By studying the long-term consequences of fasting on roundworms, an English research team discovered that this practice had a detrimental effect on three generations of offspring.
- By studying four generations of roundworms subjected to fasting, the researchers found that this reduction in food intake benefited the worms that practiced it, but not the offspring that had access to the food.
- In the non-fasting worms, this reduction in food intake from their elders had a very clear effect on their performance.
Purification of the skin, elimination of toxins, weight loss, strengthening of the immune system… Fasting has many dietary and therapeutic virtues. But is it really good for our health to stop eating for a given period?
If we are to believe the results of this new study, the effects of fasting on our body are not all beneficial, and could even harm future generations. Conducted by researchers at the University of East Anglia (UEA) and published in the journal Proceedings of the Royal Society Bshe reveals that reducing food intake in roundworms has had a detrimental effect on three generations of offspring – especially when the latter have access to unlimited food.
“We know that reduced food intake increases lifespan in many animals and can potentially improve health in humans. However, little is known about the long-term effects of reduced food intake. , including time-limited fasting, on distant descendants”says Dr Edward Ivimey-Cook, of the UEA School of Biological Sciences and lead author of the study.
Roundworms as guinea pigs
To find out the long-term impact of the practice of fasting, the researchers studied more than 2,500 roundworms spanning four generations. Transparent, measuring about 1 mm in length and living in the soil, these worms share with humans many genes and molecular pathways that control development. They are therefore regularly used to study the biological aging process, especially since their very short life cycle makes it possible to study their development and that of the generations of their offspring in a short time.
The first generation of worms were able to eat as much as they wanted or were put on a fasting diet. Four generations of offspring from these parents were then placed on a complete or fast diet.
The team then assessed the effects of different scenarios on reproduction and the longevity of future generations. Among the scenarios studied was one to study what happens when great-grandparents fast, but future generations can eat as much as they want, and cumulative fasting for four generations.
Effects on offspring performance
By tracking the different generations of worms, the researchers found that fasting actually increased their lifespan and also improved the reproductive performance of their offspring when the offspring themselves were fasted.
“However, we were surprised to find that fasting reduced offspring performance when they had access to unlimited food, the authors write. And this negative effect was evident in grandchildren and great-grandchildren. shows that fasting can be costly for offspring and that this effect can last for generations.”
How can these negative effects on offspring be explained? For researchers, the answer lies in molecular pathways “involved in the response to fasting”. These are “evolutionarily conserved, meaning the same pathways exist in a multitude of species, including humans”.
Hence the need to take into account the effects of fasting on our descendants. “This is really important because it means we need to look carefully at the long-term effects of fasting when trying to adopt healthy lifestyles, as the adverse effects may not show up for generations to come.”concludes Dr. Ivimey-Cook.
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