Fact or Myth: Sodium Raises Blood Pressure

Matt asks: Why does salt raise blood pressure?

eat-less-salt2
Well, Matt, it turns out a high sodium diet might not raise blood pressure, nor have any sort of adverse effect on cardiovascular health at all.  But I’ll cover the theory on why salt raises blood pressure below- just realize it is just a theory and one not backed up by much of any hard scientific evidence (and there is more evidence that says it doesn’t than does).

The debate over eating too much salt has been around since the 1960s. Almost every major governmental health organization embraces the idea that eating too much salt is damaging to your health. Most major news outlets report on these recommendations and people tend to try and follow them. This is most likely why most of us, especially the elderly with heart problems, know to reduce the amount of salt we eat. Those of us who like the idea that any recommendation be backed up by solid evidence, have to step back on this one. As stated, currently there is no solid evidence that salt will chronically raise your blood pressure. Yes, none.

So why have most health organizations pushed the idea of low sodium diets? The theory behind their supposition is sound, and there are some studies that show a minor risk of elevated blood pressure with extremely high salt intake. Unfortunately, there are many other studies that show no increase, and still some that show reducing salt intake might actually raise your blood pressure! Let’s look at the controversy in more detail.

The idea salt will increase your blood pressure has to do with osmotic pressure. Osmosis is the movement of a solvent (in this case water) across semi-permeable membranes (like cell walls), from areas of lower solute concentration (in this case salt) to areas of higher solute concentration. This naturally equalizes the solute concentration on both sides of the membrane. (This osmotic pressure is also why salt can be used to preserves meat.)

So the theory goes that when we eat too much salt, our bloodstream has more sodium in it than the surrounding areas of our body. This causes the water in those areas to be pulled into our bloodstream. The increase in water within the arteries and veins causes an increase in the pressure within those arteries and veins. The salt itself also acts like an irritant within the arteries causing them to constrict. This too is thought to increase your blood pressure.

The theory seems, on the surface, very sound. After all, we can make the process of salt pulling water through membranes happen time and time again in the lab. The question is, does this actually happen within our bodies, and does this actually cause long term hypertension (high blood pressure)?

In 1969, Lewis Dahl testified before Sen. George McGovern’s “select committee on nutrition and human needs”. He was concerned about the high concentrations of sodium in baby foods and thought this might cause increase in people’s blood pressure long term. His reasoning was that studies done on rats showed increases in the blood pressure of the rats.

The conversation about salt and hypertension began to circulate among health organizations. The National Institutes of Health, in 1972, began introducing “High Blood Pressure Education Programs”. As their evidence, they pointed out observationally, populations who ate very little sodium had low incidents of high blood pressure. They also pointed to the rat modeling. Scientists at the time questioned this, as the rat studies had them eating 60 times what the average person does. They also pointed out the populations who ate low sodium diets, also ate low amounts of other things, like sugar (which also affects osmosis).

Despite their objections, publicly, the idea of high sodium diets causing high blood pressure was here to stay, and remains today. The Centers For Disease Control, The National Institutes of Health, The American Heart Association, and many other organizations currently promote low sodium diets.

Despite the seemingly unified front presented by these distinguished organizations, the controversy among scientists is extremely heated. In 1998, award winning author Taubes, published “The Political Science of Salt” in the Journal of Science. He stated, “The controversy over the benefits, if any, of salt reduction now constitutes one of the longest running most vitriolic and surreal disputes in all of medicine.”

One surgeon general in a report wrote, the speed with which US federal agencies embraced sodium reduction, “stood in stark contrast to how long it had taken for recommendations to emerge on the importance of reducing blood cholesterol levels”. He also noted that the difference was even more remarkable considering the absence of published research that actually tested the theory. On the flip-side, Sir Micheal Rawlings, the chair of the National Institute for Health and Clinical Excellence, who promotes salt reduction diets argued that, “Guidance (in policy making) is based on the best available evidence. The evidence may not, however, be very good and is rarely complete.” Not a very strong argument for reducing salt intake.

Let’s look at a few relatively recent studies. In 2008, Italian researchers began publishing the results from a series of clinical trials, all of which reported that, among patients with heart failure, reducing salt consumption increased the risk of death. These studies were followed by others which showed among Type 1 and 2 diabetics, healthy Europeans and patients with chronic heart failure, those that ate salt at the lower limit of the normal range were more likely to have heart disease than those who ate salt in the middle range of normal.

In 2011, two Cochrane reviews found no evidence that low salt diets either improved or worsened peoples’ health. They stated, “After more than 150 random clinical trials and 13 population studies without and obvious signal in favor of sodium reduction, another position could be to accept that such a signal may not exist.”

