More than red meat, it’s iron. Iron regulation in the brain indirectly controls the reward pathway.

Give this 30 seconds thought.  Iron indirectly activates the reward pathway — and the higher the blood flow, the more iron, to oversimplify. The heart-pounding of anticipation and excitement, sending blood to the brain,  and the iron is yanked into the substantia nigra and sent off to potentiate dopamine signaling.

Is iron the answer to the reward-deficiency aspects of addiction?

And, of note, a study correlating big time red meat eaters with shortened lives. This is a correlation, although it looks to be reported as a causation. One might argue that early-death-by-meat is not caused by the meat, but perhaps caused by other behavior associated with seeking unexpected reward: say, spending all your money on lottery tickets so you lose your health insurance or undue experimentation involving human flight.

The papers:

1. Unexpected rewards, but not unexpected losses, are reinforced through the substantia nigra in the brain.

Kareem A. Zaghloul, Justin A. Blanco,Christoph T. Weidemann, Kathryn McGill, Jurg L. Jaggi, Gordon H. Baltuch, Michael J. Kahana, “Human Substantia Nigra Neurons Encode Unexpected Financial Rewards,” Science 323: 1496-1499, 13 March 2009; DOI: 10.1126/science.1167342

2.  Dopamine signaling  – the “reward” signal” -  is indirectly regulated through iron homeostasis in the substantia nigra.

Florian Tribl, Esther Asan, Thomas Arzberger, Thomas Tatschner, Elmar Langenfeld, Helmut E. Meyer, Gerhard Bringmann, Peter Riederer, Manfred Gerlach, and Katrin Marcus , “Identification of L-ferritin in neuromelanin granules of the human substantia nigra – a targeted proteomics approach,” MCP Papers in Press. Published on March 24, 2009 as Manuscript M900006-MCP200 in: Molecular and Cellular Proteomics (March 2009);

3.  Eating red meat is associated with a somewhat earlier death:

Sinha R. Arch Intern Med. 2009;169:562-571. (via Hemeonc Today)