Hacker News new | past | comments | ask | show | jobs | submit login
The curious case of high blood pressure around the world (economist.com)
91 points by known on Dec 30, 2017 | hide | past | favorite | 55 comments



This piece is a great example of entirely the wrong way to think about this issue.

The procession of mechanisms is as follows, starting with layer 1:

- calcification

- cross-linking

- vascular smooth muscle dysfunction

Which gives you layer 2:

- vascular stiffness

Which then, entirely and all by itself ( http://dx.doi.org/10.1371/journal.pcbi.1003634 ), causes layer 3 by messing with the feedback mechanisms for blood pressure control:

- hypertension, raised blood pressure

Which then causes layer 4:

- microvascular damage, such as stroke, kidney issues

- major vascular damage and sudden death when combined with atherosclerosis

- cardiac hypertrophy, which is a maladjustment to hypertension

Calcification may be secondary to cellular senescence and other inflammatory mechanisms. Persistent cross-linking may be made worse by dietary sugars, or may not - the better studied forms of sugary by-product are not all that relevant to persistent cross-linking that stiffens tissue. You can read up on glucosepane to learn more about that. The vascular smooth muscle dysfunction is probably caused by a combination of inflammatory mechanisms and everything else that changes with age and poor health, such as metabolic syndrome.

So if thinking about fixing hypertension, you want to be watching people building cross-link breakers, such as the Spiegel team at Yale, funded by the SENS Research Foundation, or people clearing out senescent cells, such as the current brace of senolytic therapy companies, one of which was seed funded by the SENS Research Foundation. Watching the groups looking into smooth muscle may or may not go anywhere; it is very hard to say at this stage whether there is any one target that might help enough for the usual pharmaceutical development approach to work well enough to care about in the near term.


  The procession of mechanisms is as follows, starting with layer 1:

  - calcification

  - cross-linking

  - vascular smooth muscle dysfunction
Could you please throw some links behind that? I've never heard of cross-linking before and I'd never made the connection with calcification and high blood pressure, but it sounds interesting to look into.


You seem to have a good handle on this subject. Im curious about your opinion on whole food plant based diets for inhibiting this progression through these layers you describe.


Great comment, from explanation to potential solutions. Thanks a ton


My dad got diagnosed with high blood pressure when he was 30.

For the past 26 years, our family has maintained a low-salt, low-oil diet. There is regular exercise and walking. Low consumption of alcohol and also junk/saturated fatty food, meditation and breathing exercises.

I'm damn proud of my dad and the way he's maintained his blood pressure problem throughout his life. As a by product, the entire family is health conscious. Props to my mom for making sure we always eat well and healthy. It wouldn't be possible without her constant effort.

As a result of growing up in this household, I'm extremely sensitive to salty, oily,and junk food. In the sense that, it doesn't cause a reaction or anything, but I can TASTE the HIGH amount of salt and oils in All the food that's served around me, and I see people gobbling it up without even realising.

Lifestyle diseases.


The lifestyle diseases are apparently not related to oils, and for 80% of the population, salt either (someone posted links earlier).

The culprit appears to be the combination of carbs and fat; there are cultures who have lived on mostly carbs which are healthy, and some who have lived on mostly fat that are; but the combination is lethal.

Also, salt is often demonized unfairly (though in your case, it might be right - sodium sensitivity is mostly genetic). Too little sodium is more dangerous than too much for most people. Keto flu is a flu-like condition often accompanied by rash that is a result of dropping carbs without increasing sodium+potassium+magnesium intake, with salt likely playing the largest part.

I am now increasing my salt intake gradually, after having essentially no salt for the last 40 years (grew up in a salty household but didn’t like the taste). It is hard but I am sleeping better, having less muscle cramps, and losing more weight than with the same diet before increasing salt. YMMV.


Salt does not cause the disease, but regulating salt is how you regulate high blood pressure when you have it (which his dad has). Yep, muscle cramps are side effect.

People with high pressure measure it often, so they eventually get idea on what works.


I have a relative who's a kidney patient and who only recently realised her blood pressure was getting too high- it was up to 194/112 back in February this year. She only realised when she mentioned having strong headaches during a doctor's appointment.

My relative is in a scientific discipline and she likes collecting data, I guess, so she's been tracking her blood pressure meticulously since then. I helped her to plot it out in R. You can see the resulting diagram below:

http://www.goblinopera.com/hn/dec_17_anon.png

I think anyone who sees this chart cannot fail to notice the big dip in BP in October: from an average of 140/90 from February to September, to 120/75 after October. So far, this has lasted (with a bit of a recent spike, possibly brought on by the inevitable Christmas Binge™).

