Guest Essay by Kip Hansen
Prologue: This is the first in a series of several essays that will discuss ongoing scientific controversies, a specific type of which are often referred to in the science press and elsewhere as “Wars” – for instance, this essay covers the Salt Wars1. The purpose of the series to illuminate the similarities and differences involved in each.
Warning: This is not a short essay. Dig in when you have time to read a longer piece.
From the New York Times, Wednesday, June 1 2016, “F.D.A. Proposes Guidelines for Salt Added to Food”:
“The Food and Drug Administration proposed voluntary guidelines for the food industry to reduce salt on Wednesday [1 June 2016], a move long sought by consumer and public health advocates who said the standards could eventually help save thousands of American lives.”
….
“Americans eat almost 50 percent more sodium than what most experts recommend. High-sodium diets have been linked to high blood pressure, which is a major risk factor for heart disease and stroke.”
….
“While there has been some scientific controversy over how much to reduce sodium, scientists at the F.D.A. said the health advantages are beyond dispute.”
If one follows the offered link to “some scientific controversy” one finds this report in the New York Times piece No Benefit Seen in Sharp Limits on Salt in Diet, by Gina Kolata, May 2013, regarding the Institute Of Medicine of the National Academies booklet-sized review of the entirety of modern science on salt intake and health titled “SODIUM INTAKE IN POPULATIONS: ASSESSMENT OF EVIDENCE” written by its Committee on the Consequences of Sodium Reduction in Populations issued in 2013 [free pdf].
Among the several findings and conclusions of this massive review is:
“Finding 2: The committee found that the evidence from studies on direct health outcomes was insufficient and inconsistent regarding an association between sodium intake below 2,300 mg per day and benefit or risk of CVD outcomes (including stroke and CVD mortality) or all-cause mortality in the general U.S. population.”
And further:
“…the committee found that the available evidence on associations between sodium intake and direct health outcomes is consistent with population-based efforts to lower excessive dietary sodium intakes, but it is not consistent with recommendations that encourage lowering of dietary sodium in the general population to 1,500 mg per day.”
Gina Kolata, the long-time NY Times Health journalist, summarized is this way:
“In a report that undercuts years of public health warnings, a prestigious group convened by the government says there is no good reason based on health outcomes for many Americans to drive their sodium consumption down to the very low levels recommended in national dietary guidelines.”
The American Journal of Hypertension, October 2013 issue, covered the topic extensively in this issue largely dedicated to the Salt Wars following on the Institute of Medicine’s 2013 report (mentioned and linked above). The INTRODUCTION: The Salt Discourse in 2013, written by Theodore A. Kotchen, characterizes the findings of the IOM report as:
The IOM report concluded the following:
- “The evidence supports a positive relationship between higher levels of sodium intake and risk for CVD.”
- “The evidence on health outcomes is not consistent with efforts that encourage lowering of dietary sodium in the general population to 1,500 mg/day.”
- “There is no evidence on health outcomes to support treating population subgroups differently than the general US population.”
Yet, as we see reported on the first of June 2016, The Food and Drug Administration just issued guidelines to the processed food industry based on the assumption that “the health advantages [of population-wide dietary salt reduction] are beyond dispute”.
Are the health advantages of population-wide dietary salt reduction beyond dispute?
Hardly. The latest salvo fired in what has long been called The Salt Wars1 was published last month, on 20 May 2016. A huge international review study [paywalled] led by Professor Andrew Mente, PhD, the title of which begins with “Associations of urinary sodium excretion with cardiovascular events….”, in one of the world’s leading medical journals, The Lancet. The study had a cohort of 133,000 individuals across 49 countries and was undertaken and written by 29 internationally recognized researchers, all PhDs and/or MDs. Their published interpretation of its findings is:
“Interpretation: 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.” [emphasis mine – kh]
In an accompanying Comment [also paywalled] in the same issue of The Lancet, Professor Dr. Eoin O’Brien of the Professor of Molecular Pharmacology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, and past President of the Irish Heart Foundation writes:
“When apparent dogma is challenged, we should speak not of controversy but rather accede to the all-encompassing expression of so-called scientific uncertainty, so as to avoid unbecoming rhetoric. The issue of population strategies for salt consumption is a good case in point. There is no argument other than “excessive salt in the diet raises blood pressure”, and that strategies to reduce salt in individuals with hypertension prevent the cardiovascular consequences of the disease. However, the corollary that reducing sodium intake across populations will be beneficial to all, has been challenged with the assertion that doing so might indeed be harmful.”
Todd Neale reports bluntly on the study for tctmd.com (an industry supported news aggregator covering interventional cardiology news and education):
” Consuming less than 3 grams of sodium per day is associated with a greater risk of all-cause death or major cardiovascular events compared with more moderate intake in both hypertensive and normotensive individuals, an observational study of more than 130,000 participants has shown. In contrast, consuming 7 grams or more per day is tied to worse outcomes in hypertensive patients only.
The findings conflict with advice by the American Heart Association (AHA) to consume no more than 1.5 grams of sodium per day.”
The Neale article continues with:
But Daniel Jones, MD [past President of the American Heart Association] (University of Mississippi Medical Center, Jackson, MS), speaking to TCTMD on behalf of the AHA, which issued a public statement refuting the study, strongly disputed its results.
“This is a flawed study, and no health policy should be based on this study,” he said. It’s “difficult to do good studies, but the preponderance of the evidence is that most people eat too much sodium and that people’s general health will be improved by eating less sodium. This message that people should be concerned about eating too little sodium is just something that should not be taken seriously.”
Indeed, the American Heart Association fired back with a press release and web page titled “Experts criticize new study about salt consumption”. Two experts, the current and immediately-past President of the AHA, are quoted:
Mark Creager, M.D., president of the American Heart Association…..“The link is proven between excess sodium and high blood pressure, and I find it worrisome that adoption of the authors’ recommendations may reverse the progress that has occurred in modifying dietary sodium intake and reducing the risk of high blood pressure and its effect on heart disease and stroke,” Creager said. “Today’s widely accepted sodium recommendations are based on well-founded scientific research – and that’s what people should understand.”
