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  2. Denialist comments---a brief analysis

Denialist comments---a brief analysis

By sb admin on April 9, 2008.

My recent post on a local "holistic" doctor brought a number of considered and interesting comments (all of whom are quite polite and patient, even when I disagree with them).

Some of the issues deserve fleshing out.

Heart disease is a major killer. Hypertension is one of the strongest risk factors for heart disease. In some people, salt contributes to hypertension, and reduction of salt intake reduces bad outcomes. In people with congestive heart failure, salt-restriction is crucial.

The statement of this idea led to some interesting objections, with a good helping of goalpost-shifting.

The objections raise some important points, but also engage in some typical denialist tactics.

I've just been looking for basic information, and coming up empty-handed, so I hope you can understand my frustration. I'm not one to hold on to bad ideas in the face of evidence, but I'd like to see a prima facie case made first.

and

I've also seen a study in the news in the last few months that was reported to show a significant increase in mortality among high-risk patients over a 10-year period for those who maintained a high salt intake. That raises questions that weren't answered in the news article, such as: How did the diets compare otherwise? It's reasonable to assume that someone who reduces their salt intake because of blood pressure is going to make other dietary changes as well, and vice versa. If other variables were controlled, then by what mechanism does salt increase mortality? What do those results mean for individuals with normal blood pressure?

and

The correlation between sodium intake and heart disease doesn't prove anything. This is a classic example of correlation not equalling (sic) causation. Processed and fast food, the biggest sodium offenders, also tend to be loaded with saturated fat and cholesterol. Could these not also be the cause of the artery disease, and the salt just be a relatively innocent bystander?
I am not saying that there is no place for a low-sodium diet, I'm just saying that I've yet to see any evidence for one in general. (emphasis mine --PalMD)

This is simply an argumentum ad ignorantiam. The fact that the commenter doesn't know the answers does not affect the validity of the conclusions stated. Does he think that researchers have never asked these questions?

How about a plausible method by which salt causes ateriosclerosis?

and

We have no convincing evidence that blood pressure increases resulting from salt intake contribute substantially to heart disease or stroke. You, and the medical profession in general, are taking a giant illogical leap.

Actually, I gave references. If he can't be bothered to check them, it's hardly my fault, or the fault of the medical profession.

High salt intake may raise blood pressure in some groups, but it does not necessarily lead to chronic or dangerous hypertension. And chronic hypertension might be an effect, rather than cause, in many cases. We don't really know.

I already said that there is great variability to patients' susceptibility to salt, so objection noted. Actually, we do know that hypertension is a cause rather than an effect of heart disease.

We do know that the major causes of artery disease leading to heart attacks and strokes are cigarette smoking and type 2 diabetes. So we do not have any clear connection between a high salt diet and artery disease. And you have admitted that.

In addition to cigs and diabetes is hypertension. As cited, in many patients, high salt intake leads to hypertension. Hypertension leads to heart disease. To require the most proximate cause is an absurd argument. Medical science looks for correlations, and tries to explain them. Much of the time we understand the specific mechanisms involved. To ask for more and more detailed explanations is simply moving the goalposts---if you don't like the answer, just ask more detailed questions until everyone is tired of answering you.

Unfortunately, I am not a member of the AMA, so I don't have access to that article. I did want to read it given the alarmist wording of the headline, but it wasn't $15 of want, especially since I'd need to pay for the references, ad infinitum....

If the commenter is unwilling to accept my expert status, that is quite reasonable. But then to be unwilling to dig up the data himself, well, that's just silly. To gain information, you can either listen to an expert or try to interpret the data yourself. To be unwilling to do either is simply intentional ignorance. To then expect others to buy that as a legitimate argument is not just unfair, it's asinine.

The point here is not about individual commenters---it's about strategy and errors in thinking. For complex information, we trust in experts---we have no choice. If we are curious about going deeper, we look up the primary sources.

Salt may or may not be an important cause of heart disease, although evidence favors the connection; there are certainly more important causes. But in some people, salt very directly causes increased blood pressure, and high blood pressure most certainly does lead to heart disease. That fact does not negate other causative factors (which is another non sequitur brought up in some comments).

Denialism involves, well, denial. If you don't like a fact, then just keep looking for ways around the truth. Or plug your ears and go, "la la la la la." Either has the same effect.

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I know this is beside the point, but I must say that it is refreshing to hear someone call a person with an opposing viewpoint "quite polite and patient, even when I disagree with them". If only I would hear more civility and respect in society today, especially in religious debates.

You make some good points. Unfortunately for myself, my sloppy writing makes me look worse than my actual thinking does.

