Lost your appetite for protein? It could be an early cancer warning

A sudden protein aversion could be an early, crucial warning for cancer patients. New research suggests it signals a severe wasting condition called cachexia.

The Hidden Warning Sign

Most people with advanced cancers suffer from cachexia. It's a muscle-, fat-, and organ-wasting condition. Currently, it's incurable and can be life-threatening.

Spotting it early can slow its progression. But understanding its first signs has been a huge challenge for doctors. Typically, only a general loss of appetite (anorexia) is recognised.

Now, a study in fruit flies by Harvard Medical School researchers has found an even earlier signal. A clear drop in the desire for protein-rich food appears before general anorexia.

What’s Happening in the Brain?

The team discovered two tumour-secreted molecules are behind this change. They disrupt an appetite regulator in the brain. Interrupting these factors in flies restored protein consumption. This stopped weight loss and reduced death risk from cancer cachexia.

"We found that the tumour-compromised flies had the tendency to eat less amino acid-rich food, even prior to anorexia," said study first author Afroditi Petsakou.

"This aligns with what we know from cancer cachexia patients who seem to not want to eat protein."

Hope for Earlier Intervention

All three components of this molecular system have human counterparts. They are linked with cancer cachexia progression. Many patients share symptoms with the flies, including meat aversion.

This suggests that losing interest in protein-rich foods could be a reliable early warning sign in humans too. Developing drugs to target these components could help prevent wasting.

"By identifying the tumour-derived signals that drive a loss of interest in protein-rich foods, we may be able to detect and intervene in the disease much earlier, when there is still an opportunity to improve outcomes," said Norbert Perrimon, a senior author of the study.

The Protein Puzzle

Tumours need amino acids to grow. When they exhaust the diet's supply, they take from muscles, fat, and organs. Healthy animals can sense nutrient deficiencies. However, gut tumours in flies appear to blunt this sense.

This creates an "amino-acid malnutrition."

Petsakou explained: "The fly in the organ wasting model still eats amino acids. It's just that there is a misalignment of how much the fly needs versus how much their appetites tell them to get."

Next Steps

Cancer cachexia is a complex, multifaceted condition. Understanding protein ambivalence is just one piece of the puzzle. Researchers will continue to explore metabolic imbalances and sex differences.

The team advocates for the value of fruit flies in uncovering disease principles. This could inspire new treatment strategies.

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OFFICIAL SOURCE VERIFICATION: This report is based on official data from University Newsroom. Document: [Not Wanting To Eat Protein May Be Early Herald of Cancer Cachexia](https://hms.harvard.edu/news/not-wanting-eat-protein-may-be-early-herald-cancer-cachexia) Source Link: https://hms.harvard.edu/news/not-wanting-eat-protein-may-be-early-herald-cancer-cachexia