Yesterday and today, many of the nation's leading scientists and experts on women's health met at the National Institutes of Health (NIH) in Bethesda, MD to celebrate the legacy and probe the findings and future directions of the Women's Health Initiativve, the largest and most comprehensive study of postmenopausal women's health ever conducted in the United States.

And not only the largest, the WHI is aguably the most far-reaching in terms of documenting flaws in our understanding of accepted medical "knowledge" on everything from the effects of a low-fat diet and calcium/vitamin D supplements to the dangers of hormone replacement therapy. In all these cases, WHI reseachers have turned on their head logical hypotheses supported by at least some observational studies. We now know that low-fat diets don't make much difference, nor do calcium/vitamin D supplements, and that hormone replacement therapy creates an increased risk of breast cancer and that, overall, risks from use of the hormones outweighed the benefits.

"The WHI has replaced conventional wisdom about women's health issues with evidence-based research findings, and reminded us that there aren't always simple, universal answers to complex questions," said Elias A. Zerhouni, M.D., director of the NIH, announcing the celebration. Hopefully, NHLBI director Elizabeth G. Nabel, M.D., who also spoke to the gathering, recognized the application of Dr. Zerhouni's comments to the salt and health research funded by her agency. Several days earlier, yet another study of a massive federal nutrition and health database found risks of low-salt diets outweigh any health benefit.

NIH has more on WHI on its website .

If you've agreed with several posts on this blog expressing concern about manipulating science, you'll likely enjoy Michael Fumento's column "Science journals delivering 'political science'" today at townhall.com . Don't miss the comment "The (Political) Science of Salt" at the end.

Today's New England Journal of Medicine reports the second major health outcomes study in a week from the massive Women's Health Initiative, exploding another cherished axiom of nutrition, this one about dietary calcium. Higher intakes of calcium, the study concluded, do not protect against hip fractures, although consuming more calcium does increase bone mineral density slightly (unexamined in the study is the imporant contribution calcium likely plays in blood pressure regulation). No doubt these results, like those last week finding that low-fat diets do not improve health outcomes, will rekindle debates among nutritionists and the medical establishment. Good.

No matter how we have all felt about the wisdom of eating less fat or drinking more milk, a couple other "health outcomes" seem worth mentioning.

• First, these studies offer a great and humbling reminder that our confident embrace of logical explanations for population data demands that population health advisories should be based on randomized trials, not observational studies. They should reinforce our insistence on true evidence-based public health nutrition recommendations.
• Second, randomized health outcomes trials are possible. Many have argued that the importance of the health threat targeted for dietary therapy is so compellingly urgent that waiting for health outcomes trials -- expensive and long-term to be sure -- would be unethical. How ethical is it to tell the population to reconfigure its diet to obtain health benefits that are supported only by population studies whose conclusions are extrapolated into headlines claiming improved health outcomes? Without health outcomes trials examining the validity of the assumptions underlying these extrapolations, the dietary recommendation becomes a house of cards. Let's not gamble with cardsharps.

The salt connection, I hope, is obvious here. Logically, since salt is related to blood pressure and blood pressure is related to the incidence of cardiovascular events, some countries like the U.S. and the U.K. have embraced universal sodium reduction. The theory is clean and neat. But the argument is without evidentiary support. The only health outcomes data today are observational (and those data are only about a decade old, produced long after nutrition know-it-alls confidently concluded that lowering population salt intakes would improve public health). The health outcomes data we do have today shows no improvement in heart attack rate or increased morbidity/mortality for those on lower-sodium diets . In fact, 30% of the studies have identified an increased risk while none have identified a population benefit.

Before 2000, the U.S. Dietary Guideline suggested consuming salt or sodium in moderation. Reasonable advice, if somewhat ambiguous; it matched the ambiguity of the evidence. More recent Guidelines have been more strident even as the observational health outcomes studies accumulated and consistently showed no benefit. We should go back to the pre-2000 Guidelines until we can conduct a controlled trial of the health outcomes of reducing population sodium intake levels.