Elliott Antman, M.D., associate dean for clinical/translational research at Harvard Medical School and senior physician in the Cardiovascular Division of Brigham and Women’s Hospital in Boston, said the findings of the new study should be disregarded.
“This is a flawed study and you shouldn’t use it to inform yourself about how you’re going to eat,” said Antman, immediate past president of the AHA. “The AHA has reviewed the totality of the evidence and we continue to maintain that no more than 1,500 milligrams of sodium a day is best for ideal heart health.”
So far, that’s three American Heart Association Presidents trotted out to attack the new study and its findings, which agree with and expand on the findings of the National Academies’ Institute of Medicine from 2013.
What in the world is going on here?
* * * * *
Let’s roll the clock back 15 years, to the turn of the century and look at this article from the New York Times Science section: With Dietary Salt, What ‘Everyone Knows’ Is in Dispute by Abigail Zuger (NY Times, January 9, 2001). Zuger leads with this:
“Diet fads may come and go, but low salt is forever. Or so, at least, any reasonable person might conclude from the consistent message in most guidelines over the last two decades: eat less salt.
But behind the official pronouncements rages one of the longest, most vituperative battles in medicine. It has continued despite a decades-long procession of ”landmark” studies, each designed to end the debate, and each only provoking more disagreement.”
Already, in 2001, the Salt Wars have been raging for decades. Zuger outlines the battle lines for us:
“One set of scientists, backed by most of the country’s major health organizations, maintains that cutting back on salt is good for people, whether they have high blood pressure or not.
”Salt matters,” said Dr. Frank Sacks, an associate professor of nutrition and medicine at Harvard, who led the most recent study. ”The results are so clear-cut, there’s just not much controversy left.”
Dr. Jeremiah Stamler, an emeritus professor of preventive medicine at Northwestern University Medical School in Chicago, who has spearheaded the anti-salt forces for decades, said that he himself stopped eating most salt in 1948.
”The question of salt is settled,” Dr. Stamler said. ”It’s a food additive we don’t need.”
And on the proverbial other hand:
“But other equally respected scientists still rally firmly behind the salted pretzel, maintaining that there are better tools for controlling blood pressure than salt reduction, and that low-salt eating may actually be harmful to health. [emphasis mine – kh]
”The problem is not so much whether we have too much salt in our diet as it is the deterioration of the American diet,” said Dr. David McCarron, a professor of medicine at Oregon Health Sciences University in Portland, who argues that salt makes little difference in blood pressure control when people eat balanced diets that emphasize fruits, vegetables and low-fat dairy products. ”That’s really the issue.”
Dr. Michael Alderman, a professor of medicine and epidemiology at Albert Einstein College of Medicine in the Bronx and past president of the American Society of Hypertension, said: ”I don’t believe there is any basis whatsoever for a public health recommendation for eating any particular sodium content diet. A scientific problem ought to be solved by data. And there is no data.”
Fifteen years ago, the then-recent dual studies undertaken by the National Institutes of Health – called “Dietary Approaches to Stop Hypertension” or the DASH studies – had shown that blood pressure could be better controlled by eating a well-rounded diet high in fruits, vegetables, and dairy. This so-called DASH diet produced blood pressure reductions on the same level as blood pressure medications. The second DASH study seemed to show that the DASH diet coupled with salt reduction produced even better results. Both studies have been challenged by both sides of the Salt Wars, both sides interpreting the results in favor of their viewpoints.
“….Dr. Stamler of Northwestern said….[regarding] the findings of the second DASH study, ”there is no question that for everyone else [those who do not already have optimal blood pressure] there is a significant effect from lowering salt.”
however
“Not so, Dr. McCarron said. ”The most important finding in the second DASH study is the unequivocal evidence that the first step in blood pressure control should be adding things missing from the diet: the fruits, vegetables and low-fat dairy products,” he said. ”If people have to put their money down on a dietary intervention, the blood pressure response they will get from that is far better than from worrying about salt.”
[all quotes immediately above are from the Zuger NY Times piece – kh]
On a pragmatic level, the DASH studies found that “cutting back on sodium from 3,300 milligrams a day to 2,400 milligrams [note: this recommendation has since been dropped even further to 1,500 mgs/day – kh] lowered blood pressure in the study by an average of 2.1/1.1 for people who ate a normal diet. Changing to a DASH diet lowered their pressure substantially more, by 5.9/2.8, without any salt restriction at all.” [included quote from the Zuger NY Times piece – kh]
Let’s look at that more closely. A salt reduction diet, cutting back to 2,400 mg/day, for people with a normal diet, resulted in an average lowering of blood pressure (BP) of 2.1/1.1 (mmHg). If your blood pressure (BP) was 150/95 (which was and is considered high), then, on average, salt reduction to 2,400 mm/day would lower your BP to 147.9/93.9. That amount of improvement does not stand up as a Minimal Clinically Important Difference – “The MCID defines the smallest amount an outcome must change to be meaningful to patients.” In other words, no one’s high BP is cured by a reduction of 2.1/1.1, such a small reduction doesn’t improve a patient’s well-being or general state of health. In fact, that is a fraction of the “white coat effect” which raises some people’s BP by 10 to 30 mmHg simply because their BP is being measured by a doctor – “The term white coat hypertension may be used if you have high blood pressure readings (i.e. readings that are consistently 140/90mmHg or above) only when you are in a medical setting. Your blood pressure readings may be normal when they are taken at home.”
