Salt

[Kitty]

All of this leaves the question of whether people with low blood pressure as in orthostatic hypotension do better eating more salt

I got the impression it did help. But adding salt to your meals tends to make you want to drink more, so it could just as well have been that.

 

[livinglighter]

Are you saying that increased salt intake in the general population is not linked to high blood pressure through mild hypervolemia, and this type of information is incorrect? Presumably healthy people consuming high-salt foods get thirsty and take in extra fluids.

E.g.

“Your body responds to excess sodium by holding on to water to dilute the sodium. As a result, the amount of fluid in your blood vessels increases. That raises the pressure inside your blood vessels and makes the heart work harder.”

https://www.health.harvard.edu/heart-health/dietary-salt-and-blood-pressure-a-complex-connection

I see this simple connection has been questioned:
https://www.medicalnewstoday.com/articles/317099

All of this leaves the question of whether people with low blood pressure as in orthostatic hypotension do better eating more salt - again a different question because it is about the effect of salt specifically on a dysregulated volume control system. It would be interesting to now what renin levels are like in people with OI of various sorts.

I was under the impression it helps because the Autonomics lead at a well-known neurology hospital recommends increasing salt intake to address low blood volume as well. It seems odd that the medical advice is baseless.

 

[JemPD]

It seems odd that the medical advice is baseless.

Why? Its outrageous when medical advice is baseless, but there's plenty of that going around.
Treatment for CFS in the UK is almost entirely baseless, currently.

Not saying anything about salt intake etc, i wouldnt know, just that i dont trust any medical advice to be based on sound science these days

 

[Jonathan Edwards]

It seems odd that the medical advice is baseless.

It may seem odd but it is worth remembering that although there have been physicians and hospitals for centuries almost all medical advice was baseless until around 1970 - apart from Caesarian section after sepsis was understood and penicillin around 1945.

When I first started medicine all sorts of advice was still baseless. Almost all physio advice is baseless.

My impression is that pretty much all advice around 'dysautonomia' is hot air. I am not aware of any proper trials having been done.

 

[livinglighter]

Why? Its outrageous when medical advice is baseless, but there's plenty of that going around.
Treatment for CFS in the UK is almost entirely baseless, currently.

Not saying anything about salt intake etc, i wouldnt know, just that i dont trust any medical advice to be based on sound science these days

The field of CFS research and medicine is significantly underfunded and neglected, with psychosomatic medicine taking the forefront. I am uncertain if the same issues are present in Autonomics research and medicine, but there should be a higher standard for the scientific basis of medical advice given to patients.

I cannot definitively state that salt intake increases blood volume. I am emphasising that if some of the current medical advice provided by prominent figures in the field is poorly supported by evidence, it is important to gain a better understanding of the reasons behind this.

 

[voner]

@Jonathan Edwards, thanks for your enlightening replies. I am always learning about physiology from your statements.

here is what appears to be a UK charity just set up for warning about salt consumption by humans…

Action on Salt
Wolfson Institute of Population Health
Queen Mary University of London

https://www.actiononsalt.org.uk/resources/posters/

 

[Jonathan Edwards]

I cannot definitively state that salt intake increases blood volume. I am emphasising that if some of the current medical advice provided by prominent figures in the field is poorly supported by evidence, it is important to gain a better understanding of the reasons behind this.

That's fairly easy. Doctors bullshit all the time. They are trained to bullshit - to sound knowledgeable. It is supposed to inspire confidence.

'Prominent figures in the field' often turn out to be people pushing a line. They are not necessarily prominent in the medical community as a whole. I never came across anyone 'prominent' in autonomic research. But it is easy enough to find physicians who write dozens of clinical papers about autonomic problems without much scientific content.

 

[livinglighter]

It may seem odd but it is worth remembering that although there have been physicians and hospitals for centuries almost all medical advice was baseless until around 1970 - apart from Caesarian section after sepsis was understood and penicillin around 1945.

When I first started medicine all sorts of advice was still baseless. Almost all physio advice is baseless.

Agreed.

My impression is that pretty much all advice around 'dysautonomia' is hot air. I am not aware of any proper trials having been done.

I was not aware of the lack of proper trials. It's a dilemma that patients encounter in medicine: should one refuse medical care because of inadequate evidence or follow instructions in the hope that their health will improve based on what is likely to be supported by clinical evidence? The clinical evidence for CFS is considered to be poor, with patients sharing experiences of harm endured. Is the clinical evidence or wherever else these clinicians and researchers are getting their ideas from, as equally poor in other fields where it seems patients are not suffering as adversely from the medical advice they receive? It doesn't come across as a lot of medicine is at a standard that one hopes it would be.

 

[Jonathan Edwards]

Is the clinical evidence or wherever else these clinicians and researchers are getting their ideas from, as equally poor in other fields where it seems patients are not suffering as adversely from the medical advice they receive?

The standard of evidence and practice varies greatly according to how common a problem is and how easy the problem is to understand. Giving insulin for diabetes is based on a lot of good evidence, although it has taken decades for doctors to work out the best way to use it and when I was a student we gave about fifty times as much as needed in acute situations.

