I have read this study and it is much less meaningful than the title would suggest.
They have compared a diet with a sodium intake close to the lower limit of the recommended intake, with a diet including an even lower sodium intake, slightly less than normally recommended.
A daily sodium intake in a relatively wide range around the recommended daily intake (which is of about 4 to 6 grams of salt per day) is not expected to cause any differences, so the results of the study are not surprising.
The recommendation to eat less salt is only for the people who eat mostly industrially-processed food, which always includes excessive quantities of salt and sugar, because they are among the cheapest ingredients, while enhancing the taste of the food.
Such people typically eat 2 to 3 times more salt than recommended, and only for them it may be expected that lowering the sodium intake can reduce the risk of diseases. However, lowering the sodium intake is not easy for them, because they must begin to eat something different, since the excessive salt is not added by them to the food.
Otherwise, lowering the salt intake much under 4 grams per day is a serious risk, especially for older women, and especially when they also take medication against high blood pressure.
Hyponatremia, i.e. having a too low sodium content in the body, manifests initially with symptoms like muscular weakness, constipation, lack of appetite and problems with the equilibrium, which may result in falls.
Such symptoms may be difficult to distinguish from just consequences of old age. If hyponatremia is not diagnosed in time, the consequences can be extremely severe, including the loss of life.
You missed the biggest point. Not only was the difference in salt not much, but they would have to have reduced adverse events (eg repeat heart attacks) by over 20% to have had decent odds of detecting it with their actual sample size.
So the real conclusion is that a modest reduction of salt from the recommended low levels likely does not drop the odds of a repeat heart attack by more than 20%.
This is a very, very long ways from the headline that lowering sodium doesn't help heart patients.
It's n = 800 which is way better than most studies, and it's a well designed study. Basic science research is way underfunded in essentially every country.
This is literally how the null hypothesis / statistical significance works; how is this crap science? If the measured effect is too tiny, you cannot conclude that it's a real effect.
I agree that it is better than most studies, and that is part of the problem.
The title as presented here is Lowering sodium intake doesn’t help heart patients.
The impression that people will walk away from that title with is, "If you have heart problems, there is no need to eat a low sodium diet."
This is not a hypothetical interpretation. I first saw this study at https://twitter.com/EricTopol/status/1510292643292491779, and that is exactly the impression that a well-known cardiologist drew. Many others came to the same conclusion.
Now what should we expect?
Their intervention reduced sodium consumption by 415 mg of sodium per day. (According to the least accurate method of measurement - self-reporting. The actual reduction was probably smaller.) If all else was equal, the correlation found at https://www.cdc.gov/salt/research_reviews/sodium_potassium_b... we should expect that to reduce systolic blood pressure by 1.9 mmHg. However not all else is equal, these are all patients receiving medical care. If your blood pressure is too high, you receive more medication. So all else is not equal, and we should expect blood pressure to be approximately equal between the groups, and medication not.
Therefore, to a first approximation, we should expect small differences in blood pressure, larger differences in required medication, and little difference in adverse events.
They designed a study that did not report on average blood pressure between the groups, or what levels of medication were required, and would only notice a large difference in adverse events. And so they failed to find a result that they should not have expected to see, failed to look for the result that they should have expected, and it wound up being reported in a way that undermines public health messaging around sodium reduction.
You may consider this quality scientific research. I don't.
> The title as presented here is Lowering sodium intake doesn’t help heart patients.
Yes, though this is the title posted to HackerNews, so I blame the poster. In the actual link, it's just : Reduction of dietary sodium to less than 100 mmol in heart failure (SODIUM-HF): an international, open-label, randomised, controlled trial
It’s not about repeat heart attacks. The study was in heart failure patients. The main issue is preventing events like exacerbation of heart failure and sudden death.
The study looked for a large effect size. That’s totally fine. I think it is good that non-pharmacological interventions are being studied. Calling it crap is quite unfair.