Today's Food Navigator reports: "Obesity rocketing despite record diet food spending." The headline is for Europe, but describes the U.S. as well. The headline betrays what may prove to be a critical, but erroneous assumption: that people who eat "diet food" have healthier diets, or lower-calorie diets. That linkage has yet to be tested.

For years dietitians have lectured on the fact that there are no "healthy" or "unhealthy" foods, only "healthy" or "unhealthy" diets. But "diet foods" sell, so until we have convincing medical evidence, the public goes on buying them, thinking that they're buying better health. As Peter, Paul and Mary sang in "Where Have All the Flowers Gone?": "When will they ever learn?

I loved this quote from Gina Kolata's news analysis column in today's New York Times entitled "Maybe You're Not What You Eat":

"Whatever is happening to evidence-based treatment?" Dr. Arthur Yeager, a retired dentist in Edison, N.J., wrote in an e-mail message. "When the facts contravene conventional wisdom, go with the anecdotes?"

The furious reaction to last week's JAMA report that low-fat diets don't lead to improved health outcomes reminds me of the current level of civility in Congressional discourse. "Partisan" anti-fat researchers opine in outrage reminiscent of Howard Dean.

The situation reminds me of the hysterical rejection of the 1995 study in the American Heart Association's journal Hypertension showing that hypertensive patients classified as "low-sodium" consumers had vastly higher risk of heart attacks. Critics flayed the methodology, yet all eight subsequent studies of health outcomes in populations with salt intakes typical of those in the U.S. have confirmed either no health benefit or an increased risk of lower salt intakes and the author subsequently was elected president of the American Society of Hypertension and, more recently, elected president of the International Society of Hypertension, a post he currently holds.

Hopefully, our next Dietary Guidelines Advisory Committee will not ignore this powerful new evidence -- our only controlled trial of the health outcomes of low-fat diets -- in favor of mindless regurgitation of politically-correct policy pronouncements, as they greeted the new evidence on salt.

Thank you Dr. Yeager (and Ms. Kolata) for spotlighting our options: follow the evidence or the "experts." We need to insist on evidence-based public health nutrition policies, not the anecdotally-consistent Guidelines being so loudly defended.

The front pages have been crowded with this story, blogged earlier here , and now the editorial writers are beginning to grasp the breadth of impact -- it goes WAY beyond fat.

As USA Today reminds us:

Not long ago, it was generally estimated that 400,000 Americans a year die from obesity. Oops. A new study last year by the Centers for Disease Control and Prevention (CDC) found that obesity accounts for only 26,000 deaths, and that a few extra pounds might add to longevity.

"Similarly, hormone replacement therapy was once thought to protect postmenopausal women against heart attack or stroke. Subsequent studies say it doesn't.

"Yesterday's conventional wisdom is today's myth. No wonder so many are skeptical about whether any study can be believed.

"The latest surprising finding is that low-fat diets don't reduce the rate of heart disease, stroke, breast cancer or colorectal cancer, or even result in greater weight loss. That's the conclusion of a government-sponsored study published Wednesday in the Journal of the American Medical Association. It followed nearly 50,000 overweight, postmenopausal women for an average of eight years.

...

"The low-fat study only means that there's no magic bullet, which leaves an obvious if unpleasant fact: Good health comes from a balanced diet, frequent exercise and avoiding obvious risks. Family history and genes count for a lot also, regardless of diet."

It's not that all of "yesterday's conventional wisdom is today's myth." Only when the conventional wisdom isn't based on sufficiently-rigorous thinking or evidence. Here, as in the salt case, we have a very plausible theory (hypothesis) and a bunch of obvservational studies, though far from consensus the fat studies seemed less controversial than those for salt. What we lacked was a randomized trial. Now we have it. NOW we're prepared to act on the evidence or, in the case of fat, perhaps not act.

This study may have cost $415 million, but if we learn the harsh lesson about prejudging before we conduct a controlled trial of the health outcomes of the proposed intervention, it will be money very well spent.

