tanley Feldman and Vincent Marks' book Panic Nation explores "the myths we're told about food and health." While the genre is growing in reaction to the current global spate of myth-information, the book's appearance in the UK is timely since the Brits seem furthest off-base regarding the scientific issues of salt and health.

Chapter 9 by Dr. Sandy Macnair deals with salt and has been generating news coverage since publication . While much of Dr. Macnair's review tracks earlier work such as ABC-TV's "20/20" and "The (Political) Science of Salt" in Science magazine , a couple of observations may be new even to close readers on the issue.

We're often told that humans today eat "too much" salt -- more than our cave-dwellilng progenitors. Intakes in acculaturated societies range from about 2,300 mg/day sodium to 4,600 mg/day (6 - 12 grams of salt). While most people's healthy kidneys effectively process salt-laden body fluids, excreting the "excess," some people's kidneys malfunction and problems occur. Explained this way, you get the idea that the kidney is processing roughly ten grams of salt a day. Not so, explains Dr. Macnair. The kidneys filter water from the blood in the amount of 170 liters of water a day and, get this, handle 1,500 grams of salt a day. How our bodies can distinguish one or two milligrams out of this 1,500 grams (that's 3.3 POUNDS of salt a day) is absolutely amazing, but the main point is that we shouldn't think that the kidneys are straining to hand more than a gram or two a day.

Dr. Macnair makes another interesting point in his discussion of human evolution. Fourteen million years ago, he says, our ancestors in the Rift Valley in Africa split into two evolutionary streams, one heading off to the jungles to the west to evolve into great apes while those remaining in the Valley, with ready access to salt and the need for food preservation in the seasonal climate, produced a very different diet incorporating unique essential fatty acids that produced brains three times larger than their departed primate cousins and homo sapiens learned how to salt cure meats to ensure their survival.

You can read more in the South African magazine Food Review (as mentioned in our February blog ).

Perhaps Dr. Macnair's compatriots can reconsider the wisdom in his article.

"Give me a pinch of salt," he said. "Bigger pinch. Bigger pinch. There you go!"

So instructed Michel Richard, Washington's preeminent star chef who teaches classes at his legendary Georgetown restaurant, Citronelle.

Michel earns his reputation and living by making nutritious food taste good. His students were preparing what looked to be a beautiful ratatouille or caponata of colorful vegetables.

Contrast this with the public anti-salt program being waged by the Food Standards Agency of Britain. FSA originally started their salt reduction campaign by demanding national and private label manufacturers reduce the salt content of their processed foods and then, in consumer activist fashion, went on to name and shame those who were slow to cooperate.

This week, the FSA launched their latest anti-salt campaign, entitled (I kid you not) Full of It! The "Full of It!" campaign exhorts consumers to choose their foods based upon one criteria and one criteria only - salt content. Its banner line says,

Check the label and pick the product with the lowest amount of salt.

Regardless of the nutritional value of the food, simply pick the one with the lowest amount of salt. A simple-minded message that totally ignores the role and contribution of all other nutrients in the diet to the health and well being of consumers.

A far more constructive approach was taken by the Alliance for a Healthier Generation (a joint project of the William J. Clinton Foundation and American Heart Association). Just last week their program, devised to reverse childhood obesity in America, was given the nation's most prestigious health care quality award . That program also considered sodium along with all other nutrients and made recommendations for a better quality diet for schoolchildren. Although they asked for a cap on sodium levels, they went way beyond that and made clear exceptions, going as high as three times the recommended cap, for certain foods that provided essential nutrients. They said:

"The overall nutritional benefit of these foods outweighs the potential health concerns concerning higher sodium. They contain nutrients that kids need like vitamin A, calcium and fiber. Many of the soups also contain vegetables, which we know that kids don't get enough of. In addition most soups are moderate in calories and low in fat and saturated fat."

Bitterness is a major determinant of vegetable palatability and a major reason why youngsters avoid them. Many need a bigger pinch of salt to make them taste good, and it's the overall quality of the diet that counts, not just one isolated component. The residents of Italy and Spain eat a lot more vegetables and 15-20% more salt (according to the Intersalt data) than their British counterparts, yet the WHO Health for All database shows that their ischemic heart disease death rate is half that of the UK!