There was a 27% average decrease in sodium intake. That is a big difference and this is a valid study because these were the recommendations put forth by several organizations like the Cleveland Clinic
Uhh need to based on what evidence? This isn’t the only study suggests minimal if any improvement with lowered salt intake and the often quoted reasoning for why salt would matter is flawed.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5179550/. “Graudal et al. (40) observed that sodium restriction (sodium reduction of 42–341 mmol/24 h in studies lasting 4–90 days) was independently associated with increased heart rate in healthy individuals and individuals with hypertension.”
You're quoting one small section of one referenced study in meta-study and leaving out the conclusion of this section that more serious studies are needed to determine the relationship between sodium intake and heart rate (not morbidity due to heart disease, just heart rate).
> Given the discrepancy in results, more studies in this area are required to investigate the relationship between dietary sodium intake and heart rate.
You're cherry picking one small part from a section not really related to the topic at hand and also ignoring the conclusion the study authors draw.
The sentence literally before the one you quote is
> Studies that demonstrated the effects of dietary sodium on heart rate have shown conflicting results.
And then you cherrypick the one example that agrees with your point while ignoring the examples that refute your point.
If you want to say the science is still unsettled, sure. But to pretend that it is settled in the way you want and quote one sentence out of context in a meta-study who's entire point is that the debate is not settled? Come on.
> If you want to say the science is still unsettled, sure.
I agree studies give conflicting results and there is isn’t a clear winner here.
I agree more studies are perfectly reasonable.
However, the default when faced with conflicting information isn’t to put forth effort into changing behavior. That requires justification, which isn’t available.
Consider if millions where micro-dosing Tylenol to avoid dementia and the results where inconclusive, what messaging would you provide? (Stop your wasting money), (do it it’s probably worth it), (might help, might not, we don’t know do what you want). The temptation is to say ‘do it’, the costs are low and the benefits could be significant. However, when there are known useful things people could be doing it’s probably best to stick with the third option.
PS: Ok you could jump on the latest study and constantly flip flop on recommendations, but that just confuses people and erodes trust in the process.
Look man, my comment was saying you can't just cherrypick a single sentence out of context from a long study (especially when the context of that section contradicts your own point). If you want to argue about sodium intake there's other comments in here for that.
The statement you picked made it out that there is no correlation between sodium intake and heart rate. The study you took that statement from was making the point that we can't draw such conclusions either way.
I didn't say anything about whether or not people should flip flop recommendations. But don't irresponsibly cite studies. It defeats your entire argument when you do so.
> The statement you picked made it out that there is no correlation between sodium intake and heart rate.
“was independently associated with increased heart rate in healthy individuals and individuals with hypertension.”
Cherry picking would have been linking to the study that suggested lower salt intake was unhealthy directly. Instead I linked to the meta study to give better context.
It’s great science! Now, insofar as their English and grammar, that leaves much to be desired! That said, I’m more than willing to bet that two things are in play:
A. These publications would slough off an application from someone focused on writing faster than a skin from a boiled tomato.
B. Most people who “Love science” don’t place value in other areas of learning. STEM doesn’t include “writing eloquently”, to put that mildly.
The science itself seems fine though! Testing, measuring, experimenting. Yes. But either there ought to be an onus on us as readers or them as publishers to make clear what has been done. Otherwise, as I believe you can surmise, there’s no benefit to doing at all!
There is another phenomena as well. The odds of a piece of research going viral are directly tied to how surprising it is. Water is wet does not go viral. But it does go viral that trying to exercise self-control tires your brain and makes an impulse buy of a candy more likely.
Therefore the science we encounter goes through a selection bias that picks out the most surprising results. But far too often, "surprising" translates into "unlikely to be true". And so we get a constant stream of intellectual junk food wrapped up in the language of science.
Take this result. It is surprising that low sodium would not help with cardiovascular problems. Why is it surprising? It is because we know two facts:
And therefore we EXPECT that high sodium intake is bad for your cardiovascular system. Which is why we constantly tell people to reduce salt.
Now we see this research that has a variety of limitations in what it could detect, saying that it found no correlations. We're surprised because we expect a correlation. But now people will walk around saying that science says that salt doesn't matter, ignore salt, and they're probably causing a problem for themselves.