This brings us full circle back to the most recent Salt Wars salvo, the Mente et al. study in the latest issue of The Lancet, “Associations of urinary sodium excretion with cardiovascular events….” [paywalled], which, 18 years later, confirms the findings of Alderman: “Compared with moderate sodium intake, high sodium intake is associated with an increased risk of cardiovascular [CV] 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.” In other words, while high sodium (salt) intake does increase the risk of CV or death in those who are already hypertensive (have high BP), enforced low sodium diets, population wide, will have overall negative health effects – increasing risk of CV events and increasing risk of all-cause death – for everyone, without respect to BP – the most optimum health outcomes are found with moderate salt intake regardless of BP status.
For the American Heart Association, and its allies who share its long-term anti-salt stance, these findings — no matter how scientifically sound, no matter how robust, no matter that they replicate and confirm earlier findings – are simply unacceptable. The AHA has publicly stated that these findings should be “disregarded”.
Let’s take a break for a minute. The information discussed so far represents a only a tiny bit of the vast literature involved in the Salt Wars. I have purposefully steered clear of science journalist Gary Taubes and his work in the NY Times and in Science magazine, which together comprise the best summary of the Salt Wars up to mid-1998. Taubes had written about the Salt Wars for more than two decades. [He is perhaps more well-known for his efforts in the Obesity Wars.] His work – on the pragmatic salt-is-salt side of the Wars – is legendary. I have also avoided the opinions of and work by “The Salt Guru”, Morton Satin, who came out of retirement to be the Vice President of Science and Research at The Salt Institute, a non-profit trade association based in Alexandria, Virginia, an association that taints his work in the eyes of many. (Before that, Satin spent sixteen years as the Director of the United Nations Food and Agriculture Organization’s Agribusiness Program.) Satin’s general view is that the salt debate is filled with shoddy science and outright misinformation.
In a funny aside – and many reading here will recognize this situation — it has been reported that Satin has claimed Taubes won’t even take his phone calls for fear of becoming tainted by contact. Taubes denies this. But, I mention it because, as in other modern scientific controversies, “guilt-by-association” is rampant – a modus operandi practiced by all factions.
What We Know About Dietary Salt:
- Salt is an absolutely necessary element of the human diet – humans die without adequate salt intake.
- For most people, consuming a moderate amount of salt daily (2,500-5000 mgs) has no adverse effects.
- High blood pressure (BP) is associated with cardiovascular disease and risk of premature death.
- For almost everyone, eating more salt causes an increase in BP, but the increase is not clinically important, averaging around 2.1/1.1 mmHg.
- For a certain percentage of people, believed to be in the 10-15% range, who can be labeled “salt sensitive”, dietary salt causes higher BP and for those already suffering high BP and who have a high salt intake, dietary salt reduction combined with improved diet (the DASH diet – more fruits, vegetables, and low-fat dairy, specifically) can help reduce BP to healthier levels.
- For most people, a diet too low in salt increases risk of cardiovascular events and increase risk of all-cause death.
- The science to quantify what constitutes “too low”, “moderate”, and “too high” regarding salt intake is best characterized as “somewhat uncertain”.
What We Know About Salt Politics:
- The Salt Wars have been raging for 30 years, at least.
- One side of the Salt Wars believes that because dietary salt increases BP (in most people just by a small amount) and causes a big increase BP in some people, coupled to the idea that high BP is associated with increased heart disease and risk of death, that governments should take action to reduce the salt intake of everyone – population wide – through regulation of the food industry, setting dietary guidelines, etc. Arrayed on this side we find the American Heart Association, United Nations’ World Health Organization, and the US FDA. Many food and diet advocacy groups stand with the AHA against salt. Taken together, these groups represent a view that consists of a “bureaucratically entrenched hypothesis advocating an enforced solution”.
- The opposition believes that the science is not adequate to mandate a population-wide reduction of salt intake, maintaining that, in addition to being not necessary, it will cause harm instead of good, increasing cardiovascular events and premature death among all groups. The majority of scientists on this side of the issue also hold that the DASH diet is far more effective in reducing high BP than salt reduction.
- Despite the mounting evidence of harm from population-wide enforced salt reduction, various government agencies have been passing rules, regulations, and guidelines to force the food processing industry and, most recently, in New York City, mandatory labeling of highly salted foods by chain restaurants.
- As in all modern scientific controversies, the faction occupying a societal Bully Pulpit, in this case the AHA, FDA, and WHO, has a huge advantage, even when the hard scientific facts are not on their side. [“A bully pulpit is a sufficiently conspicuous position that provides an opportunity to speak out and be listened to…. a terrific platform from which to advocate an agenda.”]
- The Salt Wars are an exemplar of what can happen when a hypothesis is scientifically correct but its real-world overall effect becomes grossly exaggerated. This can lead to a “mandated solution” which is then sold as a cure-all for some existing problem. As the underlying science is in fact uncertain, scientists in support of this view must turn themselves into advocates to make their case. Political advocates in turn pretend to be scientists, advising governments to enforce a “one-size-fits-all” solution on the whole society – even though it is probable that the claims of benefit range from uncertain, at best, to nonsensical [see footnote 2 for the my rationalization for this statement in the Salt Wars].
Modern scientific controversies, sub-category Science Wars, all follow a similar pattern and have common features. As this series progresses, it will become obvious what these features are and the harm they cause to the reputation of Science and Scientists.
# # # # #
Footnotes:
- Please note that in all instances, the word salt in this essay, and in all included quotes, refers to common table salt, sodium chloride, in all of its customary forms found in kitchens, restaurants, grocery stores and food processing plants. The use of the term “Salt Wars” does not originate with me but has been in common usage in science journalism for some time. I offer this link: Scientific American – Health – The Salt Wars Rage On: A Chat with Nutrition Professor Marion Nestle in support of its use. (Nestle is pronounced like the action “to nestle”, Dr. Nestle is not related to the famous chocolate fortune family). The term’s use in this essay (and SA) is not to be confused with the many actual armed conflicts over the ages and around the world that have shared the title Salt War.
