Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

No Association Between Salt And Blood Pressure, Study Finds

time.com

Post reply on HN
Print view View original

141–150 of 158 posts

Re: No Association Between Salt And Blood Pressure, Study Finds

#141

Post by kens »

melling wrote: post #36
delinka wrote: post #32

Oxygen is bad for us. It oxidizes and damages all kinds of organic chemicals in our bodies that are required for use to live. Oxidization, however, is exactly what provides us with the energy that supports life. Salts are electrolytes. (Electrolytes are salts?) You need them in your body so that your nervous system can conduct signals and keep things going - like your heart. We live. We grow. We hurt. We heal. We get…

That's a nice philosophy that many people take. However, don't you think it would still be a great thing if we understood, at a much deeper leve,l how our bodies really work? It's like we're running around in the Middle Ages seeking enlightenment and the best we can come up with a bunch of large studies over many years.

That's a good way of describing it. I expect that a hundred years from now, this thread will be viewed as people arguing over questions that don't even make sense. This brings to mind Paul Graham's article "What you can't say", but that article focuses on what people can't say due to moral/cultural pressures and taboos. In this case (and many others), it's what people can't say because the underlying framework is missing. Maybe in 100 years, people will wonder why we were even debating whether people should restrict salt or not, because the question won't even make sense as something to ask. Kind of like serious medieval debates over Filioque now seem pointless to most people.

[1] http://www.paulgraham.com/say.html

Re: No Association Between Salt And Blood Pressure, Study Finds

#142

Post by svsaraf »

pothibo wrote: post #132
svsaraf wrote: post #50

I'm a medical student who actually read the paper this article refers to. I would be very careful trying to draw conclusions from a study like this. I don't think many people in the healthcare community would be very surprised by it. 1) All clinically treated hypertensive patients were excluded - that means if you have kidney or vascular disease (hypertension) and are being treated for it, you aren't counted here. Do…

Oxford journal isn't your daytime television show. For a med STUDENT you show quite a lot arrogance. You also misunderstand how studies works (All clinically treated hypertensive patients were excluded for a reason. Guess which?) Can't believe you were upvoted since most of what you wrote is just self-serving and has absolutely no links with the study. (I read the original study too)

Believe it or not, I'm not criticizing the study. It certainly has weaknesses, but I agree with its conclusion and its general methodology.

I'm criticizing Time magazine for making the claim that salt has no effect on blood pressure (or implying it), which is demonstrably not true.

My point is: if you're healthy, no, it isn't surprising that your body can regulate salt intake. If you aren't, it isn't surprising that doctors will want to keep track of how much salt you're eating.

> For a med STUDENT you show quite a lot arrogance.

I wish you hadn't said this, because I think it's unnecessary and diminishes the rest of your comment.

Re: No Association Between Salt And Blood Pressure, Study Finds

#143

Post by kyasui »

sgustard wrote: post #138
bronbron wrote: post #17

Earlier quoted context omitted.

> Very long term, energy burned will be == energy taken in. Not really, unless we're counting death. Most people gain weight as they get older. > If that's consistently out of balance by... say 100 Kcal/day, that's 0.2 lb/week every week or 10 lb/year or 100 lb/decade. How many 50-year-olds do you know who are 300 pounds heavier (or lighter) than they were at 20? You're phrasing that the wrong way. Your BMR changes d…

Hm, this chart shows average weight dropping as people get older. http://www.halls.md/chart/men-weight-w.htm

Probably more due to loss in lean body mass (muscle + bone, etc) than due to fat loss.

Re: No Association Between Salt And Blood Pressure, Study Finds

#144

Post by sergiosgc »

vanderZwan wrote: post #126
sergiosgc wrote: post #125

Earlier quoted context omitted.