And this brings us to another problem with the research. The known mechanism by which salt is bad for you involves blood pressure. However if you've had a heart attack, your blood pressure is going to be monitored and medications adjusted until your blood pressure is under control. The benefit of less salt will be that you need less medication and will have less side effects. It won't be lower blood pressure and a reduced risk of heart attack! So the primary outcome that should be measured isn't adverse events, it is how much medicine was required!
I had a close relative in congestive heart failure. My understanding of the reason for reducing salt was to avoid the water retention that impairs heart function.
It was sad to see him struggle with food that was less and less appetizing. Salt tastes great :(
For some reason, salt stops my blood pressure medication from working. (Several possible diagnoses were explored without success.) This was discovered after I checked in to the ER feeling terrible with a blood pressure around 190/120 and then had to stay for a week. So I'm now on a low salt diet and my blood pressure is now fine.
I don't cheat. And after a while my taste buds kind of reset. What tastes normal to most tastes insanely salty to me, and I get to enjoy the taste of low salt food.
Good follow up! separating the actual work done vs write up, the title alone gets people to read it/open it. Roger Penrose said he had released a bunch of papers over the more recent years and the only one that got a bunch of feedback was one where there was a small note about extraterrestrial life.
If they are right that this study only proves that a small reduction in salt intake around the recommended daily level doesn't have a dramatic effect (>20%) on heart attacks, then is this really a useful study? Is it truly worth the money and time spent on collecting all this data, reviewing it etc? Will people keep referring back to it and citing it 5 years from now?
> The recommendation to eat less salt is only for the people who eat mostly industrially-processed food, which always includes excessive quantities of salt
Such a logical argument, but I could never get it across to my relative with congestive heart failure. Poor guy was terrified of food and what he did eat was almost flavorless (steamed plain proteins and veg, no fat). He was plainly malnourished. Not sure how the doctors didn’t see it.
The key is sugar and especially high fructose corn syrup. Excessive sugar intake over a long period of time will destroy your kidneys (leading to diabetic nephropathy, interestingly certain ARBs prevent new onset diabetes mellitus type-2 by protecting the kidneys), which would lead to adverse cardiac events moreso than sodium intake.
>A daily sodium intake in a relatively wide range around the recommended daily intake (which is of about 4 to 6 grams of salt per day)
Hold the phone....4000 to 6000mg? I've never seen anything that high as a recommendation. Maybe I'm an outlier, but if I get close to 4000mg I'll feel bloated the next day and my BP will be elevated.
Yes. I have expressed the daily intake as salt, not as sodium, because this is the more useful quantity to know, as this is what you can measure when cooking.
When you eat home-made food, there is some small quantity of sodium in meat and other animal-based food, but most of the sodium comes from the salt you add to food, which you should measure.
The sodium recommended intake is useful only when reading the labels of industrially-processed food, to see how much you could eat daily. However, if such food makes the bulk of what you eat, then there is not much point in reading the labels, as it is unlikely that you can achieve the recommended intake.
> They have compared a diet with a sodium intake close to the lower limit of the recommended intake, with a diet including an even lower sodium intake, slightly less than normally recommended.
Interesting. So the study produced no news at all. Just a click bait title...
This study looked at a stricter sodium goal than is typically advised (<1500 mg/day). Usually I counsel pts on less than 2000 mg a day which is what the control group targeted and seemed to achieve. This study is useful in that it shows being more restrictive isn’t necessary, but those with heart failure should still try to avoid excess salt. It is very easy to hit double the recommended intake with a typical American diet. The average American salt intake is about ~3400 mg/day from some studies.
Edit: after reading some of the replies I think there’s confusion about who the target population is in this study: it’s people who already have heart failure. I could have added in my comments that I was also referring to ppl with heart failure.
As of 2009 the average sodium consumption in 33 countries was in the range of 2,700 to 4,900 mg/day. This ranged across many cultures, and together with animal studies, this suggests that sodium intake is tightly controlled by feedback loops in the body. This makes recommendations to reduce sodium consumption below 2,700 mg/day potentially futile.[39] Upon review, an expert committee that was commissioned by the Institute of Medicine and the Centers for Disease Control and Prevention reported that there was no health outcome-based rationale for reducing daily sodium intake levels below 2,300 milligrams, as had been recommended by previous dietary guidelines; the report did not have a recommendation for an upper limit of daily sodium intake.[27][40]
Studies found that excessively low sodium intake, below about three grams (3,000 mg) of salt per day, is associated with increased mortality and higher risk for cardiovascular disease.[6][7]
But.. maybe it depends on the population.