- From the same source as Footnote 1, I quote Marion Nestle “I was once at a sodium meeting at which there were a bunch of statisticians. And I left with the statisticians and they said that “anyone who thinks that salt has anything to do with hypertension is delusional.” And that was on the basis on the clinical trials that show so little. And yet every single committee that has dealt with this question says, ‘We really need to lower the sodium in the food supply.’ Now either every single committee that has ever dealt with this issue is delusional, which I find hard to believe—I mean they can’t all be making this up—[or] there must be a clinical or rational basis for the unanimity of these decisions.” And “Everybody argues about every clinical trial no matter what the conclusion. So I find the whole thing completely fascinating.”
# # # # #
Author’s Comment Policy:
I have been sidelined for the last six-months by a heart attack that acted to reset my priorities somewhat. I have, thankfully, fully recovered and spent a month sailing with family up the Eastern Seaboard of the United States, with my youngest son acting as Captain.
As always, I will be glad to answer your questions about the Salt Wars – which I have followed since the 1980s. I am open to suggestions on which of the current Science Wars to cover in this series, I am aware of a half dozen or more.
I realize that many readers here will want to move on immediately to discuss the Climate Wars – one of the distinctive science wars of our day. I ask that you please try to restrain yourselves – we’ll get to that later on in the series.
The last essay in the series will be an attempt to layout a coherent pattern of modern science wars and maybe suggest ways that the different science fields themselves can break these patterns and return their specific area of science back to the standards and practices that should exist in all scientific endeavors.
# # # # #
1. Anyone know of studies on vegetarians? As I understand it, plants are rich in potassium (the settlers used to use wood ashes, rich in potassium carbonate, as the alkali in making soap when boiled with fats). The nervous system uses sodium/potassium ratios, so maybe vegetarians might need more sodium chloride (salt) for balance. Wild herbivores crave salt, rich in sodium, calcium (for bones?), etc., perhaps to balance the potassium in their diet (aboriginal hunters knew this, staking out salt licks). Maybe this might be why normal humans find it difficult to restrict sodium, and like the taste (although I agree that excessive sodium, like excessive anything is not good). Just a suggestion.
2. Re salt and high blood pressure. In my late 60s I was diagnosed with high blood pressure (systolic 160) and prescribed 20 mg Adalat XL daily. Before taking it, I spent a couple weeks taking background BP measurements. I found that taking 3 measurements separated by 2 minute intervals gave values varying over a 20 mm Hg range (maybe because my blood vessels do not relax totally between measurements, or because I settled down after rushing into the pharmacy; the trend was usually a decrease over time). What I noticed is that after vigorous exercise such as shovelling snow for an hour, or walking for 40 minutes, my BP dropped 20 or 30 mm Hg, although my pulse rate was higher. Makes sense to me, because what is of prime importance is the oxygen delivered to the brain, so with a higher pulse rate, maybe BP need not be as high when resting (perhaps the product of BP and pulse rate ought to be considered key). The Adalat does work, reducing my systolic BP to 130-140. However, a nurse mentioned that my BP of 140 in one measurement was worrying, so in later visits to the doc, I always walked vigorously for 40 minutes before showering and driving 30 minutes to the doc, so my measured BP was 110-120, “excellent for a man of my age”. I wonder if others have had the same experience? So a change of 1-2 mm Hg on a drastic change in sodium chloride intake might be considered irrelevant.
Reply to rogertaguchi ==> Check out the information on the DASH diet, linked in the essay, for information on potassium etc in a vegetable diet.
Good luck with your “resting BP” — 160 is, in my unschooled opinion, a bit too high. 140, however, for a man your age, used to be considered normal.
Thanks for the suggestion to check out the DASH diet, a diet rich in veggies. The increased potassium is maybe what we really need if we get so much sodium daily (this may explain why one reader got headache relief from eating bananas). This simple remedy seems to be an order of magnitude more effective than a drastic decrease in sodium chloride (salt). BTW I do take my 20 mg Adalat XL daily to keep my resting systolic BP below 140, so don’t worry! Having reached my “three score and ten”, I treat every healthy day as a bonus!!!
Yanomami Indians eat a natural, hunter-gatherer, low-salt diet. Their blood pressure stays around 100/60 from cradle to grave. That is there’s no growth of blood pressure with age. It just may be that around 100/60 is the normal, natural human blood pressure, while what we have now is skewed because of the things like a salt intake excessive compared to a natural level.
Excellent article. Thanks Kip Hansen!
Aggressively lowering blood pressure once you are elderly, according to my M.D., has been found to be potentially more risky of adverse outcome. Better to not try & get it to stay at the level healthy young adults have just because that is the empirical “normal” range of ideal blood pressure.
Doc also wised me up to the way ibupropen & naproxen (all NSAIDs actually) can raise blood pressure. Which is to point out that a vast subset of people self medicating with these over the counter “pain” medicines on a daily regimen could even be engaging in a consumption pattern
that creates higher blood pressure more directly than how much salt they ate that day.
Reply to gringojay ==> The effect of NSAIDs on BP are reported to be “small” (for most people): “NSAIDs like aspirin, ibuprofen, naproxen, and others all have the capacity to increase blood pressure. The average increase is small, but the actual amount of increase can vary widely from individual to individual.” If you are under treatment by a doctor for high BP, follow his advice and educate yourself on the issue.
Naproxen SODIUM!
“These pretzels are making me thirsty!”
I wonder how much salt is in water that a person who swims in the ocean every day inevitably swallows?
Even if you are careful not to swallow any, if you have your head under the water, i am pretty sure some will get in your mouth or nose and be absorbed.
Another thing that bothers me about these guides is that they do not seem to ever be adjusted for amount of time spent exercising, what sort of climate one lives in, and how much time ones spends outside.
