Salt & Human Health: Salt & Health Newsletter

Since the early 1950s the health promoting qualities of the Mediterranean diet have been universally acknowledged. The Mediterranean diet “is characterized by abundant plant foods (fruit, vegetables, breads, other forms of cereals, beans, nuts and seeds), fresh fruit as the typical daily dessert, olive oil as the principal source of fat, dairy products (principally cheese and yogurt) and fish and poultry consumed in low to moderate amounts, zero to four eggs consumed weekly, red meat consumed in low amounts, and wine consumed in low to moderate amounts, normally with meals. This diet is low in saturated fat (less than or equal to 7-8% of energy) with total fat ranging from less than 25% to greater than 35% of energy throughout the region.” In fact, the famous DASH diet was designed using the Mediterranean diet as the model. What is never revealed, however, is that the level of salt in the Mediterraneam diet is considerably higher than that the levels recommended for the US diet.

Drs. Leclercq and Ferro-Luzzi of the WHO Collaborating Centre for Nutrition, at the National Institute of Nutrition in Rome, Italy reported in that males consumed 4400mg sodium per day based upon 24 hr Urinary excretion, equivalent to 11grams of salt per day . It was also observed that the discretionary intake of salt for adults varied from 36% (males) to 39% (females) of the total intake. The discretionary intake alone, of salt in Italy amounts to almost 75% of the total sodium recommended in the US (2300 mg). Since many of the Mediterranean foods are naturally well salted (cheeses, olives, salted fish (cod, anchovies), fish eggs, etc., it is natural to expect that a majority of the discretionary salt is used to improve the palatability of the variety of vegetables that are such a conspicuous and essential part of the diet.

When the DASH-Sodium trial is examined, it is immediately apparent that moving to a DASH-type diet has a far greater impact on blood pressure than lowering salt consumption. Dropping from the current level of sodium consumption to the recommended dietary level dropped the systolic pressure by an average of 2.1 mm Hg. However, simply changing from a regular to the DASH diet, without any changes to sodium consumption, reduced the systolic blood pressure by 5.9 mm Hg, almost three times the drop resulting from the sodium reduction. This clearly explains why Mediterranean people enjoy an excellent cardiovascular status despite their high salt consumption. With a DASH diet, the impact of sodium on the blood pressure of hypertensives is minimal (and of no significance to normotensive people – the majority in the population).

Considering that significantly increased fruit and vegetable consumption is a key element to the DASH/Mediterranean diet models, it is entirely realistic to question whether the current recommended daily intake of sodium (2300mg/day) is realistic, given the Italian example above. Amongst the most important foods are the bitter cruciferous vegetables. While they have so much nutrition to offer, without salt, they are not palatable to adults or children (who are even more sensitive to bitterness). In addition to the benefits of the DASH/Mediterranean diet for cardiovascular disease outcomes, all other health parameters are significantly improved. Based on all the scientific evidence we have available, fruits and vegetables are the cheapest, most readily available, and most beneficial foods we can consume to give a significant degree of protection from the modern health challenges we face. Considering the hierarchy of positive health impacts, maintaining the DASH/Mediterranean diet is far more significant than reducing salt – the one safe condiment that has traditionally made this diet so agreeable.

Posted by Mort Satin at 03:54 PM | Permalink

Three weeks ago, at the GMA/FPA and CSPI Salt Conference, Michael Jacobson of CSPI categorically stated in his opening remarks, “The debate on sodium is over. There is no longer a debate whether salt is good or bad.” He was followed by Steve Havas of the AMA who stated that he did not believe any additional research was necessary to prove the beneficial impacts of a dramatic sodium reduction in the diet. This attempt to stifle discussion and pronounce, as if by imperial fiat, that there was no longer any debate concerning the benefits of salt reduction in the diet backfired.

When the audience, which was composed of professional food scientists, nutritionists, dieticians, epidemiologists and policy makers split into working sessions to consider all that was said, they concluded that the benefits of salt reduction to health outcomes had yet to be proven scientifically and that that a singular focus on salt reduction was not a viable solution. Indeed, the delegates unanimously stated that a more holistic approach was needed to improve overall dietary quality.

