceptors, vision loss, and lifespan, paving the way for new approaches to healthy aging.
"These eyes have seen too much" is often used to describe a person who has been through a lot. With a pair of clear eyes, even a centenarian can look energetic. People with cloudy eyes and declining vision, even at a young age, give people a sense of decadence.
In people's traditional cognition, presbyopia, cataracts, and declining vision are usually the accompanying results of aging. However, scientists at the Buck Institute in the United States have put forward a bold view: the eyes may not only be organs that passively bear aging, but may even actively regulate the length of life. The research results were published in Nature Communications, pointing out for the first time that eye dysfunction can accelerate aging, while promoting eye health can prolong life.
"We have always thought that the eyes are just visual organs, and never thought that they can also affect overall health." said Professor Kapahi, the corresponding author of the study. So, how did the Kapahi team discover the wonderful connection between eyes and life span?
The relationship between dietary restriction, vision and life span
The story dates back to 2016, when the team first discovered in a study published in Cell Metabolism that dietary restriction can extend the life span of fruit flies by enhancing the expression of the biological clock and its regulatory genes.
The biological clock is the "clock" in all living things. It coordinates the circadian rhythm inside and outside the body and accurately regulates our diet, sleep, mood and metabolism. However, as we age, biological clock disorders can lead to a variety of aging-related diseases such as diabetes, coronary heart disease, insomnia, etc., and ultimately accelerate aging. Dietary restriction can activate biological clock genes, so that body functions can be "well organized" again, thereby delaying aging.
Note: Under dietary restriction conditions, the expression of Drosophila circadian clock genes and their downstream regulated genes increased and their rhythmicity strengthened, AL (free diet), DR (diet restriction)
Further research shows that under dietary restriction conditions, the expression of biological clock genes in the eyes of fruit flies, especially in photoreceptors, is most significant. Dietary restriction can delay the decline of fruit fly vision, especially photoreceptors (special neurons that sense light located on the retina).
Moreover, the effect of dietary restriction on the lifespan of prCLK-Δ1 fruit flies is not as good as that of wild-type fruit flies with the same dietary restriction, indicating that dietary restriction can only play the role of delaying vision loss and prolonging life to the greatest extent when the eye clock gene is expressed. The more intuitive manifestation of the expression of eye clock genes in delaying vision loss and regulating lifespan is that the vision loss of prCLK-Δ1 fruit flies is accelerated and the lifespan is directly shortened.
Will vision degeneration directly shorten lifespan?
In order to verify whether vision degeneration directly affects lifespan, the researchers used RNA interference technology to reduce the expression of ATPα gene in the fruit fly eye and create a fruit fly model with vision degeneration. The results showed that these fruit flies had increased systemic inflammatory response, showing a state similar to "inflammatory aging", and their lifespan was significantly shortened, and even dietary restriction could not extend their lifespan.
Moreover, when the researchers used optogenetics to forcefully activate the photoreceptors of fruit flies, they also found that excessive loss of photoreceptors also shortened the lifespan of fruit flies.
Can protecting vision really prolong lifespan?
The experiment further proved that protecting vision can indeed prolong the lifespan of fruit flies. For example, fruit flies that are placed in a 24-hour dark environment have a significantly longer lifespan than those that are placed in a 12-hour light-dark environment. In addition, fruit flies that lack rhodopsin expression also have a longer lifespan because their eyes cannot sense light and are free from light damage.
This study revealed for the first time that the eyes can directly regulate the length of life. Although the impact of human eyes on lifespan may not be as significant as that of fruit flies, the study provides new scientific evidence for the importance of healthy vision.
Health Tips: Don't let the screen at night drag down your lifespan
The results of the study sounded the alarm for modern people's lifestyles: playing computers and looking at mobile phones at night may not only disrupt the biological clock, but also aggravate eye damage. In the long run, it may bring potential health risks and even affect the length of life. In the future, more research is needed to further explore the complex relationship between eyes and healthy aging.