The reason I bring this up is that it is quote obvious that a sweat contains a lot of salt. On days with low humidity, I sometimes get home with white stains on my shirt from dried up perspiration salts.
I live in Florida, and work outside, and am a heavy perspire to begin with. For someone like me who works outside, spends time swimming biking, laying in the sun reading, and doing yard work, et…nearly every day, there is no chance I do not sweat out far more than someone who lives up north and works inside and does not work out much and almost never breaks a sweat.
Plus, it seems to me drinking plenty of water must be a factor in whether or not you might be consuming too much salt, if there is such a thing. Some people are known to consume too small of a volume of fluids every day.
I was also wondering about the fact that people, on average, live a very long time nowadays as compared to long ago…even though back then salt was one of the principle ways to preserve many sorts of foods, whether by pickling, salting or whatever. Imagine how much salt one might have eaten if food was salted instead of refrigerated or frozen, or dehydrated. And they did not have access to every kind of food, all year around, in fresh form.
Finally, i have known a lot of people with very high BP who consumed low salt, or tried to, as a result of doctors orders.
I do not know of a single one who ever was able to stop taking BP medications as a result of not eating salt, or that had their BP go down after they stopped eating salt.
I have never worried about it, love salty snacks and salt a lot of the food i eat. My BP is between 110/70 and 120/80, my pulse ranges from 40 in the morning to about 55 if I am up and about.
I am 55 and male.
Sorry about typos and punctuation errors.
*meep*
Nutritional science is junk science – just look at the “Fat wars” over the past 30 years – saturated fats a
good place to start
Reply to aurthur4563 ==> Your statement is unfortunately over broad.
Nutrition science has found dietary cures for illnesses that used to kill hundreds of thousands of children and adults: scurvy, beriberi, VAD (Vitamin A deficiency – the leading cause of preventable childhood blindness), rickets, Pellagra, and other dietary related diseases and conditions. General discoveries related to forming a “well rounded diet” have improved nutrition, and thus general well being, for almost all persons in the developed world.
It is true, and I agree, that what often passes today for “nutritional advice”, most of it promulgated by food faddists, the “health food” industry, and vitamin and supplement manufacturers is nonsense at best, and ranges all the way to outright intentional fraud.
Kip, glad to hear your recovery is going well. Enjoy the sailing.
Reply to b fagan ==> Thank you. Good to hear from you.
Kip, you’re welcome – too may people on this internet thing confuse “disagreeing on a topic” with “deadly personal enmity”. I disagree with your opinions on climate and sustainability, but wish you the same good health I wish everyone. Glad medical science has improved the prospects of people with heart conditions. I’ve got a close relative who’s doing quite well know with a cancer that would have been quickly lethal just a decade ago. Like all the sciences, it continues to progress through and by mistakes made.
Regarding sailing – I’ll be watching the America’s Cup events here in Chicago this weekend. First time on fresh water. First time seeing the big winged racers up close.
Reply to b fagan ==> On the sailing front, my youngest son, who sailed over 10,000 miles with my wife and I when he was in his teens, recently received his Captain’s (and Master’s) License from the US Coast Guard and is working this summer for the first time as a professional Captain, taking out sailing charters on the glorious Hudson River. Later in the year he will Captain and teach sailing for older teens attending a Sailing Camp.
Our 42 ft cat is on the hard in North Carolina, but we sail the Hudson in our son’s Rhodes 22 — the Merlin — a fast and fun little light-wind boat.
Maybe you can post an essay here on lessons learned watching the America’s Cup — maybe the scientific differences between the boats and their approach to the race. I’d love to read it.
The insurance industry tables back it up, and I wonder if it’s some co-dependant variable type of correlation. E.g. many people who eat high-salt diets tend to do other stuff that hurts their health. In logical speak… while A may not cause B, the presence of A is strongly associated with the presence of B.
“Big Data” does a lot of this stuff. One of the more famous cases involves Target figuring out that a teenage girl was pregnant… before her father found out. http://www.businessinsider.com/the-incredible-story-of-how-target-exposed-a-teen-girls-pregnancy-2012-2
A sprinkling of facts:
1. The “epidemic” of overweight started in America following the issuing of dietary guideline back in the 70’s. Reduced fat, more carbs. Correlation is not causation, but it is suggestive.
2. Genetics is a whole lot more complicated them Mendel ever suspected. There are genes that can change expression depending on sustained environmental stimuli. The fastest one relates to food availability. Nine months of bountiful food, and the metabolism shifts to store a significant percentage of calories. The utility of this to a wild animal, subject to significant swings in food availability, should not need elaboration. I suspect that this is involved in our weight issues.
3. Socialism attracts cranks. George Orwell observed this in his “The Road to Wigan Pier” (1937).
“In addition to this there is the horrible —- the really disquieting —- prevalence of cranks wherever Socialists are gathered together. One sometimes gets the impression that the mere words ‘Socialism’ and ‘Communism’ draw towards them with magnetic force every fruit-juice drinker, nudist, sandal-wearer, sex-maniac, Quaker, ‘Nature Cure’ quack, pacifist, and feminist in England.”
Kip,
This is a great article and from the comments you have struck a chord with many readers, myself included. But I think your main thrust is to examine the various “Wars on…” in science and see how they have played out.
In climate science, one of the greatest tocsins are the unknown-unknowns. We have a parallel in the 120 year old War on Bacteria.
Since the invention of the microscope, Pasteurization and Penicillin, medical science has assumed that all bacteria are bad and need to be killed immediately and without reservation. This has led to what I think will be recognized (and is being recognized by all sentient medical scientists today) as the most destructive “War” in the history of medicine.
Only since 2010 and a ground breaking study by the NIH, have we had any idea of the speciation and population of our microbiome. Turns out that 80% or more of our immune system is our gut bacteria – and 80% of the species (many thousands) were previously unknown. Which antibiotics kill. The biggest unknown-unknown disaster in the history of medicine. Now in your meat and water. Wonder why all the kids today in developed countries are sick? Why diabetes and Celiac disease are skyrocketing, along with many others?