1) In trying to find out if, generically, there is a causal effect between salt intake and blood pressure, it is sensible to select a healthy population. The hypothesis being tested is "In good working condition, the human body maintains correct NaCl levels". You do not want to test people with faulty metabolism, because they are outside the scope. 2) See explanation in number 1. 3) I have not read the original paper…

> In trying to find out if, generically, there is a causal effect between salt intake and blood pressure, it is sensible to select a healthy population. That only holds if the causal relationship does not affect health in any other way. > The hypothesis being tested is "In good working condition, the human body maintains correct NaCl levels". Maybe I'm misinterpreting things, but isn't maintaining correct NaCl levels…

> Maybe I'm misinterpreting things, but isn't maintaining correct NaCl levels is by definition part of a good working condition? Sounds a bit circular.

You're misinterpreting the definition of "good working condition". Good working condition, as I meant it means that it is operating as "designed" (no religious meaning intended), i.e. no malfunctions in any part are identified. It could be perfectly possible that, in good operating condition, the error margin on the NaCl control system allows for NaCl levels that cause hypertension. The hypothesis negates this possibility, and the hypothesis test seems to prove that the error margin on the body's NaCl level control keeps it narrow enough to exclude salt intake as a cause of hypertension (on healthy adults, of course).

Re: No Association Between Salt And Blood Pressure, Study Finds

#145

Post by sergiosgc »

svsaraf wrote: post #140
sergiosgc wrote: post #125

Earlier quoted context omitted.

1) In trying to find out if, generically, there is a causal effect between salt intake and blood pressure, it is sensible to select a healthy population. The hypothesis being tested is "In good working condition, the human body maintains correct NaCl levels". You do not want to test people with faulty metabolism, because they are outside the scope. 2) See explanation in number 1. 3) I have not read the original paper…

I almost completely agree with this comment. I should have been more clear - my gripe is not so much with the study but with its interpretation by Time. The study may have its own problems, but draws a conclusion I agree with, that the relationship between salt and blood pressure in healthy people may be overstated. As for your point 3: I disagree. I think the news article makes a case that salt and blood pressure ha…

> As for your point 3: I disagree. I think the news article makes a case that salt and blood pressure have no relationship, which isn't true. It is only true if, almost by definition, your salt / water regulation system is healthy.

It never states the inference directly, although as is common in mainstream media, the title of the piece is stronger than what is then told in the text. I think you may be getting too hung up on the title, and I understand the reason. Mainstream media often over-generalizes scientific findings, more so in the field of nutrition.

In the same vein you have a pet peeve with media behaviour, I have one with M.D. behaviour. One that may paint the overly generalized title in a kinder light:

Doctors often prescribe life-style changes: Eat less, eat better, exercise more, don't smoke, sleep well, sleep regularly, avoid stress. They fail at prioritizing, because they fail at recognizing that patients will never completely change their lifestyle. Willpower is a limited resource, and should be allocated as such.

The prioritization of lifestyle changes is important. If reducing salt intake is competing with reducing BMI, it should be a no-brainer that BMI reduction should come first. It is rarely the case. They are either presented as equally important changes or, since reducing salt intake is easier than shedding 20kg, doctors go for the easy goal.

The prioritization problem should be obvious. The closer to the root of problems you attack, the better the result you'll get. Salt intake is way way down the causal chain to health problems.

As such, blanket stating that you shouldn't care about salt in your diet may be good, if it leads to freeing willpower to do other lifestyle changes.

Re: No Association Between Salt And Blood Pressure, Study Finds

#146

Post by pbreit »

lutusp wrote: post #79
pbreit wrote: post #68

Earlier quoted context omitted.

The headline used "association". Plus, the article seemed to indicate it was a causation, just not universal.

It's important to understand that, until a cause-effect relationship is explained instead of being merely measured, it's not science. A more complete explanation is here: http://arachnoid.com/science_of_mind/

I was making a simple observation that the headline clashed with the article.

