Salt & Human Health

Federal nutrition labels permit food manufacturers to make "health claims" for the healthfulness of their foods, but require any food making any health claim (e.g. that the product is healthier because of its low-fat or high-fiber content, etc.) to also be low in sodium. The Salt Institute and food manufacturers have urged repeal of this "disqualification" provision since it prevents otherwise-healthy foods from touting their nutritional advantages based on a fundamentally-flawed decision on sodium.

Recently, Bill Clinton's foundation and the American Medical Association united in the Alliance for a Healthier Generation announced agreement with five major US food companies to promote new guidelines for sale of healthier foods in schools. While the guidelines incorporate an unjustified cap on sodium content, they wisely provide exemptions: some soups, for example can have more than triple the "maximum" amount of sodium. As the AHG explains:

"Why do the guidelines alow more sodium for vegetables with sauce and soups and for certain fat-free and low-fat dairy products?

"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."

Humans, like other animal species, love the taste of salt. It's not the "salty" taste alone that's responsible. Perhaps even more important is salt's capacity to mask the otherwise-bitter taste of such nutritionally vital foods as many vegetables. Animal nutritionists responsible for livestock and poultry have long fed bitter-tasting -- but essential -- trace minerals by combining them with salt. A recent Rutgers University study in adult women found that the 25% of the group who were most sensitive to bitterness were 20% thinner than the average! Recent studies specifically conclude that children's sensitivity to bitterness was a primary factor in their dislike and low consumption of vegetables.

Hats off to the Clinton Foundation for this real-world accommodation. Listen up, FDA!

Posted by Dick Hanneman at 01:55 PM | Permalink

That's a teaser headline. An article earlier this year in Nephrology Dialysis Transplantation by Dr. Markus G. Mohaupt and colleages in Berne, Switzerland, found that treating hypertensive pregnant women with a diet of 20 mg/day of salt (nearly triple normal intake) lowered their blood pressure significantly.

A generation ago, obstetricians routinely advised expectant mothers to cut down on their salt intake...until experience and controlled trials found the advice was producing miscarriages. So, that advice is an historical footnote. But giving MORE salt? That's a new one!

And the high salt therapy integrates nicely in addressing emerging concern that pregnant women need to consume more iodine -- since iodized salt is public health's preferred option for adding iodine to the diet.

Posted by Dick Hanneman at 12:29 AM | Permalink

Bob Messenger's Morning Cup today commented: "Last week's action by WASH on salt levels has bigger implications than being yet another pressure group action against problem ingredients and their 'users'."

Seems the new anti-salt activist group was mightily selective in its inaugural news release pointing out that some fast food restaurants' choices are higher in sodium than others. By citing only the highest offering, relating it neither to the chain's overall sodium profile (or, unmentioned, ignoring the overall population sodium intake), the group crashed and burned its credibility -- at least with Bob Messenger. As Bob explained:

WASH PR has very successfully placed the findings in many newspapers and magazines around the world and now we can all read which products “our” country has “extra” salt in, and the perception is that its those bad manufacturers again.

Maybe they are and then maybe again they’re not. I think that most companies were merely following that old dictum – Think Global, Act Local. We can probably all imagine the scenario. Brand X is International, but run by subsidiaries in each of its major countries. The local brand team is testing local taste preferences and discovers that in their country, consumers like it to taste saltier – so they adapt the recipe. Some time later medical research points to perceived dangers from too much salt in the national diet and Brand X again re-formulates and claims “now with less salt”.

No problem, a responsible manufacturer acting in the best interests of their consumers. But that I think was then. Now consumers of Brand X compare their salt levels to those in other countries, but they don’t think “we like more salt here”, they think “what a bad manufacturer you are”

Its time I think to re-work the old dictum, perhaps it should now be Think Global and Act Local, very very carefully because to rather misquote Marshall McLuhan the world really is a village now.

Why can't WASH just stick with the science instead of fabricating the illusion that countries around the world are consuming massive amounts of salt? In the U.S., for example, sodium intakes are average or below average around the world. You'd never know that reading the misleading WASH news releases. Is this simply backlash against dishonest "spin" or are we being fed backWASH? (unfamiliar with the term? Ask any parent!)

