Often when the decibels rise and the tone turns shrill it's akin to a stock market contrarian's moment of vindication. Sometimes it seems that politically-correct conventional wisdom can never be changed. But it can.
The American Academy of Pediatrics which had been advising mothers of infants with a family history of allergies to avoid cow's milk, eggs, fish, peanuts and tree nuts while breast-feeding has taken a fresh look at the science and updated its advisory conceding that there's no good evidence for avoiding certain foods during pregnancy, using soy formula or delaying introduction of solid foods beyond six months.
So, dogma can be changed. Hang in there, those of you who've joined our seemingly-lonely effort to combat the unscientific demonization of salt.
An Associated Press story quoted Dr. Scott Sicherer of Mount Sinai School of Medicine's Jaffe Food Allergy Institute in New York City, one of the authors of the revised AAP policy statement:
They say, 'I shouldn't have had milk in my coffee. I've been saying, 'We don't really have evidence that it causes a problem. Don't be on a guilt trip about it.'
Of course, for Americans 2008 is a political year with a new president to elect. But while the electorate seems to be tiring of political polarization already, some lobby groups are becoming more assertive. Since New Year's day, the American Medical Association, has displayed a feisty combativeness urging its members to pressure Congress to pursue a path antithetical to the approach recommended by the U.S. Preventive Services Task force and endorsed by the Salt Institute. We'll have to wait and see if the AMA membership supports this campaign or returns to a more science-based approach to public health policy.
The January 14 edition of amednews.com, the AMA online newsletter, editorialized "Time to pinch off the salt " with the explanatory subtitle "The AMA calls on the FDA to revoke salt's 'generally recognized as safe' status to allow more regulation of sodium in food." The editorial liberally quotes AMA vice president for science, quality and public health Stephen Havas, who has almost single-handedly radicalized the AMA strategy on salt restriction.
About the same time, AMA issued a news release, not mentioning salt, but calling for Congress to pursue an aggressive assault on risk factors for cardiovascular disease. The AMA's January 11 release announced:
American Heart Association President Daniel W. Jones, M.D. urged Congress to pass legislation to help Americans control their risk factors for cardiovascular diseases. With obesity, hypertension, diabetes and other risk factors on the rise, the association is calling on elected officials to support measures that focus on research and prevention.
"Risk factors, such as unhealthy weight, poor diet, smoking and diabetes could undercut many of the gains we've made to reduce cardiovascular disease deaths," said Jones, vice chancellor, University of Mississippi Medical Center. "We must ratchet up efforts to convince policymakers that a strong and sustained investment of government resources is essential."
The association's 2008 Health Policy Agenda addresses risk factors through legislation and initiatives that would combat the obesity epidemic, curb tobacco use, particularly among children, increase funding for medical research and prevention and reduce health disparities.
This year alone, cardiovascular diseases will cost Americans an estimated $449 billion in lost productivity and medical expenses. Treatment costs for cardiovascular diseases are expected to rise 64 to 84% by 2025. Stroke treatment alone is projected to exceed $2 trillion by 2050.
While the AMA's specifics are a bit extreme, the concept of extending the effectiveness of "research" and "prevention" enjoys as much support today as "motherhood and apple pie" did of yore. The Salt Institute joins that chorus. We'd add, however, that federally-funded research should be available for independent confirmation and used to support government policy only if findings can be replicated. And, while we strongly support the prevention of cardiovascular disease and its resultant heart attacks and strokes, we are less sanguine concerning prevention of "risk factors" as semantacist Dr. Jones has stretched the term. How do you prevent age, for example, the surest predictor of cardiovascular events and deaths? How about being an African-American, another powerful "risk factor"?
The proper focus of public health policy is to prevent disease, extend life and improve the quality of that life. A focus on "risk factors" presupposes that they can be modified as part of our public health efforts. Some "risk factors" cannot be modified. Others, like "salt sensitivity," as recently as a decade or two ago were thought to be immutable and unchangeable and are now properly understood to be the product of deficiency intake levels of other nutrients, in this case, calcium, magnesium and potassium; correct those deficiencies (as with the DASH Diet) and the "salt sensitivity" disappears. So, the proper policy focus should not be on "risk factors" but on the effectiveness of HOW we try to modify those risk factors .