Almost as it on cue, within two weeks of the Salt Conference, two peer-reviewed medical journal articles appeared, both demolishing Michael Jacobson’s assertion that “the debate on sodium is over.” In a paper published in the October issue of the European Journal of Epidemiology, prominent Dutch scientist D.E. Grobbee and colleagues in the Rotterdam Study concluded that urinary sodium is not significantly associated with myocardial infarction, stroke, or overall mortality, adding: “The absence of a relationship between salt intake and mortality in our study corroborates the findings from the large Scottish Heart Health Study among almost 12,000 middle-aged subjects with 24-h urine samples.”

Shortly thereafter, in the Journal of Interactive Cardiovascular and Thoracic Surgery, Drs. Jay Walker, Alastair MacKenzie and Joel Dunning of the Department of Cardiothoracic Surgery at James Cook University Hospital, in Middlesbrough, UK reported their in-depth review of all available evidence to determine if restricting dietary salt intake would provide protection from adverse cardiovascular events or mortality. They found it impossible to find a link between salt and heart disease due to a “lack of adequately powered randomized trials or observational studies conducted with sufficient rigor.” Dr Dunning went further – he dismissed the theory that salt can cause strokes and heart attacks as,

...an argument of hope over reason....

These two publications reinforce the conclusions of the recent evaluation of the health outcomes study from Finland’s three decade long salt reduction program.

Today saw a scathing denunciation of the poor science that has gone into the UK’s public health policies. Dr. Phil Peverley, a GP from Sunderland in Northern England is this year's Magazine Journalists and Designers Association Columnist of the Year. Last year, he won the Press and Periodical Association's columnist of the year award. In his article, “A Very Large Pinch of Salt,” Dr. Peverly criticizes

those doctors and politicians who have for years promoted the nannying theory that we should be forced to eat less salt in our diets. The obvious lack of a correlation between elevated blood pressure and salt intake should have been good enough for them.

He goes on to describe Public health minister Dawn Primarolo, who was recently quoted as saying that a low salt intake was an essential part of a healthy diet.

Ms Primarolo’s only qualification to spout off on this subject is a six-year pre-MP career as a ‘mature student’, so I would always have regarded her pontifications as profoundly suspect…

Delving deeper, he states:

However, my remit is a wider one. This is further evidence that it is us, the medical profession, who don’t know what we are talking about. I never fell for the bollocks about salt, but I have been as guilty as the rest of spreading disinformation and inaccurate advice about a whole manner of other medical subjects. It is becoming embarrassing.

Bravo Phil Peverly! There are not many like you, but hopefully there will be enough to drive away the fog, so we can get back to the science.

Posted by Mort Satin at 06:16 PM | Permalink

For years, the anti-salt advocates have ducked the scientific evidence and relied on the support of the largest medical and health institutions to prop up their contention that there is an unassailable link between salt intake and cardiovascular disease. This fallacious strategy is known as Argumentum ad Verecundiam – the reliance on known institutions and entrenched doctrines, rather than experimental data - the sort of thing that Francis Bacon grappled against in his struggle to bring us the scientific method.

Predictably, science eventually finds it way to the surface and in this case, the Argumentum ad Verecundiam is showing signs of collapse in the face of mounting evidence against a link between salt intake and cardiovascular disease.

In the most recent issue of the Journal of Interactive Cardiovascular and Thoracic Surgery, Drs. Jay Walker, Alastair MacKenzie and Joel Dunning of the Department of Cardiothoracic Surgery at James Cook University Hospital, in Middlesbrough, UK carried out an in-depth study of all available evidence to determine if restricting dietary salt intake would provide protection from adverse cardiovascular events or mortality. Using reported search parameters, 462 papers were identified of which 14 papers represented the best evidence on the subject. They concluded that restricting sodium intake to levels below 6 g per day as most international guidelines, such as those of the AHA, the US Dietary Guideline Committee and the Scientific Advisory Committee on Nutrition recommend may reduce blood pressure, but found it impossible to find a link between salt and heart disease due to a "lack of adequately powered randomised trials or observational studies conducted with sufficient rigor."

This information corresponds with the recent publication of the Rotterdam Study by Geleijnse et al, as well as the evaluation of the health outcomes from Finland’s three decade long salt reduction program.

The myth-information about salt and cardiovascular health outcomes has gone on for a long time and misdirected our focus from more practical and effective approaches to achieving good health. It’s time we start devoting our resources to solutions that have scientific merit, such as improving the overall diet through systems and products that encourage greater consumption of fruits, vegetables and low-fat dairy products.

Posted by Mort Satin at 10:47 AM | Permalink