This week's (January 5th) National Journal cover story, "Data Bomb ," set off reverberations in my mind. The article recounts the release of grossly-misleading data immediately prior to the 2006 Congressional elections that exaggerated tenfold the number of deaths in Iraq; the study fed popular disillusionment with U.S. engagement in Iraq and contributed to capture of both houses of Congress in the elections several weeks later. The study was produced by the Johns Hopkins School of Public Health. The researchers, it turned out, were anti-war activists, though they claimed their errors didn't reflect their political views.

Bad memories. Six years earlier, researchers from the Johns Hopkins School of Public Health published misleading statistics in the DASH-Sodium trial - and refused to release further statistical calculations that would likely have unmasked their charade. Again, the Johns Hopkins researcher was an activist, a member of the lobby group World Action on Salt and Health (WASH). Again, the incompletely-reported and misleading research was instrumental in an important policy decision - to establish a Daily Recommended Intake level for sodium and a Dietary Guideline supporting reduced salt intake. Even worse, this time, despite the incontrovertible conflict represented both by his WASH lobby group membership and heavy involvement in the research itself, the researcher was installed as chair of the DRI project committee and the Dietary Guidelines subcommittee where he blocked consideration of the full data from the study.

Putting the National Journal aside, I plunged into an editorial in the journal of another advocacy organization, reading an editorial entitled "Eat your fruits and vegetables, but hold the salt ." The editorial writer acknowledged his funding support from the same federal agency that had funded DASH-Sodium for a study he has underway exploring the effects of the "DASH Diet" on individuals with isolated systolic hypertension. I expected little comfort, but hoped that, perhaps, the editorial would confess the over-interpretation of the results (as had an earlier article in 2005 where a DASH-Sodium investigator revealed that in six of the eight subgroups - subgroups that represented a large majority of the public - the reported findings were statistically insignificant even though the authors described them as valid.

All these discussions of DASH-Sodium have attempted to portray the DASH Diet as salt-reduced and demonstrating benefit from lower sodium intakes. This has been frustrating to those of us - including the salt industry - who have strongly endorsed the DASH Diet because it does not reduce salt and the blood pressure effect is produced by the fruits, vegetables and dairy products - not the salt. But the federally-funded PR juggernaut rolls on.

In the editorial, Dr. Paul Conlin of Harvard University's Brigham and Women's Hospital, indeed, endorsed salt reduction and noted a study of blood pressure in chimpanzees supported increased intakes of fruits and vegetables, two of the triumvirate of "good" foods in the DASH Diet. But note the caveats Conlin incorporates into his conclusions:

Elliott et all have provided new information, albeit in chimpanzees, showing that long-term salt restriction in the setting of a diet rich in fruits and vegetables produces sustained reductions in blood pressure. These data are relevant to humans but should be approached with caution and respect for the sample size, the lesser effects when adjusted for key factors, and the inability to add knowledge on the health and/or cardiovascular benefits of salt restriction beyond blood pressure lowering. Major next steps include …confirming that eating such a dietary pattern provides unquestioned health benefits. (emphasis added)

Last year, other WASH advocates took an important step forward in conceding the validity of health outcomes measures instead of controversial statistical extrapolations based solely on blood pressure (ignoring other metabolic changes that occur in salt reduction). As one observer sagely observed, their embrace of health outcomes in a Finnish study "backfired" when the data showed that improvements in Finns' cardiovascular health lagged their European and North American peers. Still, anti-salt advocates have claimed it would be "immoral" to ask study subjects to consume "normal" levels of salt since they "know" it is unhealthy. The Conlin editorial cedes the point, admitting that such a study is not only feasible and moral, but needed to "add knowledge on the health and/or cardiovascular benefits of salt restriction beyond blood pressure lowering" and confirm "that eating such a dietary pattern provides unquestioned health benefits." Those benefits - projected to be improved cardiovascular outcomes like less heart attacks and cardiovascular disease - have not been confirmed in the several studies that have examined them.