Posted by Dick Hanneman at 10:04 PM | Permalink

It was somewhat of a surprise to read the Washington Post's latest conspiracy theory - it must be the influence of the Da Vinci Code.

No one has ever disputed the impact of salt on blood pressure, nor for that matter has anyone ever disputed the impact of the myriad stresses we routinely encounter on blood pressure. There is, however, a great debate on whether these impacts per se lead to negative health events.

Hypertension is not a proxy for death, nor is it a surrogate for cardiac disease. Yet the anti-salt lobby ask us to believe it is, without the benefit of any scientific data. They rely exclusively on epidemiological studies using hypertension as an end point, ignoring all other variables. They rely on the famous Intersalt Study (Brit. Med J., v. 297, July, 1988) which compared per capita salt consumption to blood pressure in populations around the world. What they did not do was compare salt consumption to longevity. Using the same Intersalt data on salt consumption and the US Census Bureau data on life expectancy across the world, the resulting curve draws the inescapable conclusion that those populations which consume the most salt live the longest! No joke, no fudging figures - those populations which consume the most salt live the longest.

Of course, there are many other factors involved in longevity just as there are many other factors associated with blood pressure, but it still remains that the more salt a population consumes, the longer they live.

Indeed, one of the most outspoken and effective British anti-salt advocates, when confronted with data from Japan, whose citizens are amongst the highest per capita salt consumers in the world and also have the longest lifespan, dismissed this simply by stating that they would probably live even longer if they didn’t eat so much salt. Some analysis, some science, no?

Before we all go around hoisting placards claiming Bland is Grand, let's consider the science and the data a bit more carefully.

Posted by Mort Satin at 03:58 PM | Permalink

Rather than join in a constructive debate on the policy options based on scientific evidence, anti-salt activists continue to finger-point at personalities and "special interests" to divert public attention to the fact that scientific studies do not identify an improved health outcome from reducing dietary salt.

The latest blast, typified in today's Washington Post, attributes the controversy to economic interests including "Big Salt" -- the Salt Institute. I've submitted this response to the Post:

"Big salt"? As president of the Salt Institute: thanks for the compliment. A few years ago, Gene Weingarten's Below the Beltway profiled the Salt Institute as a prime example of the notion that even the smallest and most insignificant interests have a not-for-profit organization (see http://www.saltinstitute.org/pubstat/beltway.html). But that's another matter.

The article says "Too much salt is bad for you, right?" By definition, "too much" is, well "too much" ergo "bad."

But who's to say that the amount of salt Americans eat (and we're very average around the world) is "too much"?

I guess it depends on who you ask. The Cochrane Collaboration, inventors of "evidence-based medicine" feel there is no evidence supporting a population intervention. So, too, does the U.S. Preventive Services Task Force, guardians at the HHS of the "evidence-based" approach to public health nutrition policy.

This is an enduring debate among scientists. While we don't fund research due to our modest means, we've seen the debate transform itself from the old debate: will lowering salt help a significant number of people reduce their blood pressure? to a new, better line of inquiry: will reducing dietary salt lower the risk of heart attacks and improve health outcomes?

Surprise. When the question is framed in terms of health outcomes, the answer is clear: none of the studies show a population benefit by reducing dietary salt. Some show increased risk. The president of the International Society of Hypertension published an article earlier this year, using a massive HHS database, and found 37% greater mortality among those following the Dietary Guidelines' recommedation.

We've reviewed the controversy on our website, http://www.saltinstitute.org/28.html and comment regularly on our blogs http://www.saltinstitute.org/rss/health-other/ and http://www.saltinstitute.org/rss/saltsensibility/. We are a very transparent organization and you can also find all our public statements on this issue online at http://www.saltinstitute.org/advocate.html.

Dick Hanneman
President
Salt Institute

This may be David and Goliath, but we're not Philistines, in Webster's terms: "disdainful of intellectual values."