Using antibiotics for non-life threatening infections is like killing the crab grass in your lawn by napalming your entire forrest.
The greatest danger of making policy decisions based on what is “known” are the unknowns lurking out there. Of course the sun and stars revolved around the earth – until the first telescope was turned on. Of course bacteria are bad and need to be eliminated – until the telescope doors of genetic sequencing were opened onto that world around 2010.
Kip, I applaud your efforts and look forward to the fruits of your research. The scientific quest for knowledge is agnostic in its effects – this is how it is, take it or leave it. However, that quest is fraught with human weaknesses – a little knowledge is a dangerous thing and weak humans are only too willing to engage in confirmation bias and declare their ultimate knowledge.
Maybe we should declare a War on Wars…
Marko
“…This can lead to a “mandated solution” which is then sold as a cure-all for some existing problem. As the underlying science is in fact uncertain…”.
I would add that it is an issue not just with being uncertain, but of inconsistency.
Something may be true or useful in some instances, but not others, meaning mandated solutions and exaggeration often occurs when one ignores the fact that the particular feature or issue is inconsistent.
Like trying to impose an equation on the stockmarket, or ignoring variations within a population, nature is often inconsistent (note the tautology); it even drives evolution, economies, and is a feature of many natural and human systems.
To me, the point is not so much inconsistent but more variably contingent, with way to many of the variables not known, not considered, equated to zero when small, and more.
The list of possible “Wars” for you to write about is endless…
Sugar, Fat, Alcohol, Meat and the list goes on I tend towards the line of “everything in moderation”>
I get suspicious when people tell me this is how it is and don’t ask questions and anything that says otherwise is not science.
James Bull
Sea salt contains a fair amount of iodine from the microscopic shrimp like critters. Most processing plants now filter the water and remove the microscopic critters and the iodine. People living near the coast get plenty of iodine from the storms blowing in from the ocean. The goiter belts are all areas separated by mountains or distance from the storms. Some thyroid problems are more common along the coast because of the iodine in the soil.
Unfortunately, the goiter belt in Africa persist because of the lack of iodized salt and cretinism persist almost unchanged from a hundred years ago. A few pennies per year would totally prevent the disease.
charles kaluza
Homeostasis…..The End.
http://numberwatch.co.uk/zealots.htm
Thank you Kip for this interesting read.
Suggestions for further topics to investigate:
The great cholesterol scam
acid rain
DDT
Ozone layer
Salt and BP
I first had high BP s 12ish years ago. The first suggestion was to reduce my salt/sodium intake, which I did. After it had absolutely NO effect, my doctor agreed that salt wasn’t the problem. I resumed my previous diet and again, no change.
But it went down significantly when I started training in karate again.
That experience got me looking into things a bit. I had already seen the problems with the ‘common knowledge’ on fat and cholesterol. Seeing the real state of nutritional science was quite revealing. The whole experience significantly increased my skepticism on all subjects of science.
Reply to Tony G ==> Blood Pressure, its causes and effects, is still itself the subject of a lot of uncertainty — in my opinion simply because itself is so very complex — there are so many factors at play. If our arteries and blood vessels were more like solid pipes, it would be easy, but blood vessels are flexible, dilate and constrict; the heart beats at different rates for an uncontrollable number of reasons, the tissue surrounding blood vessels constricts or relaxes, blood volume changes…this list goes on and on — and we haven’t touched on the idea of what causes each of those changing factors.
Adequate moderate exercise, 20-30 minutes most days, gives most people 90-95% of all the health benefits available from exercise. Your BP improvement from karate may be a result of this.
This part of your comment: “That experience got me looking into things a bit. I had already seen the problems with the ‘common knowledge’ on fat and cholesterol. Seeing the real state of nutritional science was quite revealing. The whole experience significantly increased my skepticism on all subjects of science.” demonstrates the societal harm that results from Science Wars.
And thank you again for this interesting essay.
Mr. Hansen is a master at this medium, it seems to me, Anthony (as are several of your regular contributors, including you). I thank you as well, again, for facilitating a great many interesting essays and the ensuing (extremely well moderated) discussions, which together constitute the best employment of this interactive medium I am aware of.
Science is a terrible marcher, it seems to me . . but a wonderful dancer ; )
Kip,
I hope you plan on covering the “diet wars” on fats vs carbs – lots of people have touched on this in the posts. Perhaps something that more awareness of can lead to immediate health benefits for many.
With the epidemic of obesity, diabetes, neurological diseases, there is something clearly wrong with how we are collectively living . And this has a real cost to everyone, both healthy & unhealthy, in the form of increased insurance rates & increased national debt (due to Medicare ). This is arguably one of the most pressing issues of our time if you sit back & think about it.
Reply to Jeff L ==> Yes — I will be covering the Diet Wars (by that or some other name).
A great deal, but not all, of the seeming rise in ‘epidemics’ results from an aging population, we are collectively getting older and collectively suffering from the diseases and conditions of advancing age.
For some time now, I have been intrigued by the idea that the obesity epidemic may be just that — an epidemic of some sort of an infectious transmittable disease or condition. There have been some hints of this in some recent small studies — that would be an interesting outcome to the continuing research into the causes of obesity, wouldn’t it?
All in all, I do not think that there is some single cause — something that has been added or removed from our diets, that is causing the apparent rise in the conditions you mention. Nor do I think that “the modern Western diet” is to blame. Affluence, however, may be the blame for some of the problems involving overindulgence — in food, alcohol, sex and recreational drugs.
On the other hand, it all may be a matter of perception — we are being told over and over how sick everyone is.
Overall, people are living longer better lives in the developed world than ever before. The developing world is beginning to catch up.
Yet another problem with “Single Factor Science”.