I don't really think that I shifted the goalposts on this issue. I do know, and stated, that certain individuals do benefit from a low-sodium diet, and I understand the basics of why, even if I don't know all the nitty gritty details. I wasn't questioning that issue.

From what I wrote, making assertions rather than asking questions, I definitely was arguing from ignorance. I am ashamed. However, you'd think that somewhere, sometime, one of those alarmist articles, especially from someone like the CSPI, would have some real information in it. I was more expressing my disgust for journalism than trying to argue from ignorance, though I did manage to do the latter....

I do think that the inclusion of my request for "a plausible [mechanism] by which salt causes arteriosclerosis" was disingenuous. That was after you rightfully decided that you couldn't ethically provide me with a copy of the JAMA article, and I was asking for something that I *could* research on the Internet at 11 pm or so. If I asked you for the same about how type 1 diabetes can kill you, it's simple enough to say, "ketoacidosis." I fail to see the problem with my request.

I also don't think that my mention of other causative factors was a non sequitur. If A and B both correlate with C, and A is shown to cause C, it doesn't mean that B causes C. I've sat here for a few minutes trying to determine how the fact that A and B are not independent variables affects this, or whether it affects it at all. I'll have to think about that one. It's been too long since I took stats....

I don't think that my questions are original. I'm not that knowledgeable or imaginative. If scientists haven't asked the questions I've asked, then they probably should just give up on the whole science career and start writing for the Answers Journal. However, if they have answered them, then they, or the people who interpret their work, have done a piss-fucking-poor job of communicating those answers to the public.

We are looking for evidence that chronic hypertension is an important causal factor in heart disease and stroke.

"high blood pressure most certainly does lead to heart disease"

What does that mean? A person with chronic hypertension is more likely to have a heart attack than someone with normal blood pressure? We know that, but we don't know if the relationship is causal -- or the direction of causality, if it is causal.

"Medical science looks for correlations, and tries to explain them. Much of the time we understand the specific mechanisms involved."

And just as often, you don't.

I think we all agree that the importance of dietary salt in preventing heart disease has been greatly exaggerated. It's more of a myth, or medical tradition, than a scientifically demonstrated fact.

If a patient has artery disease, and they also have high blood pressure, we can imagine that a heart attack could be more likely than if they had normal blood pressure. We don't necessarily know if the high bp caused the heart disease or vice versa. But we can acknowledge that high bp might cause more damage to diseased blood vessels.

We may not have any reason to suspect, however, that blood pressure levels make any difference for people who do not already have artery disease.

We also might not have any good reason to assume that lowering dietary salt will decrease the risk of high bp, to any meaningful extent.

Since cigarette-smoking, type 2 diabetes, genetics, physical inactivity, stress, inadequate sleep, and junk food are known to be major causes, we can account for most cases of heart disease and stroke without even considering salt intake levels.

So we have weak evidence, if any, for the salt - artery disease connection. Yet salt restriction is promoted as essential for preventing artery disease. I think it's merely a medical tradition.

Has anyone done a controlled experiment that created artery disease in animals, where both groups started out healthy, and the only treatment difference was level of dietary salt?

Egeaus, thank you for your thoughtful response.

pec, you're still an idiot.

I can always tell when you can't think of any logical response, PalMD.

If your claim that chronic hypertension leads to -- causes -- heart disease and stroke were true, there should be controlled experimental research that supports it, using animal subjects.

And if dietary salt is an important contributor to artery disease, via chronic hypertension, it should be demonstrated by more than associations.

I realize you are probably not a researcher since you have such a terrible time understanding all of this.

I think that's the first time that the phrase "piss-fucking-poor" has been described as thoughtful. :)

On the hypertension causes heart disease issue, I know that at least one consequence of significantly elevated blood pressure is (let's see if I can get this right without Google) left ventricular hypertrophia (so close...it's hypertrophy, like atrophy, duh). I fale at suffixes. Hypertension -> heart disease.

And while I'm not sure that salt causes the fundamental problem there, that's one instance where reducing it can help with the symptoms by lowering blood pressure, and decreasing the strain on the heart.

Pec wrote: "We are looking for evidence that chronic hypertension is an important causal factor in heart disease and stroke... What does that mean? A person with chronic hypertension is more likely to have a heart attack than someone with normal blood pressure? We know that, but we don't know if the relationship is causal -- or the direction of causality, if it is causal."

