Gaby
Experiments on common fruit flies (Drosophila melanogaster) turned up an intriguing result. Researchers at the University of Michigan think the results might also apply to humans. If true, the findings could boost interest in intermittent fasting, a trend in recent years.
What the Researchers Discovered
To explore the molecular mechanisms of fasting, the researchers turned to the humble fruit fly. This tiny creature has helped scientists identify many neural signals tied to hunger and satiety in the brain. About 75 percent of the fly’s genes are linked to the same diseases that affect humans.
To understand how the sensation of hunger might influence aging, the researchers periodically deprived the fruit flies of food. Specifically, they withheld amino acids essential to fly survival.
These amino acids, known as branched-chain amino acids (BCAAs), are vital nutrients for Drosophila melanogaster. Eating these BCAAs makes the flies feel full.
The flies that received a low-BCAA snack during the experiment later ate more food. They also showed a preference for high-protein foods over carbohydrates. This suggests their hunger was driven by nutritional need rather than craving. Ultimately, the scientists found that flies on this restricted diet lived significantly longer than those that consistently received their usual intake of amino acids.
Further experiments showed that lowering BCAA levels prompted neurons in hungry flies to produce modified histone proteins. These proteins, known as histones, bind to DNA and help regulate gene activity. The researchers say histones may link diet, hunger response, and aging. Previous studies have linked higher histone levels to longer lifespan.
The team says these findings could help explain why a low-BCAA diet might benefit health. A low-BCAA diet might give the body enough nutrients while still allowing hunger signals in the brain to remain active.
Of course, the connection between hunger and aging needs much deeper investigation. One fruit-fly study, published in the journal Science, is far from definitive. The scientists plan to run more experiments before applying the results to humans.