This dip follows from her decision to control her salt intake, starting around October. She no longer cooks with salt, or salt her food, she eats very little cheese and generally stays away from food she hasn't prepared herself and can't control the salt content of.

So this is the message I keep from this chart: salt intake can really affect blood pressure.

Obviously, that's a single case and it's hard to generalise- but on the other hand it's impossible to deny that a specific intervention (controlling salt intake) was taken in the hopes of having a desired effect (lowering BP) and that the expected effect directly followed the intervention.

There were confounding factors, to be sure. I've marked various medication milestones in the chart (anonymised, to protect her privacy). My relative was suspicious that "Drug 1" was affecting her blood pressure and the chart has helped convince her doctors that she should stop taking it (see the big spike after "Drug 1" is taken at the end of May). She is now taking an alternative ("Drug 3"). My relative also lost some weight between February and September and that definitely contributed.

However, the fact remains that she was able to lower her blood pressure to the levels considered safe for kidney patients (those are lower than in the general population) only when she started controlling her salt intake.


Given that kidneys are responsible for filtering excess electrolytes out of the bloodstream it makes sense to me. A person with compromised kidney function may need to limit intake to a level that the kidneys can handle. This doesn't necessarily mean that a person with healthy kidneys needs to limit intake.


Of course. But high blood pressure can damage the kidneys, which can in turn raise blood pressure further- so if blood pressure is high then it's probably a good idea to start lowering one's salt intake, anyway.

My relative has been complaining that she was not made aware of the detrimental effect that high blood pressure has on the kidneys, and how salt affects this, even after multiple visits to a nephrologist. She could probably have avoided those crazy high values at the start of the graph if she was aware.

I was not aware of the connection either and I believe many people are also oblivious to it, so it's probably a good idea overall to highlight it.


What is "essentially no salt"? Considering that the AHA's daily target is 1,500mg, or only 3/4 tsp, were you even far below that?


Yes and no. You overstate the risks. I consume almost no sugar, because I have no taste for it, but I consume prodigious quantities of salt at levels far higher than the average American. My blood pressure is perfect, naturally. Those are my family genetics; we don’t eat sugar, and salt is utterly harmless to us. I realize what I am eating.

There is a lot to be said for a healthy diet, I agree with that. I am a fish/chicken and veggies guy myself, so my diet tends toward healthy anyway. But that reflects personal preferences, I don’t conflate it with a moral position. And anecdotes aren’t the same as science. The basis for being judgmental is less than most believe.


>> I'm damn proud of my dad and the way he's maintained his blood pressure problem throughout his life. As a by product, the entire family is health conscious. Props to my mom for making sure we always eat well and healthy. It wouldn't be possible without her constant effort.

And props to all of your family for having the patience to follow your dad's low-salt regime. From my personal experience with a family member that has problem with her blood pressure, it's hard to convince healthy people to eat less salt, even to help a relative.


>"diets that include too much salt"

Hasn't that been debunked I thought I read? I certainly hope so.

I had the pleasure of visiting with my Grandma's sister who was down for the holidays with us. She did not eat much of our cooking as she stated that her doctor had her on a "low sodium diet". She said she couldn't eat alot of things she liked, but it wasn't so bad as there was no restriction on sugar intake so she "gets to eat all the sweets" she wants.

And that was demonstrated several times at the dessert table and by the several bags of candy she brought with her from back home. I was quite dumbfounded.


What I've read is that only about 20% of the population has salt induced hypertension. Regarding low salt diet which I am on due to kidney disease, our tastes actually adapt the lower salt contents if you do it long enough however you still need enough to bring out the flavor in many things. My solution is to pick things that have other stronger tastes like sweet, sour, spicy, etc.


Vinegar or lemon juice also help perk flavors up.


Don't forget lime juice!


Also low salt can result in muscle cramps.

https://www.webmd.com/fitness-exercise/heat-cramps#1


Recent studies have, in fact, shown that dietary salt has a significant effect on blood pressure for many people, and on endothelial function for everyone.

https://nutritionfacts.org/video/sodium-and-arterial-functio...


"My doctor" (scare quotes included free of charge) says that it's only really important for people who are hypersensitive to sodium.

I didn't ask if there was a test for that, though. So you know, take it with a - I'm so sorry I can't help it - grain of salt.


I read the transcript, and this describes a temporary affect. There are better studies on the long term effect that say the effect of salt is very low on long term health outcomes.


Debunked is too strong a word. It has undergone revision.