Come to think of it, I can't think of a better name for this latest FSA anti-salt campaign than "Full of It!" because that is exactly what it is.

The Salt Institute has been engaged in the cyber-debate over the British Food Standards Agency's promotion of salt-reduced diets. FSA released a report yesterday stating that in five years, Britons had reduced their salt intake from 9.5 g/day to 9.0 g/day. A typical newspaper story ran the story this way:

Salt consumption in Britain is still on average 50 per cent higher than the recommended amount, new research has revealed today. Tests on 1,287 adults showed their average salt intake was 9g per day. Although this is adrop from 9.5g when the last tests were done in 2001, the consumption is far higher than the national target of 6g per day, the Food Standards Agency said.

That set off a string of reader comments -- you can read them yourself .

First of out the box was the accusation that salt manufacturers who object that the intervention might entail risks should "tell us which consumers could be harmed by a blanket approach and of course, the evidence?"

OK. We did. I responded:

Two groups come to mind, based on peer-review, published studies: the populations of Mr. Schmulian's Scotland and the population of the United States. The massive Scottish Heart Health study found additional risk for Scots and two studies of the US National Health and Nutrition Examination survey found 20% and 37% greater cardiovascular mortality among those consuming FSA-recommended amounts of salt.

The FSA contention of lower CV risk is based on extrapolations that have not been confirmed in studies of the direct question: will lower salt diets be healthier.

That's why the experts in evidence-based medicine at the Oxford-based Cochrane Collaboration have concluded there is insufficient evidence to recommend universal salt reduction.

That prompted another reader to complain "Your claim about the cochrane institute is wrong," adding that blood pressure is improved by salt reduction. To keep the record accurate and in further response, I added:

The Cochrane review "Advice to reduced dietary salt for prevention of cardiovascular disease" which the Cochrane Library issued in November 2003 (http://www.cochrane.org/reviews/en/ab003656.html ). It concluded:

"Intensive support and encouragement to reduce salt intake did lead to reduction in salt eaten. It also lowered blood pressure but ... not enough to expect an important health benefit. It was also very hard to keep to a low salt diet....

"There was not enough information to assess the effect of these changes in salt intake on health or deaths."

But, the question really isn't about blood pressure, it's about health outcomes. Blood pressure is an interim variable affected by salt. So is insulin resistance, plasma renin activity, sympathetic nervous system activity, etc. What we need to focus on is the net effect: are people healthier? living longer? having fewer heart attacks, etc?

Just keeping the science front and foremost.

Can anyone sort through the confusion of various and conflicting medical journal articles to understand what science is telling us about the basis for sound public health nutrition policy? Perhaps so, venture Drs. Neff Walker of UNICEF and Jennifer Bryce and Robert E. Black of Johns Hopkins University in the current issue of The Lancet, "Interpreting health statistics for policymaking: the story behind the headlines ." They explain:

Politicians, policymakers, and public-health professionals make complex decisions on the basis of estimates of disease burden from different sources, many of which are "marketed" by skilled advocates. To help people who rely on such statistics make more informed decisions, we explain how health estimates are developed, and offer basic guidance on how to assess and interpret them. We describe the different levels of estimates used to quantify disease burden and its correlates; understanding how closely linked a type of statistic is to disease and death rates is crucial in designing health policies and programmes. We also suggest questions that people using such statistics should ask and offer tips to help separate advocacy from evidence-based positions. Global health agencies have a key role in communicating robust estimates of disease, as do policymakers at national and subnational levels where key public-health decisions are made. A common framework and standardised methods, building on the work of Child Health Epidemiology Reference Group (CHERG) and others, are urgently needed.

Just because it's "in black and white" -- even in a bolded headline, doesn't make a statement scientifically valid. Everyone claims their conclusions are "evidence-based," but we need to follow careful rules to understand just which "evidence-based" conclusions are, in fact, "evidence-based."

Two themes of frequent mention here are the crucial importance of quality evidence and a laser-like focus on health outcomes. Others use their own issues to raise these points as well, reinforcing the building pressure for action.

