For the first time, a rare connection has been found between diet, eye health and life expectancy. These three variants could be linked to each other due to circadian rhythms, as explained by the researchers at the Buck Institute (USA) who have carried out the tests to reach this conclusion in fruit flies (Drosophila).
Previous research has already found an association between eye problems and health disorders, however, the new research indicates that it is more than a correlation, since dysfunction in the eyes could cause damage to other tissues. Furthermore, the study, published in the journal Nature Communications, indicates that fasting and calorie restriction may have a beneficial effect on various body functions.
“The finding that the eye itself, at least in the fruit fly, can directly regulate lifespan was a surprise to us,” explains lead author Brian Hodge. This connection could have its explanation in the circadian clocks, that molecular machinery that exists in each cell of the organism.
Effects of restricted diet on circadian rhythms
The results show that these biological clocks could have evolved to be able to adapt to daily stress, such as changes in light and temperature that occur during the day. These 24-hour oscillations could affect complex animal behaviors, such as predator-prey interactions or sleep-wake cycles, until a temporal regulation of molecular functions of gene transcription and translation is adjusted. of proteins.
The genes most activated by dietary restriction appeared to come from photoreceptors in the eye, suggesting a link between the two
As for diet, a previous study published in the journal Cell Metabolism already indicated that fruit flies that had a restricted diet had altered circadian rhythms and had a longer lifespan. This insect was chosen precisely because it is genetically similar to humans –between 61% and 75% coincidence–, in addition to the fact that it has such a short lifespan it is a perfect model for detecting many things at the same time.
The results in this topic showed that many genes were responsive to diet and had ups and downs at different time points or rhythmic genes. It was observed that these types of genes that were activated more with dietary restriction seemed to come from the photoreceptors of the eye, the neurons of the retina that react to light.
Darkness increased the lifespan of fruit flies
Based on this, the researchers did various light tests, and found that fruit flies that were in constant darkness had a longer lifespan. “That seemed very strange to us. We thought that flies needed lighting cues to be rhythmic or circadian,” explains Hodge.
For his part, Pankaj Kapahi, another of the researchers, points out that “staring at the screens of computers and phones, and being exposed to light pollution until late at night are very disturbing conditions for circadian clocks. It breaks down the protection of the eye and that could have consequences beyond vision, damaging the rest of the body and the brain.”
But do mammalian photoreceptors have the ability to affect longevity? According to the authors of the study, it could affect less than what is observed in fruit flies, since in these insects the eyes are the ones that consume most of their energy. However, circadian rhythms and their role in neuronal functioning throughout aging could affect us a lot.
This is what the authors will continue to investigate, and once they understand how these processes work, they could unravel how the molecular clock could be used to slow aging, which Hodge believes could be achieved through diet, lifestyle changes or thanks to drugs.
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