Until yesterday, everyone "knew" that low-fat diets were the cornerstone of a healthy diet. Publication in the Journal of the American Medical Association of results of an 8-year, $415 million study of nearly 50,000 American women found that what everyone "knew" was dead wrong. There was no health benefit among the almost 20,000 women on low-fat diets. They had the same incidence of breast cancer, colorectal cancer, heart disease and stroke as the 29,000 women who ate regular diets. Experts on every side of the issue agree the study is conclusive due to its size and quality ... and $400+ million pricetag.

Expensive study? You bet. Worthwhile investment? Priceless.

Not only have we spent billions of dollars researching low-fat diets, but food manufacturers have invested additional billions re-engineering the foods we eat. Americans have not only paid premium prices for specially-concocted low-fat foods and kept low-fat cookbook publishers in business for the past quarter-century, but consumers anguished over their inability to strip even more fat out of their daily diets. No more.

This was a front-page, above-the-fold story in every newspaper in the country (e.g. The Washington Post - "Low-fat diet's benefits rejected" - and NY Times - "Low-fat diet does not cut health risks, study finds"). The New York Times editorialized: "The results clearly surprised the investigators and may sound the death knell for the belief that reducing the percentage of total fat in the diet is important for health."

While this is clearly the diet-related news story of our new millennium, most discussions have omitted mention of three additional key lessons we should be learning:

• First, medical science is evolutionary. What we "know" today is subject to further investigation and revision as we learn more. It is a process of creative destruction. We need to be prepared to "move on" when the evidence demonstrates the error of our ways.
• Second, we can save time, expense, anguish -- and people's health -- if we are a bit more patient and humble about the confidence we place in the results of medical studies. All studies are not of the same quality. This was a high quality randomized controlled trial -- the "gold standard." A well-done randomized trial of health outcomes should be required before our officials begin the drumbeat -- and trigger billions of dollars of expenditures -- for a massive dietary change. To re-state an earlier post on this blog : this is why we should insist on true evidence-based public health decision-making. Evidence-based decisions follow a rigorous process defined by the world-renowned Cochrane Collaboration.
• Third, we should require the same kind of controlled trial of the health outcomes of advice to restrict dietary salt as we now have to restrict dietary fat. There are only ten observational studies of the health outcomes of reducing salt in a U.S.-like population. We need to ask the outcomes question: does eating less salt reduce heart attacks or extend life? We need a controlled trial of this question even though it may cost $100 million or more. As in the case of low-fat diet advocacy, the government is spending multi-fold that amount and compliant food manufacturers are investing huge amounts trying to reduce salt intakes when, in truth, we have no evidence that it will make a difference. In fact, the observational studies show that in populations with salt intakes like the U.S., there is no health benefit and may even be a risk in low-salt diets (see our website discussion ).

It is hard to exaggerate the importance of this JAMA study. And it's impossible to ignore the validity of the Salt Institute's observation that pursuing a policy of universal sodium reduction without a randomized health outcomes study is sheer folly.

The UK's Advertising Standards Authority has chastised the government's Food Standards agency for misleading anti-salt statements breaching standards of social responsibility, substantiation and truthfulness. FSA was also forced to recant its statement that snacks were unhealthy.

It is refreshing to see recognition of the obvious fact that government bureaucrats can have every bit as much bias as "private" interests. All parties to public health strategic discussions should insist on fair statement of the evidence. There is room for disagreement whether, for example, messages should be directed to the entire public or to sensitive individuals or sub-groups, but there is no place for abusing the data -- or the public trust.

So says Dr. Donald Kennedy, the editor of America's foremost scientific journal, Science, in an article in yesterday's New York Times about a Congressional briefing on the intersection of science and public policy.

Right on!

Replication is the key. If scientists cannot replicate a study because its design is not divulged or if their replicated protocol does not produce the same results, then science has failed.

That's why the federal Data Quality Act establishes replication as one of the key criteria for determining whether a study meets the high standards that we should require in using science to support public policy.