An example is the recent column "Medical Information: The Good and the Bad " by Dr.s Michael Arnold Glueck and Robert J. Cihak aka "The Medicine Men."

Dr. Cihak asks:

What should be done, if anything, about the flood of medical information from news stories, popular magazines, TV shows, advertising, and even our own doctors?

Is information overload even a bad thing?

Moreover, are we missing the forest while looking at the trees? Very often, I'd say yes.

It's often best to ask, "What are we really concerned about?" For example, too much cholesterol in the blood can lead to hardening of the arteries, which can lead to plugged-up arteries in the heart or brain, resulting in a heart attack or stroke.

The effect of the abnormally elevated cholesterol level is the concern, not the cholesterol itself, because lowering abnormal cholesterol levels can reduce the likelihood of disability or death from blocked arteries.

So the goal is to prevent illness, not to reduce cholesterol for its own sake. And, there are always tradeoffs. Taking medicine takes time, money, and other resources away from other uses. Plus, the medicine might not work or even cause additional medical problems.

The same dynamic pertains to the health impacts of dietary salt. The public is being fed an alarmist diet of concern about blood pressure when that is but one of several impacts of restricting dietary salt. Others include increasing insulin resistance, skyrocketing plasma renin activity and stimulated sympathetic nervous system activity. So the Salt Institute's been urging HHS to undertake a study of the health outcomes of salt-reduced diets using this same argument. If you read the above quote, substituting "blood pressure" for "cholesterol" and you'll see what I mean: "The effect ... is the concern, not the cholesterol) itself, because lowering abnormal cholesterol levels can reduce the likelihood of disability or death from blocked arteries. So the goal is to prevent illness, not to reduce cholesterol for its own sake. And, there are always tradeoffs. Taking medicine takes time, money, and other resources away from other uses. Plus, the medicine might not work or even cause additional medical problems."

We couldn't say it better -- though we tried . Thanks as well, doc, for your cautionary summary: "Cookie-cutter approaches are dandy for cutting cookies but not for dealing with human beings."

The United Nations Children's Fund (UNICEF) has released The State of the World's Children 2007 with statistics from nearly 200 countries around the world on the percentage of households with access to iodized salt. While progress over the past 15 years has been dramatic, its pace has slowed. A decade ago, only 54% of the world's households had access to iodized salt; today it stands at 70%. But it has increased from 66% in 2000 and only from 68% from 2006 to 2007. Country tables are included .

With this provocative title for its March 2007 featured article, the UC-Berkeley Wellness Letter caught our attention, particularly because they mentioned the Salt Institute. Because it may have caught others' attention, these thoughts to correct some misinformation in the article.

MythStatement: "As concern (with salt intake) has faded, people have been eating more salt. Since the early 1980s, U.S. per capita salt intake has risen by about 50%."

Fact: US food salt sales entering the 1980s were a shade over 1 million tons. Today they are 1.586 million tons -- up about 50%, right? But not "per capita." The US population in 1980 was 227 million; today it exceeds 300 million, up over 32%. And that is "sales," not ingested salt. Looking at the baseline data of entrants to clinical trials who are tested for 24-hour urine sodium, there is no evident increase in per capita sodium intake over time.

MythStatement: "Many large observational studies over the years have linked a high sodium intake to high blood pressure and increased deaths from heart attacks and strokes. For example, the Intersalt study looked at 10,000 people in 32 countries and concluded that high salt intake was directly related to hypertension and deaths from stroke." The article then states that pro-salt critics have found methodological problems with Intersalt.

Fact: Intersalt was a great study, though not an intervention trial. The primary hypothesis of the study was that salt intake was directly related to blood pressure. Contrary to the Wellness Letter, the study did not confirm this hypothesis; neither for systolic blood pressure (the primary hypothesis) nor diastolic blood pressure (the secondary hypothesis). There was no relationship. The Salt Institute has always considered Intersalt a high quality study. Salt opponents did too, until the results were announced; after that, they began to find reasons to back away from its findings. As for other "large observational studies ," none have found higher incidence of cardiovascular events nor higher CV mortality on diets with US-levels of salt.