Yes. Yes we do know VERY well that the relationship is causal Uncontrolled hypertension absolutely increases the risk of heart attack. How do we know (you ask incredulously)? Through multiple very-well-designed, long-term prospective trials. And yes, these studies controlled for cofounding variables (ie obesity, diabetes, smoking, sex, age, etc. etc. etc.) And they showed quite clearly that uncontrolled hypertension is an independent risk factor for subsequent heart attack. It's something they teach in first-year medical school (or in my case, first year PA school).

Pec wrote: "We may not have any reason to suspect, however, that blood pressure levels make any difference for people who do not already have artery disease."

Again, see above. Yes. This has been well-studied, and we know with absolute certainty that, if left untreated, chronically elevated blood pressure will cause disease in previously normal arteries (even when controlling for possible confounding variables) in the vast majority of individuals.

The more times you post here, the more I have to agree with PalMD. Your firm disbelief in well-proven concepts displays your ignorance; your insistence in your correctness in the face of widely-available evidence to the contrary is, well... There is a term for people with fixed false-beliefs. It's in the DSM.

Pec wrote: "If your claim that chronic hypertension leads to -- causes -- heart disease and stroke were true, there should be controlled experimental research that supports it, using animal subjects."

If by "animal subjects" you mean "human subjects", then yes, this research has been done. YEARS ago. Or do you require that this be studied in pigs, cats, monkeys, or mice instead of humans?

There is a term for people with fixed false-beliefs. It's in the DSM.

Are you saying that religion is a disorder now? Can it be treated? Cured?

From my persepctive, the first link is most interesting, both in the fact that it was all available, and its conclusions. My only issue with it is that the high-sodium diet given to the rats was still very high (though not unknown, I'm sure) by human standards, while the "low-sodium" diet is roughly equivalent to the average sodium consumption according to the CSPI (http://www.cspinet.org/salt/AverageSodiumConsumption.pdf). NaCl weighs ~58.5 g/mol. You can do the math if I can.

I don't know much about the extrapolation of rat data to humans, but if it's straightforward, then it suggests that the average american isn't consuming too much salt, and it takes an extremely high intake of salt to cause damage.

The second link said, "Dietary sodium intake was not significantly associated with cardiovascular disease risk in nonoverweight persons." Not really helpful for my question.

The third was similar to the first, except for even higher sodium intake.

Pec said, "If your claim that chronic hypertension leads to -- causes -- heart disease and stroke were true, there should be controlled experimental research that supports it, using animal subjects.

And if dietary salt is an important contributor to artery disease, via chronic hypertension, it should be demonstrated by more than associations."

I don't know jack shit about salt and hypertension. I just did a simple google search and found those in about 3 monutes. They appear to be "controlled experimental research using animal subjects."

I feel confident that I could find more if I were actually interested in the subject.

Just a wild idea for the guy worried about accruing costs of tracking references.... most public universities, even those without medical schools, subscribe to JAMA, the New England Journal of Medicine, etc. One can find a cheap nearby lot, walk in, and even request assistance from a librarian. A day of reading in a dusty library might be less sexy than an instant .pdf, but it works!

By Dr. Matthew (not verified) on 09 Apr 2008 #permalink

One can find a**lot more* if you use PubMed and type in the keywords salt and hypertension. 1584 review articles and 9206 research articles about the subject. Most of them will not be the exact thing that you might want since most of the research articles will be using different measurements, methods, subjects, etc., but it certainly shows that there has been a lot of research in the area. You will usually find only abstracts in the links provided [the little page icon], but get cracking anyway, pec.

By natural cynic (not verified) on 09 Apr 2008 #permalink

It has not been shown that salt is an important factor in causing heart disease. Yes there has been lots of research showing chronic hypertension preceding heart disease. Did they ever do an experiment giving blood pressure lowering drugs to one group and nothing to another? No, because it is considered unethical. The causal connection has not been demonstrated, and the research is confusing and inconclusive.

Just one example. If you think this question has been resolved you are what PalMD called me.

"Whether dietary sodium reduction should be recommended for the general population remains questionable because of marginal benefit and the suggestion of possible deleterious effects on cardiovascular outcomes independent of blood pressure. "

http://www.ncbi.nlm.nih.gov/pubmed/10505491?ordinalpos=1&itool=EntrezSy…

By Anonymous (not verified) on 10 Apr 2008 #permalink

Re: JLT

You'd be surprised what denialists can ignore. They remind me of the Sesame Street sketch of the guy with bananas in his ears.

"You've got bananas in your ears."
"What?"
"You've got bananas in your ears!"
"I can't hear you. I've got bananas in my ears."

"...recommended for the general population..." Of course, if you have any of the *other* risk factors for heart disease, you're not really part of the "general population" they are discussing.

"The evidence doesn't say to much about salt in healthy people."