That is a key issue before the 4th U.S. Circuit Court of Appeals when it convenes in Richmond tomorrow to receive oral argument in Salt Institute v. Leavitt, the first challenge reaching a federal appeals court seeking to define how the Data Quality Act will be interpreted.

The issue here is that the National Heart, Lung and Blood Institute has been characterizing results of studies it pays for without allowing qualified experts access to enough data to be able to judge whether the statements are true or not.

Kennedy is quoted saying "Peer review isnot a process that guarantees truth. If it were, no one would ever repeat experiments. Replication is the ultimate test of truth in science."

Talk about misbranding! In 1997, the federal National Heart, Lung and Blood Institute (NHLBI)-sponsored Dietary Approaches to Stop Hypertension (DASH) study found that -- holding salt intake at a constant level -- blood pressure could be improved significantly by adding fruit, vegetables and dairy products to the American diet. Hypertensives subjects dropped their systolic BP by 11.4 mmHg -- impressive.

Those interested in improving dietary quality and lowering cardiovascular risk -- including the Salt Institute -- rejoiced and called for the DASH Diet to be the guiding principle for the new year 2000 Dietary Guidelines for Americans. It took a bit longer, but the 2005 edition of the Guidelines, in fact, explicitly endorsed the "DASH Diet." So far, so good.

But in the last nine years, those with their own nutrition agendas have tried to hijack the "DASH Diet" by asserting that the DASH Diet is now fruits, vegetables and dairy products AND salt-restricted or, in current headlines, fruits, vegetables and dairy products AND carbohydrate-restricted and protein-enhanced. Well, folks, there is no such thing as a South Beach DASH Diet.

The DASH Diet offers an exciting possibility that correcting nutritional (mineral) deficiencies in the American diet can confer health benefits, but it has nothing to do with dietary salt, dietary carbs or dietary protein.

Unfortunately, NHLBI, rather than defend its original findings, has been playing along with the misbranding of these later studies. FDA should call "halt" on its sister agency; this misbranding is akin to "bait-and-switch."

For more on how this plays out for dietary salt, see the Salt and Health or Salt for Human Nutrition pages on the Salt Institute website.

Reasononline's science correspondent Ronald Bailey's Jan. 6 post revisits the issue of objectivity/politicization in science, asking: "Has science become politicized? A better question might be: When has it ever not been?" He sees no way out of the current situation where funding sources - both industry and government - seem to bias "scientific" conclusions. He continues:

"Surveys of studies show that scientific reports sponsored by drug companies generally find the supporting company's drugs to be safe and efficacious, whereas independent studies often do not. Interestingly, studies supported by the $132 billion in federal research and development expenditures rarely occasion such scrutiny. Perhaps that's because they are generally above reproach. But it is also true that most academic research is funded by government agencies and it will not help a scientist's career to bite the federal hand that feeds him and his postdocs. I also suspect that most agency funded research generally finds that what the agency guesses is a problem turns out to be a problem.

"In a liberal secular society in which traditional sources of authority-the Church and the State-have eroded, science stands the ultimate arbiter of truth. So, both the right and the left loudly seek to claim that scientific findings justify their political goals.

"Not surprisingly, when a scientific finding doesn't support their policies or programs, both sides suspect that it has been "politicized." In this case, "politicized" meansdisagrees with what we good people want. Naturally to prevent politicization,both Republicans and Democrats have sought to legislate scientific objectivity."

Bailey then concludes.

"What these efforts to legislate scientific objectivity really point up is that science, as the chief arbiter of truth in our society, will remain unavoidably enmeshed in politics. The government official who ordered the ban on DDT despite the scientific evidence for its safety, William Ruckelshaus, the first administrator of the EPA, brought admirable clarity to the issue. In 1979, Ruckelshaus wrote to Allan Grant, president of American Farm Bureau Federation president, stating , "Decisions by the government involving the use of toxic substances are political with a small 'p.' The ultimate judgment remains political." What was true for the EPA in 1972, is even more true for federal agencies today. The science wars are here to stay."