The Salt Institute has called for a controlled trial of whether there is any health benefit from reducing dietary sodium. Now, even those who support salt reduction for blood pressure lowering are beginning to see that this isn't the right question and are embracing our view of the need for a new study.

Perhaps those bad memories of incomplete data reporting by Johns Hopkins' researchers can, indeed, be relegated to history and not the basis of public policy.

Two child specialists issue a timely reminder in the December 22 issue of the British Medical Journal . Indianpolis-based Rachel C Vreeman, a fellow in children's health services research, and Aaron E Carroll, an assistant professor of pediatrics, remind physicians not to be taken in by myths perpetuated in medical science:

Physicians understand that practicing good medicine requires the constant acquisition of new knowledge, though they often assume their existing medical beliefs do not need re-examination. ...

Even physicians sometimes believe medical myths contradicted by scientific evidence.

The prevalence and endorsement of simple medical myths point to the need to continue to question what other falsehoods physicians endorse.

Examining why we believe myths and using evidence to dispel false beliefs can move us closer to evidence based practice.

Let's face it, doctors are busy people. Reading all the latest journals -- and, particularly, the methods sections that often contain the key statistical manipulations -- is a virtually insurmountable task for GPs or area specialists like those serving our children. Take, for example, an aricle on salt and blood pressure in children published in the Journal of Human Hypertension in September 2007 by anti-salt war chief Graham MacGregor and his associates. MacGregor et al reported that

An increase of 1g/day in salt intake was related to an increase of 0.4 mm Hg in systolic and 0.6 mm Hg in pulse pressure....The consistent finding of our present analysis of a random sample of free-living indiviudals with that from controlled salt reduction trials provides further support for a reduction in salt intake in children and adolescents.

That's the item that may have caught readers' attention and, if so, it would have perpetuated another myth -- that salt was important to the blood pressure of children. Don't blame the journal, however; the editors commissioned an editorial to attempt to keep the story straight -- and they continue to make that editorial available as their top-listed Featured Article. In that corrective editorial , fomer International Society of Hypertension president Michael H. Alderman explains:

Specifically, a difference in salt intake of 1 g was associated with a 0.4 mm Hg rise in blood pressure. However, the significance of this relationship disappeared after correction for energy intake. ...

Regrettably, the current report provides little information regarding other associations to blood pressure or variations in other characteristics that might be associated with variations in sodium intake. For example, stature and physical maturation are associated with blood pressure. Bigger children may be muscular or pudgy. Children who exercise vigorously may have large energy (and sodium) intakes, and be taller and leaner than youngsters who have the same body mass index and different life styles. Cooper et al. postulated that the strong link of creatinine to blood pressure might reflect muscle mass and perhaps be a marker of body size. This, in turn, might be the most powerful determinant of blood pressure in children-more important than age or sodium. Perhaps, the best measure of growth and development available here is mid-arm circumference. The strong arm to blood pressure correlation may reflect muscle mass and suggests that diets high in energy (and therefore, among other things, sodium) may be conducive to physical maturation, along with a slightly higher blood pressure. In short, if this were the causal pathway, then higher pressure might even be a desirable sign in children.

Dietary intake is complex, and to characterize it on the basis of one element may well oversimplify any assessment of its value. For example, given the high correlation of energy with virtually all other nutrients, it is possible that those consuming more sodium (and energy) had more satisfactory consumption of other important dietary elements-both known and unknown. In any event, blood pressure is not the only measure of the health of children. The British Survey of Young People probably includes, in addition to physical and physiological data, information on other social, economic and developmental characteristics whose explanation might well inform our understanding of the relation of blood pressure, diet, health and development in these youngsters. Of note, He et al. also provide some other interesting information. For example, they note that 18-year-old British residents, in 1997, were consuming 2.6-g of sodium per day. That was similar to levels found in Chicago a decade earlier, and falls within the range of adult sodium intake seen world-wide in most countries and suggests that, a decade and 2 ago, these near adults were within that range.