That is a quote from PalMD in the comments section of the salt post.

"we know with absolute certainty that, if left untreated, chronically elevated blood pressure will cause disease in previously normal arteries (even when controlling for possible confounding variables) in the vast majority of individuals."

We do not know that chronic high bp is the initial causal factor in artery disease. Another variable may cause both, and artery disease may cause high bp.

And, of course, we don't know that dietary salt generally causes chronic high bp.

Where is experimental evidence that bp over a certain level will eventually cause artery disease, unless it is lowered by drugs? The research would require two groups of healthy individuals, with no signs of artery disease, both with elevated bp. And you would give one group bp-lowering drugs and wait for years to see which group developed more artery disease.

That experiment could not ethically be done with humans because of assumed possible risk to the untreated group.

I have already said that high bp would probably make artery disease worse in patients who already have it. The question is whether high bp alone can cause artery disease, and whether dietary salt can cause high bp in healthy individuals.

Where is research showing all of that? And yet hardly anyone questions the high dietary salt > chronic hypertension > heart disease and stroke story. Is it backed by scientific evidence, or is it just one of our medical myths?

Ooh! A deliberate misunderstanding AND an obtuse misquote! Classic!

Does he think that researchers have never asked these questions?

The answer to this is "yes". It's something I've seen over and over in dealings with anyone advocating any sort of fringe or pseudoscience; they simply have no idea of what scientists do or what has been done in the field they're supposedly interested in. It's an offshoot of the logical fallacy argument from ignorance.

Humans are very intelligent animals, and when they recognize patterns (i.e. make a discovery) they get very giddy. Sometimes, they think they are the first one to have ever thought of something.

Given the 6 billion or so of us, and the hundreds of thousands actively thinking about science, a unique understanding of medicine is a fairly rare occurrence. I doesn't seem likely that me or one of my commenters will happen to discover that medical science is incorrect about the fundamentals.

It has been very reliably shown that high blood pressure all by itself can cause heart failure. Two major mechanisms for inducing heart failure in experimental animals do exactly that. There is the method of constricting the artery that leaves the heart so the heart has to exert a higher pressure to get enough flow. There is also the method of pacing failure where the heart is caused to beat more rapidly through external electronic pacing.

Both of these methods produce characteristic heat failure in a couple of weeks virtually 100% of the time (if it is done correctly) on just about every animal. Structural abnormalities in humans do the same thing.

The heart failure is induced with no drugs, no dietary changes, no changes other than in the hemodynamics of the heart.

It is thought that the mechanism relates to regulation of energy production in the heart. High blood pressure requires the heart to produce more ATP, and the characteristics of heart failure (dilative cardiomyopathy) reflect the adaption of the heart to this.

Did you notice that we were talking about artery disease, not heart failure? Your comment is entirely irrelevant.

Artery disease, leading to heart attacks and strokes, is currently a major widespread problem. That is what we are talking about.

Lots of people are questioning the salt - artery disease link. Maybe you accepted it without question, if you are the type to believe what you're told without evidence. Within a given profession there is usually a standard mythology that no one in that profession doubts. Recommending a low-salt diet to everyone results from one of the current myths.

I have not seen anyone here provide a good reason to accept it. Even PalMD said there isn't much evidence regarding salt. So why tell patients to avoid it?

The chronic hypertension - artery disease link is more complicated, since we can imagine elevated bp could be hard on already damaged blood vessels. But we don't know if bp over a certain level creates a risk for people with no artery disease. Especially if the elevation is only slight.

Yet I have a suspicion that MDs will sometimes recommend bp-lowering drugs for healthy patients with slightly high bp.

If your middle-aged patients with high bp stop smoking, start exercising (a lot, not one hour per week), and avoid processed high-carbohydrate junk food, they will have no need for bp-lowering drugs.

And then the fairies will come and make them all healthy and happy and wise, and they will live together in peace forever!

...Meanwhile, back in the real world...

Middle aged patients are notoriously hard to convince to change their lifestyle. Every doctor will tell them to stop smoking, start exercising, and avoid junk food... and prescribe blood pressure medication anyway, because those things are not certain to happen, and the high blood pressure is a problem now.

After a few months of surveillance, the doctor may reduce or eliminate the medication if the patient has modified his lifestyle.

That's how doctors tailor treatment to fit the patient.

Even PalMD said there isn't much evidence regarding salt.

Try not to quote-mine me.

There isn't a helluva lot of data (of which I'm aware) about salt intake in normals.

Low salt diets are terribly hard to adhere to, but some folks do it quite well.

Ultimately, most hypertensives will be on 2-3 medications---to lower their bp, yes, but also, pec, to improve survival and reduce heart attacks, strokes, kidney failure, and premature death.