If you have normal blood pressure (normotensive population), then a high-salt diet has no association with cardiovascular events and death:

http://www.thelancet.com/journals/lancet/article/PIIS0140-67... /"Compared with moderate sodium intake, high sodium intake is associated with an increased risk of cardiovascular events and death in hypertensive populations (no association in normotensive population), while the association of low sodium intake with increased risk of cardiovascular events and death is observed in those with or without hypertension. These data suggest that lowering sodium intake is best targeted at populations with hypertension who consume high sodium diets."/

Eating too little salt can result in increased risk of cardiovascular events and death: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3558770/ /"we cannot extrapolate that lowering sodium consumption would reduce cardiovascular risk or premature death. In fact, randomized controlled trial evidence suggests just the opposite: that lower sodium intake may lead to worsened cardiovascular disease and earlier death."/

Low salt == higher risk of a heart attack resulting in death: https://www.ncbi.nlm.nih.gov/pubmed/21540421 /"Among 3681 participants followed up for a median 7.9 years, CVD deaths decreased across increasing tertiles of 24-hour sodium excretion... Lower sodium excretion was associated with higher CVD mortality."/

Salt intake is not associated with blood pressure, although body mass index and age are: https://academic.oup.com/ajh/article/28/3/362/2743418/Relati... /"Considering their squared partial correlation coefficient, age and BMI were the most important parameters relating to SBP [systolic blood pressure] level. Salt intake was not associated with SBP in either sex after multiple adjustments."

If you do have high blood pressure, supplement with potassium: https://www.ncbi.nlm.nih.gov/pubmed/26039623 /"Potassium supplementation is associated with reduction of blood pressure"//

Salt intake is not linked to heart problems for adults 71 to 80 years old: http://jamanetwork.com/journals/jamainternalmedicine/fullart... /"we observed that sodium intake estimated by FFQ [food frequency questionnaire] was not associated with mortality or risk for CVD [cardiovascular disease] and HF [heart failure] in a cohort of adults 71 to 80 years old. These findings extended to sex-based and race-based subgroups and in participants with and without hypertension at baseline."/


>If you do have high blood pressure, supplement with potassium

Note that for some very common blood pressure meds, potassium is contraindicated and can lead to hyperkalemia (excessive potassium). This should be indicated in a warning printed on the bottle.


Hyperkalemia can kill you by stopping your heart.

Which is why it’s impossible to buy potassium supplements in some parts of the world.


Is there a particular gene that is linked with high sodium causing hypertension?


>> Hasn't that been debunked I thought I read? I certainly hope so.

I have heard of no such "debunking". With all due respect, but you should really try to do a bit of research and backup such assertions, when they can start rumours that could affect peoples' health. "I thought I read" is not nearly enough to claim some health guideline is now "debunked".

Btw, sugar intake is definitely not known to raise blood pressure, at least until it leads to other problems like diabetes, which can ruin your kidneys and then cause raised blood pressure. Your grandma's sister was probably misinterpreting her doctor's advice, most likely along the lines that "sugar isn't bad for blood pressure" to mean that she can have all the sugar that she likes. That your grandma's sister had a very unreasonable reaction to the unfortunate restrictions imposed on her diet, does not have anything to do with whether salt raises blood pressure, of course.



Yes, there are a few studies like the ones you quote that contradict the received wisdom about the relation of salt and blood pressure, but they are still very few (compared to the studies that show the opposite) and very new, to be anywhere near "debunking" anything.

On top of that, current recommendations (from the WHO, US CDC and others) are to limit salt intake to between 3-5mg daily (for healthy adults) and while those recommendations stand, dismissing them as "bunkum" is irresponsible.

In general, a handful of studies is never enough to challenge long-standing assumptions, in science. It takes a lot more work and a lot more time. Until then, spreading rumours that the assumptions have been "debunked" risks being harmful.

For an example: a friend of mine is convinced, after reading some article in the popular press, that it is not salt that raises blood pressure, but the additives put into it, so she insists on cooking meals for her hypertensive partner with sea salt, that doesn't have additives (so, according to her, it doesn't raise blood pressure). Her partner is on anti-hypertensive medicine, has had a bypass and should really be keeping his salt intake under control. His health is in danger because of someone's haste to report an isolated study as a paradigm shift.


Amazing to me that the most basic biological system for survival - stress - is no where mentioned. And we've known for 40 years that relaxation techniques are as effective at treating hypertension as prescription medications.


It's a weakness of empiricism that scientists remain reluctant to consider the role of (unmeasurable) psychological states, such as pleasure or stress, in the context of a (measurable) physiological response, such as raised blood pressure.