I know that if you're outside in the heat, insufficient salt is far more dangerous.
Agreed. The title of the post is misleading. A strict restriction of sodium versus usual care (a recommended low sodium diet) was tested. There was no benefit to a strict low sodium diet. As a cardiologist, it doesn't not change my advice regarding usual care -- recommending a low sodium diet in patient with heart failure.
The measured goal in the study was to reduce heart failure exacerbations, which included ER visits and admissions to the hospital, not blood pressure per se.
Low carb diets can be really unhealthy for your heart. Sure if you do low carb with mostly salad you're probably fine. But many people start eating red meat, bacon and other things that cause heart disease.
Isn't that just clinging to the old advice without evidence? This study shows it has no effect. A lesser restriction would logically also have no effect.
Let's give up on the old urban legend that salt has f-all to do with heart health.
It seems the control group was following the current advice while the experimental group went beyond it, which would mean this study has nothing to say about the efficacy of the former.
The problem with this is the assumption that dietary sodium is bad.
People had this weird rage boner against cholesterol. Cholesterol in the blood is bad. So cholesterol in food must be bad too. This is based on the ridiculous assumption that your body just dumps the cholesterol in your body with no processing or regulation of cholesterol in the blood. Suddenly, there is this relevation that cholesterol in eggs is no longer harmful and you can eat as many eggs as you want. In fact, science has progressed so far that total cholesterol levels predict nothing if you adjust for oxidized cholesterol. If you are in a hurry to oxidize your cholesterol just smoke cigarettes or eat heat processed fats/transfats. The saturated fat scare also feels completely pointless. Saturated fats are solid at room temperature and they are harder to oxidize which means all the supposed harmful effects are overshadowed by the fact that they extend your lifespan. People care about avoiding specific causes of death but if your cells simply get damaged slower because they are less reactive? Nobody gives a damn.
How far away are we from reaching that understanding for salt?
I feel that this sort of simplification is common to our mis-understanding of health and nutrition. I also heard similar myths like: Calories in = Calories out, you are what you eat (meaning if you eat high fat you'll gain fat), etc.
Can you explain why you think salt raises blood pressure?
It's a very well understood effect -- as your body absorbs salt, it also retains more water to maintain osmotic pressure. This additional fluid in your circulatory system necessarily causes your blood pressure to increase.
That's the very simple chemistry behind salt increasing blood pressure. The biology is more complex and the effect isn't necessarily long lasting or linear, but there is indeed a direct relationship between sodium intake -> blood pressure.
It would seem to make sense, until biology gets in the way. Mammals have several exquisite mechanisms for regulating sodium. Unless you're very sick, they work fine. So there is no 'direct' relationship at all.
It should also be noted this is a study evaluating a reduced sodium diet (standard treatment for those having heart failure) vs. an even further reduced sodium diet. Further reduction yielded little difference in results. That is to say reducing your intake below 1,500 mg per day doesn't present any net benefits. The study should not be interpreted as salt intake has no effect whatsoever on your blood pressure.
You do know we have kidneys, right? They are amazing organs, they conserve the 0.9% salinity of your blood, roughly 40 grams in total. When you take in too much, the kidneys simply excrete it in urine. When you take in too little, they hold on to as much as they can.
We can shortcut a bunch of pedantic arguments by just reading their conclusion;
> In ambulatory patients with heart failure, a dietary intervention to reduce sodium intake did not reduce clinical events.
Ambulatory = walking around, e.g. not hospitalized. The patients were already diagnosed with chronic heart failure and were followed for a year to see if a low-sodium diet would prevent further cardiac events. There wasn't statistical evidence that the low-sodium diet did so. Tada!
No, they tried out whether reducing sodium intake beyond the ordinary low-sodium diet helps, and there wasn't statistical evidence for a difference between a low-sodium diet and a extra-low-sodium diet.