Even in the face of no clear scientific evidence to support it and some to the contrary, in 2010 the Centers for Disease Control and Prevention, the Institute of Medicine, and the American Society of Hypertension all continued to promote low sodium diets as a means of controlling high blood pressure.

In the end, being a medical professional and someone who needs clear evidence to make a decision about whether I get to add copious amounts of salt on my fries, I am pleased to find that so far there is very little! All the major health organizations seem to promote low sodium diets, but none have actually published consistent studies that show low sodium diets help in health, particularly not in cardiovascular health. What I find most annoying, a pet peeve of mine, is that none of these organizations tell people that the science behind their policies is controversial and they might be flat wrong. Ronald Bayer, David Merritt Johns, and Sandro Galea said it best in their article “Salt And Public Health”- “After a careful consideration of the debate over salt, we have concluded that the concealment of scientific uncertainty is a mistake that serves neither the ends of science nor good policy.”

So you should you go out and smother everything in salt now? As with most things, if science hasn’t been able to answer the question definitively one way or the other, and you want to be safe rather than sorry, just go with the age old rule of “moderation in everything”.  If you, like me, like to salt everything like the rim of a margarita glass and moderation be damned, at least now you can feel a little better about it as science seems to be leaning more and more towards low sodium diets being unnecessary and high sodium ones not being harmful at all.

If you liked this article and the Bonus Facts below, you might also like:

Bonus Facts:

  • High blood pressure is neither a disease nor an illness in and of itself. It’s merely a risk factor for other problems. For instance, if you have chronic high blood pressure, your risk of having a heart attack or stroke goes up significantly. This high pressure could be caused by excessive plaque on the inside of your artery walls, making those arteries in effect, smaller. Think plumbing. When the pipes that transport fluid get smaller, the pressure that same volume of fluid exerts goes up. What happens if your blood pressure gets too high? I’ll answer that question with another one. What happens if the water pressure in your houses pipes gets too high? Your pipes burst. Same thing here. Should your blood pressure get too high, your arteries have a greater chance of bursting. If there is too much gunk inside your pipes (plaque inside your arteries), that ball of gunk could get too big and clog off your pipes! Seems bad too me! Especially, if those arteries are in your brain, or heart. It’s not like kidneys, where you have two! You spring a leak in those organs, and your family finally gets that big paycheck from your life insurance policy! Not really the best way to get paid, well, unless you’re really a jerk and everyone in your family hates you!  Then they might not mind so much, but you certainly would.
  • Blood pressure is measured in millimeters of mercury. For reference, 1 psi (pounds per square inch) is equal to 51.7149326 millimeters of mercury. If you were bleeding and wanted to stop the blood-loss with direct pressure, and you should, you would only need to use about 3 psi to stop it. Unless they have really high blood pressure, then maybe 4 psi. Basic math saves the day again!
  • The first known experiment to measure the exact pressure of blood was performed by Stephen Hales on December 1, 1733. He took a live horse. Attached a tube to her left crural artery, then allowed her blood to rush through the tube and it rose to a height of 8’3”. He noted that “when it was at its full height, it would rise and fall at and after each pulse 2, 3,or 4 inches”. Yes the horse bled out, but don’t think Mr. Hales was too cruel, he performed the experiment on a horse that was about to be put down anyway!  To the horse, I’m sure this distinction didn’t matter much of course. 🙂

*Legal Disclaimer: While I am a medical professional, this article contains general information about medical conditions and treatments. The information is not direct advice for your specific situation, and should not be treated as such. You should never delay seeking medical advice, disregard medical advice, or discontinue medical treatment because of information in this article…. There, I’ve covered myself.  ;-)

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  • I’m getting more and more convinced that salt does significantly increase my BP. Whenever I eat crisps (chips if you live in the USA) which have a fairly large amount of salt, my BP goes up significantly the next few days.

    I tried getting saltless crisps about a week ago and added my own “lo-salt” (a salt substitute consisting of potassium chloride and sodium chloride (salt), but twice as much as the former than the latter).

    Anyway the lo-salt flavoured crisps (chips) diodn’t raise my BP at all.

    OK I know that further experiments on myself is required. But at the moment I’m strongly suspecting salt as the culprit. I’m also suspect that sugar increases my BP too. But lots of investigation required to establish that!

    Ian

    • lisa

      Maybe you have a poor potassium to sodium balance. My mum has hypertension and was on a low sodium diet but she was not getting enough potassium and her blood pressure was not stable. If you are concerned you may want to have your blood potassium level checked.