"most hypertensives will be on 2-3 medications---to lower their bp, yes, but also, pec, to improve survival and reduce heart attacks, strokes, kidney failure, and premature death."

So where is your evidence that the bp-lowering drugs will "improve survival and reduce heart attacks, strokes, kidney failure, and premature death."?

You keep making statements without evidence. Would you prescribe bp-lowering drugs to a healthy patient with bp somewhat above the level considered normal? The drugs can have adverse effects, so they should not be used just in case they might help a little in some way.

Hey Pec,

Why is it unethical (as you claim) to give withhold antihypertensives from one arm of a study on the efficacy of lowering blood pressure in the prevention of heart disease?

"Why is it unethical (as you claim) to give withhold antihypertensives from one arm of a study on the efficacy of lowering blood pressure in the prevention of heart disease?"

This is a general problem with drug research -- if there is any suspicion at all that a drug is effective it is considered unethical to deprive patients of the drug. Even if the safety and effectiveness of the drug have not been well documented, it's considered risky to not prescribe it.

pec, unsurprisingly you appear to have no knowledge of study design. Read some of the studies before you reveal your next level of ignorance.

Pec, I was just finished reading this.

Treatment of High Blood Pressure Appears Worthwhile in Very Elderly Patients: Presented at ACC

"Researchers randomised 1,912 patients to placebo and 1,933 patients to active treatment with indapamide sustained release 1.5 mg with the addition of oral perindopril 2 to 4 mg once daily as needed to reach a target blood pressure of 150/80 mm Hg. Mean age of the entire cohort was 84 years, and systolic blood pressure was 160 to 199 mm Hg."

This study does exactly what you say isn't done.

By the way, this was a study regarding the benefit of reducing BP in the elderly.

"After 4 years of follow-up, all-cause mortality was 23% in patients taking placebo and 18% in the active treatment group, Dr. Beckett said. That represents a 21% relative risk reduction, which achieved statistical significance at the P = .019 level.

Stroke mortality was reduced by 39% in the active-treatment patients (P = .046). All strokes were reduced by 30% in the active-treatment group (P = .06). Fatal and nonfatal heart failure was reduced by 64% in the active-treatment group (P < .001). There was a 34% reduction in cardiovascular events (P < .001)."

I can see that reducing bp in patients who already have damaged arteries could prevent heart attacks or strokes. My question is, and I have asked several times, if there is evidence that high bp (above 120/80, or whatever they now consider high) is an important causal factor in artery disease.

This question matters, because if high bp is a major cause, then of course they will try to get people with high bp to take bp-lowering drugs (after lifestyle changes have, of course, failed). If high bp is just another effect of the lousy American lifestyle, correlating with other effects that actually do cause artery disease (diabetes, smoking, junk food, never moving, etc.), then lowering bp with drugs would not make a lot of sense.

This is similar to the situation with cholesterol-lowering drugs. They have been prescribed to millions, but it now turns out that high cholesterol might not be a causal factor (statins reduce inflammation, not just cholesterol, and inflammation is considered more significant as a cause of artery disease).

I am very suspicious of the drive to get everyone over 50 on bp-lowering and cholesterol-lowering drugs. For the reasons I have explained several times.

That's the good thing about written communication. You can't go back and deny what you posted.

Pec said, "So where is your evidence that the bp-lowering drugs will "improve survival and reduce heart attacks, strokes, kidney failure, and premature death."?

The study that I referenced addressed improved survival, reduced heart attacks, reduced strokes in a specific age group. I'm not sure how to address premature death, because I am not sure how to define it.

I wrote a lot of comments you did not read. I said I wanted to know if bp level matters in healthy individuals, with no artery disease. Because it is very possible that chronic hypertension is more of a result than cause of artery disease.

Pec: In response to my question about the ethics of withholding treatment in one arm of a study you wrote:

"This is a general problem with drug research -- if there is any suspicion at all that a drug is effective it is considered unethical to deprive patients of the drug. Even if the safety and effectiveness of the drug have not been well documented, it's considered risky to not prescribe it."

