Is Salt Addictive? An Appetite for Salt and Drugs
To be "worth your salt" is a compliment, derived from ancient Roman times when soldiers' wages were paid in salt because it was so valuable. Our bodies have a need for salt that can result in cravings. And now researchers have found that the pathways in the brain that control our appetite for salt are also the ones that cause us to crave addictive drugs.
Scientists from Duke University Medical Center in Durham, North Carolina and the University of Melbourne in Australia teamed up and found that the nerve connections stimulated by the instinctive appetite for salt are the same grouping associated with cocaine or heroin addiction.1 These genes are all regulated in the hypothalamus of the brain, which controls our levels of salt, water, energy, and reproduction, among other basic needs.
This study may help explain why an addiction to narcotics is so difficult to treat and overcome, especially when you are talking about complete withdrawal of the substance. It also provides quite a bit of food for thought (pun intended) about why certain people have such a strong appetite for salty, unhealthy items such as fast food. Not that it's an excuse to indulge -- my hypothalamus made me do it! -- but simply a subject that scientists studying food addictions may want to explore further.
The research team focused on how particular genes turned on or off depending on whether rats were provided with salty water or deprived of it. To increase the rats' salt appetite, the scientists either withheld salt and gave them a diuretic or they gave the rats the stress hormone ACTH to raise their bodies' salt needs. The genes responded within minutes of the rats finally being provided with salt.
The rats with a hearty salt appetite experienced changes within the hypothalamus that made them more sensitive to dopamine, the brain's "feel good" neurotransmitter, responsible for sensations of pleasure and reward. So, at its most primitive level, when the body is lacking salt and then increases its intake of salt, the hypothalamus triggers a feeling of satiety similar to that of a junkie getting a drug fix, but on a smaller scale.
Now, obviously you can't compare eating salty foods to taking illegal narcotics. Drug addiction harms us, while salt is vital to us. Our bodies need salt to function properly as it is a primary component of the body's extra-cellular fluids, helping carry nutrients into the cells. It also helps regulate other body functions, such as blood pressure and fluid volume, and works on the lining of blood vessels to keep the pressure balance normal.
But there are major differences in the kinds of salt we ingest. In today's market, we have two distinct choices when it comes to salt: unrefined and refined. Unrefined salt is mainly sodium chloride with more than 50 other trace minerals. Refined salt is also mainly sodium chloride, but the trace minerals have been replaced by chemical additives.
Unrefined salt is either freshly dried from the sea or mined from ancient inland ocean beds -- and it is all natural. Refined salt, on the other hand, is a manmade creation of the last century that contains anti-caking chemicals and added iodine. Iodine was added for those who lived inland and could not benefit from natural iodine found in seafood. Refined salt is created by processing sea salt at high temperatures, which alters the molecular structure of the salt, rendering it unfriendly to the human body, and removes the beneficial trace minerals.
Refined table salt upsets your fluid balance, dehydrates the cells of your body, and contains no trace minerals. The added iodine may have helped eliminate the incidence of goiter, but it has increased the incidence of hypothyroidism. And the anti-caking agents prevent the salt from mixing with water, which also prevents the salt from fulfilling one of its important functions: regulating hydration.
Therefore, if your body is craving salt as the rats' bodies did in the Duke/University of Melbourne study, you need to choose and balance the salt in your diet wisely. Excess refined salt increases general appetite and decreases bone density. Use unrefined sea salt in moderation and make sure you get plenty of potassium in your diet to assist your body in utilizing the sodium. The more potassium in your diet, the more sodium you can handle. Also, read labels to limit refined salt intake from packaged foods, and minimize fast food consumption since most of it is off the charts in refined sodium levels.
1 Liedtke, Wolfgang B.; McKinley, Michael J.; et al. "Relation of Addiction Genes to Hypothalamic Gene Changes Subserving Genesis and Gratification of a Classic Instinct, Sodium Appetite." Proceedings of the National Academy of Sciences of the United States of America. 11 July 2011. National Academy of Sciences. 4 August 2011. <http://www.pnas.org/content/108/30/12509.abstract?sid=611a7af6-4d84-46d5-951f-049a484cb80b>.