      Now that she is consuming enough potassium she her blood pressure has been normal for over a year while consuming sodium within normal ranges(more than 2500 mg)

  • Salt (Sodium) DOES raise your blood pressure. I went to the doctor and my blood pressure was 130/90. She told me to control my salt (sodium 1500mg limit) and I had a check up two days later with my blood pressure 108/87. Anytime I eat lots of salty foods, I get a spike in my pressure. I am definitely salt sensitive.

    SALT (SODIUM) DOES affect your blood pressure. You have to be careful (it sneaks up on you good) and adjust your diet to limit sodium intake and watch for signs of your pressure raising. Especially when your body behavior changes.

    Work out as well! If you are lazy or not that active, take 30 minute walks 5 days a week (150 minutes total) minimum to get a decent exercise.

    • lisa

      I think the point is that recommending a lower sodium diet, that maybe affects a specific set of people, those who already have hypertension and are salt sensitive, to an entire population is ridiculous. Another point is whether high salt intake leads to chronic cardiovascular problems, which is being touted as fact to the public but has no research to back it up. I consume way more sodium than the CDC recommends and my BP has never been higher than 117/70, my highest ever, normal about 100-110/65-70. Neither of our cases prove one way or the other the effects “high” sodium intake has on the general population.

  • As for Sugar, women should limit their sugar (Total Carbs is what matters and watch out for certain sugar alcohols) 20g-30g a snack and 30g-45g each meal. Men should keep their snack the same as women 20g-30g a snack and 60g – 75g a meal. The lowest numbers are the lmit for diabetics of course.

  • whakers

    I believe that some people have a sensitivity to sodium. I’m convinced that I do. After being on 3 different BP meds at one time and still having uncontrolled hypertension, I started reading food labels and drastically reducing my sodium intake. Most processed foods are loaded with sodium. I have been able to stop 2 meds completely and reduce the third one to 1/4 the prescribed dosage. For me, reducing sodium has made a huge difference. Last night I took 10 mg of lisinopril, which is 1/4 of the prescribed daily dosage. Today my BP is too low, 105/48. I really have to consistently monitor it, as low BP isn’t much fun, either.

  • Yea, whatever. Believe what you want. I have been reading health books for years….DECADES…and I’ve have read in them EXACTLY what is printed in this article. There NEVER has been a proven link between salt and high blood pressure. Furthermore, in one of books it pointed out that salt is used to make stomach acid, and it’s ironic that as we age, the low sodium diet so often touted leads to digestive problems.

    Keep believing doctors who take 3 credits of Nutrition in college and pitch compounds that cause worse side effects than the actual disease.

    Doctors, who say Chiropractic is “not real medicine.” Read the Winsdor papers. A doctor who set out to prove Chiro was fake by doing autopsies found that 99 out of 100 organ failures were due to lack of nerve energy caused by “subluxations” which pinch the nerves and interrupt nerve energy flow. (I’m not a chiropractor).

    Go read books by Norman Walker, (especially “Fresh Fruits and Vegetables.”), TC Fry, and Herbert M. Shelton (Superior Nutrition, Fasting can save your life). I’ve read them all.

    BOTTOM LINE this is an excellent article and I’m actually surprised to see the truth so openly posted in an article like this…but you believe what you want & take chemicals pushed by the medical profession…eat what you want, drink what you want, don’t exercise and when things go wrong just take a pill….

    • Alan

      I attempted to look up these “Winsdor Papers” and even Google doesn’t know what you are talking about. If you really want to win people over, you should actually post links to the information you want us to read.

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  • marco

    Guys you all are missing one point: sodium is poisonous to us. Even if does not raise BP, its still poison ;/ not good at all

    • Daven Hiskey

      @Marco: You would die instantly without sodium in your body.

    • Marco

      I am not the same Marco as Mr. “Salt is poison”. Just to be clear

      • Daven Hiskey

        Ha, noted!

    • Alex

      Of course – everything in excess is bad – heck, even drinking too much water will kill you.
      Now, every person is different so you have to find what works for you. Mine, I like salted 🙂

  • Mike

    This article is misleading. Just because salt’s negative effect on blood pressure is a “theory” doesn’t mean we should ignore it. In fact most of medicine and science is carried out on plausible theories. The truth is a low salt diet is less harmful than a high salt diet and like all things the real moral of the story is moderation. Also this author contradicts themselves by saying there is “no evidence… Yes none” to support this theory, but then goes on to cite at least one study that shows the negative corrolatuon in humans and another involving rats. That’s evidence, at least some not none. Most of medicine is black magic and many doctors will admit that. Sure sometimes we are far from knowing but in this case there’s enough science behind salts impact on BP to make it worth considering. Also remember the human consumption of high salt quantities is a fairly new thing on the evolutionary scale, so it’s impact on our bodies is fairly unnatural.