No. No. NoNoNoNoNoNoNoNo. Once again your ignorance of science, scientific research, and (in this case) study design and ethics is astounding for someone with such strident, firmly-held views. The ethics of this have nothing to do with the particular drugs involved; we could do this study with any number of old, cheap antihypertensives with well-known safety/risk profiles. The ethics of withholding treatment in a study have to do with outcomes. Studies are done to answer the very question "what would the outcome of intervention X be?" If the pre-supposition is that there is no difference (in this case, your claim that treating high blood pressure does not reduce cardiovascular disease,) then it would be ethical to study the question. An argument that it is unethical to study the question presumes that participants in one arm of the study would be harmed relative to the other participants by the intervention (or withholding of intervention) being studied. For example, it would now be unethical to conduct a study to see whether it is beneficial to give aspirin to a patient suffering an acute myocardial infarction, because we have strong evidence that those patients randomized to receive placebo would be harmed by the withholding of aspirin. (Incidentally, the reason studies are sometimes halted before enrolling a full panel of participants is that it becomes apparent that one arm is being harmed, making it unethical to continue the study.) As such, your argument that it is unethical to study the effect of treating hypertension to reduce the risk of cardiovascular disease inherently presumes that the study would harm one group. So... Is it the cohort having their blood pressure treated that is being harmed, or is it the cohort not being treated who is being harmed?

"your argument that it is unethical to study the effect of treating hypertension to reduce the risk of cardiovascular disease inherently presumes that the study would harm one group. So... Is it the cohort having their blood pressure treated that is being harmed, or is it the cohort not being treated who is being harmed? "

No -- I did NOT say it would be unethical. I said it would be considered unethical by the researchers. I was trying to explain why we do not have clear research outcomes to answer the question of whether high bp causes, or is caused by, artery disease.

I have a very visceral response to this, which is based on seeing my experimental subjects fall over dead because of excess dietary salt. Yes, they were rats, but the ill effects of dietary salt were illustrated very graphically for me. These were obese rats with high blood pressure, so they were at high risk. But plenty of people are obese and have high blood pressure too. And they may be at risk for kidney failure and stroke from too much salt in the diet, just as my rats were. I'm sure most people think animal researchers are cruel and heartless, but believe me it is upsetting to lose creatures you work with and care for on a daily basis. I fed them 4% salt --not a huge increase from the normal level of 0.8% in regular rat chow pellets. Japanese people actually eat more than that --and guess what, Japan has some of the world's highest rates of stroke (despite low rates of heart attack).

By metabopharm (not verified) on 11 Apr 2008 #permalink

Well, Pec, I stand corrected. I guess you CAN go back and deny what was said, even though it is there in black and white.

I never said I was responding to every question you had asked.

I hate to say "I told you so," but...

Yea, verily did I try to warn thee of the deniers with the fingers in the ears...

Okay. I'll stop now.

Pec wrote: "No -- I did NOT say it would be unethical. I said it would be considered unethical by the researchers. I was trying to explain why we do not have clear research outcomes to answer the question of whether high bp causes, or is caused by, artery disease."

And yet earlier Pec wrote: "Where is experimental evidence that bp over a certain level will eventually cause artery disease, unless it is lowered by drugs? The research would require two groups of healthy individuals, with no signs of artery disease, both with elevated bp. And you would give one group bp-lowering drugs and wait for years to see which group developed more artery disease. That experiment could not ethically be done with humans because of assumed possible risk to the untreated group."

So, I guess you DID say that it would be unethical. You didn't say "others have felt it would be unethical, although I disagree." You made an editorial assertion. So let's not shift goalposts and try to weasel out of your prior assertion. Either defend your statement or retract it.

"That experiment could not ethically be done with humans because of assumed possible risk to the untreated group"

It was carefully worded so that no one would think I believe everyone with high bp should have it lowered with drugs. I said it "could not ethically be done," rather than "it would be unethical." I said "assumed possible risk," meaning that the researchers have that assumption, NOT that I necessarily believe it.

I am skeptical about bp-lowering drugs, especially for people who are generally healthy. We do not seem to have clear experimental evidence that high bp is a causal factor, rather than an effect or association, of artery disease.

We know that artery disease can raise bp. We know that metabolic syndrome and type 2 diabetes can cause both high bp and artery disease.

No one here has cited research showing a clear causal link from high bp to artery disease, in healthy individuals. Or from high salt intake to chronic hypertension.

Why not try an experiment with rats? Restrict salt for one group and let the other have as much salt as they want. Make sure the rats get enough exercise and food that is healthy for rats. Do not use obese or sick rats.

There may be some weak causal connections. But I suspect the important causes of both chronic hypertension and artery disease, for the majority of Americans with these problems, is the American lifestyle.

How much is seen in traditional non-western cultures?

Pec, your words ("That experiment could not ethically be done with humans") speak for themselves. We'll have to let readers decide what it was you actually wrote and what those words mean. I'm done here.

because of ASSUMED possible risk.

When there is a suspicion that a drug works, nowdays, thanks to the power of the big drug companies, it is CONSIDERED unethical to deprive human subjects of that drug.

