The most recent research, just published in the peer-reviewed scientific journal, Cell Metabolism, has shown that the Government’s dogmatic salt reduction agenda is not based on sound science (1). An international team of researchers, working on the long-term space simulation projects, Mars105 and Mars520 at the Institute for Biomedical Problems in Moscow, have determined that all the studies relating hypertension to salt consumption are critically flawed .
Up until now, it has been assumed that the gold standard for calculating salt consumption is the amount of sodium found in a 24 hour urinary analysis. However, in what was the largest and most highly controlled, long-term study of salt metabolism ever carried out in a fully enclosed system, these researchers found that that the body does not eliminate the sodium from consumed salt on a regular basis, but stores and releases it in a fixed biological cycle. So measuring the amount of sodium excreted in any 24 hour period is meaningless. Sodium excretion has to be measured over a much longer time period to accurately estimate salt intake. This explains why so many previous studies have been so inconsistent.
(1) Rakova, N. et al. Long-Term Space Flight Simulation Reveals Infradian Rhythmicity in Human Na+ Balance.Cell Metabolism. 2013; 17: 125–131. (January 8, 2013)
Health advocates, who do not have a firm scientific basis upon which to promote their cause, often elect to characterize available data completely out of context in order to further their case. Followers of this column have often read how members of the global anti-salt groups CASH (Consensus Action on Salt and Health) and WASH (World Action on Salt and Health) are willing to say anything and attack anyone in order to further their population-wide salt-reduction agenda. They approach the issue of salt and health as if they were members of a religious cult and consider all scientists who question the public-health value of salt reduction as infidels.
Today brings us another picture-perfect example of this. BMJ Open has just published an article entitled, “Spatial variation of salt intake in Britain and association with socioeconomic status ,” by Chen Ji, Ngianga-Bakwin Kandala, and Francesco P Cappuccio. The senior author and correspondent is Professor Cappuccio, a longtime member of WASH. The key conclusion of this study was that low socioeconomic status was associated with higher levels of sodium (or salt) intake. The authors went on to state, “…measures of low socioeconomic status are associated with higher salt intake, indicating a higher risk of hypertension and CVD.” In other words, the authors contend that if you reduce the amount of salt that poor people eat, you will reduce their risk of hypertension and cardiovascular disease. It’s that simple, is it?
But wait. We have long known that low socioeconomic status was associated with a great many risk factors for health and mortality. Epidemiological studies have repeatedly shown that increasing wealth is associated with less heart disease and better overall health.
Dr. George Davey Smith and colleagues have made it clear that socioeconomic hardships are grouped or clustered together [i] . Low economic status is characterized by a multitude of adversity. The poor work harder and are less educated than the well-off; they smoke more; they eat cheaper foods that are higher in calories and lower in essential nutrients; they eat more processed foods that last longer; they can’t afford to eat the same ratio of healthy fresh green vegetables and fruits than better-off individuals do, so they weigh more; they worry more about paying bills, their children’s education, medical costs and simply surviving than richer people do. They live in nastier conditions with far more noise, crime and environmental pollution. Is it any wonder that they’re more prone to hypertension and other cardiovascular disease?
Anyone who believes that the answer to improving the health of people at low socioeconomic status is salt reduction can’t be serious. The answer is as complex as the problem. If anyone were to insist on a single solution, it can only be to improve their overall economic status. But nothing is that simple. If one were to look to changes in the diet that could significantly reduce the risk of hypertension and CVD, then the very first action to take would be to give the poor greater access to fresh vegetables and fruits – the single most important dietary factor to lowering the overall burden of disease.
Effective public health policy development will never result from a myopic view of risks, particularly if it is not supported by the preponderance of science. The authors of the BMJ Open article would be far more effective if they placed people ahead of their parochial salt-reduction agenda.
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[i] Bruna Galobardes, John W. Lynch, and George Davey Smith. Childhood Socioeconomic Circumstances and Cause-specific Mortality in Adulthood: Systematic Review and Interpretation. Epidemiol Rev 2004;26:7–21.