Posted by Dick Hanneman at 01:03 PM | Permalink

Carefully coordinated, even choreographed, the anti-salt campaign launched another publicity barrage today, announcing that the UK CASH (Consensus Action Against Salt) has been superseded by WASH, the World Action Against Salt. CASH experts (Dr. Graham MacGregor, et al) will be in Paris tomorrow and Friday, having persuaded the World Health Organization to host a one-sided symposium on salt to build pressure for action. The announcement was made in foodnavigator.com.

Meanwhile, the science is unchanged, trending against WASH as public health agencies consider whether their earlier focus on the blood pressure effects of salt reduction should remain the scientific focus or whether, as advocated by the presidents of the International Society of Hypertension and American Society of Hypertension, the focus should broaden to consider whether reducing dietary salt will improve public health.

Posted by Dick Hanneman at 09:26 AM | Permalink

Researchers from the University of California at Berkeley argue in an article published yesterday in the British Medical Journal recommending the "Parachute approach to evidence based medicine," that there are times when it is unethical to wait for controlled trials of a health intervention. People die before the intervention is tested, they say, citing as their most impressive evidence the case of Oral Rehydration Therapy (ORT). They explain:

In 1980 childhood diarrhoea was killing an estimated 4.6 million children annually. Treatment with an intravenous drip is life saving but requires health facilities. Studies from 1977 onwards showed that infant diarrhoea could be treated with oral rehydration. The World Health Organization initiated a highly successful programme of oral replacement therapy in 1981 after it became obvious that the treatment saved lives and no alternative home based treatment was possible. Randomised controlled trials were later conducted in health facilities, confirming that oral replacement therapy was as effective as intravenous therapy. The initiation of large scale programmes for oral replacement therapy before the randomised trials meant that by 2000 there were three million fewer deaths from diarrhoea annually.

Treating diarrhea with a mixture of salt, sugar and water has, indeed, saved millions of lives. The authors advocate the "parachute" principle, explaining:

Evidence based medicine and randomised controlled trials are not synonymous. The parachute approach can be the most appropriate, especially in situations of high mortality and low resources, when a simple intervention can have a large impact. Randomised controlled trials are essential in many other settings and they have defined many life saving strategies and corrected some important mistakes. They are often needed when mortality has reached a low level because new treatments require large investment for relatively small improvements in therapy that may be difficult to distinguish.

All that may be well and good, but BMJ has also editorialized that they feel confident in recommending universal sodium reduction. Perhaps a caveat is needed before we call in the airborne assault on salt. In the case of ORT, the small scale studies produced strong consensus of a health benefit. While there is no such concensus that reducing salt would reduce blood pressure to a meaningfull degree, because the effect is so heterogeneous, the UC-Berkeley authors and BMJ editorial staff should be chastened by the consensus of the observational studies of low-salt diets -- there is no benefit in terms of reducing heart attacks or reducing mortality.

Let's not "parachute" in to reduce dietary salt -- at least until the clouds clear and we can see the landing area.

Posted by Dick Hanneman at 02:45 PM | Permalink

Used to be all dietitians would chant the mantra of varied diets where all foods could find a place. "We need to focus on the question of "good diets" and "bad diets," they'd say, and avoid labeling individual foods as "good foods" or "bad foods."

The science is unchanged, but the mantra is gone. When nutrition experts gather these days, they're shaking their heads and wringing their hands: the public doesn't "get it." While consumers pretty well understand the concepts of the dietary guidelines, they don't buy into them in terms of personal eating decisions. What to do?

Demonize foods, say some like the Center for Science in the Public Interest which has pushed the "good food/bad food" dichotomy for 30 years. Make people feel that the foods they eat are poisoning them. Ostracize foods with "bad" nutrients and limit diet choices to "good foods" with plentiful "good" nutrients.

The food industry is buying into the "good foods/bad foods" story too -- for marketing reasons. Food companies want to deliver what their customers want. If you can put a "healthy" label on your foods, it makes a difference in product placement and sales -- if you can make it taste good!