The standard of evidence is particularly poor for relatively uncommon conditions and for conditions where physiology is not well understood. ME/CFS is relatively uncommon as compared to coronary heart disease or stroke or cancer. Autonomic failure is also uncommon and although it is relatively well understood in late diabetes or rare syndromes like Shy-Drager, much of the time it is very unclear what is thought to be wrong.

Autonomic failure leads to heart rate changes, gut changes and circulatory changes in the legs in particular. But 'autonomic experts' often deal with quite different things like so-called PoTS. In PoTS the autonomic system seems to be responding well. The question is why it is responding in an unpleasant way, if indeed that is the problem . We have an excellent thread on all the uncertainties about PoTS.

If there was autonomic failure behind OI I do not see why eating salt should help. But very likely OI in ME/CFS or 'PoTS' is not related to autonomic failure. It comes across to me as all very confused and when I read papers about these things they look pretty naive and ungrounded to me. Doctors constantly thin they understand enough physiology to predict what treatments will help. What was shown unequivocally in research into intense care regimens in the late twentieth century is that no way can you predict. You have to test things out. Treatments that everyone thought must be good turned out to be bad.

And if Harvard puts out a dumbed down account about salt and blood pressure of the sort posted it seems likely that pretty much everyone in the field is talking hot air.

 

[Mij]

Do all people with OI have low blood pressure? I don't, but I do feel somewhat more relaxed when I eat sea veggies which are full of electrolyte minerals, such as calcium, magnesium, sodium, and potassium.

 

[Jonathan Edwards]

Do all people with OI have low blood pressure? I don't, but I do feel somewhat more relaxed when I eat sea veggies which are full of electrolyte minerals, such as calcium, magnesium, sodium, and potassium.

PoTS is supposedly OI without low blood pressure.

Other electrolytes like calcium, magnesium and potassium (sodium is salt) are not going to have any relevance to the effect of salt. Potassium is mostly inside cells, not in blood plasma. I rather doubt sea veggies are different from bananas in these ions! They are mostly known for continuing iodine.

 

[Mij]

Could be that my diet is lacking in iodine considering I add sea salt to foods for the last 25yrs which doesn't contain iodine like regular salt.

 

[JemPD]

The field of CFS research and medicine is significantly underfunded and neglected, with psychosomatic medicine taking the forefront. I am uncertain if the same issues are present in Autonomics research and medicine, but there should be a higher standard for the scientific basis of medical advice given to patients.

I cannot definitively state that salt intake increases blood volume. I am emphasising that if some of the current medical advice provided by prominent figures in the field is poorly supported by evidence, it is important to gain a better understanding of the reasons behind this.

agreed

 

[Hutan]

There's some discussion of the recommendation of increasing salt intake here:
ME Association funds development of new protocol for Dysautomnia

 

[Arnie Pye]

One thing I wonder about in reference to salt/sodium is that I rarely see any mention of potassium in connection with salt/sodium (on ME forums). And yet, in the body they have a very important relationship.

If people have problems maintaining salt levels at a point that is healthy for them, then this suggests their potassium levels might be wrong for good health too.

Just for interest :

Sodium-Potassium Pump : https://en.wikipedia.org/wiki/Sodium–potassium_pump

Electrolyte Imbalance : https://en.wikipedia.org/wiki/Electrolyte_imbalance

Potassium deficiency : https://en.wikipedia.org/wiki/Hypokalemia

Potassium toxicity : https://en.wikipedia.org/wiki/Hyperkalemia

Sodium deficiency : https://en.wikipedia.org/wiki/Hyponatremia

Sodium toxicity : https://en.wikipedia.org/wiki/Hypernatremia

 

[bobbler]

Getting back to the topic of salt, and whether there is evidence for high sodium diets helping certain patients -

The first post in this thread uses the term Orthostatic Hypotension (OH). Terms and definitions can differ, or overlap, but I think most folks use OH to mean a fairly quick drop in blood pressure after standing. One definition I found:


By this definition, I do not have OH at all. I can quickly stand up without any sudden drop in blood pressure. I get no symptoms - no dizziness, no seeing stars, no graying out of vision, and definitely no fainting - when I first stand up.

I think if my only diagnosis was OH, and nothing else, I'd only have to be careful about standing up quickly - that transition from sitting or lying to standing up. I wouldn't have all these other disabling symptoms.

And if I did have OH symptoms, I probably would have been diagnosed a lot sooner when I first got sick. I always passed those standard BP tests (take blood pressure when lying/sitting/standing) in the doctor's office. It took five years after the onset of my OI symptoms (pre-syncope symptoms while standing - in the shower, in line at stores, when temperatures were high - but never any fainting/syncope) before someone suggested a tilt table test.

All my OI symptoms are delayed. My symptoms do not happen during the transition from sitting to standing. I start to feel uncomfortable after standing still for about 4-5 minutes. Then it takes 20-30 minutes (roughly) on a tilt table test before my blood pressure plummets and I pass out.

I don't understand all the diagnostic differences between OH and different forms of Orthostatic Intolerance (OI). Also, I think people can have OH along with other diagnoses.