My guess is that, together with stress, it is visceral pleasures (arising from our relationship to food, sex, drugs, alcohol, or other substances/habits) that are responsible for high blood pressure. Eating food with salt is just one of the ways it can be made more tasty, and thus more pleasurable, since salt heightens the response of our taste buds.


Because it's difficult to objectively measure stress and pleasure between people.


So we continue to look for our keys under the streetlight rather than in the bushes where we dropped them.


Except we don't actually know where the keys were dropped, so might as well start under the streetlight.


Science starts with problems, not observations.

If excessive pleasure is unhealthy or bad, why do people seek it? We can use folk psychology as starting point, e.g. consumption of Ben and Jerry's in response to relationship difficulties.


Right! I’m quite convinced many people with high blood pressure have a lot of stress.

That’s one thing. And for some this stress naturally goes together with larger alcohol consumption and/or less sleep and/or bad food choices and so on.


So I recently found out I'm one of those many people with high blood pressure. This knowledge has been stressing me out (I don't want to die yet).

I'm reasonably active as far as software engineers go: 10k+ steps daily and exercise 2-3 times/week.

My BMI is 28, which is in the overweight category, but I carry a fair amount of muscle along with my flab.

My diet is the hardest part to control. I live alone and spend a lot of time at the office, so I often eat takeout Chinese and other convenience food.

My point is that a lot of us HN-y folks probably lead comparable lifestyles. The kind that we may think aren't too unhealthy, but for at least some of us, that assumption is wrong. Please keep an eye on your blood pressure and your waistline. I wish I had started paying attention to this much sooner. Now I'm not sure whether I can still reverse the outcome.


but I carry a fair amount of muscle along with my flab

Is this honest truth? Ever step on one of those body composition scales? I used to tell myself when I was super skinny that, hey, at least what I did have was muscle and I wasn't weak. But it was not true, there was very little muscle, and I was weak as hell. I was like 18% BF at a BMI of 17. It's one of those pernicious lies we tell ourselves that we want to believe because they make us feel better about ourselves.


I have been diagnosed with borderline high bp (around 140/90, sometimes a bit lower, sometimes higher) 5 years ago and tried everything to reverse it, as the Doctor did not want to put me on meds so early. Lost 10kg (BMI 23.5), 60km of cycling a week, 2x exercise a week, reasonably good diet, no smoking, little alcohol.

From all those measures my BP did not improve a lot, the systolic is nowadays mostly okay, but i seem to have a problem with the diastolic bp which is often in the 90-95 range. Right now i am undergoing more checks again and will probably resort to meds now, which i wanted to avoid (which otherwise healthy, fit 35 year old wants to start taking bp meds) but it seems like i can't and i don't want to damage myself more than i already have.

Until now, no real cause has been found, it could even be some nervous disorder because of high stress times i had in the past, but nobody knows. I also have no family history of high bp, so it still puzzles me and freaks me out to the point i got an underlying anxiety.

If losing weight etc. does not help much, also get your kidneys and thyroid checked. I have some kidney checks coming up and it freaks me out...

The good thing is that it made me a lot more conscious of what i eat, drink and do, i just wish i would have monitored it earlier because i don't even know when it started.


Something consider: elevated diastolic blood pressure with a systololic blood pressure of <140 is apparently not correlated to more negative outcomes. Apparently home blood pressure monitors are prone to overreport the diastolic reading by about 7mm in those instances. Source: recently read a paper about this, which looked at multiple large scale studies. Don't have the link on mobile, sorry.

Bottom line: well done on the lifestyle changes, and don't worry if only the bottom number is high.


Interesting, I have read quite conflicting information on that though, link would be appreciated. The problem is not just with home monitors though and I read while it’s more disregarded in older people it could point to underlying issues in younger people which is what freaks me out since nobody found anything yet.


In the same boat as you but don’t exercise as much and drink more, similar age and BMI. I would go vegetarian and train for a marathon. :). If that doesn’t help, then only drugs will in my non medical opinion.


Could be the Chinese food? Most takeout or food that you don't cook yourself is high in sodium, which raises your blood pressure. If you cook for yourself with non-processed ingredients and without over-seasoning - and stay well-hydrated - then maybe you'd be fine. As someone that moved to the USA and started eating out a lot, I quickly realised my sodium intake shot up drastically and that I should cook for myself more to be healthy


White coat syndrome cannot be ignored too. This is where your BP can increase by a lot just by being in a doctor's exam room.

