Last week, we reported on a study on how fatty foods triggered marijuana-like chemicals in the body (http://bit.ly/pDMcxb). Now, we move onto the hard stuff: salt, cocaine and opiates.
Researchers at Duke University and the University of Melbourne have found that the same nerve cells and brain functions that account for how much we like salt are also strongly associated with addiction to such drugs as heroin and cocaine.
When they stimulated the appetite for salt in mice, the researchers found that they were also activating the gene groups regulated by drug addiction. Blocking certain pathways responsible for drug addiction also curbed salt appetite.
"Some scientists have theorized that drug addiction may use nerve pathways of instinct," said the study's co-lead author, Professor Derek Denton of the University of Melbourne. "In this study, we have demonstrated that one classic instinct, the hunger for salt, is providing neural organization that subserves addiction to opiates and cocaine."
The authors of the study note that taste for salt has evolved over 100 million years, while the phenomenon of drugs causing pleasure and leading to addiction is a good deal more recent and illustrates how "contemporary hedonic indulgences" have usurped evolutionary systems with high survival value.
The study is published in Proceedings of the National Academy of Sciences http://bit.ly/opbj60 (abstract only).
