Here are some interesting things to read that might make you think twice about categorizing a mans attempt to help society with 20 years of research as "just a gimmick to sell a book!".
Salt and High Blood Pressure
The view that salt is bad for health and leads to high blood pressure was based on outdated research. Many more recent research pointing to this conclusion has been ignored, even though it has been verified by independent researchers.
This whole concept of sodium being the "bad guy" is based on the water-loving characteristic of sodium. The theory is that an excess of sodium will cause retention of water in the intra- and extra-cellular fluids and thus raise the pressure on the blood vessel walls. The basis for low sodium consumption was started with a poorly designed study in rats wherein the rats were fed the equivalent of over eighty times the amount of salt a human would eat under normal conditions. This is clearly ludicrous, as even the most excessive consumer of salt would use only twice as much salt as the average person. There should be no parallels drawn between this study and the actual effects on humans.
In the majority of the time, high blood pressure is a symptom of underlying chronic dehydration that is unnoticeable to us and not due to excessive salt intake at all. As the body becomes dehydrated (consumption of less than 6 to 8 glasses of water a day), the pressure in the vascular system falls due to insufficient fluid. The body reacts by secreting hormones that constrict the blood vessel. This is the body's compensatory mechanism to increase blood and therefore oxygen to the brain. If the body is well hydrated, the constriction signal will be shut off and blood pressure will return to normal.
Separate studies published in 1982 and 1984 analyzed nutrient intake and concluded that sodium is harmless, but calcium, magnesium and potassium protect against hypertension. These three minerals are also powerful medicines that can help to lower blood pressure.
In 1997, a large scale study was published in the New England Journal of Medicine. It reported that those subjects who were given a diet low in dairy products and vegetables, which are high in calcium and other minerals, had higher blood pressure compared to those who had sufficient quantities of those foods. The difference can be as much as 5-6 mm of pressure among those who had normal blood pressure to start with and can go up to 11-22 mm of pressure among those who already had mild hypertension initially. Clearly salt is not the culprit, but deficiency in key minerals can play a significant role.
Therefore, if one is to look for the roots of hypertension in the diet, then the focus should be on calcium, magnesium and potassium, not sodium. A diet excessively low in sodium can instead lead to negative effects like decreased blood volume, low blood pressure (because of the loss of fluid volume of the blood), an upset in the acid base balance in the body, constipation, just to name a few.
Excessive loss of sodium in the body can lead to lethargic, coma, and ultimately death. When people have low blood pressure together with chronic fatigue symptoms, it can be at least partly relieved by adding salt back into their diets.