A new study from Buck Institute for Research on Aging in the US found that eye health may directly impact the overall health of the body and how long a person lives.
They also found a correlation between longevity, circadian rhythm, and diet. Previous studies have shown an association between eye disorders and poor health, which inspires the new research that argues eye dysfunction can drive problems in other tissues.
Circadian Rhythm is the Key
Senior study author Pankaj Kapahi, Ph.D., a professor at Buck Institute, said in a media release that they are showing that fasting could improve eyesight and that the eye itself plays a role in influencing longevity. His laboratory has demonstrated for years that fasting and restricting calorie intake can improve bodily functions.
Brian Hodge, Ph.D., the lead author of the study, who did his postdoctoral studies in Kapahi's laboratory, added that they did not expect their findings to point out that the eye can directly regulate lifespan.
Hodge explained that the secret lies in circadian rhythm, the molecular machinery in the cell of every organism that evolved to adapt to daily stresses. He noted that the 24-hour oscillations affect complex animal behaviors, from the predator-prey interactions and sleep/wake cycles, down to the fine-tuning of temporal regulation of molecular functions.
According to an article in Study Finds, a 2016 study in Kapahi's lab showed that fruit flies on a restricted diet experienced significant changes in their circadian rhythm that influenced their lifespan and extended it. Hodge noted that drosophila has a short lifespan, so they make a perfect model for screening a lot of things at once.
In their study titled "Dietary Restriction and the Transcription Factor Clock Delay Eye Aging to Extend Lifespan in Drosophila Melanogaster," published in Nature Communications, researchers examined which genes oscillate with a circadian pattern when drosophila is on an unrestricted diet. They compared the findings to another group that ate 10% of the protein in the first group.
They found that multiple genes responded to changes in the diet and displayed ups and downs at different points during the day. They also noticed that the rhythmic genes most activated by dieting come from the eyes, especially the photoreceptors in the retina. From there, the team conducted experiments that revealed that flies in constant darkness attend to have longer lifespans.
"That seemed very strange to us," Hodge said in the media release. "We had thought flies needed the lighting cues to be rhythmic, or circadian."
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Do Genes in the Eye Influence Your Maximum Lifespan?
The eyes may provide organisms with vision, but the new study shows that it is also something that must be protected for the overall health of an organism, SciTech Daily reported.
Kapahi says that the immune defenses are critically active in the eyes since they are exposed to the outside world, leading to inflammation that may present for long periods of time and could worsen chronic diseases. The light itself can cause the degeneration of photoreceptors in the eyes.
He added that staring at computers and phone screens exposes the eyes to light pollution, which disturbs the circadian rhythm. Using gadgets, especially at night, messes up the protection for the eye and could have consequences beyond vision and damage the rest of the body and brain.
There is much left to study on the role of the eye in the overall health and lifespan of organisms. Hodge believes that although the genes in the eyes do not affect lifespan in humans as much as the drosophila, which spends their major energy on their eyes, the circadian rhythm and diet play key roles in general.
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