MythStatement: "It's much harder to dismiss the research on the DASH (Dietary Approaches to Stop Hypertension) diet, which consists of fruits, vegetables, and whole grains, plus small servings of meat and dairy. It also provideds a lot of potassium, magnesium, and other minerals that help control blood pressure. DASH comes in two versions -- one with 2,300 milligrams of sodium a day, the other with 1,500. Both diets lower blood pressure in healthy people, but most dramatically in those with hypertension. The lower-sodium version lowers blood pressure even more. "

Fact: Where to start? The Salt Institute has endorsed and strongly promoted the DASH Diet since it was first reported in 1997. It is not properly described in the Wellness Letter. It is high in fruits, vegetables and dairy products and low in meat -- not reduced in dairy as stated. In fact, half the blood pressure benefit is from the dairy. The DASH Diet is also not reduced in sodium at all. A second "DASH" trial was held reducing sodium to 2,300 mg and 1,500 mg. Judge the results for yourself. As the Wellness Letter points out, those with high blood pressure benefit the most. The original trial found they achieved a drop of 11.4 mm/Hg in systolic blood pressure when on the DASH Diet (with no sodium reduction). When DASH Dieters were placed on the 1,500 mg salt-reduced diet, they achieved an 11.5 mmHg SBP reduction. We call that statistical noise. We think it's clear the benefit is conferred by the improved quality of the DASH Diet (11.4 mmHg) and the additional contortions to reduce sodium by 60% produced only an insignificant change (0.1 mmHg). Furthermore, while the nutrients stated are likely to be responsible for erasing the "salt sensitive" blood pressure response, the trials were for foods, not nutrients.

MythStatement: Finland achieved a decrease in deaths from strokes and heart attacks over the past 30 years by reducing dietary salt.

Fact: The US has reduced its rate of reduced cardiovacular events and mortality over this same time span by the same amount without reducing dietary salt (the Wellness Letter even says salt intake in the US has increased).

MythStatement: "Here's what the salt industry advises: There's no ironclad evidence a high salt intake is bad, so don't worry. Eat what you want, and enjoy yourself. Help us make a lot of money out of salt."

Fact: We have no evidence that they're still smoking stuff on the Berkeley campus; this statement could just be a coincidence. The Salt Institute has long supported "moderation" in sodium intake, supporting the US Dietary Guidelines until 2000 when the Guidelines left this safe harbor. It may be that high-salt diets such as in Japan are problematic; experts disagree (see previous blog ), but we are at the polar opposite of hedonists who say "eat what you want." The answer, as we've repeatedly testified, is that we need to improve the overall quality of the diet, particularly improving the mineral density of the diet (more calcium, magnesium and potassium).

MythStatement: "Most people can quickly get used to a lower-sodium diet..."

Fact: Reducing dietary salt is NOT easy. In the DASH Diet, they achieved compliance by providing free food. In the Trials of Hypertension, with heavy hands-on encouragement and coaching of highly-motivated volunteers, salt reduction was reduced by about a third over the three years of the trial. (Note: during that three years, the body adjusted and blood pressures returned to their former levels -- how come the Wellness Letter didn't mention that?)

There are more assumptions and leaps-of-faith, but this gives you an idea of how a supposedly unbiased and expert review can go awry when confronted with the near-religious zeal to cut salt.

The International Journal of Epidemiology has just published (February 2007) "Dietary patterns and cardiovascular disease mortality in Japan: a prospective cohort study ." Taichi Shimazu and colleagues studied 40,547 Japanese over seven years and reported on the 801 cardiovascular deaths in the group. They reported, unsurprisingly, that the Japanese dietary pattern is high in sodium (my note: possibly the highest in the world). Their conclusion: "The Japanese dietary pattern was associated with a decreased risk of CVD mortality, despite its relation to sodium intake and hypertension."

The authors point out that while the Japanese consume more salt than western diets, their age-adjusted mortality due to cardiovascular disease is about 40% lower than the UK and about 30% lower than the US. They point out that earlier studies of particular nutrients or foods in the Japanese diet (such as sodium) have generated great concern among public health activists, but when the entire diet is considered, those associations disappeared.

