The full title of this book by Dr James DINicolantonio is “The Salt Fix: Why the Experts Got it All Wrong and How Eating More Might Save Your Life”, which has just been published (1). I have been convinced for some time that the advice to reduce the intake of salt (sodium) was not based on sound science and that this is one more example of how committees of the “great and the good” produce fundamentally flawed reports. Now Dr DiNicolantonio has examined the issues in detail and reaches conclusions that confirm my worst fears.
Blood pressure (BP)
Those who have formulated the official line seem to have been obsessed with BP. However it turns out that 80% of the population are not sensitive to the BP raising effect of salt at all. So any possible benefit of salt lowering would be restricted to a small proportion of individuals. It is argued that the reduction in BP associated with salt restriction in people with hypertension justifies the recommendations. However the reduction is small and only happens in less than half. It also ignores any harms that may occur, many of which actually increase the risks of heart disease. These include increased heart rate; compromised kidney function and adrenal insufficiency; higher triglycerides and insulin levels, which can all contribute to the development of insulin resistance, obesity and Type 2 Diabetes (T2D).
The dangers of low salt intakes
The truth is that the stringent low salt guidelines were based on a guess and a totally unjustified assumption that these small benefits to BP observed in some patients would extend to large benefits for the whole population. At the same time there was woeful failure to consider any adverse effects that might result. It is somewhat ironic that the advice to restrict salt may be one of the factors contributing to the current poor quality of public health worldwide as shown by the rapidly growing levels of obesity and T2D. Rather perversely it is those who are interested in eating healthily that may be at special risk because they take note of the guidelines and also switch to diets low in salt such as Low Carb or Paleo. On top of all this there are many medications that do cause salt loss.
Why salt is needed
Based on his clinical experience and extensive research, Dr DiNicolantonio has reached the following conclusions about salt:
- Low salt is miserable;
- Low salt is dangerous;
- Our bodies evolved to need salt;
- Low-salt guidelines are based on inherited “wisdom”;
- All the while, the real culprit has been sugar;
- Most important: salt may be one solution to – rather than a cause of – the worldwide chronic disease crisis.
Why did things go so badly wrong?
The story is very familiar. A number of strongly opinionated individuals who are very forceful and politically influential push the case for a particular dietary recommendation. They argue that it is necessary to act in order to improve health and save lives. The fact that there is not compelling scientific justification is simply brushed aside on the grounds that it is imperative to move quickly. Anyone who has the temerity to object can be subject to abuse and accused of being linked to vested interests. Dr DiNicolantonio provides a fascinating account of the skulduggery behind these salt restriction recommendations. In particular, scientific data are manipulated in ways that have been exposed in recent years. For example, the Intersalt project was an epidemiological study conducted in 52 different countries. It was claimed by the US Food and Nutrition Board that this proved BP increased with age if the sodium intake was greater than 2.4 g/day. The reality was that it showed the direct opposite. Only five out of the 52 populations consumed less than 2.4g/day, and four of them had been studies with primitive societies. The fifth population that consumed these low levels had a higher systolic BP compared to several populations with a higher intake of salt. If the four primitive societies were excluded, it became clear that the BP decreased as the salt intake increased.
What is even more disturbing is that Intersalt group did not report information on heart rate, even though these measurements had been taken. The reason this was not included in the published papers was:
“…because of the need to preserve the independence of scientific investigation, the integrity of the data, and the confidentiality of information.”
This is just a load of bullshit and there must be very strong suspicions that the heart rate data may have shown harm and would therefore have been damaging to the case for diets low in salt. In fact there are indications that diets low in salt increase the stress on the heart and arteries and so INCREASE the risk of hypertension and heart failure.
The usual approach when devising official recommendations is to assess how much is needed to ensure that the body has an adequate supply to function effectively. This is not easy to do and should probably be regarded more as an “art” than a “science”. Although there may be characteristic deficiency symptoms with low levels of intake, the actual requirement may be much higher than this. This can be illustrated by the case of Vitamin D. The initial attempt to determine the requirement was based on the amount needed to prevent rickets. However we now know that for a person to achieve optimum health, there must be much higher intakes. With salt however there appears to have been an obsession with the dangers of a very high intake (that were never substantiated) and therefore the recommended daily intake should be as low as possible. The overriding consideration was that there would be “benefits” in having a low intake because of the impact on BP, which of course is very dubious. Unbelievably there was no attempt to evaluate the dangers of salt restriction caused by increases in renin, aldosterone, insulin and heart rate.
When the body suffers from an inadequate supply of salt one of the defence mechanisms is to stimulate the production of insulin because this helps the kidneys to retain more sodium. However the increased insulin causes insulin resistance, which is now recognised as a critical factor in the development of a range of chronic diseases, including T2D, heart disease, various cancer and possibly even Alzheimer’s Disease (2).
There are actually reasons it is important to ensure that there is plenty of salt available. Obviously those who sweat because of exercise, high temperatures or using saunas lose salt and this will have to be replaced by increased consumption. As Professor Tim Noakes has found excessive fluid consumption by long distance runners does cause excretion of salt leading to hyponatraemia, which may be fatal (3). Additional salt may be needed to replace that lost as a result of bleeding or other loss of body fluids. It is also critical to consider other factors that may affect the requirements for salt. For example, women who are pregnant have an additional demand and this is even greater during lactation because salt is present in the milk. Salt restriction may impair kidney function.
The authorities also disregarded crucial epidemiological information based on societies with a relatively high intake of salt. These include Japan, France and South Korea, which are among those countries with the lowest death rates from coronary heart disease in the world. In fact these countries also have very long life expectancies.
The official advice on salt in the USA and in many other countries including the UK is just one more in a catalogue of dietary recommendations that were not only WRONG but have proved to be major contributors to the deteriorating standards of public health all over the planet. The consequences have been absolutely disastrous. However what is much worse is that there is an almost universal failure by the leaders of the medical and healthcare professionals to recognise the fundamental flaws in the scientific justification for current policies. Anyone who objects runs the risk of being castigated by the main stream. We need more like Dr DiNicolantonio who have the knowledge and confidence to set out the facts so that the private individuals can be informed of what is really happening. The more people who read this book and understand it the better. Ultimately, things have to change for the better. Hopefully this will be sooner rather than later.
“I strongly recommend everyone pick up a copy of Dr. DiNicolantonio’s new book The Salt Fix. This should be required reading for the medical community.”
- J D DiNicolantonio (2017). “The Salt Fix” Piatkus: London ISBN 978-0-349-41738-7 http://thesaltfix.com/