Another curse of reductionism in science
“The fact that salt is a powerful emetic as well as a potent laxative should convince the most skeptical that it is not meant to form an important part of the human diet.” — John H Tobe (in Salt and Your Health)
There is an old adage in this part of the world. “There is no one more loving than a mother and there is no food tastier than salt.” Some of these sayings come from hundreds of years of observation-based holistic research which appears much more reliable than the present-day cross-sectional short-term studies of reductionism and surrogate end-points.
Salt has got a bad name. If you have high blood prssure (BP) and heart conditon, eat a salt-free diet. Says who? Says a single study. The one-study basis of salt restriction in the world is a longitudinal study of Lewis Dahl which showed that higher salt intake seems to keep the blood pressure up.
Further scrutiny of this study did show major fallacies in his calculations; but, for some unexplained reasons, the official stand has been to observe salt restriction, to stay healthy and be fit.
A common diagnosis in elderly people hospitalised these days is hyponatremia which results in neurological manifestations ending in coma. In my younger days, we did not see it as frequently as we see it nowadays.
There are many reasons for this increased incidence. The number of patients on diuretics, for various reasons, is increasing while, at the same time, salt restriction has become more and more aggressive in hospitals. Many other drugs in common day-to-day use also upset the electrolyte balance in the human system.
All in all, patients pay for their ignorance with their lives. The time has come to take a re-look. What made me do this was a study recently published—of nearly 1,000 patients with heart failure —who were observed for the effect of conventional salt restriction on outcome, through mortality and morbidity. Dr Rami Doukky, a cardiologist and associate professor at Rush University Medical Center in Chicago, leading a team of resarchers, found that patients with moderate heart failure who stuck to a low-sodium diet were 85% more likely to die or require hospitalisation for heart disease, compared to similarly ill patients who didn’t restrict their salt intake.
Since this is only an observational study, a prospective randomised controlled study might be better. However, having said that, I feel that the study has thrown much light on this vexed problem of sodium chloride and human health.
As I never tire of saying, the universe does not work in bits and pieces. It works as whole. Trying to understand how nature works is called science.
But in reductionist science, which the Western medicine follows as the basis of human physiology, scientists only get a keyhole view of the goings on inside, missing the essential, always. That is why medicine is not a perfect science; it is only a statistical science treating all patients as identical (‘one size fits all’ hypothesis) which they are NOT. All our efforts at RCTs (randomised controlled trials) have, per force, to be unreliable as two human beings are NOT like two molecules in your laboratory to be compared.
Let me assure you that we will never be able to get a clear cut black & white demarcation here. “Truly man is a marvellously vain, diverse, and undulating object. It is hard to form any constant and uniform judgement on him,” was Michel de Montaigne’s opinion about us humans. Human physiologists have yet to fully understand the enigma of water and electrolyte balance in the human body.
It is now known that human system can even get any electrolytes it wants from other electrolytes. This is a new concept, known to Russian scientists for decades but kept away from the West. This is called transmutation. All these compound our confused understanding of these electrolytes. Sodium taken in isolation (reductionism) might increase the BP and abet heart failure. God only knows what it does in the whole body with many other players in the field and its capacity to transmutate.
Any talk about our underlying physiology might not be true because our thinking is stunted, thanks to our reductionist science. Long-term outcomes research is our future guide and the study cited above is a good pointer for us to know that all is not well with the way of treating heart failure. Mortality due to heart failure, with or without treatment, remains almost the same except for the dent (small gain) that diuretics have made in that area. Repeated hospitalisation has also not come down after we introduced so many drugs for heart failure treatment.
The only drugs which help, for sure, are diuretics. Beta-blockers, ACE (angiotensin converting enzyme) inhibitors, ARBs (angiotensin-II receptor blockers) and all other newer modalities have not had a long enough experience in the field. None of these drugs had any independent studies to recommend its use. Available studies are all company-funded!
We need more unbiased, independently-funded studies to answer these questions. Drug company-funded studies will, of course, give results acceptable to their funders. The above-cited study also showed another important parameter. Salt restriction did not improve treatment outcomes or quality of life but did increase significantly the incidence of low-salt syndrome, especially in the old elderly in the ICUs.
Drawing sustenance from our ancient wisdom, which will be frowned upon by my ‘scientific minded’ colleagues, gives us another angle to this problem. The best diet to help us in the lean seasons, like long rainy seasons, is our pickles. Studies on pickles have shown that the salt in the pickle does not damage human health; but increases pickle’s shelf-life. Western junk foods, on the contrary, contain so much of pure sodium chloride that it is bad for health. Professor Macgregor’s studies in London on cornflakes showed that cornflakes contain fourfold salt, compared to sea water, and is bad.
Our ancient rock salt, not the present-day refined salt, contained many other salts, in addition to sodium, like potassium and magnesium chloride, that might be good for health in the long run; the sodium content does not differ in the two, though.
Our ancient food preservation techniques were also based on salt but not the ‘pure’ and refined salt of today. We have to study their goodness to extrapolate their use modern food-processing methods.
In conclusion, the above-mentioned study needs further clarifications. As of now, our idea of connecting salt to hypertension and heart failure has not been questioned but what we have to establish are two things: 1) Is salt intake detrimental to health in the long run? And 2) Should we restrict salt for the young people in the fond hope of keeping them away from hypertension and heart failure?
Human physiology of water and electrolyte balance needs to be re-looked at to make our interventions in seriously ill patients more rational. For the time being, my take on the subject would be to let nature decide our future benefit as far is salt is concerned. Let us get enough salt from fresh, plant-based foods. Let us avoid adding ‘refined’ table salt to food. Let us also avoid very high salt containing foods like the Western junk preserved foods.
“You are the salt of the earth. But remember that salt is useful when in association, but useless in isolation.” — Israelmore Ayivor
(Professor Dr BM Hegde, a Padma Bhushan awardee in 2010, is an MD, PhD, FRCP (London, Edinburgh, Glasgow & Dublin), FACC and FAMS.