Salt & Human Health

The United Kingdom has adopted the world's most shrill anti-salt policy, drawing the usual complaints about a nettlesome and meddlesome "nanny state" atmosphere. The policy was enshrined based on projected reductions in heart attacks, cardiovascular deaths and health care cost savings, worthy public health objectives all.

Britain's anti-salt policy may produce just the opposite results and turn into a "major public health disaster," predicted Dr. David McCarron, Executive Director of Shaping America’s Youth, in London as part of his international efforts to reduce childhood obesity. Dr. McCarron registered his views with new UK Health Minister Alan Johnson and met with the Director General designate at the British Nutrition Foundation.

Dr. McCarron pointed out that the anti-salt campaign displays parallels to earlier public health initiatives which produced more harm than good:

“Recent experience over Hormone Replacement Therapy (HRT) and trans-fats demonstrates all too clearly that you cannot put a fundamental public health policy into place without proper controlled trials. If you do, you are putting lives at risk.

“Assumptions were made that HRT reduced the risk of heart attacks and cancer, and that all women benefited. The reality now that they have finally commissioned large-scale trials is that there is an increased stroke risk at initiation and a greater cancer risk than was ever recognised.

“It’s a similar story with trans-fats. The absence of proper trials was equally responsible for the fact that it took 40 years to act in eliminating trans- fats from the food supply. Previous public health policy had an adverse outcome that affected the whole population.”

British policy is based on simple extrapolations of the blood pressure impact of salt reduction, Dr. McCarron explained:

“Simple reasoning can get you into trouble if you don’t do the right studies and ask the right questions. What is needed is a long-term, large-scale, carefully constructed controlled trial with a hypothesis of ‘does a low-sodium diet improve life-expectancy?’

“No public health policy should be implemented unless it’s been proven to work. At the moment, the British public is being asked to follow advice that has not been proven to reduce heart attacks or strokes. People deserve to know whether a low-sodium diet will mean that they are going to live longer or not.”

“Seat belts save lives, exercising saves lives – these are good public health policies. Do we know that a low sodium diet saves lives? No, we don’t. The secondary evidence from trials so far says that there’s no benefit and there may be harm – these studies do not support a benefit to public health.

“My view is that it is very likely that low salt will ultimately prove to be another public health disaster. There is already sufficient evidence to suggest that low salt could actually result in increased risk of cardiovascular disease. But the reality is that the international community needs to commission controlled trials so that we have the evidence as to whether the current policy is safe and effective. To do anything less is irresponsible.”

Shaping America’s Youth is a private/public partnership of the Office of the US Surgeon General, The American Academy of Pediatrics, The American Academy of Family Physicians and the American Diabetes Association, which is the principal effort in the US directed against childhood obesity. SAY's Executive Director Dr. McCarron is also a visiting professor within the Department of Nutrition, University of California-Davis and former Head of the Nephrology Division at Oregon Health & Science University. He received the International Award for Modern Nutrition 2004 in recognition for outstanding research contributions to our understanding the role of nutrition in hypertension. Dr. McCarron serves as a consultant to the Salt Institute.

Posted by Dick Hanneman at 08:22 AM | Permalink

Information Today reported that on July 19, the US House of Representatives approved measures directing the National Institutes of Health (NIH) to provide free public access to agency-funded research findings within 12 months of their publication in a peer-reviewed journal. Of course, agency-funded research is taxpayer-funded research, so you would think that NIH would be happy to accommodate this idea. Not quite.

When first asked to do this on a voluntary basis, less than 5% of the eligible research was made available. Why is there this reluctance to make the results of publicly-funded medical research more widely available?

Most of the resistance comes from the scientific publishing companies, who would like to maintain their full rights over published materials for as long a period as possible, so that they can maximize the return on their investment into these publications, which includes the peer-review and editing infrastructures. Those opposed to this measure, such as Professional and Scholarly Publishing Division of the Association of American Publishers, and a coalition of academic and society publishers from within the DC Principles Coalition of scientific publishers, wrote a letter to members expressing strong concern with the language in the appropriations bill .

My sense is that scientists, who are constantly on top of the latest developments, will not wait 12 months to see the results of ongoing research, they will continue to buy the journals as they always have. It is highly unlikely that this development will negatively affect the current system of peer review and quality editing.

There are several benefits to having this information openly available 12 months after publication as highlighted in an open letter to Congress by a group of 26 Nobel Prize winners. Greater availability will also allow scientists in developing countries, scientists in other disciplines, industry researchers and interested lay people, most of whom could not ordinarily afford to subscribe to these journals, free access to the information. This is a very large constituency that should never be overlooked when considering the opportunity to advance medical science.

Posted by Mort Satin at 11:11 AM | Permalink

The Journal of the National Cancer Institute has just published "The U.S. Food and Drug Administration's Evidence-Based Review for Qualified Health Claims: Tomatoes, Lycopene, and Cancer". FDA's Claudine J. Kavanaugh and colleagues found no credible evidence that lycopene, either in food or in a dietary supplement, was associated with reduced risk of cancer.