    • Daven Hiskey

      @Mike: “No evidence… Yes none” I think Scott is meaning “No reputable evidence” Or, rather, “No evidence that is not flawed.”
      .
      “Everything in moderation” Yep, exactly. As Scott is fond of saying, “Even water will kill you in high enough doses.” He even once told me a story of a woman he attempted to treat for this very thing- she drank massive amounts of water and ended up dying from it.
      .
      “Most of medicine is black magic and many doctors will admit that.” I don’t think any doctors would ever say that. Maybe a century or two ago. But there is an amazing amount of good science involved here these days. We are far from knowing everything, but it’s certainly not black magic or just guess work, as that would seem to imply.

      • Rafael

        Sorry to disagree with you Dave. But even on the sources of the video, the rise of blood pressure on high-salt diets is evident. While in the end of one of them, while talking about softdrinks and snacks companies:

        “Some of these companies have been preeminent in trying to create an artificial controversy doubting the relationship between salt intake and blood pressure,16,17 presumably in the hope of stopping or slowing down any reduction in population salt intake to protect soft drink sales.”

        Even, I’m not a specialist in the area, the lacks of a literature review in source about this matter is disturbing.

    • Marco

      I suggest you read the book “Salt”. It is mostly a geopolitical historical account of salt in our civilization, but it also has a good deal of science in it. We built our civilization on salt.

  • George Vieira

    The first paragraph says ” just realize it is just a theory and one not backed up by much of any hard scientific evidence,” I believe that since this is a scientific minded website it shouldn’t use the word theory in this context, since in science, a theory is an accepted explanation of a phenomenon, proven by testing.

    • Jack

      Yeah, he should have used hypothesis. I’m going to have to look up the history of theory and see if anyone knows how it ended up with two such different meanings.

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  • Mark

    For a medical professional (which leads to an assumption of advanced education), you have a horrible grasp of grammar and spelling. This discredits much of what you say, in my mind. Having someone else review your work before publishing would go a long way.

    I will continue to listen to my cardiologist on this matter and limit my salt intake.

    • Daven Hiskey

      @Mark: Something you’ll find seemingly true about a large number of medical professionals, the stereotype of their handwriting being horrible is generally correct. (Scott’s is particularly bad.) And their technical writing can also sometimes be particularly terrible, pre-edit. (They study medicine and the human body, not writing, after all) But, in over 100+ articles Scott has written, he has never been shown to be wrong on a main point (and only a few cases of being wrong on a minor point). Typos? Awkward sentence? You will always find at least one of these in each of his articles, despite my sincerest efforts to get rid of them all. But in the end, I care about accuracy much more than grammar. Both would be good, but finding a writer of Scott’s particular expertise and ability to think critical and process vast amounts of medical knowledge is extremely difficult. These people aren’t a dime a dozen. 🙂
      .
      But really, the strength of Scott’s arguments are never based on his extensive medical knowledge. That just helps him thoroughly vet the various studies on the subject where most would get lost in the terminology, let alone be able to think critically about them and their methodology. The strength of the argument is the studies themselves. In this one, you’d do well to actually read the two Cochrane reviews, and perhaps forward them to your cardiologist for his/her thoughts.
      .
      Don’t be surprised if he/she has already ready them though, and maybe even agrees with them. What doctors tell their patients doesn’t always line up with what they actually know or believe to be true. Particularly in cases like this where lawsuits may be a very real possibility if they told you to eat all the salt you wanted, then you died of a heart issue (but having nothing to do with the salt), then your family sues them and cites what various government agencies say on the subject, rather than what the medical world actually thinks. 🙂 Watching your sodium isn’t likely to hurt either, but covers the cardiologists’ backside. (I actually had an interesting discussion about this with Scott just last night about a doctor he was discussing this with who said something very similar as to why despite that he knows sodium isn’t going to be harmful in this way, he still tells certain of his patients to watch their sodium intake.)
      .
      In the end, as I always say, “Question everything,” but also when questioning, do the research to find the answers too, and then double check that research just to make sure. 🙂 And, maybe don’t make the mistake of equating grammar and writing ability with knowledge of a subject or intelligence. I’ve worked with a ton of writers. I can say, journalists (and other such people with a writing background) are great at writing… They almost all are horrid at research, which surprised me on the journalists, but maybe explains a lot about the state of media reporting on scientific studies. Funny enough, the best combo of writing ability and research seems to be lawyers. They are phenomenal at both in my experience. Scientists, or people with a science background, tend to be poor at writing, but incredible at research and critical thinking. Of course, that’s only going with a sample-size of a few dozen writers I’ve worked with, and there is one exception I’ve found in that, but it’s a trend I’ve observed.