Who's to say Bailey's wrong? I hope we never entirely replace our healthy skepticism with a crusty cynicism that forecloses a healthier outcome for our polity. As I blogged earlier , the objective criteria of good science termed "evidence-based medicine" by scientists united in the Cochrane Collaboration seem, to me at least, to offer hope. The concept is that the rules of the game are set out before the evidence itself is assessed - sort of like an election where we agree to accept the outcome because we know the process itself has integrity (or at least it does in Baghdad if not Broward).

Still catching up from the holidays. A Dec. 30 commentary in the Wall Street Journal made much the same point in the Vioxx debate as raised earlier in this blog : even our most prestigious medical journals are "mere magazines."

Thomas Stossel, the American Cancer Society Professor at Harvard Medical School, decried MSM coverage of Merck's Vioxx situation, stating the media conclusion: "Medical academics are saints -- devoted selflessly to patient care -- and corporate people are sinners, morally blinded by greed." Stossel obviously disagrees: "But having worked in academic medicine for over 35 years and consulted for companies, this Manichean duality is inconsistent with my experience and a woeful distortion of reality. In a Sept. 8 article in the New England Journal of Medicine, I reported that no systematic evidence exists that corporate sponsorship of academic research contributes to misconduct, bias, public mistrust or poor research quality." Stossel urges medical journals to "stick to their core business of facilitating imperfect communication between researchers. Leave drug and device monitoring to the FDA -- and theology to theologians."

Picking up on the last point, it is disturbing how anti-scientific (theological) have become the calls to restrict dietary salt against accumulating evidence that the intervention just doesn't deliver health benefits for the general population. The anti-science has a theological tenor -- faith in the absence of evidence. In this case, it's worse -- faith in the face of evidence to the contrary . As in the case of the all-knowing Wizard of Oz, we're advised: "Pay no attention to the man behind the curtain."

We need truth-tellers like Dr. Stossel...and Dorothy.

Reiterating a point the Salt Institute has raised for years, this December 14 post by NewsTarget.com explains the growing medical view that mineral deficiencies are responsible for high blood pressure more than "excess" dietary salt. We can't vouch for all the quotes, but the sentiment is mightily appreciated. Our reading of the DASH Study is that correcting deficiencies of calcium, magnesium and potassium in the diet largely eliminates "salt sensitivity" with regard to blood pressure.

Two articles in recent days in New York City newspapers caught my eye. On Dec. 16, the New York Post ran an op ed by Dr. Elizabeth Whelan, president of the American Council on Science and Health entitled "A Year of Public Health Lunacy ." She laments how public health advocates "seem to put politics before science," citing Iowa's ban on the preservative thimerosal in vaccines or banning soft drinks from schools to combat obesity (both regular and diet soft drinks). She notes the fall of the Harvard School of Public Health which has recently embraced junk science on at least a couple issues.

Then, today's New York Times story "Global Trend: More Science, More Fraud " highlights research shennanigans in South Korea. The Times story cautions: "To be sure, most scientists resist pressures to cut corners and adhere to the canons of science, honoring the truth above all else. But surveys shuggest that there are powerful undercurrents of misbehavior and, in some cases, outright fakery.

Just as we need strong and authoritative science so help us sort out issues like the healthfulness of dietary salt, science is under an attack that threatens its credibility. Preserving this credibility is of paramount importance, given the proclivity of both corporate marketers and "public interest" advocates, including those embedded in the federal bureaucracy, to cloak their policy preference in claims they are "evidence-based." It matters not whether the motivation is to increase market share for a product, raise funds by sounding a public alarm or protecting or advancing a professional reputation for advancing the frontiers of medical knowledge. Insidious "insider" manipulation of data and/or their interpretation risks depriving society of any authoritative source.

As in other areas where sophistication outstrips morality, we must "go back to basics." In this case, that means to strip away the pretense of "science" and looking at the fundamentals such as study design and standards of interpretation. Everyone says theirs is "high quality" science, of course, even high schoolers' science projects.