The articled prompted commentary from Sandra Szwarc at Junkfoodscience:

We’ve often reviewed the inferior evidence surrounding fruits and vegetables and their abilities to prevent major chronic diseases, including the 2004 comprehensive examination of the scientific literature done for the Produce for Better Health Foundation campaign, 5-A-Day, under the National Cancer Institute. That year, a study led by Walter Willet, M.D., DrPH, professor of epidemiology and nutrition at Harvard School of Public Health in Boston, MA, was also published. It had followed 71,910 women and 37,725 men for 15 years and found no relationship between fruits and vegetables and cancer, or any statistically significant associations with major chronic disease or cardiovascular disease.

But, time and again, the media makes little more than a whisper when studies are published questioning claims surrounding the “emerging” science of functional foods and supplements. For instance, how many heard about the May study in the journal Cancer Epidemiology, Biomarkers & Prevention on lycopene and prostate cancer? Researchers based at the National Cancer Institute and Fred Hutchinson Cancer Research Center had examined 692 cases of prostate cancer diagnosed among 28,000 men enrolled in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, an ongoing, randomized National Cancer Institute trial to evaluate cancer screening methods and to investigate early markers of cancer. They found no association between serum lycopene and total prostate cancers or aggressive prostate cancers.

No doubt it was a coincidence, but the recently-approved House ag appropriations bill contained language (Section 746) prohibiting FDA from authorizing qualified health claims for conventional foods. Including tomatoes.

Posted by Dick Hanneman at 01:00 PM | Permalink

USA Today turned 25 this week and ran a series of articles about changes in the world in the past quarter century. In their list of "25 Top Medical Events" was no mention of salt at all, not even recognition that during that time frame there's been a 50% increase in the number of infants born protected against the scourge of mental retardation. This achievement is due almost entirely to the massively successful global campaign to iodize salt.

One of the 25 was of some interest, however. Ranked 16th was the odyssey of hormone replacment therapy. USA Today says:

Hormones begone

Hormone therapy was once thought to be a fountain of youth for postmenopausal women, but a landmark study in 2002 found that estrogen plus progestin raises the risk of breast cancer, heart attacks, stroke and blood clots. Women stopped taking the hormones in droves, and today, they're prescribed only for relief of hot flashes and other symptoms.

As tragic as is the HRT story, it's important lesson is to teach us to demand high quality science on health outcomes before we launch a major population health recommendation. Before the government began to advise all Americans to reduce dietary salt, it should have looked at the health outcomes studied. Had it done so, we could have avoided the expensive delays -- and potential risks -- of having the "salt hypothesis" blow up in its face as HRT already has. Too bad.

Posted by Dick Hanneman at 12:08 PM | Permalink

The long-playing drama of watching the World Health Organization, once again, perform an insincere, sham "public consultation" has a depressing familiarity. Just as it did in its disregard of science that failed to find a health outcomes benefit from salt restriction, now WHO is plowing ahead on its staff-driven quest to remineralize drinking water despite its public acknowledgement of the lack of expert consensus . In a new draft report just issued -- public comments invited until October 31 -- WHO concedes "uncertainties," and its bottled water policy statement declares that "WHO is unaware of any convincing evidence to support the beneficial effects of consuming ... mineral waters." But WHO continues: "Currently the evidence supports the view that a magnesium concentration on the order of 10 mg/litre and a calcium concentration of 30 mg/litre would be appropriate for addition."

The Salt Institute and Water Quality Association have led critics of the proposal who are apparently just being ignored by WHO staff in Geneva.

Posted by Dick Hanneman at 11:07 AM | Permalink

The pernicious impact of advocates' use of junk science is to undermine public confidence in all science, argues an articulate letter in yesterday's Wall Street Journal. William Heller of Greenwood, Indiana, quotes an earlier WSJ op ed piece by Richard Grinker on claims that vaccinations cause autism. Grinker opines: "The antivaccine movement may be evidence that public confidence in science is eroding. . . ." Heller continues:

Proponents of the view that vaccines cause autism provide anecdotal trial "evidence" while the other side cites scientific study after scientific study that shows no such connection. A Gresham's Law effect of junk science and opinion debasing real science seems in evidence. The same factors are at work in the climate change debate. There are reams of scientific data that debunk the carbon dioxide theory of global warming, but the only data that seem to get media play is the junk science of the global warming alarmists.

Useful perspective. Bad science driving out good.

Posted by Dick Hanneman at 10:28 AM | Permalink

Two terms don’t always mean what we believe they do: “research” and “evidence-based.” Take the research just published in the Journal of Epidemiology Community Health entitled: “Evidence-based Public Health Policy and Practice: Could targeted food taxes improve health?”