      • Marie

        I think everyone must be different. For me salt raises my blood pressure a lot. I check the bl pr 4-6x a day. Stays low enough when i stay under 300 mg of salt. As soon as i eat a lot of salt, like chinese food or even a meat and cheese sub or two slices of pizza my bl pr goes to 170/98. It takes a couple days to get the salt out of my body. Then it will go down to 130/80 and sometimes a bit lower. I am 67.

  • Marco

    I was wondering if I could ask the author of this article for a small favor.
    At the beginning I read this sentence in regard to salt intake:

    “But I’ll cover the theory on why salt raises blood pressure below- just realize [it is just a theory] and one not backed up by much of any hard scientific evidence…”

    Here you are using “Theory” in its popular parlance. WHich is fine and all. The problem is that this is a scientific related article and when a theory is not supported by evidence we call it a “Hypothesis”.

    Those of us that write in the scientific realm should make an effort to make this distinction, mostly because the next time I get some Young Earth Creationist telling me evolution is “just a theory” I swear I am going to start jumping up and down like a Chimpanzee and make backward sammerault. Then I’ll throw feces at him/her.

    I am sure you don’t want such a scene to become reality. Heck, you probably don’t want to think it up in your mind.

    So let’s start a campaign to call a Theory a “a coherent group of tested general propositions, commonly regarded as correct, that can be used as principles of explanation and prediction for a class of phenomena” and call anything that is meant to be pulled from one’s rear orifice an “Hypothesis”.

    BTW: I know the dictionary return both meanings. FOr the sake of Science, let’s change the meaning back since we already have a good working word for “I just pulled this out of my ass”.

    • Daven Hiskey

      @Marco: That’s a good point. I’ll start working that distinction in to future articles. 🙂

  • John Fischer

    Not a single legitimate conclusion can be drawn from a single blood pressure measurement. BP varies widely even from moment to moment. I have many times seen 160/100 drop to 130/75 over the course of a few minutes. As well, BP measuring equipment is highly variable and susceptible to wide variations from things like cuff size and user variations.

    Any conclusions drawn from a few measurements are nothing more than speculation and wishful thinking.

  • Michael Stelly

    First, this is not a peer-reviewed journal article. I agree, the correct use of “theory” has been obfuscated by the colloquial “just a hunch” version. But, let’s move on, ok?

    I don’t get that the article is in the least bit misleading. I do get that the author makes the point that apparently is lost on many — “As stated, currently there is no solid evidence that salt will chronically raise your blood pressure. Yes, none.”

    He also mentions to think critically. So, if you don’t believe him, a) continue with your belief, or b) find out for yourself. Do the legwork. Read the articles. Now you have a starting point. Thank him for that.

    In my opinion, focusing on the occasional grammatical error or “theory vs. hunch” debate unnecessarily diminishes the author’s intent. My takeaway is that this article helps challenge my assumptions about what I thought was already scientifically concluded. I learned something. That’s the point.

    • Marco

      @Michael Stelly I am not sure if you were referring specifically to my post in regard to the usage of “theory”, but I assure you that my comment was not intended to criticize the writer at all. At least not in the same terms as a grammatical or spelling “error”.

      My comment is not about an “error” rather it is a suggestion that those of us that read and write about science do our part to reclaim the usage of the word “theory” from the mainstream or that at least we try.

      There are those that comment on obvious spelling errors and I agree they are not important in the context of the information provided in the article (although I agree they can be distracting and I am speaking from a non native English speaker), but unless their number and character is such that they make understanding the article difficult or even impossible, you won’t find me posting about them.

      The word “theory” on the other hand is a word that is being actively used by certain factions of the science / religion discussion to discount 200 years of scientific advancement and it is being actively used to mislead children into discounting science as a whole.

      If you have watched the Nye – Ham debate, Gawker asked some creationists to write a question to evolution supporters on a piece of paper and they published these questions in the form of pictures. Invariably the “it’s just a theory” question appeared.

      It’s in that spirit that I have asked the curators of this website to try to use the word in its scientific meaning. If we in the science and technical fields don’t do that, we cannot expect those that want to distort science for their objectives to do it on their own.

      So, with all due respect, I won’t take your advice. I will certainly let slide silly spelling errors but this is important to me and it should be important to all of us that love science.

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  • Alan

    One fact I would like to add:

    Thiazide and thiazide-like diuretics are another piece of evidence in this controversy. Interestingly, thiazides are called diuretics but when taken daily this diuretic effect becomes almost zero. After a period of chronic thiazide therapy, the primary benefit these medications provide is that they increase the elimination of sodium and chloride ions from the blood by way of the Na/Cl symporter in the distal convoluted tubule (along with other effects such as retention of calcium). Despite losing the diuretic effect thiazides retain their blood pressure lowering effects long-term and are one of the medications used first line for lowering blood pressure. This lowering effect is generally attributed to the elimination of sodium and seems to be in line with the idea that high sodium levels do increase blood pressure.

  • Gino

    Believe it or not. Salt appears to lower my BP. If I eat too many chips I actually get dizzy from low BP. Can’t say I get it.

  • Jenny

    This “theory” is simply stupid. Salt DOES increase blood pressure big time! It’s a fact, observed, monitored. Accidentally eat some pretty salty stuff one day than needed a week of diuretics to get rid of all that salt from the body and bring the blood pressure from 190-200 (!!yes, that high it got!!!) back to normal (120-130). So don’t tell stories which aren’t true.

  • Not all people respond the same to dietary salt. My suggestion for us is to take note of the sodium level in our normal lab results in minimal annual physicals.

  • Ashutosh Mahajan

    From childhood, I am used to take more salt with my meals, but never faced the problem of High BP, instead sometimes it goes below normal. I Googled this problem & came to the conclusion that my body needs salt more than normal to compensate for genetically transmitted ‘Low BP’ problem. So? Your Brain is the instructor for your health. You must follow its orders to stay Really Healthy!

  • EmilieGM

    Well, I’m just a nutritionist (like a University Nutrition major that will be graduating in May) and maybe what I learnt is bull, but after being thought about the pathophysiology of how sodium can impact blood pressure, I find that the recommendation makes sense, but you would need to do more than just cut sodium. One thing that’s important is the sodium: potassium ratio (ie you eat a bunch of high processed, sodium added foods compared to fresh or frozen fruits and vegetables). I’ll admit that not everyone is salt sensitive and that we have consciously decided, in the health field, to assume that everyone is because testing for salt-sensitiveness (if that’s a word!) is expensive, long, and impractical. But the idea that there is no good plausible evidence linking salt and hypertension is false. Here’s just 6 articles. These aren’t the ones that were given by our professors to read (though if you want me to find them for you I’m sure I can), but they’re good one’s nonetheless and you don’t need a special University code or membership to access them. Anyways, here you go in case you want to read more:

    http://www.ncbi.nlm.nih.gov/pubmed/24535442

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4308954/

    http://www.onlinecjc.ca/article/S0828-282X(14)00070-1/abstract

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4092877/

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160564/

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  • rod

    I have been torn between to eat more salt or not, because eating more salt reduces my heart rate and BP and makes me sleep better; my hands and feet feel full and warm. My sweat volume increase as I bike or walk. But then after taking it for a week or 2 then I notice that BP becomes persistently high; which makes me feel I did wrong by eating. What this article mentions is fluid volume increase which is interesting. Before increasing my salt intake my fingers feel thin. Maybe after fluid levels feel normal cut back on salt to normal levels. So I am just hypothesizing that people who have are salt sensitive have good fluid volume and should watch salt intake, others can take salt but stop when it feels full. Basically use salt maintain fluid volume.

  • rod

    Based on self-experimentation, I think maintaining fluid volume is very important. At times, I find that I feel thirsty and drink water and that it keeps coming out; that calls for some salt intake. Basically, I do not eat canned food or much fast foods, my salt intake is what is purposely added in cooking. After exercise, (eating by the book and working out etc cause problems too) I notice that when I stand up from sitting position, I feel dizzy but not normally. I think I may be sweating out salt and , of course, I drink a lot of water during the exercise. I am not proposing eating more salt. What I am stating is the way the body is telling you that your salt is depleted is when you are not feeling full in your feet and hands. I think this is correct to some extent, as the body works more on concentration of things than the absolute amounts. It is not a comprehensive theory as there are other things that may increase blood volume, you may be already having too much salt in blood etc. For the record, my sodium in the blood is always near the low end of the range so my err wont push me outside of the range.

  • Pavan

    Ok what is the conclusion? do I use the salt shaker now or not? I have been holding too long.

  • Jim porter

    I think this article is irresponsible in that salt absolutely does raise bp in those who have a salt sensitivity. If I eat something very salty I can literally go into hypertensive crisis in a matter of an hour.

    This type of sensitivity is common and to not mention it (because it does not fit with the authors theory?) is dangerous.

    • Daven Hiskey

      @Jim porter: “because it does not fit with the authors theory?” The “author’s theory” doesn’t exist. That’s really not what we do here. This is an article simply writing about scientific studies on the topic and saying what they say, so you don’t have to sift through them and all the medical jargon; we do it for you- essentially what we write about reflects the current state of human knowledge on the subject at hand. If it changes at some point, we update the article. In this case, however, most notably the two Cochrane reviews are pretty convincing: “After more than 150 random clinical trials and 13 population studies without and obvious signal in favor of sodium reduction, another position could be to accept that such a signal may not exist.” There are exceptions to every rule, and seemingly you are one and that’s very interesting if so and it would be interesting to learn the root cause. But, again, we look at what the scientific studies say and try to reflect that in what we write. Essentially we write a form of “light-reading” style entertaining survey papers on subjects, rather than write research papers.

  • josh

    Stressing about salt will likely kill you long before salt itself will. Do what makes you happy and you will likely live longer than otherwise; and even if you don’t, at least you’ll enjoy the time you have.

  • Anne

    I believe the problem is when salt is mixed with fat and THAT causes high blood pressure. For example, someone talked about theirs rising when eating crisps/chips-that’s because the chips contain fat. The same would apply say to french fries or other fatty dishes. However, if you were to sprinkle salt on something like fruit, it wouldn’t have the same effect and not raise your blood pressure.

    I do think sodium gets a bad rap and some people actually do consume too little. I think having salt with fruit or salads is o.k. but the problem is the salt/fat combination and if you think about it, that’s where people usually get their salt-in potato chips, french fries, heavily seasoning meats, in creamy dishes, etc.

  • Steven S

    The person who wrote this article adds nothing of value to the discussion about high blood pressure except to encourage people to stick their heads in the sand.

    I have been wrestling with high blood pressure for about 12 years since a serious accident caused me to be physically inactive for about a year after the accident.

    High blood pressure can be controlled with and without medications and individuals respond differently to different treatments and there are natural cures for this affliction.

    High blood pressure can cause strokes, brain hemmorhages and contribute to diabetes and kidney disease.

    The balance between potassium and sodium in our blood is very critical and unfortunately most doctors don’t have a clue about the effect that nutrition and proper hydration has on this condition.

    Most of the doctors I have been to just give out prescriptions which may or may not work.

    There are natural substances which have enabled me to lower my blood pressure within a few days from extremely high to almost normal while doctors and pharmacists will say that medications (like Cozaar and Norvasc)may take up to a month to work.

    I’ve found that the juice of one lemon with zest or essential oil added to 16 ounces of mineral water
    had significant effects.

    Drinking this once or twice per day has had a very significant effect in my case; my blood pressure went from 220/95 to 130/90 within 3 days.

    Garlic (deodorized) also helps and fruit or vegetable juices with lowered salt content and high potassium content also help. (V-8 low salt or V-8 green).

    This is not wishful thinking; it has to do with chemistry; this doesn’t mean that everyone will respond the same to these treatments but I disagree very strongly when someone says that salt has no effect
    on blood pressure.

    This seems to me to be irresponsible and cavalier, unless of course you work for one of the salt manufacturers.

    Salt is necessary and most table salts have iodine in them, which is an essential nutrient for humans.

    Drinking sufficient amounts of pure water is also very important; something that my doctors never bothered to mention.

    This enables the body to rid itself of excess salt and helps the body cleanse itself.

    There are many natural substances and some foods (like pesto) which can help lower blood pressure and you can find many posts on the internet about them.

    Web Md and The Mayo Clinic both have posts on the subject and I trust them a hell of alot more than the author of this post.

    This appears to me to be an exercise in defending the indefensible.

    To what purpose?

    Who was Hippocrates anyway and what the hell did he know?

  • Yocheved

    I have extremely low blood pressure. If I stand up too fast, I’ll faint flat on my face. My doctor told me to eat as much salt as I want, no worries.

    In any case, I’ll take all of this advice with a pinch of… you know what. ;-D

  • Curt Nicol D.D. Ph.D.

    I eat a lot of salt (and I do mean a *LOT*). A few years ago after getting fed up with constantly being told how bad this is, I decided to put it to the test. As a Ph.D. I know how to scientifically plan a test, and over several months minimizing as many variables as possible, I tested my blood pressure while at my regular salt intake versus low salt intake. The results were pretty much as expected, although some people /may/ be slightly intolerant to relatively high levels of salt intake, for me there was no difference at all. I have returned to eating food the way I like it (salty), and tell anybody who advises against this they simply don’t know what they are talking about LOL

  • anonymous

    I’m 27 female. I started having high blood pressure while I was taking Accutane a year and a half ago (Accutane increases cholesterol buildup). What I experienced was intense, my pulse was at 120bpm, I was dizzy, my hands clamped up into an unusual claw shape and they tingled until they lost feeling. I thought I was actually dying. I was told it was just a panic attack, but I’ve never had any real anxiety issues. I was given oxygen for an entire hour when suddenly I started craving salt. I asked my friend to run to mcdonalds and get me some extra salty fries. Within minutes of eating all that salt, my blood pressure was back to normal, my hands got their feeling back, and I could walk and breath normally again.
    I find the things that trigger it the most for me are a lack of sleep, not eating anything all day, corn, wheat, and chemical salts such as MSG. But sea salt and normal table salt don’t make it worse, they make it better! With that said, I’ve always had blood test results showing high levels of potassium. Could this somehow be involved? My Dr. Just shrugs it off as caused by my love for potatoes and citrus fruits lol

  • Chris

    Pharmacist here. Thank you for all the helpful comments on this site. One can see all the intelligently written posts from people who have reduced their high blood pressure by limiting salt. I am one of these people. My blood pressure a year ago was running on average 180/120 when not medicated, and when on 3 different medications, on average 140/90. After feeling awful, either from adverse effects from the meds or from headaches from high blood pressure, I decided to alter my diet. The results I achieved were stunning. Blood pressure perfectly normal, 120/80. No headaches, or feeling like my throat was swollen, or feeling like my head was too hot….I could go on and on. I did this with NO expensive products. I just, as much as is possible nowadays in the U.S., ate non-processed foods, and avoided all added salt. Notice, all “added” salt. As many have correctly pointed out, salt is necessary to human life. And many foods naturally contain all the salt we need, so it is not necessary to add any. Listening to these supposed experts, I wonder how any humans ever survived 10,000 years ago if they weren’t lucky enough to find a salt block to lick every day! I read one comment about someone who has had good results from “the juice of one lemon with zest or essential oil added to 16 ounces of mineral water”. I would challenge him and others to just try the lemon juice with water. I find that if I clean myself out with just one glass of lemon-water once a week, it has had a splendid effect on my health. The other ingredients may help, but it would be an interesting experiment for you. So I, like, many, many others, am sensitive to salt. Maybe some people can eat a huge amount of salt on a regular basis with no adverse health effects. That is not true for many of us, and it is offensive when so called “professionals” or “scientists” dispute this. One thing I always tell my patients, “When it comes to your health, trust yourself above all others”. If you are convinced a particular medication is making you feel sick, and your doctor or pharmacist imply it’s all in your head, trust yourself, not them. If you, like me, feel a thousand times better when you limit your consumption of salt or processed foods, then please, keep doing what you are doing, and don’t listen to those who suggest otherwise! You will be healthier and happier. Thanks for listening, my friends from far away.

    • Eboshi

      While it’s certainly possible that you are salt sensitive, when you decided to alter your diet, you changed many other things in addition to how much salt you ate. Two of the easiest ways to lower blood pressure without altering salt are 1. lose weight. 2. eat more veggies and fruits (aka foods rich in potassium). Numerous clinical and observational studies have shown that the sodium-potassium ratio is likely more important than how much sodium you eat. [Note that this only applies to the 99.999999% of humanity who eats between 3k and 6k mgs of sodium a day. Salt probably is a problem if you’re eating way out of the normal range, like 12,000mg + of sodium a day.]

  • Ted Stanwood

    This article is dangerous and might convince someone to use all the salt they want. But all I have to do is eat a couple of big bags of Potato chips and I am getting 180/90 within a couple of days, stay off the salt then for 3-4 days and hydrate well, back to 130/70. Now “maybe” I am hypersensitive, but since this has repeated a half dozen times, I avoid salt. There is plenty in normal foods/

  • usucdik

    A lot of people here saying that eating a bag of chips increases their blood pressure. Do they not realize it isn’t a health food? Do they think it possibly doesn’t contain all the wrong stuff?

    There has to be some other high sodium food they can use to show how salt affects their blood pressure.

  • Jeff

    I would not be credulous enough to think for a minute, that salt is NOT related to high blood pressure, and increased body temperatures, for it certainly DOES. I reduced my 160 over 80 blood pressure down to 119 over 81 in a few weeks by cutting my salt intake severely. Why is it everytime I eat a several servings of potato chips, or eat Mc Donald’s french fries, I get immediately face flushed and feverish? I have even felt and heard, yes, the constricted veins in my own head, after having high blood pressure, dilate, expand, and break open again,after drinking cups, and cups of water, with the disappearance of the fever, disappearance of discomfort or congested head feeling, and reduced blood pressure.