It is also interesting to note that measures of discretionary sodium use did not correlate with blood pressure. This supports the Cochrane Collaboration conclusion that there was not sufficient evidence for a general dietary recommendation to reduce sodium intake. (emphasis added)

Medical myths can cause real damage. With regard to children, it seems that once corrected for caloric intake, there is no association of blood pressure and salt intake, but there IS a strong association of calories (and salt) with healthy development of children. Perhaps the biggest myth is that diet is less important than its component nutrients. Don't let your pediatrician get duped or pass on medical mythology.

Or should we title this: "Get government out of the bedroom ... and the kitchen"?

Don't miss the "Brave New Diet" op ed piece by Sally C. Pipes in today's Washington Post . To give you a flavor, she points out that basketball superstar Kobe Bryant and undefeated New England Patriot's QB Tom Brady -- to say nothing of "Hollywood hearttrobs" Brad Pitt, Matt Damon, Tom Cruise and George Clooney" -- are all "fatties." They're overweight using today's metrics. Besides some useful facts on government games-playing on the obesity issue, the political insight about dietary guidelines is particularly timely -- and planned -- for this holiday season with its parties and feasts. Ms. Pipes notes that

"underlying this ["common political refrain that America faces a childhood obesity epidemic"] is the premise that we're helpless before gingerbread cookies and honey-roasted hams -- unable to resist these and other foods and incapable of putting down our forks. We can be cured, it seems, only by government intervention such as the banning of trans-fats and sodas from public schools.

But is it the food, or is it us? Is it a proper role of government to tell us what we can or can't eat?

She poses some questions she'd like answered "[b]efore we let Uncle Sam into our kitchens, at school or at home" and concludes:

People make choices. And government should protect -- not restrict -- the freedom to make those choices so long as we're not harming others.

While we may not always like the choices others might make, it is essential that we all have the freedom to choose for ourselves. Once we accept the idea that the Nanny State should step in when it's "for our own good," we've taken a very big step down the road to something like the scene painted in George Orwell's "1984" -- when citizens wake each day to mandatory exercise classes on the Telescreen.

Most of us would prefer to choose for ourselves whether to exercise or have an extra helping of apple pie. And if we gain an extra pound over the holidays -- so what? That's why we have New Year's resolutions.

How can it be that Americans are living longer and healthier lives than ever before and yet dying in unprecedented numbers from chronic diseases? Are we confusing risks of proxy conditions for real risks of adverse health events?

Successful people live in the present, but they think seriously about the future. They invest themselves and their resources to make tomorrow better than today and to cushion the inevitable bumps in life's road. Through learned precept or harsh experience, they know that "an ounce of prevention is worth a pound of cure." They've also learned to count their blessings along the way, to temper their worry about the future by appreciating the good fortune they've enjoyed.

We use the same thought process to fashion public health policy. As a society, we have never been healthier nor longer-lived, yet these hard-won achievements are tempered with recognition that many amongst us and elsewhere in the world live Hobbesian lives. We recognize the fragility of our personal health and the imposing shadow of chronic disease in our lives and in our families. We invest ourselves, sometimes wisely, sometimes not, in quests to improve our diet and fitness and otherwise protect our health and that of our loved ones. We crave security in matters inherently uncertain. We sacrifice to prevent potential threats, often accepting taxes and social regimentation, believing that using a seatbelt or getting a flu shot is a reasonable trade-off against injuries in car crashes or a flu pandemic.

Just as we do as individuals, as a society we accept risk trade-offs, but we do it based on our belief that these risks have been fairly described. While each of us has a unique set of risk tolerances, the entire calculus is undermined if the information fed into this vast social "brain" is compromised by poorly-understood data limitations or manipulated by unseen parties with special interest bias.

Not to say that these choices are easy. We are beset, as individuals and citizens, with media coverage of emerging science which often seems conflicting. We hear blaring warnings about health threats and advocates' impassioned appeals for action on divergent strategies based on different diagnoses. It's confusing.