By our count, that's 14 studies relating health outcomes to dietary salt . None confirm any health benefit for lower salt intakes in the range of the American diet and of the two in high-salt-consuming Japan, this one finds no benefit while the other found reduced stroke incidence on levels where the "low salt" consumers ate more salt than the U.S. average. See our online discussion .

The National Association of Manufacturers has just issued its seventh edition of The Facts About Modern Manufacturing . It's a reference book about the value of manufacturing the the US economy.

As such, it counters the notion that we are a post-industrial economy, pointing out that if manufacturing would be considered by itself, it would be the eighth largest economy in the world.

Some key facts:

Manufacturing makes the highest contribution to economic growth of any sector, being responsible for more than 70% of private sector research and development.

Manufacturing achieves a high productivity rate year in and year out, increasing by more than 50 % in the past decade.

Manufacturing contributes more than 60% of U.S. exports or about $50 billion a month.

Manufacturers pay wages and benefits that are about 25% higher than in non-manufacturing jobs.

More than other sectors, each dollar spent by manufacturing generates an additional $1.37 in economic activity.

The report also documents policy changes NAM believes necessary to ensure future growth of manufacturing, including:

An educated and productive workforce. Eighty-one percent of respondents in NAM's 2005 Skills Gap survey said they could not find qualified workers to fill open positions.

High built-in costs. Structural costs such as taxes and health care add 31.7% to U.S. manufacturing costs, making it more difficult to produce from a U.S. base.

There's lots more.

Anyone who has ever kept tropical fish knows the health benefits of treating them with hypertonic saline. If I ever saw one or more signs of stress or disease, such as clamped fins, body sores or gasping at the surface I immediately added 1 tablespoon of sea salt for every 5 gallons of aquarium water. The theory was that the osmotic shock was not enough to harm the fish, but sufficient to control pathogenic microorganisms. However, I always felt there was something more to it.

Very recently, a number of articles on the use of hypertonic saline have highlighted how it has been successfully used to treat severe trauma patients as well as people with critical brain injuries such as soldiers in Iraq or people in car accidents. (Every 15 seconds someone suffers from a traumatic brain injury within the US alone, leading doctors to refer to this as the silent epidemic.)

Hypertonic saline is any solution of sodium chloride (NaCl) in water with a concentration higher than physiologic (0.9% w/v). When administered in vivo, hypertonic saline (HTS) exhibits several physiological effects beneficial to cerebral or other tissue injury including: 1) osmotic and vasoregulatory - by promoting the flow of excess water from the tissues to the blood via osmosis and decreasing edema in the vascular endothelium of injured tissues, thus lowering vascular resistance and allowing more blood flow; 2) hemodymanic - by effectively expanding plasma volume; 3) immunomodulatory - by preventing leukocytes from becoming activated and adhering to injured neurons and; 4) neurochemical - by counteracting detrimental excitatory amino acids through the normalization of neuronal cell membranes and by restoration of normal electrolyte and neurotransmitter levels in brain cells, and normal cell volumes.

In addition to its value in trauma treatment, hypertonic saline has also been successfully used to improve lung function in cystic fibrosis in both adults and children as well as leading to quality of life improvements through reduction of chronic sinus complaints.

Chalk up a few more applications to the 14,000+ uses of hyperfunctional salt!

The Japanese diet has the highest salt level among populations around the world. The Japanese have the longest living population on Earth. Granted, there are lots of confounders, but those are hard facts and relevant to the question of whether low-salt diets are healther and extend life.

A new study, e-published on February 22 in the International Journal of Epidemiology by Taichi Shimazu, et al. reports the results of a seven-year follow-up study of 40,547 Japanese men and women, ages 40-79. The authors identified high blood pressure and high sodium diets as characteristic outcomes of the Japanese diet but concluded that no evidence of any dietary pattern linked to cardiovascular mortality. In fact, the study showed the high-salt Japanese diet to have about 40% fewer CV deaths than in the UK and about 30% less than in the US.

The authors clearly expected another result. They state:

The Japanese diet has so far been considered to increase the risk of CVD because it includes a large amount of salt. In the present study, the Japanese dietary pattern was related to higher sodium consumption and higher prevlance of hypertension. In spite of these risk factors, the Japanese dietary pattern was assocaited with lower CVD mortality.