They did not find (or even try to find) whether a low-sodium diet helps in comparison to a normal, average diet.
They followed the diets and measured intake -- the low sodium group was instructed to stay under 1,500mg/day -- they didn't quite get there but had substantially lower sodium intake as compared to the 'control'. The study group decreased median sodium intake by 27% compared to the 'control' group who decreased intake by 2%. There's always a issue of 'the human element' in studies like this where people lie and don't follow instructions but claim they did, but good study design and follow-through typically minimize those issues.
> Between baseline and 12 months, the median sodium intake decreased from 2286 mg/day (IQR 1653–3005) to 1658 mg/day (1301–2189) in the low sodium group and from 2119 mg/day (1673–2804) to 2073 mg/day (1541–2900) in the usual care group.
Is it possible that salt intake is just correlated to heart disease because the real foods causing heart disease (highly processed foods with refined vegetable oils, sugar, preservatives, etc.) are loaded with salt?
Anecdotally, I put salt in everything I cook - sometimes to the point where others find it salty. My blood pressure has always been firmly in the healthy range (low 30s Male).
I don't have a source but I vaguely remember reading about how salt is no different than fat or cholesterol in terms of how it correlates to your body. Fat does not make you fat. Cholesterol doesn't raise your cholesterol. Salt doesn't raise your sodium levels. Excess calorie consumption combined with lots of fat (high in calories), will indeed, make you fat. Excess calorie consumption combined with lots of cholesterol, will raise cholesterol levels. Salt is no different.
This is an interesting read about salt from a 2011 article.
"Intersalt, a large study published in 1988, compared sodium intake with blood pressure in subjects from 52 international research centers and found no relationship between sodium intake and the prevalence of hypertension. In fact, the population that ate the most salt, about 14 grams a day, had a lower median blood pressure than the population that ate the least, about 7.2 grams a day."
As others have said, this study is comparing a very low salt diet to a recommended level of salt diet, and only in people who already have pre-existing cardiac issues.
Apparently the average American has a diet that has 1.5 times the recommended level, so what this study is looking at isn’t anything like that, let alone an even higher-salt diet. So you can’t take the study as saying anything about preventing heart disease generally.
The one conclusion you perhaps could extrapolate from it is to say that the recommended limit is probably pretty good since it doesn’t seem to help going lower.
Yes, it is like a co-morbidity. These are factors that amplify each other. Salt is likely fine if you don't have kidney or liver issues. However, heavy salt on top of trans fats and high sugar and .. and .. and .. is likely hard on our body.
I wonder if the commonly thought of causation relationship for sodium and health problems is inverted.
Speculatively, i.e... your body has a greater need to use the sodium-potassium pump more when you're stressed, which makes you crave salt, and eat more sodium. The high stress is what causes bad health outcomes, the high sodium levels just happen to correlate with it.
Seems like a lot of people are missing the fact that is study of people with heart failure not a study of otherwise healthy people.
The study is decreasing sodium intake even further from the current guideline for patients with heart failure.
The effect of sodium intake is very different for people who need to maintain very tight tolerances to survive. And a ton of effort is spent keeping people with heart failure out of the hospital.
I have heart failure and have an implant that measures electrical conductivity of heart tissue and will warn if I am approaching fluid overload due to too much sodium.
The issues with sodium intake are caused more by high osmolality than by absolute quantity. We can't tell if a particular patient's sodium consumption is too high without also knowing their fluid intake.
I think a lot of people don't realize that the impact of sodium and other "bad stuff for you" varies from person to person. Only 25% of the population is subject to high blood pressure as a result of high sodium intake.
So, if you create an experiment that can subtly select for the 75% of the population doesn't experience high blood pressure, then you can show that sodium doesn't raise it. I don't if that's what's going on here but a lot interested parties will try to go this route in order to show that salt is harmless.
Your theory can be anecdotally refuted by simply observing that people will eat more when food is well salted. French fries are an easy example. If you have two piles of fries - one salted, one not salted. Which do you think you'd eat more of?
I mean your test can be juked both directions... perhaps you eat more of the salted pile because you are salt deficient and that pile provides the salt your body needs, while the none salted pile isn't solving the problem and thus is deemed unhelpful by your system?