Take, for example, two recent "authoritative" pronouncements. In the new publication from the Department of Health and Human Services (HHS), Health, United States, 2007, a compendium of more than 150 tables reporting data from the Centers for Disease Control and Prevention, as we reported earlier :

Life expectancy is at an all-time high. Females live longer than males, but a baby born in 1900 would live until 1948 (men) or 1951 (women) -- 48 and 51 years, respectively. Boomers born in 1950 will live, on average until 2015 (men) or 2021 (women) -- 65.5 and 71 years, respectively). The new report predicts children born in 2004 will live until 2079 (men) and 2084 (women) -- 75.2 and 80.4 years respectively. We take it for granted, but it's big news. And good news.

Children are healthier. In just the past quarter century, the number of children who died before age 14 has been cut in half -- in half! (since the mid-20th century, the rate has been cut 80%). Youth and teens are 60% less likely to be in "fair" or "poor" health. Almost as good as Ivory Soap, 98.2% of our children are healthy.

Adults are thriving, too. Despite our aging population, the percentage of all people in "fair" or "poor" health has dropped in a decade by more than 10% -- from 10.4% in 1991 to 9.2% in 2005. Physical limitations have also been dropping, from 13.3% to 11.7% over the past eight years while age-adjusted vision- and hearing-impairment, over the same period, have improved a remarkable 65% (dropping from 10% to 3.5%).

Mortality continues to decline. The new figures confirm those we reported earlier this year in comparing the U.S. with Americans' steady salt intakes with mortality figures in Finland which compromised its health improvements as it reduced its population's salt intake. Overall, age-adjusted mortality for all of the leading causes of death are in decline -- cut in half since 1950. In just the past 14 years, deaths from the leading cause, heart disease, have dropped by a third. Deaths from the second-leading cause, cancer, have fallen 14% and the third, stroke, by a whopping 72% (with no reduction in dietary salt). The key is age-adjusting. If we don't die of something in our youth or early adulthood, we reach old age where we (all, eventually) die of "old age" ailments like respiratory infections or Alzheimers's. In fact, the biggest risk of dying is getting old.

But, just as we were feeling that perhaps all the doom and gloom of rising health costs and millions without health insurance, was a manageable challenge, The Partnership to Fight Chronic Disease, a new national coalition of business and labor groups, issued its "Policy Platform" declaring that "rising rates of chronic health problems pose a significant and unsustainable burden on the U.S. health care system" and called for Americans to display "a willingness to enact policies that help Americans better prevent and manage chronic illnesses." The Platform calls on the presidential candidates to "highlight common-sense reforms." Pointing out that 77% of U.S. healthcare costs are due to chronic disease, it cites (other) CDC figures showing two-thirds of American children will develop diabetes leading to "lower life expectancy than their parents." Scary stuff. The Platform throws around a lot of numbers, too, such as alleging that obesity costs society $200 billion a year.

Head-scratching time. What about the other CDC figures that show that overweight Americans are actually healthier than their thinner fellow-citizens ( 1 2 3 4 )? You may remember: the ones CDC issued as revisions to their earlier obesity alert .

Now, let's accept that the people making these analyses are most likely fair-minded advocates for their views. The first thought in sorting this out is the correct one: consult the data; a close reading of the studies may help explain the discrepancies and where the authors of various studies may have claimed more than their data show. There is another possibility, however.

While there is general consensus that preventing cancer or heart disease is better - and likely less expensive - than caring for the victim after a malignant tumor is discovered or a heart attack occurs, the differing statistical worldviews as described in Health, United States, 2007 and the PFCD Platform may come down to how risk is defined.

Take the seat belt example. Unrestrained car drivers and passengers are clearly at greater risk of injury or death than those who "buckle up for safety." We'd never, knowingly, combine the two groups to determine the average risk when the documentation of the very different risk profiles is available.