Although actually I am glad to see that what I said was an over-statement. This study suggests high bp can result from vertebral misalignment:

http://www.ncbi.nlm.nih.gov/pubmed/17252032?dopt=AbstractPlus

That study suggests very little. I've gone over it many times, and written about it, because it is so often misinterpreted.

http://whitecoatunderground.com/2008/03/17/chiropractic-and-hypertensio…

"A pilot study is not powerful enough to show causation"

No, you don't understand what "power" means, in this context. If the effect is significant in a small study, the effect is MORE likely to be significant in a larger study. Borderline effects in a small study may be worth pursuing with a larger N, and that's the reason for pilot studies. If pilot studies often showed results to be significant when they were really due to chance, there would be absolutely no reason for anyone to do them.

So you got it backwards.

"there is no plausible explanation for why adjusting the spine should have any effect on arterial hypertension"

That is NOT a reason to discount the research. YOU may have no plausible explanation, but anyone who believes in chiropractic, or yoga, etc., does.

"PubMed and OVID MedLine both give under 30 hits for chiropractic AND hypertension"

Maybe it's a relatively new research area. That is not a reason to ignore it.

A problem that I have with the Bakris study is the claim that there was a mis-aligned vertebra that was re-aligned by a chiro. First off, a Yale anatomist has determined that chiropractors cannot change the relationship among vertebrae: http://www.chirobase.org/02Research/crelin.html

I wonder who was reading the x-rays, a chiro? Chiros used to "see" subluxations on them, till blinded readings proved they could not (although, some may still do so). They still monkey-around with x-rays, in this report a chiro showed a customer someone else's film to demonstrate a serious problem http://www.sciencebasedmedicine.org/?p=91

In one case I found (sorry, no longer On-Line) the chiro filmed a kid "before" with his head slightly tilted to one side and claimed his skull was not aligned with his spine. Then he filmed the kid (sitting ramrod straight) for the "after" picture. Maybe the kid figured out that good posture would prevent the fool from yanking his head any longer

According to Bakris "Lateral displacement of Atlas vertebra (1.0, baseline versus 0.04 degrees week 8, NUCCA versus 0.6, baseline versus 0.5 degrees , placebo; P=0.002)." I find it difficult to imagine that one can read such small angles, reliably, on an x-ray. And why give "lateral" displacement in degrees instead of distance? This gives me more reason to suspect that the "mis-alignments" are imaginary.

If the authors thought this was good work, wouldn't they have submitted it to a better journal. The fact that it came up on the Nature journal club suggests a lot of interest in it.

Pec, getting the last word doesn't mean that you are right, it just means that everyone else is tired of playing.

Mis-alignments are not imaginary. Anyone who cares to can perceive and correct their own mis-alignments with yoga, or something similar. Once you experience the differences for yourself, you will not doubt it.

"getting the last word doesn't mean that you are right"

Well PalMD doesn't seem to have any reasonable arguments against this study. Of course it should be followed up by more research. But if it turns out that chiropractors are definitely right one thing, it will be a sad day for all you chiro-deniers. What else might they know that you don't?

I read that and answered it previously, PalMD:

A pilot study is not powerful enough to show causation"

No, you don't understand what "power" means, in this context. If the effect is significant in a small study, the effect is MORE likely to be significant in a larger study. Borderline effects in a small study may be worth pursuing with a larger N, and that's the reason for pilot studies. If pilot studies often showed results to be significant when they were really due to chance, there would be absolutely no reason for anyone to do them.

So you got it backwards.

"there is no plausible explanation for why adjusting the spine should have any effect on arterial hypertension"

That is NOT a reason to discount the research. YOU may have no plausible explanation, but anyone who believes in chiropractic, or yoga, etc., does.

"PubMed and OVID MedLine both give under 30 hits for chiropractic AND hypertension"

Maybe it's a relatively new research area. That is not a reason to ignore it.

BZZZT! Wrong again, pec! How many ways can one person be wrong? Join us as we explore the depths of pec's ignorance! All next... um... MONTH!

Yes, PubMed and MedLine have hits for chiropractic and hypertension. How many of those are negative? I would wager that they all are. Chiro-woo is notorious for fantastic claims that don't stand up under actual examination. It is impossible for a spinal mis-alignment too small for measurement to affect arterial blood pressure. There is no mechanism by which it would happen. It has never been seen in the lab. It has only been seen in chiro-woo offices.

And why am I not surprised that pec is a chiro-woo?

The depths of his ignorance, all next month on the Woo channel!