Re: No Association Between Salt And Blood Pressure, Study Finds

#147

Post by grhino »

smeyer wrote: post #130
sergiosgc wrote: post #125

Earlier quoted context omitted.

1) In trying to find out if, generically, there is a causal effect between salt intake and blood pressure, it is sensible to select a healthy population. The hypothesis being tested is "In good working condition, the human body maintains correct NaCl levels". You do not want to test people with faulty metabolism, because they are outside the scope. 2) See explanation in number 1. 3) I have not read the original paper…

>Sodium and chlorine are very active chemical elements How active are the sodium and chlorine ions, which I assume is what you actually get since the salt is dissolved. Do they still have a major effect on most of the chemical reactions in the body? It's not like anyone is ingesting sodium metal. Disclaimer: I have a physics degree but haven't taken chemistry or biology past high school, so I'm very ignorant here.

Admittedly not a biochemist, but I believe sodium and chlorine lose most of their activity when they give up or accept that electron, respectively, to fill their octet. From a biochemistry perspective, they are mostly used as convenient ions to generate voltage differences or activate structural changes in enzymes.The chemical difference between sodium ions and potassium ions are relevant at times, free sodium ions or chloride ions are not nearly as reactive as their neutral complements. It's also very unlikely that sodium ions or chloride ions would spontaneously transform into their neutral complements.

Re: No Association Between Salt And Blood Pressure, Study Finds

#148

Post by baddox »

tmod wrote: post #10
lincolnq wrote: post #2

The state of nutrition science is pathetic. The science is conflicted over a simple question of fact -- whether or not a trivially measurable short-term effect occurs when you eat one of the most common food additives in the world. If we can't even answer THIS -- it seems like it should be incredibly easy to answer -- I don't see why people can claim anything at all about diets and macronutrients. Nutrition science n…

I'd recommend this book by Ronald Gaucho It's Great! Oops, No It Isn't: Why Clinical Research Can't Guarantee The Right Medical Answers "The truth is, few people know the first thing about clinical research. The public reads about a medical research project that announces unbelievable results for a miraculous drug. Some years later, another investigation completely wipes out those initial favorable findings. Hormones…

What is the fundamental difference between nutrition and something like evolutionary biology? With evolution, there are obviously a lot of people who don't believe it, but pretty much everyone (including the doubters) recognizes that the mainstream scientific consensus is that evolution is a correct theory.

So, is the difference that there isn't much consensus among scientists for nutrition, and if so, why not? It seems to me that a hypothesis like "salt consumption affects blood pressure" should be fairly straightforward to test.

Or is the difference that the public simply isn't aware of what the scientific consensus is regarding issues in nutrition?

Re: No Association Between Salt And Blood Pressure, Study Finds

#149

Post by baddox »

equoid wrote: post #93
laichzeit0 wrote: post #77

Earlier quoted context omitted.

I read something interesting about high GI vs low GI foods that I didn't know [1]. The TL;DR "The GI value of a food is determined when it’s eaten in isolation after an overnight fast. As in, this is how this food will affect your blood sugar when it’s the FIRST and ONLY thing you’re eating after a full night of not eating anything." So the whole high GI is bad thing taken to the extreme e.g. clean eating, is probabl…

Don't be silly. That measurement technique is to allow you to isolate and measure the effect. You seem to want to infer that the effect does not occur in any other circumstances. That is as inane as disregarding crash test dummy results because they take place in a controlled environment which is not the same as 'real life'.

To be fair, you would also want tests to determine the effect of other recently-consumed foods, because combining foods might not lead to strictly additive results.

Re: No Association Between Salt And Blood Pressure, Study Finds

#150

Post by eik3_de »

amorphid wrote: post #134
eik3_de wrote: post #109

Can't confirm. Whenever I use salt, my blood pressure goes up fairly quick. That's why I use Ansible instead.

"eik3_de is controlled by the cook's union, and is merely a puppet for the chef industry." --C. F. Engine

haha n1
Post reply on HN