This is the second health outcomes study of salt intake in Japan. An earlier study found an association between stroke and salt -- but at salt levels much higher than in North America and Europe. In fact, the "low salt" group in that diet had substantially more salt than the U.S. average intake. This study should cause even the high-salt Japanese to consider whether lowering dietary salt will reduce CV risk.

On the other hand, it is yet another study that consistently concludes there is no improvement in health outcomes among populations consuming lesser amounts of salt -- no matter what the government asserts.

The latest USGS figures for 2006 are in and for the first time, the production and salt in China (48 million MT) has exceeded production in the US (46 million MT). As is readily apparent from the figures published on the Salt Institute World Salt Production Webpage , China has shown largest growth during the last 15 years, doubling its output from 24 - 48 million metric tons. Very significant production gains have also been experienced in India and Australia. Where will the next decade take us?

In reviewing the burden of disease attributable to nutrition , Joceline Pomerleau, of the Lab at School of Hygiene and Tropical Medicine and her colleagues concluded that the variations of health patterns in Europe were largely attributable to the differences in dietary intake. More specifically, they were able to show that intakes of fruits and vegetables were responsible for differences in age-standardized death rates from ischemic heart disease. The Salt Institute followed that line of thinking and, using the FAO and WHO databases on diet and health, determined the role of fruits and vegetables on cardiovascular disease in those countries included in the well-known InterSalt study. Predictably, the data revealed that the higher the percentage of fruits and vegetables and the diet, the lower the rate of cardiovascular disease. At the same time, the data indicated that cardiovascular disease decreased as sodium consumption increased. The data corresponds to the results of the initial DASH diet study which made it plain that a balanced diet, high in fruits and vegetables leads to good health, and is unaffected by salt intake.

In an effort to encourage lower sodium consumption, UK policymakers have removed the salt shakers from school lunchrooms. As a result, students are not only eating less sodium but also, unfortunately, fewer vegetables. Simply put, the most nutritious cruciferous vegetables (such as broccoli, cauliflower, kale, collard greens, cabbage, Brussels sprouts, and turnips) have a strong bitter component. Since it has been universally established that most children (and adults as well) need to increase their vegetable consumption significantly, the UK approach of substantial salt reduction seems misguided to say the least. The use of salt to improve the palatability of vegetables will do far more to promote an optimal diet than reducing the small amount of sodium chloride needed to make vegetables more palatable. The Salt Institute has initiated a research project at Ohio State University to determine the optimal level of salt required to increase the likelihood of people eating more cruciferous vegetables. Having this quantitative information will allow US policymakers to consider the inclusive benefit/risk package before repeating the rash actions of their UK counterparts. This project is scheduled to go ahead this month.

After millions of pounds sterling have been invested in a comprehensive anti-salt media campaign to convince British consumers to reject salt, the government's Food Standards Agency, which has led the charge, reported this week on Consumer Attitudes to Food Standards . Bottom line: the money's been wasted!

Britons remain unconvinced on salt despite the media barrage disparaging salt. Unpromped, 3,513 respondents were asked "Are there any issues related to food that you have concerns about?" Only 4% identified "salt content" as a concern, fourth among concerns and only 1% higher than in 2005. Less than half (46%) have been convinced that there are any issues with food (Chart 30).

British consumers, however, well know the politically-correct answer. Prompted by the massive PR campaign to answer "yea" or "nay" about whether they are "concerned" about "the amount of salt in food," more than half (54%) agree, ahead of fat (46%)(Chart 35). Thus, FSA may feel it is getting the taxpayers' money's worth -- except that respondents don't seem to be internalizing the message, just regurgitating what's expected. And the reason is also clear: most rely on TV news and somewhat fewer on newspapers for their information; missing entirely is any mention of reliance on health care providers as information sources (Charts 37 and 41).

FSA may find trouble brewing in one other finding. While one-third of respondents continue to feel the information the agency provides is "independent/unbiased" there was a sharp 29% increase in consumers who agreed that the agency was promoting official government policy (Chart 49).