I went in for a checkup a few years ago and they took my BP and it was like 140/93 with an 87 heartbeat (I was 32 and in decent shape), so my doctor was like, hey I don't want to put you on any medication but your BP looks a little high, let's chart your BP at home for the next 2 months and see how it goes.

So I grabbed a BP machine and about 3 times a week I took my BP, alternating arms and doing it at various times in the day. I could see that my BP was a little high for weeks, but by the end of the 2 months I had a 2 week stretch where it was about 120/80 steady.

I took the same BP machine I bought and took it to the follow up exam and it was 138/87. That's a pretty big spike.

Now I take it myself twice a month or so (just for good measure) and it's usually 120/80ish with a resting heart beat of 58-62. My dentist likes to take your BP before doing any type of work and it was 135/88 before a cleaning too.

I don't know about you, but I generally don't like getting my BP taken. It causes some anxiety.

I wouldn't immediately discount high BP to white coat syndrome, but you should ask your doctor if you can track your BP at home if you're on the cusp of high BP.


I've read a couple of studies [1] [2] [3], relating specifically to home BP monitoring for kidney patients. The studies seemed to indicate that home BP monitoring ("ambulatory BP monitoring", ABPM) is more accurate than office, or dialysis unit, monitoring.

I think one part of this may be because ABMP allows for more frequent measurements to be taken throughout the day and under similar circumstances each time.

There may also be a factor of allowing yourself to relax a bit before taking your BP. Guidelines for BP measurement instruct you to sit still for a few minutes, before taking your BP, which is something that is often not convenient to do in a doctor's office (for instance, if your BP is taken the moment you walk in etc).

___________

[1] Ambulatory blood pressure in chronic kidney disease; https://www.ncbi.nlm.nih.gov/pubmed/23595357

  "ABPM has been shown to be a better tool for predicting CV risk, CKD progression, 
  end stage renal disease (ESRD) or death than office-based pressures."
[2] Home blood pressure monitoring in CKD; https://www.ncbi.nlm.nih.gov/pubmed/24529535

  "Home BP monitoring provides more data than conventional clinic or dialysis-unit BP 
  measurements and is relatively easy to accomplish, is cost-effective, and has been 
  shown to have an increasing role in the management of BP in the CKD population."
[3] "The complex relationship between CKD and ambulatory blood pressure patterns."; https://www.ncbi.nlm.nih.gov/pubmed/25704346

  "ABPM has been shown to be superior to clinical BP measurement for correlating with 
  end-organ damage and prognosis in CKD."


Can you recommend a particular BP machine? I have $100 in an FSA I need to spend in the next 16 hours and I've had a similar experience to you with white coat syndrome.


My doctor recommended this one https://www.amazon.com/gp/product/B000NY6JXA (it's $42).

Keep in mind, that I'm not a doctor and I don't know if this one will work for you. I would definitely ask your doctor. Maybe run this one by him/her for a confirmation.


I've had high blood pressure since 24. I've had every possible diagnostic test, tried medication (no avail). I'm not overweight and do walk about 50 minutes a day, eat as healthy as can be expected. And still it averages around 170/90. I gave up on it. If global disaster doesn't kill me first, it'll probably be a heart attack around 50. There are worse ways to go. Seriously, even lifestyle changes for the relatively healthy only seem to make a 10 mmHg difference, so eh. Whatever.


High blood pressure is a largely diet-related western only disease. It's not normal that it rises with age either, just something we got used to it.

If you want to cure your blood pressure, watch this video till the end - https://nutritionfacts.org/video/how-not-to-die-from-high-bl...

Then if you want the details, have a look at this playlist - https://www.youtube.com/playlist?list=PL5TLzNi5fYd8jLx2M6exR...


What does the data say about the risks to someone like you (i.e., otherwise healthy, healthy lifestyle, etc.)? Certainly if you didn't take care of yourself the risk would increase. But, perhaps, high BP isn't as risky if it's the only risk you have.


Try intermittent fasting and/or keto diet.

My pressure changed from 140/90 to 120/70 only with the diet. Needless to say that literally all aspects of my life improved with this change. Come to the Church of Intermittent Fasting®.


Have you ruled out sleep apnea?



I think it's fair and necessary to ask: Are the (negative) effects of high blood pressure the same for all genders across all gene pools?

Also, what is the breakdown of high blood pressure being a disease? Vs being a symptom (of another disease)?

We need deeper data.


Age factor must be also relevant:

A friend of my father has the same lifestyle and food habits today at 60's as during his 40's and 50's. He always had normal blood pressure until recently.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: