How to Treat Asthma with a Low-Salt Diet

How to Treat Asthma with a Low-Salt Diet
5 (100%) 15 votes

Cutting 2 teaspoons of salt’s worth of sodium from one’s daily diet can significantly improve lung function in asthmatics.

Discuss
Republish

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

In the 60s and 70s, a mystery was emerging. Why were childhood asthma rates in the developed world between 2 and 5%, but in the developing world as low as 0.007%? So, instead of 1 in 20 kids affected, or 1 in 50 kids, it could be more like 1 in 10,000 kids—extremely rare. And, when they moved from a low-risk area to a high-risk area, their risk went up. So, it wasn’t genetic. What was going on? Were they exposed to something new? Or, did they leave some protective factor behind?

Well, way back in 1938, scientists showed they could stop asthma attacks by lowering children’s sodium levels. But, this was done with a diuretic drug, but subsequent dietary experiments showed that diets high in salt seemed to increase asthmatic symptoms, and “lowering the salt [seemed to decrease] asthmatic symptoms.” But, this body of evidence was apparently forgotten—until it was picked up again, in the 1980s, as a possible explanation for why Western countries had higher asthma rates. Maybe, it was the salt.

They graphed out childhood death from asthma versus family salt purchases, and it seemed more salt meant more death. But, just because a family buys more salt doesn’t necessarily mean the kids are eating more. The way you find out how much salt someone is actually eating is you collect their urine over a 24-hour period, and measure the amount of sodium—since how much salt we eat is pretty much how much salt we excrete.

The way you test for asthma is called a bronchial challenge test, where you look for an exaggerated response to an inhaled chemical. And, indeed, there was a strong correlation between how their lungs reacted, and how much sodium they were taking in. But look, there’s all sorts of food additives, like preservatives, that can trigger these so-called “hypersensitivity reactions.” And so, maybe, high sodium intake was just a marker for high processed-food intake. Maybe, it wasn’t the salt at all.

Or, maybe, it was other components of the diet. For example, the reason sodium may be a risk factor for another inflammatory disease—rheumatoid arthritis—may be that sodium intake is just a marker for increased meat and fish intake, or decreased fruit and vegetable intake. What we needed was a study where they take asthmatics, change the amount of salt in their diets, and see what happens. And so, that’s what came next.

Take ten asthmatics, double their salt intake, and in nine out of ten, their lung sensitivity worsened. No control group though. Maybe they would have all gotten worse anyway? Which brings us to the 90s—a “randomised, double blind, placebo controlled” trial. Put everyone on a low-salt diet, but then, give half of them these sustained-release sodium pills to bring their salt intake back up to more of a normal intake. The other half gets placebo. You try that for five weeks, and then, you switch them around for another five weeks. That’s how you can randomize people to a true low-sodium diet without them even realizing it—genius! So, what happened?

Asthmatics on the salt got worse. Their lung function got worse, their asthma symptoms got worse, and they had to take more puffs on their inhalers. This is comparing asthmatics consuming about three teaspoons worth of salt a day, to those consuming less than one. So, they were effectively able to drop their sodium intake two teaspoons of salt worth. If you do a more pragmatic trial, and only effectively reduce people’s salt intake by a half-teaspoon a day, it doesn’t work.

Even if you are able to cut your sodium down enough to get a therapeutic effect, though, it should be considered an adjunct treatment. Do not stop your asthma medications without your doctor’s approval.

Please consider volunteering to help out on the site.

Image credit: Jack Lawrence via flickr. Image has been modified.

Video credit: Daniel Black

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

In the 60s and 70s, a mystery was emerging. Why were childhood asthma rates in the developed world between 2 and 5%, but in the developing world as low as 0.007%? So, instead of 1 in 20 kids affected, or 1 in 50 kids, it could be more like 1 in 10,000 kids—extremely rare. And, when they moved from a low-risk area to a high-risk area, their risk went up. So, it wasn’t genetic. What was going on? Were they exposed to something new? Or, did they leave some protective factor behind?

Well, way back in 1938, scientists showed they could stop asthma attacks by lowering children’s sodium levels. But, this was done with a diuretic drug, but subsequent dietary experiments showed that diets high in salt seemed to increase asthmatic symptoms, and “lowering the salt [seemed to decrease] asthmatic symptoms.” But, this body of evidence was apparently forgotten—until it was picked up again, in the 1980s, as a possible explanation for why Western countries had higher asthma rates. Maybe, it was the salt.

They graphed out childhood death from asthma versus family salt purchases, and it seemed more salt meant more death. But, just because a family buys more salt doesn’t necessarily mean the kids are eating more. The way you find out how much salt someone is actually eating is you collect their urine over a 24-hour period, and measure the amount of sodium—since how much salt we eat is pretty much how much salt we excrete.

The way you test for asthma is called a bronchial challenge test, where you look for an exaggerated response to an inhaled chemical. And, indeed, there was a strong correlation between how their lungs reacted, and how much sodium they were taking in. But look, there’s all sorts of food additives, like preservatives, that can trigger these so-called “hypersensitivity reactions.” And so, maybe, high sodium intake was just a marker for high processed-food intake. Maybe, it wasn’t the salt at all.

Or, maybe, it was other components of the diet. For example, the reason sodium may be a risk factor for another inflammatory disease—rheumatoid arthritis—may be that sodium intake is just a marker for increased meat and fish intake, or decreased fruit and vegetable intake. What we needed was a study where they take asthmatics, change the amount of salt in their diets, and see what happens. And so, that’s what came next.

Take ten asthmatics, double their salt intake, and in nine out of ten, their lung sensitivity worsened. No control group though. Maybe they would have all gotten worse anyway? Which brings us to the 90s—a “randomised, double blind, placebo controlled” trial. Put everyone on a low-salt diet, but then, give half of them these sustained-release sodium pills to bring their salt intake back up to more of a normal intake. The other half gets placebo. You try that for five weeks, and then, you switch them around for another five weeks. That’s how you can randomize people to a true low-sodium diet without them even realizing it—genius! So, what happened?

Asthmatics on the salt got worse. Their lung function got worse, their asthma symptoms got worse, and they had to take more puffs on their inhalers. This is comparing asthmatics consuming about three teaspoons worth of salt a day, to those consuming less than one. So, they were effectively able to drop their sodium intake two teaspoons of salt worth. If you do a more pragmatic trial, and only effectively reduce people’s salt intake by a half-teaspoon a day, it doesn’t work.

Even if you are able to cut your sodium down enough to get a therapeutic effect, though, it should be considered an adjunct treatment. Do not stop your asthma medications without your doctor’s approval.

Please consider volunteering to help out on the site.

Image credit: Jack Lawrence via flickr. Image has been modified.

Video credit: Daniel Black

35 responses to “How to Treat Asthma with a Low-Salt Diet

Commenting Etiquette

The intention of the comment section under each video and blog post is to allow all members to share their stories, questions, and feedback with others in a welcoming, engaging, and respectful environment. Off-topic comments are permitted, in hopes more experienced users may be able to point them to more relevant videos that may answer their questions. Vigorous debate of science is welcome so long as participants can disagree respectfully. Advertising products or services is not permitted.

To make NutritionFacts.org a place where people feel comfortable posting without feeling attacked, we have no tolerance for ad hominem attacks or comments that are racist, misogynist, homophobic, vulgar, or otherwise inappropriate. Please help us to foster a community of mutual respect. Enforcement of these rules is done to the best of our ability on a case-by-case basis.

  1. Does anyone else find it hard to read the text from the studies when it is in perpetual motion? I normally like to read the details while listening to the voice over but find it too uncomfortable to do so when the text won’t hold still. Thanks for the interesting information.




    1
    1. I agree. It’s not just uncomfortable; it’s dizzying. Nutrition facts for video gamers? Dr. Greger: please imagine yourself giving a brief seminar when designing these videos. What matters is the effectiveness of the videos, not whether they incorporate the latest technology.




      1
    2. Agree with you completely. I can’t absorb all the quickly moving text and still comprehend his words. I have been a longtime NutritionFacts video viewer, but now I just go directly to transcript so that I can fully digest the great info.




      1
  2. Long time lurker chiming in. Just wanted to add to the general consensus that I preferred the old format of videos over the new formats you guys have been trying out. On the new ones, the text moves much too quickly, and I find the video actually distracting from the overall message. On the old videos, it was easy to follow along with the texts as Dr. Greger was reading it, as well as pick out the author and title of the study for reference. If it ain’t broke, don’t fix it!




    2
    1. YES, I think so too–the old style videos are THE BEST!! The new “try-outs” are quite frankly annoying and even nauseating (as those quick motions often make me nauseous).




      2
  3. I agree with what people have said so far about prefering the older videos. Surely the main (successful) features of previous videos could be translated into newer software ? I also noticed the number of ‘shares’ is no longer featured – no biggy.. perhaps it just isnt an edifying feature for anyone.




    1
  4. I am in agreement that I prefer the old videos. Too much motion in new ones.
    Thanks for continuing to provide such important information that we can’t get anywhere else.




    1
  5. I know I’m going against the tide here, but I LOVE the new video format. I think this style actually holds my attention much better than the older style, and I think it’s because the narration flows well with the images. I noticed that I’ve been using the pause button a lot less with this style. They’re beautifully done, and I think people will eventually get used to the movement. Also, I think the movement is more subtle than some of the people are complaining about (causing nausea, etc.). It’s not like watching a roller coaster ride or even an eagle nest cam on a very windy day. It’s very gentle.

    Another great topic. Will be sending this to a friend of mine, who has asthma.




    0
  6. I realise this is a sideways move, but with summer approaching in the UK and with the hay fever season already upon us, is there any research out there regarding the best nutritional ways of dealing with pollen?!
    By the way, I too find the new style of video graphics a bit difficult to watch.
    Cheers.




    0
    1. I have found that going fully whole food plant based has almost eliminated my seasonal allergies. A little stuffy in the sinuses still but the itchy eyes, nose and mouth are gone!




      0
  7. It’s my understanding that excitoxins can cause problems in our respiratory systems, and that the anti-caking agents used in salt that’s in processed food contains excitotoxins. Then why is salt being blamed for causing problems that the excitotoxins in the salt could be causing? Doesn’t it make sense that salt might not be as much to blame as the chemicals in the salt? Wondering if the asthma could be treated by having folks switch to pure, chemical-free salt. Is there any research supporting or disproving any of this?




    0
  8. Interesting stuff, as always. Thanks!

    I suffer from a similar problem to asthma, namely, vasomotor rhinitis, in particular caused by cold weather (especially when it’s windy out). I basically “treat” it by draining my nose all the time, which is kind of gross. Do any of the wise folks out there know of any WFPB-esque ways to treat this annoyance? I already eat a (mostly) WFPB diet but maybe I’m missing a key food or something.

    Thanks!




    0
  9. Is this effective for exercise induced asthma too?
    Interesting….this goes against some information I received from Dr. Popper (who is also pro WFPB diet) who said dissolving sea salt under your tongue could help w/ asthma symptoms. She also said drinking lots of water was beneficial….at least 64 oz per day…and more depending on exercise habits.
    Anyway, maybe I’ll try ditching the salt based on this video!




    0
    1. Thanks for your question Brian.

      I found two publication on this subject.

      This review states:

      in studies that evaluated the severity of EIB in asthmatic individuals and involved altered dietary salt intake, data have been more convincing. A low-sodium diet maintained for 1 to 2 weeks decreases bronchoconstriction in response to exercise in individuals with asthma. There are no data regarding the longer-term effects of a low-sodium diet on either the prevalence or severity of asthma or on EIB. As a low-sodium diet has other beneficial health effects, it can be considered a therapeutic option for adults with asthma, although it should be considered as an adjunctive intervention to supplement optimal pharmacotherapy, and not as an alternative.

      Another review has found stated that:

      work conducted in our laboratory clearly indicates that alow-salt diet has a positive impact on airway inflammation andpulmonary function in exercise-induced asthma (EIA) (3, 4).This reinforces the suggestion that airway narrowing in frankasthma may occur by a different mechanism than it does in EIA.

      This last review, points to two other studies, one of which clearly states that:

      These data suggest that individuals with EIA might benefit from lower salt diets.

      Hope this answer helps.




      0
  10. Wow! Keep up the great work.

    There is nothing more frustrating to me as a physician regarding medicine then never being taught this information in the first place. Believe me I read a lot and unfortunately your valuable information never makes it into mainstream medicine. Why? My personal and educated view is a “cure” doesn’t keep the Beast of Sickness care bringing in the streams of cash to feed the insatiable appetite of greed for The Beast. In other words, if I give you a pill you will have to see me every three months for the rest of your life!!! However, if I give you information to heal yourself, I may never see you again. This is what the “Beast” (Sickness care system) is afraid of — information to the public that would cause a decrease in revenue for all the sickness care entities involved in making money off the uneducated and sick.

    Causes are THE most important thing to know in medicine because if we know the cause we can educate our patients and communities about the foods or substances that cause these problems in the first place and begin the process of healing. Unfortunately the current Sickness care system is deeply and disappointingly corrupt. Thank you for helping change the face of medicine!




    2
    1. You’ve started a very dangerous topic here, ie. doctors being miseducated. But even worse than being miseducated is being illogical and unreasonable (if one is logical and reasonable, one can find a way to the knowledge even when it’s long and bumpy) So, let me elaborate…
      As I understand you are not a rheumatologist – and they are the worst.

      They are the worst because there are practically no mechanisms of the disease explained or to be more precise – there were no such mechanism when these doctore were learning (20 years ago or so…).
      So any explanation they might have thought about – it might have been as well true. Instead of logical explanations they only offer BS theories of the disease, and expensive drugs sold by the large and notorious companies (drugs which are not effective and they do not cure you, they only allow you to manage the disease).
      Almost the same applies to oncologists (runner-ups) (here, however the mechanisms are much much better explained now, and there are drugs which WILL cure you and the diet will help you avoid cancer altogether). The third place is occupied by neurologists – again same things and mechanisms apply.
      I’ve been to all of them and know what I’m talking about though it may be difficult to explain… But let me try… Yes, it’s a rant, but it’s an attempt to explain how a doctor should not talk with a patient…

      So a few weeks ago I visited a rheumologist. I navigated him through different lab test results, showing him which results were out of range.
      I was meticulous because I was hoping to find something that could be useful in furthering the diagnosis. Needless to say that I am pretty sure of what I say, I research pretty much every result that is out of normal etc.
      But the rheumo’s answer was always like this: the statistics do not confirm that this result is important, we’ll have to wait for this result to get even worse etc. Finally he says that there is nothing that can be done when if fact there was quite a lot that could have been done but I will not explain it here, it’s terribly complicated. But quite understandable for a specialist. The outcome of this visit was that I spent quite a lot of money (obviously… – while it was not worth it) and I got so pissed off that I basically started following protocols that I figured out in the response of being pissed off. The response of my body is very encouraging – my joints and tendons are healing and when the injuries in them are healing, the overall level of inflammation in my body decreases and my arthritis is healing (whatever type I may have and I suspect that osteoarthritis is the closest to what I have). I can even tell you what I take: beta-sitosterol and campesterol (simply: phytosterols). These turn in the body in potent anabolic steroids as well as have other actions. It took 5 days to notice the difference.

      And yes, this is the same mix used for cholesterol lowering and it seems that this is the main ingredient of avocado usaponifables (there is a research paper claiming just that but I wonder what else is there in the usaponifables that is good for the joints) which are recommended for joint lubrication. However, phytosterols are 4-8 times cheaper than avocado usaponifables.

      But back to our rheumatologist and his annoying argumentation… so he noticed that I’ve had vit D tested. And it was insufficient (23 ng/dl).
      Rheumo says: It’s good of you to have had it tested, it’s important. You should take your vitamin D suplement, even 6000 IU per day.
      Me says: Ok, I know all about that, that’s why I had it tested, afterall. It’s a pity though that the doctors only recently started prescribing vit. D supplement to their patients… Like two years ago…
      Rheumo says: No way, I have always recommended it… (and he kept explaining how doctors did the right thing)
      Me says: Ok.
      Me thinks: Ok, if you are such a smartass and you are doing everything correctly then why aren’t you telling me in this very minute that along with vitamin D I should be taking vitamin K and magnesium in high doses, especially that everybody is talking about this now, and especially that in my case there are indications for this because I have osteophytes (at a young age) and (vitamin D induced) hypercalcemia and I consumed a lot of (calcium-loaded) dairy and there are studies that show that these auxilliary supplements are effective in battling osteophytes, hypercalcemia, the so-called pseudogout and arterial calcification. However I never said that because there was no point. This rheumo just had to wait for yet another ten years for the statistics to confirm without a doubt that vitamin K is necessary as if this was confirmed not well enough. I found about vitamin D requirement in 2006 and back then I had problems with testing (doctor didn’t want to order and when tested, normal range was too low, below 15 so I got confused for yet another year), buying the supplement (it was prescribtion only in my country). It took this many years to figure all this out (with my additional problems like hypercalcemia and all) when doctors were actually confusing me but now at least this problem is solved.
      This doctors’ relying heavily on statistics instead of their own common sense comes I think actually from misinterpretation of this basic rule: first, do no harm. “Instead of taking a little risk and try to help a patient, let’s just rely on statistics and better do nothing, we might just hurt our patient in the process”. That’s how I see almost every visit to the doctor…




      1
      1. Sorry you’ve had such bad experiences with doctors. I’ve had some really awful ones also (both incompetence and ethics issues). However, I have to say that there’s at least one really good rheumatologist out there – best doctor I’ve ever met. I wasn’t even his patient; I was interviewed by him for a PhD program in immunology. I was desperately trying not to show any signs of ill-health since no one wants a sick grad student. He noticed the petechiae on my forearms (I tend to get worse when under stress). At the end of the interview came the ‘Do you have any questions for me?’ question, I asked him why he chose rheumatology. His answer: ‘It’s the most challenging of the non-surgical specialties’.




        0
    1. Thanks for your question.

      According to one of the studies mentioned by Dr Greger, it appears that:

      The way in which increased salt intake may cause increasedbronchialhyperreactivityisunclear.Animal studies have shown that sensitised smooth muscle shows hyperreactivity as a consequence of increased activity of the cel membrane sodium pump and sodiuminflux.4Increasedsodiumintakemaypossibly augment this efect.’ As the degree of histamine spontaneously or after treatment. Three were taking an inhaled agonist daily, and seven were also receiving an inhaled steroid. All were non-smokers. Five non- asthmatic subjects (one man, four women; age range 23-48years) volunteered to act as controls. The dietary salt intake of al participants was reactivity is related to the severity of symptoms in asthma these results also indicate that a high dietary salt intake may contribute to the severity of asthma

      The other study, also mentions similar mechanisms and intracellular calcium concentrations, as well as the mechanism of Na+/K+ ATPase inhibition.

      Hope this answer helps.




      0
  11. I have to say I didn’t like the new video formats because of all the motion but this one seems to strike a good balance. The one thing about the old videos that I thought could be improved was showing more of the scientific study. With the slow panning you can start the top and pan lower to have more of the text shown




    0
    1. I agree with you on both counts. This video style is nice. Very gentle/slow panning from the title to the quoted/highlighted text section is nice.

      And for folks who still feel the movement is excessive or too fast, remember you can use the space bar to toggle the video on or pause it. And using the back arrow or forward arrow jumps the video back or forward about 4 seconds too. A very handy feature to quickly go back or forward to a section.




      0
  12. Another video by Daniel (Experiment 1: Vit D, March 17) .
    Again, unwatchable. I assume he was contracted to make several but a return to the old or at least (Edit: just read in previous talk there’s 6 more weeks of these awful video experiments)

    The scientific explanation from the viewpoint of perceptual psychology for why the majority of viewers get sick watching these “motion graphics” still applies – see my lengthy comment to Experiment 4: March 24 video to understand why these video experiments don’t work.




    2
  13. Fascinating! I’ve seen so many articles over the past decades trying to figure out the asthma riddle and yet the info was here all along! The one I saw the most attributed the rise in asthma to the fall in dirt, ridiculous as that sounds. They said kids on a farm had less asthma than city kids because city kids lived in such clean environments. Wow, how clueless! I bet those farm kids were eating more fruits and veggies –unsalted!




    0
  14. One of the greatest videos I ever watched here was one that included animation of cellular activities and made the concepts being discussed a great deal easier to understand by giving visual references. If I recall correctly (IIRC it was about fat and blood and insulin, thus Diabetes).

    Otherwise I’ve never been much interested in moving text and the 999 ways it can be presented into and out of “the shot”

    I do often pause or rewind videos to see a particular chart or graph or troublesome text. Sometimes I read the non-emphasized text to get a better feel for the context. Sometimes I look up documents and sources-which is easy to do here-thanks!

    But the last time I saw a video and thought,

    “Hey, that’s great and well-done and I’ve got to share this right away because it really could advance others’ understanding of all this silly plant-food talk.”

    ‘Twas that video with animations, not any flip-flit-flittering, pop-slide-peeling, fade-twist-bouncing bundles of “textcerps” from medical research and reports. I’m quite sure of it.

    Maybe we are at fault for not applauding that video enough.

    Eat well and be well. Cheers Y’all!




    1
  15. I have had asthma for many years, and also, like most of us, a low salt diet too. I have been on a WFPBD for a couple of years now, and whereas low salt had no effect on my asthma at all – eating a ton of green leafies a day cured it! I would suggest that an increase in potassium might have shown similar results as decreasing salt.




    0
  16. Dr Greger How can i leave the corticosteroids for asthma? specifically BREXOTIDE LF 250-25 mcg DRUGS: Fluticasone and Salmeterol
    Im on a whole foods plant based diet but I can not stop the corticosteroids because I get purple and I can not breathe
    Thank you so much for your reply, dont know how much help it will be for my life!




    0
  17. More and more of my patients suffer from hypO-natraemia. I myself often suffer from weakness and low blood pressure after heavy physical work, which is fixed after 3 cups of salty vegetable broth.




    0
  18. It’s interesting to think that a low salt diet could help with asthma. Who would have thought that developing worlds were developing asthma in kids at such a low rate? I guess that means I should stop eating fast food and chips!




    0

Leave a Reply

Your email address will not be published. Required fields are marked *

Pin It on Pinterest

Share This