Transfer that thinking to the question of the risk of high blood pressure. About 20% of Americans have high blood pressure, hypertension. And hypertension is responsible for about 16% of heart disease. The 20% with high blood pressure include, of course, those whose current blood pressure exceeds the defined minimum 140/90 mmHg. But the calculation also includes all those whose blood pressure would have been at the "hypertension" threshold except that they took medications or made lifestyle adjustments to lower their blood pressure. Those who managed their blood pressure (like those with seat belts), surely have a lower risk. Unlike the seat belt example, however, they are all lumped together: "once a hypertensive, always a hypertensive." The group that modified its blood pressure should be considered a separate, lower-risk group. By lumping them together, we inflate the number of people identified at risk and targeted for public health concern.

Better data would, thus, help us understand why we continue to have a large number of people with hypertension while at the same time we have achieved fantastic reductions in the rate of heart disease. Hypertension is often "sold" as a disease when it is, rather, an indicator, a marker, an intermediate variable. We are concerned about heart attacks, strokes and mortality. When it comes to treating this surrogate marker, we must never lose track of the real objective: improving health outcomes, not modifying "risk factors" - especially one that explains only one-sixth of the problem. The body is complex and its systems, redundant and interconnected. Simple solutions may make great headlines, but they don't change the "medical facts of life."

So, as we marshal our resources and prioritize our public health targets, let's keep in mind that efforts to prevent chronic disease must be assigned using real-world data. We can prevent high blood pressure, but if the side-effects (e.g. increased insulin resistance, elevated plasma renin activity, etc.) impose unanticipated costs, we need to prevent heart attacks using the best weapons we have. And those weapons are proven. They include medications. They may include lifestyle interventions like weight control and fitness. They don't include salt reduction for the general population.

The World Health Organization (WHO) is concerned about the scientific basis of its health recommendations (a concern with WHO we've been vocal in expressing as well). In 2003, the WHO Cabinet recognized the need for process changes to improve the scientific evidence foundation for its policies. Its report appears in today's edition of The Lancet (free registration required).

Authors Andrew Oxman et al note:

WHO's regulations emphasise the role of expert opinion in the development of recommendations. In the 56 years since these regulations were initially developed, research has highlighted the limitations of expert opinion, which can differ both across subgroups and from the opinions of those who will have to live with the consequences. Experts have also been known to use non-systematic methods when they review research, which frequently results in recommendations that do not reflect systematic summaries of the best available evidence.

That's certainly the case in WHO's Report 916 , coincidentally generated in 2003, which selectively cited the literature and reached historically-extreme recommendations regarding dietary salt.

Oxman continues:

Evidence-informed dissemination and implementation strategies are increasingly recognised as a core part of the business of development recommendations.

Unfortunately, the authors found that WHO "almost always" employed the subjective expert committee approach in preference to the systematic review of published evidence. "The guidelines for developing WHO guidelines do not seem to be closely followed...," the report states, neutrally. In fact, they continue:

Although the WHO guideline recommendations are consistent with those developed by other organisations, the actual processes used to develop recommendations at WHO seem to be less rigorous than those of others. None of the directors [note: 23 WHO department directors were interviewed for the research] reported using the guidelines for WHO guidelines and only two reported plans to use them. Few directors reported using processes that were consistent with the guidelines.

Our experience with WHO in Geneva is that developing the nutrition guideline was virtually complete when the staff selected its expert panel; everything subsequent was a sham. With unfortunate results.

In the area of salt, evidence-based organizations like the Cochrane Collaboration and the US Preventive Services Task Force (HHS) have done systematic reviews of the health benefit potential of reducing dietary salt and both agree evidence is lacking to support such an intervention.

Everyone registering an opinion on dietary recommendations claims their advice is "evidence-based," but -- as this WHO study illustrates -- the truth is that governments and advocacy organizations routinely use the lowest form of evidence, expert committees, to formulate recommendations. It brings to mind a verse from the New Testament in the Bible (Matt. 15:8), "This people draweth nigh unto me with their mouth, and honoureth me with their lips; but their heart is far from me."

We need to do more to elevate the place of true evidence-based decision-making in public health nutrition policy through such means as ensuring effective enforcement of the U.S. federal Data Quality Act and opening the rich databases created for federally-funded studies to independent analysis by qualified experts. But, as the authors of this study lamented concerning WHO, achieving this broader objective "will require leadership."