That's the question posted by Junkfoodscience author Sandy Szwarc who attributes the authors' "yes" answer to creation of a mathematical computer model which, necessarily, includes countless "arbitrary decisions and assumptions" and, unnecessarily, introduces a false sense of certainty about relationships where none may, in fact, exist. The phrase springs to mind: figures don't lie, but liars can figure. In the case of this study, she observes:

For their model, the authors in this study attempted to predict the number of lives saved by assuming that lowering salt and saturated fats in the diet (assuming low-fat diets work by lowering blood cholesterol levels) would reduce deaths from cardiovascular disease and strokes. For example, they estimated that every 3 gram/day reduction in salt intake would lower incidence of heart disease by 9-10% and strokes by 12-14%. Their estimated health benefits for low-fat diets were based on the assumption that every 1 mg/dl reduction in low-density lipoprotein (“bad cholesterol”) would reduce heart disease by 1%.

Without the need to go any further, it'a already clear these assumptions contradict and exceed the actual clinical evidence on the ability of “heart healthy” low-salt diets and low-fat diets to prevent deaths from cardiovascular disease and strokes. In fact, as we’ve examined, even the latest Cochrane review of 39 clinical trials conducted in multiple countries over the course of three decades on the ability of “heart healthy” dietary interventions (reducing saturated fats and salt) and lifestyle interventions found: “Contrary to expectations, these lifestyle changes had little or no impact on the risk of heart attack or death...”

You'll want to read the whole blog, but, in summary, she notes the various assumptions about several variables including food consumption, then returns to the salt example:

Most disturbingly absent from their computer model was consideration of any potential harmful effects of compelling “heart healthy” diets. (emphasis in original)

Salt reduction, for example, doesn’t appear entirely benign, according to growing medical research. The European Society of Cardiology Guidelines for the Management of Arterial Hypertension, for instance, reported recent research showing low-salt diets can have negative effects: activating the rennin (sic)-angiotensin system and the sympathetic nervous system, increasing insulin resistance and hypodehydration (especially with the elderly). This, they concluded, could lead to increased risks for cardiovascular disease. Similarly, people who might benefit from salt in their diets wouldn’t be helped, but weren’t included in their computer model, either. Salt also improves the flavor of many nutritious foods, helping to prevent nutritional deficiencies especially among vulnerable populations, such as children and elderly.

We've blogged before ( 1 2 3 4 5 6 7 8 ) on the disturbing gap between true "evidence-based" health policy-making as defined by the Cochrane Collaboration and the damaging abuse of the term by authors or editors trying to fabricate news from the end product of computer models whose results reflect the programmer's biases more than the data of the study itself. We've seen this abuse in the Intersalt Study, the DASH-Sodium Study and in an alarming number of national dietary guidelines which seize the mantle of being "evidence-based" while ignoring the discipline inherent in proper application of that term.

Posted by Dick Hanneman at 11:30 AM | Permalink

A June 26 story on "Sodium Shakeout: Salt and Health" by Kimberly J. Decker in Food Product Design discussed the salt and health issue, referring to a resolution approved a year ago by the American Medical Association.

“Sodium has been in discussion for many years, and the problem is that it’s a very controversial discussion,” agrees Markus Eckert, technical vice president, flavors, Mastertaste, Teterboro, NJ. “There have been studies for many years already showing that it can lead to cardiovascular health issues.” However, “there have been other published studies that followed subjects on low-sodium diets for several years and found that, actually, the risk for cardiovascular health issues is higher here than for regular diets.”

In one such study, published in 2006 in the online version of the American Journal of Medicine (119(3): 275.e7-275.e14), researchers at the Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, studied survey data from the second National Health and Nutrition Examination Survey (NHANES II) and found that, among 7,154 survey participants, those who consumed less than 2,300 mg of sodium per day were actually 37% more likely to have died from CVD. The researchers acknowledged it wasn’t a clinical trial, nor did they propose that the results dictate sodium nutrition policy. They did point out that their findings cast some doubt on across-the-board advice to lower sodium consumption.

Decker summarized for her food industry subscribers:

So, following the AMA’s 2006 sodium statement, the Institute of Food Technologists, Chicago, offered a voice of reason by noting that we do not now consume substantially more (or, alas, substantially less) salt than we have over the past quarter century. Other food industry organizations, such as the Grocery Manufacturers/Food Products Association, Washington, D.C., and the Salt Institute, Alexandria, VA, issued rejoinders of their own, with the latter’s president, Richard L. Hanneman, going so far as to call the AMA’s recommendations “scientifically unjustified and a waste of time and money.” Ouch.

Ouch, indeed. Thanks to IFT for its efforts to sort out the controversy. Actually, sodium intakes have been generally unchanged not just for the past quarter century, but for the hundred or so years that we've been able to measure intakes with some accuracy. We need a "truth squad" to prevent anti-salt zealots from trying to distract the public health policy discussion from its proper focus on whether lowering dietary sodium would provide any health benefit to the population. There's no evidence on the table that it would, just computer-generated model projections based on flawed assumptions drawn from intermediate variables. Yes, ouch. That hurts all of us.

Posted by Dick Hanneman at 11:47 PM | Permalink