There are very few things in this world explainable by a single factor.
When you hear something to the effect of ” that the cause of this is this”, chances are that the argument is fallacious.
Reply to Walt D. ==> Single Factor Science — nice turn of phrase — related to, I suppose, Single Issue Fanatics.
In the Epilogue, I linked to my earlier essays on Chaos and Climate. It is my opinion, shared by many others familiar with the field of nonlinear dynamics, that almost all physical systems (including biological systems) are, in a deep sense, inherently complex, complicated and involve nonlinear dynamics. In this essay, we get a hint at how complex the factors related to blood pressure can be.
It is unlikely that NaCl , table salt, is the Big Red Control Knob for blood pressure.
Enjoy the findings of a credible doctor:
Reply to BernardP ==> Yes, the study discussed was yet another salvo fired in the Salt Wars and represents a moderate support of the AHA position.
The authors have the following associations:
“Competing interests: All authors have completed the ICMJE uniform disclosure form at http://www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: FH is a member of Consensus Action on Salt and Health (CASH) and World Action on Salt and Health (WASH). Both CASH and WASH are non-profit charitable organisations and FH does not receive any financial support from CASH or WASH. GM is board member of World Hypertension League (WHL), chairman of Blood Pressure Association (BPA), chairman of Consensus Action on Salt and Health (CASH) and chairman of World Action on Salt and Health (WASH). WHL, BPA, CASH and WASH are non-profit charitable organisations. GM does not receive any financial support from any of these organisations.”
All three authors are members of, and in one case, Chairman of, two different anti-salt advocacy organizations: Consensus Action on Salt and Health and World Action on Salt and Health . That doesn’t mean that the study is invalid, but it is a meta-review that depends solely on statistical interpretations for its findings.
The latest studies, mentioned in the main essay, find contradictory results — welcome to the Salt Wars.
The Australian, today has an article about a scientist, Peter Ridd, that was censured by authorities at James Cook University for pointing out the very low quality of science involved in the photos claiming catastrophic bleaching of the Great Barrier Reef. He was found guilty of “Failing to act in a collegial way and in the academic spirit of the institution.” In plain language, I think that means he didn’t keep their dirty little secret.
It’s paywalled, unfortunately, or I would post a link.
Reply to Hivemind ==> Please post the link anyway — and include a substantial quote — for my research on the GBR Wars.
Thank you!
Reply to Hivemind ==> It is possible to read the story by first going the Google news aggregator link and then selecting the story titled “Reef whistleblower censured by James Cook University”. You must do it in that order, if I posted the link to the story, you’d hit the paywall. (The technical point is that the Australian’s website shows the page to those coming from the Google site — the right referrer — but not if you go to the story directly — my guess)
Hmmmmm…it worked for me several times, then quit working…some tricky coding down under, I suspect.
“I am grateful for the many suggestions regarding which Wars to highlight.”
I would suggest the “nuclear rocket war.” Notably the Orion rocket that proposes the use of mini atomic bombs for propulsion. It was proposed since 1950s and studied and supported by big names such Stanislaw Ulam, Freeman Dyson, Carl Sagan, Arthur Clarke, etc. I wonder why this science fiction refuses to die. My own calculations and common experience show it’s a big blunder.
Supporters believe the steel pusher plate of the rocket will somehow withstand the nuclear blast and plasma shower. The plasma is at 67,000 C. A plasma cutter is ‘only’ 28,000 C and it vaporizes steel plates upon contact.
Calculations using Newton’s 2nd law and kinematic equations reveal the rocket’s flaw. From Orion’s design data:
ms = mass of ship (less pusher plate) = 380,000 kg
mp = mass of pusher plate = 500,000 kg
Ws = weight of ship (less pusher plate)
Wp = weight of pusher plate
P = pressure on pusher plate = 340 MPa
D = diameter of plate = 25 m
A = area of plate
dt = time of contact of plasma = 300 microseconds
The force F on the pusher plate is
F = P A = 1.67 x 10^11 N
The acceleration a of the plate is
a = F/mp = 333,795 m/s^2
Note this is equal to 34,000 g’s. 50 g acceleration is enough to kill a man. But as supporters will say that’s why we have shock absorbers to reduce the deadly acceleration. Can it really do that? Let’s see
The velocity of the plate is
Vp = a dt = 100 m/s
Let’s say the shock absorbers can handle 50 g acceleration (no point in increasing the maximum because it will already kill the astronauts at 50 g) and 10 m is the maximum compression of the shock absorbers. The force at 50 g is
F = ms 50 g = 1.86 x 10^8 N
And the average force Fa is half of that. We can solve the following kinematic equations:
ap = (-Fa – Wp)/mp
as = (Fa – Ws)/ms
xp = Vp t + ap t^2/2
xs = 0 + as t^2/2
Where ap and as are the accelerations and xp and xs are distances traveled by ship and plate respectively at time t. 50 g is reached when
xp – xs > 10 m
The solutions to the above equations show that the ship will reach 50 g in 0.13 second. Instant death to the astronauts. The shock absorbers slowed down the acceleration from 34,000 g in 0.0003 second to 50 g in 0.13 second. Still deadly
I hope this put to rest the ‘nuclear rocket’ war
Reply to Dr. Strangelove ==> Personally, I have never heard of such a thing. However, I have recently toured the Kennedy Space Center in Cape Canaveral and seen information on the Orion rocket system.
Orion will not be powered by anything that could possibly be considered “mini atomic bombs for propulsion.”
The Orion SLS (Space Launch System) “will rely on two solid rocket boosters in addition to the huge, 200-foot-tall (61 meters) core stage, which will carry liquid hydrogen and oxygen to fuel four RS-25 engines. The RS-25 rocket engine is a workhorse: It powered the space shuttle…”
Where in the world did ever get the idea that “mini atomic bombs” were involved?