Again, salt is illustrative. Blood pressure is a risk factor for CV events and mortality. Few would deny that. But HOW blood pressure is modified is what's important, not the raw number itself. Blood pressure is not the disease, it is the symptom, the "risk factor" for CV disease, myocardial infarcts and strokes. Treating the symptom is not prevention. It may even make the underlying condition worse and increase the risk of an event rather than prevent it. That's what we discovered when scientists started examining the question of whether cutting salt (a "risk factor") would yield in actuality the "prevention" benefits predicted by mathematical models such as those used by Dr. Havas and the AMA. It turns out, they don't. In a long string of "health outcomes" studies , no pattern of a health benefit is correlated to diets lower in salt. It turned out that other "risk factors" such as insulin resistance, plasma renin activity and sympathetic nervous system activation were also affected by reducing dietary salt. These "risk factors" increased the risk of salt reduction, proving, once again, that HOW we seek to modify "risk factors" is more important than announcing a campaign focused only on change.
In this political year, we've heard virtually all the presidential candidates call for significant "change." Let's be reminded that the specifics of what should be changed and how it should be changed are as important as lamenting our current situation. That's as true in public health nutrition policy as it is in presidential politics.
Nobody is arguing that we should shift from prioritizing prevention and accept the projected $2 trillion cost of treating strokes, but let's focus our efforts on preventing heart attacks and strokes, not waste our money on "risk factors." Proven interventions identified by the U.S. Preventive Services Task Force specifically exclude general salt restriction as having no proven benefit. The president of the International Society of Hypertension used his presidential address a year ago to make the same point: let's focus on health outcomes, not intermediate "risk factors." That's the way we see it too.
I have never figured out who said "confession is good for the soul," but she was right. And a confession is in order tonight. Four days ago, I succumbed to the very sin I've decried publicly so often in the blogosphere: the sin of bestowing credibility, even endorsing results of a medical study whose conclusions support one's own worldview. It's natural. Understandable. But, sans apology and full repentance, nigh unto unforgivable.
Still, we learn from our experiences. As I humbly recant the ill-considered, cyber-published product of my passion, I hope I can be granted not only absolution, but insight into the difficulty others may likewise be experiencing when jumping quickly to endorse a "politically correct" end result without regard to the quality of the "science" employed to reach that result.
Four days ago I celebrated a new study, declaring with exuberance :
Today's publication in PLoS Medicine of a massive (20,244 persons) 14-year mortality study, showed that four simple interventions -- increasing fruits and vegetables, becoming physically active, not smoking and consuming no more than moderate amounts of alcohol -- increased lifespan by 14 years.
Kay-Tee Khaw et al report that "the trends were strongest for cardiovascular causes." It's time we got serious about promoting the DASH Diet and stopped diverting resources to interventions like salt reduction which have been endorsed by experts but are unsupported by actual scientific evidence.
My enthusiasm and endorsement of the DASH Diet remain intact, but my respect for the Khaw study is gone. Having now read the January 10th post by Sandy Szwarc on her Junkfood Science blog , I am hoist on my own petard. My admonition to "get serious" about the science underlying nutrition recommendations is exposed as pure self-righteous cheerleading. Not to excuse my excesses, but as Ms. Szwarc points out:
Within hours this week, television newscasters, as well as some 500 published articles - for scientists, medical professionals, nursing professionals, business professionals and consumers - were all reporting the same interpretation of this study. The script was provided by the publication's press release: "4 health behaviors can add 14 extra years of life."
Thank you, Sandy, for your very relevant reminder:
Simply making extraordinary statements about a study, however, does not make them true - no matter how much we might want them to be. And who wouldn't want to believe that by doing just four easy things we could add 14 years to our lives?
After reviewing the methodology, Szwarc cuts to the chase:
Their key finding, which has not been reported, was they were unable to find a tenable correlation between any of the health behaviors and mortality: all-cause, cardiovascular disease, cancer or any other cause of death. The relative risks all hugged either side of 1 - null findings. (emphasis in original) …
In other words, reports of higher relative risks associated with not engaging in four healthy behaviors were based on 49 people, 0.2% of the cohort. But the absolute (actual) risk of dying differed only 0.2% between those doing zero and those doing all four healthy behaviors (0.25% and 0.05%, respectively). (emphasis in original)
This is just the kind of book-cooking that we've prided ourselves on exposing here at the Salt Institute. And it stands exposed - at least in this instance - as that proverbial pride that goeth before a fall. Mea culpa. Note to self: pay attention to details. Look at the "p value." Beware author bias. May I learn patience and sympathy for others of you who ascribe authority to a medical study that "sounds right" because it confirms what one is predisposed to believe. May I find the discipline to "walk the talk" and insist to myself as I've admonished others to insist on quality science, eschewing the authors' news releases and the funding agencies' "spin."
Let us sinners go forth together seeking truth.