Fortunately, we can go back to basics by reviewing what it means to embrace "evidence-based" public health policy. Our Dietary Guidelines claimed to be evidence-based, but didn't hew to the definitive standard crafted by the Cochrane Collaboration . As governments slip into politicized health care policy, inviting scientists to explain their findings against the outcomes-based scientific method pioineered by the Cochrane Collaboration offers the most promising way to re-establish the credibility we need for science-based public health policy.

Using its rigorous methods, the Cochrane Collaboration offers its views on "advice to reduce dietary salt for prevention of cardiovascular disease ," specifically: "There was not enough information to assess the effect of these changes in salt intake (a reduction) on health or deaths."

Let's move away from scientific fraud and the public health lunacy that follows in its wake and insist on true evidence-based public health policies.

Marketers would have us believe that the self-selecting online community is composed of above average intelligence information sponges, perhaps suffering info overload, but certainly well informed. A recent poll suggests otherwise.

Last week, A.C. Nielsen reported results of an online survey of 21,261 "regular Internet users" conducted earlier this year asking about their views on functional foods. Not too surprisingly, pollsters found consumers skeptical of food manufacturers' health claims for foods. I'm sure they'd also be skeptical about carrots and broccoli, much less foods engineered or fortified to provide additional health benefits. U.S. consumers, incidentally, were far more accepting of enhanced foods than Europeans or the global sample.

But can we believe the pollsters? A look at the poll details suggests they may be wrong.

The survey asked whether consumers used functional foods. The first "functional food," many know, is salt fortified with potassium iodide or potassium iodate. American salt producers began adding iodine to salt in the 1920s in the U.S. and Switzerland to prevent goiters and mental retardation. Salt iodization has been promoted heavily since then; it was UNICEF's top children's health initiative in the 1990s. Iodizing salt is the public health community's preferred choice because it is very inexpensive and iodine-fortifying salt changes neither the taste nor food properties of the salt. Unless they read the label on the container, consumers cannot know whether the salt is iodized or not - except in those countries which require ALL table salt to be iodized (e.g. Canada).

In the U.S., 70% of table salt is iodized - that percentage has been stable for several generations. That means more than two out of three "round cans" purchased are iodized and it follows, since salt is consumed, on average, in a relatively narrow range, that about seven in ten consumers are using iodized salt.

U.S. consumers told pollsters, however, that only 3 in 10 were using iodized salt, 30% - a somewhat lower percentage than globally (33%). Almost more shockingly, when the U.S. and Canada were combined, only 24% reported using iodized salt - despite the fact that all Canadian table salt is iodized. Since the Salt Institute collects comprehensive market statistics, the certain conclusion is respondents knowledge is the exact reverse of the dictum that "the customer is always right."

It's quite discouraging that there are 70% who claim not to be using iodized salt when actually 70% Americans and virtually all Canadians DO use iodized salt. What is more discouraging is that these erring respondents go on to prove just how clueless they are. Asked about why they chose plain salt over iodized salt, 35% doubted that iodine-fortified salt was any healthier (obviously none were endocrinologists! Iodized salt is the consensus public health solution for iodine deficiency). An additional 17% said they didn't like the taste of iodized salt (fact: the iodine has no taste whatsoever); 6% said the fortified salt is too expensive (fact: it's sold at retail for exactly the same price as plain salt); 5% said it wasn't available where they shop (check this out yourself: iodized salt is always available even if plain salt isn't) and, finally, 1% complained of poor quality (I won't even dignify that with an answer).

Bottom line: consumers mistakenly think they're not using iodized salt and provide nonsensical reasons for their fallacious opinions. Why? Could the answer be as simple as the likelihood that "regular Internet users" aren't as well-informed as previously thought? In mid-19th century U.S. politics, the "American Party" was nicknamed the "Know Nothings." They had nothing on Americans in the Nielsen Poll.

For more on iodized salt, see http://www.saltinstitute.org/37.html .