Notice that PalMD had no answers to my comments on his criticism of the hypertension-chiropractic study. I thought he would at least sputter vulgar insults. I think even he has to admit chiropractic threatens to become mainstream and evidence-based.

Nope. It just has gotten to the point where you are SO wrong, and refusing to listen to the corrections, that we have better things to do than play with you.

Have fun playing with yourself.

Goodbye.

He had no valid corrections or explanations for the hypertension-chiropractic study. He said it was a low-power pilot study and therefore can't tell us anything about causality. So PalMD is -- as he would phrase it -- an ignorant f*cktard when it comes to research methodology.

Pec, if you had read the references, especially to sciencebasedmedicine.org, you would know that scientifically implausible results are easily magnified in these types of studies. That is why it must be replicated to have any real meaning.

Please...step away from the goalposts.

OK, now I've managed to get a copy of the full text of the paper. It is entirely based on a false premise, that of the NUCCA. I know the hypertension researchers to be quite reputable, but this study is complete and utter crap. It is based on an unproved practice, and should make the authors and editors blush.

Anyone care to make a bet whether pec can admit the flaws in this paper? Or will he continue to cherry-pick and deny modern medicine?

*crickets*

Anyone?
Anyone?
Bueller?
Bueller?

"scientifically implausible results are easily magnified in these types of studies"

You are wrong. If there is a strong effect and low variance, then a small N may be adequate.

Of course we cannot draw any definite conclusion from one experiment, whatever its power. But your statement is utterly wrong. Low power studies are NOT likely to magnify non-existent effects. If they were, they would be useless.

"It is based on an unproved practice"

Yes, a practice would remain unproved if it were never studied scientifically. So these researchers have begun to study it.

Are you saying the journal should not have published the research, because the practice is unproved? So how would anything ever be proved, if you can't study it until after it has been proved?

http://www.nature.com/jhh/journal/v21/n5/full/1002134a.html

"According to a double-blind, placebo-controlled study design, hypertensive patients with documented evidence of vertebral misalignment were randomized either to a chiropractic vertebral realignment procedure or to a sham intervention. The primary efficacy end point of the study was represented by the effects of the approach on sphygmomanometric systolic and diastolic blood pressure values, which were reduced at the end of the 8-week follow-up period by about 14 and 8 mm Hg, respectively (placebo-corrected values).1"

Ok, what exactly do you find wrong with this study?

1st, it's "published" in a garbage chiro-woo "journal"

2nd, it has never been repeated by non-woo researchers. This is the primary problem with chiro and other garbage. Their results never show up in the real world. I'm still not seeing any plausible mechanism for a spinal misalignment that only a chiropractor can see to affect blood pressure.

3rd, it's the usual steaming pile of quote/study mining.

Give up, sparky... you're losing.

As I already stated, first, some of the researchers are quite legitimate hypertension folks. They fucked up though. This study relies on methods that have been thoroughly discredited (the cervical manipulation crap). Since the entire study relies on operational measures based on NUCCA, the entire study is invalidated.

So some of the researchers are legitimate, the journal is mainstream, the results are positive -- but it's still crap, because you don't believe it's possible???

You are not a scientist PalMD.

And WHERE is the evidence that "thoroughly discredited" NUCCA? And why are you pretending the the adjustment in this study was without physical contact?

You really don't understand this, pec? Really? So you're not just a liar, you're an idiot?

One more time, loudly for the people in the cheap seats...

Chiropractic is bullsh*t. The entire field is full of cranks, crackpots, quacks and liars. Period.

Sheesh.

What an intelligent and scientific argument, LanceR!

Please, pec. You have yet to respond to an actual scientific argument. You have done nothing but ignore scientific arguments since this thread started. I am starting to wonder if you could recognize a scientific argument if one bit you on the nose. I thought perhaps a little plain English might clear the matter up for you.

You are a classic crank, as described here.

Sorry about the tone, PalMD... but SIWOTI!

It's just pec's death of a thousand cuts. You show him one thing and he keeps asking for more, ad absurdum. If you tell him a paper was made up out of whole cloth, he'll just ask if you were there to see the fraud in person. If you saw it in person, he'll question your definition of observation and reality.

Total BS, PalMD. If you told me that hypertension/chiropractic paper was "made up out of whole clothe," why the heck would I believe you, rather than the journal and its editors? Where is your evidence that is was made up?

And you never answered my comment about your idiotic misunderstanding of an experiment's power.

When you can't win an argument logically you resort to throwing around utter nonsense, hoping no one will notice.

Hello, Kettle? Yeah... Pot called. Something about being black...

Classic projection. All he has is utter nonsense and poor reading skills.

Epic Fail!