But it seems like there might be different mechanisms that drive OH vs. other types of OI?

And if that's true, then maybe salt can reduce OI symptoms but not OH symptoms?

I have no idea, but it does seem like they are different.

Hope this makes sense. Off to rest - too much brain work this morning!

Yes it’s such an important area that I guess could easily be better on knowledge and GPs then educated more on and would/could transform lives because effects can be so debilitating- but are just poo poohed

I know I’ve had this for over a decade but wouldn’t even know what type to describe - given the level of debilitation I think is associated with it then if these basics are easily done it’s terrible I suffered that for so long and ended up like this. It probably wouldn’t have been hard for these things to have been on check lists and then they’d have known what helped for who too.

 

[bobbler]

One thing I wonder about in reference to salt/sodium is that I rarely see any mention of potassium in connection with salt/sodium (on ME forums). And yet, in the body they have a very important relationship.

If people have problems maintaining salt levels at a point that is healthy for them, then this suggests their potassium levels might be wrong for good health too.

Just for interest :

Sodium-Potassium Pump : https://en.wikipedia.org/wiki/Sodium–potassium_pump

Electrolyte Imbalance : https://en.wikipedia.org/wiki/Electrolyte_imbalance

Potassium deficiency : https://en.wikipedia.org/wiki/Hypokalemia

Potassium toxicity : https://en.wikipedia.org/wiki/Hyperkalemia

Sodium deficiency : https://en.wikipedia.org/wiki/Hyponatremia

Sodium toxicity : https://en.wikipedia.org/wiki/Hypernatremia

I think potassium is more likely to be picked up - is it either in the standard battery or more likely to be thought of than sodium by HCPs?

 

[Sly Saint]

not directly related but may be of interest

"
Does Salt Really Cause High Blood Pressure? Think Again..."

In short, no. The castle was built on a foundation of sand.

While it’s easy to find an array of studies demonstrating small drops in blood pressure with lowered salt intake, these results do not necessarily indicate any sort of causative role of salt consumption in high blood pressure. The results seen are typically so minimal that it becomes obvious to a scrupulous eye that there is a more intricate story at play.

For example, the Department of Health and Human Services funded an 11 trial salt restriction study executed by the Cochrane Collaboration in 2004, that demonstrated an average of just a 1.1 mmHg drop in systolic blood pressure and 0.6 mmHg drop in diastolic blood pressure with salt restriction in healthy humans. This is basically going from 120/80 to 118.9/79.4, results that can easily be achieved in any number of ways.

However, the headlines in popular media outlets chimed out the bells that “Salt causes high blood pressure!” further perpetuating the myth in the public’s mind and within the medical community, while continuing to ignore highly contradictory results from other wide scale population studies, such as the Intersalt Study of 1988, a data-driven collection of results from 52 international research centers, that demonstrated that the highest salt-consuming individuals (up to 14g of salt per day) had lower blood pressure levels on average than people who consumed half of that amount.

The results of the 2004 government-funded Cochrane study, and ensuing media attention, become even more tenuous when you understand that the Cochrane Collaboration had conducted a study just one year prior, in 2003, reviewing 57 salt restriction trials, and concluded that “there is little evidence for long-term benefit from reducing salt intake.” A large study done in 1995 on 3000 people over 4 years led by Dr. Michael Alderman, and published in the journal Hypertension, demonstrated that individuals who ate less salt indeed actually had a higher prevalence of increased mortality rates than those who ate more salt. They also found that by adding more salt to their diet, the subjects had a 36% decrease in heart-related mortality events. Three years later, in 1998, the Alderman team published another set of findings on a 22 year long study they’d been conducting with over 11,000 people that showed a clear inverse relationship between salt intake and mortality.

In basic biochemistry, it’s well-understood that the breakdown of ATP to ADP + phosphate is required for the cell to use glucose and oxygen in order to maintain homeostatic functioning of the body’s core metabolic processes. This breakdown to ADP and phosphate cannot happen without the presence of adequate sodium in the fluid around the cell. The more sodium present in this fluid, the better the cell is able to increase its energy consumption, which leads to more CO2 production, fueling the metabolism properly and balancing the effects of intracellular calcium.

When unchecked by sodium, and the resulting lack of CO2 production, calcium can exert toxic effects on the cell, causing premature cell death. All of these compounds must be present in healthy levels in order to ensure the proper functioning and movement of ions through ion channels on the membrane.

Does Salt Really Cause High Blood Pressure? Think Again... - YouTube

 

[Jonathan Edwards]

Does Salt Really Cause High Blood Pressure? Think Again..."

I always thought it was fairly implausible that salt intake would make much difference to BP. The article seems to confirm that. It may of course be based - the last bit on ATP is pseudoscience so there is clearly an agenda behind it.

It tends to confirm my suspicion that salt intake really doesn't matter much unless you are stranded at sea or in a desert or something. Similarly, I doubt it makes much difference to symptoms of OI. We still do not have any useful trials I think although there may be one coming up.

 

[rvallee]

Ah, so they took correlations and ran with them being causes because it came with an easy lifestyle change that people could do all on their own. A tale as old as time.