I'm not saying either are correct, I'm saying this hypothetical is a bad one.
Your theory doesn't seem too far off. Perhaps it is not a deficiency but more of a craving associated with hormones like ghrelin.
I find that salty processed foods such as Cheeze-Itz (flavored) are very addicting and not filling at all. My theory was always that anything with onion powder, salt and refined carbs is a craving that can't be satisfied easily.
I'm not an expert by any means, but I thought it is common sense that what really matters is to have equivalent sodium and chloride ion counts ( or their equivalents ), because in nature one would basically never deviate from this. In modern times we do, relatively a lot.
I can't read the article, but it's my impression that high sodium isn't as much a threat to general health as increased BP is. I'd like to know what sodium reduction did for BP, and how much the two groups then differed.
If the goal for patients is not reduction of BP, then the presumption of this study is that sodium is affecting the heart and vessels in more complex ways than pressure alone, and such patients might suffer in a diverse multitude of complex ways that are much harder to attribute directly to the level of sodium.
The authors' conclusion seems to be only that the correlation between sodium intake and death in heart patients is not simple and linear.
> This is NOT the first study generally disproving a link between sodium and CVD.
That's a weird way to phrase it because this study has nothing to do with cardiovascular disease generally. It's specifically about non-hospitalized patients already diagnosed with heart failure.
This does nothing to disprove the very clear link between sodium intake above a certain level and heart disease in a previously healthy individual.
No, it is not. It's difficult to correlate CVD to high sodium intake when the majority of people in the U.S. are overweight/obese, and is the largest factor in CVD.
“link between sodium intake above a certain level and heart disease in a previously healthy individual”
I know this is common knowledge but could you provide any recent studies or citations for curious readers? Anything from the past 5 years? I could never understand how they factor in body weight and physical activity, which should change the recommended levels. Someone who sweats a lot because of intense exercise might need sodium above that limit. Or if you drank more water than average, etc…
Human beings are like plants that must be watered. Our difference is that our “soil” is our blood, and to get it “dry” to absorb more water means two things:
Changing the level of salinity to allow more water via osmosis, and altering the composition of neurally-reactive cations and anions.
It’s not so much balancing them out as letting them enter and leave the system at intervals, like we do with air and respiration.
It's frustrating that on one hand you want to hit a decent amount of sodium per day for the optimal operation of one's body, while at the same time if you go over 2500mg of sodium per day, you increase the likelihood of building kidney stones.. there's no way to win, from what I can tell. Is there a trick here or is that just the way the human body is built, and that's that?
My understanding is that the human body is so complicated and so individual that very few things can be systemized like that unfortunately. Maybe if there are biomarkers to indicate specific people should have specific ratios??? I don't know.
I'm going to make a bet the sodium intake is correlated with calorie consumption which is why these studies all find it so difficult to figure out why salt sometimes seems to cause similar issues to high calorie diets.
Let's be honest here, if you eat a bowl of food with no salt on it you will get bored and find the food hard to finish.
“Don't know of its my opinion of the field or the journal but i don't rate the lancet”
Lol. It’s every field! Unless you live under a rock you’ve heard terms like p hacking, publication bias, publish or perish and in and on. All a manifestation of the glaring problems in higher education.
If you uniquely don’t trust the lancet, you’re doing it wrong. Be skeptical of all research until it’s been replicated a bunch, ideally by your own research team.
To the broader topic of health information going wrong, at the top of the Lancet page I see an ad for Hydroxychloroquine Sulfate. Anyone else? I'm in western US.
I see that, although it links directly to an 18 page pdf of prescribing information (which includes no mention of COVID.) Maybe satisfying some sort of legal notification requirement?
Wait'll the news gets a hold of it. The same study will probably generate "low salt diets cause heart attacks" and "skipping salt saves lives" news headlines.
In general, if you have super high sodium intake, you also have other major problems with food, weight and exercise that are far more likely the primary causes of CVD. For example, you are usually eating a ton of processed foods with high fat and high carbs in calorie counts in an unhealthy range.