Kip, obviously you have never heard of the Orion nuclear rocket. I got the idea of mini atomic bombs from the sci fi world of Arthur Clarke and Freeman Dyson. I’m sure you have heard of them.
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
http://i.imgur.com/B5HlKyU.jpg
Back in the 1950’s both the Americans and Soviets had concepts with nuclear-power propulsion. None actually flew. Many names of space programs have been re-used through the years.
They were not as silly on the face of it as Dr. Strangelove makes it seem but, obviously, they had problems that were not overcome.
In 1865 Jules Verne wrote a sci fi novel ‘From the Earth to the Moon’ where the heroes were blasted from a giant cannon to the moon. Scientists at that time knew the idea was silly as the heroes would instantly die from the huge acceleration. The Orion nuclear rocket was just as silly in 1960 except some brilliant scientists liked the idea.
A less silly idea is the atomic airplane proposed by the great Richard Feynman. Instead of atomic bombs, it uses a nuclear reactor for propulsion which is more sensible. Had Feynman asked Orville Wright in 1948, he would have been educated why his atomic airplane would not fly (pun intended) Engineers like their airplanes to be lightweight. Nuclear propulsion operates on a Rankine cycle like a steam engine. Engineers don’t put steam engines on airplanes because they are heavy compared to internal combustion engines and jet engines. Physicists have a lot of new ideas but engineers pick only the practical ones.
Reply to Dr. Strangelove ==> Actually I had heard of the Sci-Fi idea, back when I was a child, in the 1950s. If you had linked to the Wiki, it would have helped. Like many things, a confusion of names (Orion also being the name of a current rocket system) prevents understanding — that and the leaving out the time context — there has been no serious consideration of the idea for 50 years.
While the original idea was canned for both practical and political reasons, the ideas of using advanced power schemes for space-to-space propulsion may involve nuclear in some way.
Can’t see this as a modern science war in the sense being discussed in this series, as it is not ongoing, and lacks the wide public exposure that is a hallmark of these this series.
Thanks for participating here.
“I am grateful for the many suggestions regarding which Wars to highlight.”
I suggest the “nuclear rocket war.” Notably the Orion rocket that proposes the use of mini atomic bombs for propulsion. It was proposed since 1950s and studied and supported by big names such Stanislaw Ulam, Freeman Dyson, Carl Sagan, Arthur Clarke, etc. I wonder why this science fiction refuses to die. My own calculations and common experience show it’s a big blunder.
Supporters believe the steel pusher plate of the rocket will somehow withstand the nuclear blast and plasma shower. The plasma is at 67,000 C. A plasma cutter is ‘only’ 28,000 C and it vaporizes steel plates upon contact.
Calculations using Newton’s 2nd law and kinematic equations reveal the rocket’s flaw. From Orion’s design data:
ms = mass of ship (less pusher plate) = 380,000 kg
mp = mass of pusher plate = 500,000 kg
Ws = weight of ship (less pusher plate)
Wp = weight of pusher plate
P = pressure on pusher plate = 340 MPa
D = diameter of plate = 25 m
A = area of plate
dt = time of contact of plasma = 300 microseconds
The force F on the pusher plate is
F = P A = 1.67 x 10^11 N
The acceleration a of the plate is
a = F/mp = 333,795 m/s^2
Note this is equal to 34,000 g’s. 50 g acceleration is enough to kill a man. But as supporters will say that’s why we have shock absorbers to reduce the deadly acceleration. Can it really do that? Let’s see
The velocity of the plate is
Vp = a dt = 100 m/s
Let’s say the shock absorbers can handle 50 g acceleration (no point in increasing the maximum because it will already kill the astronauts at 50 g) and 10 m is the maximum compression of the shock absorbers. The force at 50 g is
F = ms 50 g = 1.86 x 10^8 N
And the average force Fa is half of that. We can solve the following kinematic equations:
ap = (-Fa – Wp)/mp
as = (Fa – Ws)/ms
xp = Vp t + ap t^2/2
xs = 0 + as t^2/2
Where ap and as are the accelerations and xp and xs are distances traveled by ship and plate respectively at time t. 50 g is reached when
xp – xs > 10 m
The solutions to the above equations show that the ship will reach 50 g in 0.13 second. Instant death to the astronauts. The shock absorbers slowed down the acceleration from 34,000 g in 0.0003 second to 50 g in 0.13 second. Still deadly
I hope this put to rest the ‘nuclear rocket’ war
test post
Reply to Dr. Strangelove ==> Please use the Test Page for test posts. Commenting there allows you to see the result of your post, formatting etc.
If you have “test post”ed because you think your posts are being binned or failing to appear, addressing a comment to MODERATOR (simply including this word) will bring your comment to their attention.
I love this post and I suspect I will love the future posts in this series. I have embarked on a high fat low carb diet for 4-5 years now. I occasionally push all the way to ketosis and I’ve never felt better or been more lean. My athletic endurance has increased and I love my fat rich foods (butter, cheese, beef, fatty fish, olive oil, avocado, etc…). My overall lipid profile is great (although what great is, is very debatable) and I have very low inflammation markers.
There are incredible parallels between nutrition and climate “science”. It’s sad really. I have a pretty liberal group of friends and unfortunately they never listen when I try to persuade them that the popular science in these areas is misleading people. Whenever I see something in the liberal media that questions the science (rarely) I try to share it with them in the hope they will at least read it. Unfortunately and frustratingly that mostly doesn’t happen. It is very frustrating. I’m sure many of them think I’m a raging conspiracy theorist.
Reply to McMark ==> The efforts to discover “the ideal human diet” are probably misguided and have resulted in a lot of nonsense. Unfortunately, the nonsense has tended to make people gun-shy of nutritional science and advice altogether — except for those few who seem perfectly happy to “go along” with whatever the latest advice is.
Glad you’ve found a personal diet that suits your needs and lifestyle.