Salt may play a role in the overproduction of immune-system cells that attack an organism's own tissues.
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The incidence of autoimmune diseases, such as multiple sclerosis and type 1 diabetes, has spiked in developed countries in recent decades. In three studies published today in Nature, researchers describe the molecular pathways that can lead to autoimmune disease and identify one possible culprit that has been right under our noses — and on our tables — the entire time: salt.
To stay healthy, the human body relies on a careful balance: too little immune function and we succumb to infection, too much activity and the immune system begins to attack healthy tissue, a condition known as autoimmunity. Some forms of autoimmunity have been linked to overproduction of TH17 cells, a type of helper T cell that produces an inflammatory protein called interleukin-17.
But finding the molecular switches that cause the body to overproduce TH17 cells has been difficult, in part because conventional methods of activating native immune cells in the laboratory often harm the cells or alters the course of their development.
So when researchers heard a talk by Hongkun Park, a physicist at Harvard University in Cambridge, Massachusetts, about the use of silicone nanowires to disarm single genes in cells, they approached him immediately, recalls Aviv Regev, a biologist at the Massachusetts Institute of Technology (also in Cambridge) and a co-author on two of the studies.
Park showed last year that these nanowires can be used to manipulate genes in immune cells without affecting the cells’ functions. For the first of the Nature studies, Regev and her colleagues used Park's technology to piece together a functional model of how TH17 cells are controlled, she says. “Otherwise,” she says, they would have been only “guessing in the dark.”
In the second study, an affiliated team of researchers observed immune cell production over 72 hours. One protein kept cropping up as a TH17-signal: serum glucocorticoid kinase 1 (SGK1), which is known to regulate salt levels in other types of cells. The researchers found that mouse cells cultured in high-salt conditions had higher SGK1 expression and produced more TH17 cells than those grown in normal conditions.
“If you incrementally increase salt, you get generation after generation of these TH17 cells,” says study co-author Vijay Kuchroo, an immunologist at Brigham and Women’s Hospital in Boston, Massachusetts.
In the third study, researchers confirmed Kuchroo’s findings, in mouse and human cells. It was “an easy experiment — you just add salt”, says David Hafler, a neurologist at Yale University in New Haven, Connecticut, who led the research.
But could salt change the course of autoimmune disease? Both Kuchroo and Hafler found that in a mouse model of multiple sclerosis, a high-salt diet accelerated the disease’s progression.
All this evidence, Kuchroo says, “is building a very interesting hypothesis [that] salt may be one of the environmental triggers of autoimmunity”.
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9 Comments
Add CommentWhat a 'saline solution' indeed! We have to de-salinate, in order to get the sodium-potassium balance right! It's basic biochemistry; after all, when you come to think of it, we are the ONLY creatures on earth that artificially SALT their food. No wonder our immune system is alarmed, and not only that of our foetuses when they willy-nilly have to swallow their mums'-to-be vegemite-as shown recently .
Reply | Report Abuse | Link to thisALL Processed food- from simple bread to sauces- is laced with salt, because it SELLS like nothing else, due to its addictiveness. ( The body's equilibrium has to adjust to a far more concentrated salt intake.) Even the humble potato has now been found to have 'our' type of ion channels in its cell membranes, through which sodium-potassium transfer takes place. Australian farmers know what havoc is wreaked on plant life from soil degradation through salt seeping up from below after clearfelling.
And we still think we can get away scot free with our pickled food habits?
Try eating only fruits and vegetables in their natural state for a day or two and sense the difference it makes to your taste buds!
Youthevity.com
Sure, I'd like to go through all experiences that might evolve to something more healthy, but I'm not so sure it would be that simple. For instance, I have a very low blood pressure (not a problem), and feel very good eating salty things. Isn't there a benefit too?
Reply | Report Abuse | Link to this@loureiro - just to back you up - yes I think the needs definitely vary from person to person. We are heterogenous(sp?). I personally also have a lower blood pressure if I don't eat a lot of salt. I've also found that if I don't eat a lot of salt my thinking becomes foggy. It may be the Iodine though. Ideally I should find a separate source of iodine.
Reply | Report Abuse | Link to thisTo be clear I should find the separate source of iodine and lower my salt intake to see if that helps.
Reply | Report Abuse | Link to thislicorice, the real stuff, also raises blood pressure.
Reply | Report Abuse | Link to thisI am curious what sort of salt they used in this study. Like was it iodized salt, sea salt, kosher salt...For those interested in reducing salt from diet but concerned about iodine, dulse flakes are a good source of iodine. Also, I use pink Himalayan salt when I do use salt. It taste really good and has a lot of minerals in it. Also, I agree that most Americans eat way too much salt, but keep in mind that some salt is necessary,(most life on earth has its evolutionary roots in salt water). So, I wouldn't recommend totally eliminating salt from diet, but I do think reducing salt and replacing regular processed salt, which has anti-caking additives, with Himalayan salt would be a good idea.
Reply | Report Abuse | Link to thisIt's weird, but I never ate salt until long AFTER I was diagnosed with Lupus. I grew up eating no salt because my Dad was on a no-salt diet and Mom decided everybody could do without salt. After I married, my husband got used to doing without salt too, because I just forgot to salt his food, or even to fill the salt shaker. The past few years, though, I've wanted salt on my food and sometimes can't even taste the salt unless it's briny to other people. Don't know if the Lupus caused it or if my taster is just fritzed.
Reply | Report Abuse | Link to thisSalt is simply NaCl, sodium chloride, wherever it comes from; and the body has to use nine parts of water for every on part of salt to flush the excess out again; and we eat it excessively, 10 times as much as is normal! No wonder it causes obesity, hypertension, and thereby kidney damage.( from the high blood pressure damaging the fine capillary structures).
Reply | Report Abuse | Link to thisThe fact that we 'like' it is due to the salt-lick reflex which automatically make our mouth water:salivate means:salt-weep- in order to dilute this salt excess! So, physiologically, it is an emergency reaction to get rid of the sodium unbalance.
I know from my own experience how addictive salty food is; just think: Pringle!
But it's easy enough to cut down on it; gradually replacing it by spices like raw grated ginger or garlic did the trick for me. No more pickled tongue - taste buds like new - a great new feeling!
Just because salt was used for pickling, that is, preserving, for thousands of years, it escaped being classified as a preservative. Let's eat preservative-free! But:
Meat eaters would not be able to eat meat without salt-
Like sugar,the other toxic preservative, salt brings life to a halt,
cell life that is. After all: Our own life is only as good as the life of our cells.
Does each and every immune cell have to be genetically reprogrammed with these nanowires?
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