High fat and carbs are not the issue, it's solely caloric intake that's the issue. Of course, anything in excess is bad, but it's the caloric surplus that is the major cause of chronic illness.
Do we fully process everything we eat? What role does insulin have in how we process food, and how is insulin controlled?
I generally agree that too many of us eat too much for our own good and that of other life on the planet, but to reduce the issue solely to caloric intake seems off.
From my own experience, timing and order of what I eat matters more than total calories. If I eat a morning meal until I'm full, well that was fun but now I'm tired, and the day just started. If I start the evening meal with bread or a handful of chocolate chips and eat the greens and veggies and fruits last, I feel different than if I do it the other way around, a worse-different. I suspect there are reasons (some for health, some for economics) that multi-course meals include a salad early on. Since I'm not couting calories, and I am eating until I'm full (regardless of how many meals I eat in a day, which is part of my problem, and why I spend more time fasting these days), I don't actually know what the calorie difference would be if I mix up the order, but I've settled on starting with the plants and fats, then proteins, then carbs and that feels good. On days (thankfully not habitual, now) when I snacked all day, interspersed with full meals, I had acid reflux, low energy, was irritable, had teeth problems, and gained unwanted bodyfat. Lump all those calories into two full meals (a lunch and dinner, say) and I felt better. Bring it down to one meal a day and I feel better yet (and, to your point, I'm likely consuming fewer calories, so win-win?). If I was more physically active I might do it differently.
Before refrigeration salt was the most popular method of preserving food, so do we really consume that much more of it compared to people who lived in the past?
Probably because it's in every processed food. Back then you wouldn't be directly salting every meal because salt was expensive, you'd add salted meat, a sauce that contains salt, etc... to a stew with vegetables...
Salt was expensive.. but in the quantities we shake onto our food today, the price was pretty much negligible. Salt was considered expensive because they used a lot of salt when preserving food.
For reference, US Army regulations during the American Civil War called for soldiers to be given 3 pounds 12 ounces (1.7 kg) of salt every 100 days. Sprinkling a little bit of that onto a meal would not exactly have been opulent. Of course, those ration regulations were aspirational and soldiers were lucky to get what they were owed, but it gives an idea of how much salt people considered reasonable.
The first step in preparation of salt preserved foods was often to wash away as much salt as possible. For instance, by soaking your salted pork in fresh water to leach out as much of the salt as you could.
Depends on your definition of high. They seem to be comparing normal higher sodium diet to a low sodium diet. So high seems to be relative.
At a certain level sodium does become excessive and can lead to high blood pressure and kidney issues (I believe the liver issues are blood pressure related). This is basically due to the kidneys not being able to process the extra minerals. As long as you stay within the kidneys limits of function, then you're fine.
I thought that it was changes in salt intake that caused high blood pressure rather than high levels of salt intake. That is, if you increase your daily salt intake by 500 mg or whatever you'll see you blood pressure go up immediately but converge back to its normal level over the course of a month as homeostasis does its thing.
They have compared a diet with a sodium intake close to the lower limit of the recommended intake, with a diet including an even lower sodium intake, slightly less than normally recommended.
A daily sodium intake in a relatively wide range around the recommended daily intake (which is of about 4 to 6 grams of salt per day) is not expected to cause any differences, so the results of the study are not surprising.
The recommendation to eat less salt is only for the people who eat mostly industrially-processed food, which always includes excessive quantities of salt and sugar, because they are among the cheapest ingredients, while enhancing the taste of the food.
Such people typically eat 2 to 3 times more salt than recommended, and only for them it may be expected that lowering the sodium intake can reduce the risk of diseases. However, lowering the sodium intake is not easy for them, because they must begin to eat something different, since the excessive salt is not added by them to the food.
Otherwise, lowering the salt intake much under 4 grams per day is a serious risk, especially for older women, and especially when they also take medication against high blood pressure.
Hyponatremia, i.e. having a too low sodium content in the body, manifests initially with symptoms like muscular weakness, constipation, lack of appetite and problems with the equilibrium, which may result in falls.
Such symptoms may be difficult to distinguish from just consequences of old age. If hyponatremia is not diagnosed in time, the consequences can be extremely severe, including the loss of life.