A new study reported by the European Food Information Council sums up this way:

There is widespread interest for nutrition information on food packages. Consumers generally understand the link between food and health, and many are interested in using information about the nutritional properties of the food they eat. However, the degree of interest differs between consumers and varies across situations and products. In addition, it can conflict with other interests in food, notably taste, traditional eating, and indulgence.

Consumers like the idea of simplified front-of-pack information but differ in their liking for the various formats. These include health logos, ‘traffic lights’, GDA-based systems and energy labels. Differences can be related to conflicting preferences for ease of use, being fully informed, and not being pressurised into behaving in a particular way. For example, many consumers like colour coding, but some regard reds and greens on food products as too coercive.

Most consumers understand the most common signposting formats in the sense that they themselves believe that they understand them and they can replay key information presented to them in an experimental situation.

There is still virtually no insight into how labelling information is, or will be, used in a real world shopping situation, and how it will affect consumers’ dietary patterns.

The real question is will food buyers follow the red-yellow-green stoplight the same way they follow traffic speed limits -- by applying their own judgment in the absence of an officer writing speeding tickets? As EUFIC points out: "There is still virtually no insight into how labelling information is, or will be, used in a real world shopping situation." Are we ready to buy another set of unintended consequences?

Posted by Dick Hanneman at 10:45 AM | Permalink

A recent blog post on salt and health by Carl Hampton "Watch out for the salt!" gets part of the story right:

There have also been discussions between the Salt Institute (didn’t think there was such a thing, did you?) and the Department of Health and Human Services (DHHS). The Salt Institute has pushed for the DHHS to finance a comprehensive study about the health effects of salt. But here is no word as to whether that study will be conducted or not. Funding is really an overall deciding factor.

But Hampton continues: "Many thousands of Americans die each year because of gradual health effects that were caused by high sodium diets."

Just so we all understand what's going on here: in both the U.S. and the U.K. the anti-salt crowd has indicted sodium chloride for hundreds of thousands of deaths annually based on an extrapolation of blood pressure changes plotted against cardiovascular outcomes. Here's the deception: while the blood pressure effect of severe salt restriction is heterogeneous, cutting salt intake in half will, in fact, lower the population's average blood pressure. And it's true, as well, that populations with lower average blood pressure, in fact, have a lower incidence of cardiovascular events. The deception is to assume that lowering blood pressure is the only relevant metabolic effect of reducing dietary salt; it's not. Lowering salt intake stimulates plasma renin activity and sympathetic nervous system activity and worsens insulin resistance. It is the net effect of these changes that should motivate our concern and guide our policy, not the estimates of a statistical model with built-in assumptions that lower blood pressure will cut heart attacks.

What do those studies of the health outcomes of low-salt diets tell us? Short answer: they don't confirm the current policy of cautioning everyone to reduce dietary salt. Read all about it on our website and look at the underlying studies to make sure we have interpretted them correctly (some of the anti-salt researchers were so dismayed not to be able to find a benefit for their favorite course of action that they did not seek to publish their results, though they were presented to their peers in medical society meetings).

Everyone wants to reduce the tragedy of our massive cardiovascular disease risk. Drugs are part of the answer and diet can be too. But what little evidence we have from controlled trials suggests that the better dietary approach would be to improve the quality of our diets with something like the "DASH Diet," high in fruits, vegetables and dairy products -- but silent on the amount of salt.

What we really need, as Mr. Hampton referenced, is a randomized controlled trial of the mortality consequences of low-salt diets -- will they deliver what CSPI and Dr. MacGregor predict or will they confirm the existing observational studies showing no benefit or even a higher risk among those who cut back on salt. The government has already funded the Trials of Hypertension Prevention which examined blood pressure outcomes; substitute hard outcomes like mortality and the design question is solved. It would be costly, but our current policy is trying to mobilize billions of dollars of public health education and food industry technology. We cannot afford to base those very expensive interventions on a theory and an extrapolation. We need a controlled trial of the health outcomes of low-sodium diets.

Posted by Dick Hanneman at 10:19 AM | Permalink