An intriguing link between diet, eye health and life expectancy has been revealed – ScienceDaily

Researchers at the Buck Institute demonstrated for the first time the link between diet, circadian rhythms, eye health and life expectancy. Drosophila. Publication in cash from June 7, 2022 Natural communicationsthey further and unexpectedly found that the processes in the fly’s eye actually drive the aging process.

Previous studies in humans have shown that there is a link between eye disease and poor health. “Our study suggests that this is more than a correlation: eye dysfunction can actually cause problems in other tissues,” said senior author and professor Dr. Pankaj Kapahi of the Buck Institute, whose laboratory has demonstrated for years that starvation and restriction Calories can improve many body functions. “We are now showing that fasting not only improves vision, but the eye actually plays a role in influencing life expectancy.”

“The finding that the eye itself, at least in the fruit fly, can directly regulate life expectancy was a surprise to us,” said lead author Dr. Brian Hodge, who did his postdoctoral research at Kapahi’s lab.

The explanation for this connection, Hodge said, lies in the circadian clocks, the molecular machine in every cell of every organism that has evolved to adapt to daily stresses, such as changes in light and temperature caused by rising and setting sun. the sun. These 24-hour oscillations – circadian rhythms – affect complex animal behavior, such as predator-prey interactions and sleep / wake cycles, to fine-tune the temporal regulation of molecular functions of gene transcription and protein translation.

In 2016, Kapahi’s laboratory published a study in Cellular metabolism shows that fruit flies on a restricted diet have significant changes in their circadian rhythms in addition to prolonging life. When Hodge joined the lab later that year, he wanted to dig deeper to find out which processes that improve circadian function have been altered by changing the diet and whether circadian processes are necessary for longer life. under dietary restrictions.

“The fruit fly has such a short life, which makes it a really beautiful model that allows us to screen many things at once,” said Hodge, who is currently a scientist at Fountain Therapeutics in South San Francisco. The study began with an extensive study to see what genes fluctuate in a circadian way when unrestricted diet flies were compared to those fed only 10 percent of the unrestricted dietary protein.

Hodge immediately noticed many genes that corresponded to the diet at the same time and also showed ups and downs at different time points or “rhythmic”. He then discovered that the rhythmic genes that were most activated by dietary restrictions appeared to come from the eye, in particular from photoreceptors, specialized neurons in the retina of the eye that respond to light.

This discovery led to a series of experiments designed to understand how eye function fits into the story of how dietary restrictions can prolong life. For example, they set up experiments showing that keeping flies in constant darkness prolongs their lives. “It seemed very strange to us,” Hodge said. “We thought flies needed light signs to be rhythmic or circadian.”

They then used bioinformatics to ask: Do genes in the eye that are also rhythmic and responsive to dietary restrictions affect life expectancy? The answer was yes, they do.

“We always think of the eye as something that serves us to provide vision. We don’t think of it as something that needs to be protected to protect the whole body, “said Kapahi, who is also an associate professor of urology at UCSF.

Because the eyes are exposed to the outside world, he explained, the immune system is critically active there, which can lead to inflammation, which, when present for long periods of time, can cause or worsen a variety of common chronic diseases. In addition, light itself can cause photoreceptor degeneration, which can cause inflammation.

“Looking at computer and phone screens and exposure to light pollution until the end of the night are very disturbing conditions for circadian watches,” said Kapahi. “This confuses the protection of the eye and this can have consequences beyond sight, damaging the rest of the body and the brain.”

There are many things that need to be understood about the role that the eye plays in the overall health and life expectancy of an organism, including: how does the eye regulate life expectancy and does the same effect apply to other organisms?

The biggest question raised by this work, as it may apply to humans, is simply whether mammalian photoreceptors affect longevity? Probably not as much as fruit flies, Hodge said, noting that most of the energy in fruit flies is dedicated to the eye. But since photoreceptors are just specialized neurons, he said, “the stronger connection I would argue is the role that circadian function plays in neurons in general, especially with dietary restrictions, and how they can be used to maintain neuronal function throughout aging. “

Once researchers understand how these processes work, they can begin targeting the molecular clock to slow aging, Hodge said, adding that it may be that people can help maintain vision by activating clocks in our eyes. “It could be through diet, medication, lifestyle changes. There are a lot of really interesting studies ahead,” he said.

Leave a Comment

Your email address will not be published.