Debunking medical urban legends - Salt and hypertension

For thousands of years, salt has been used as a commodity in trade and other industries and has been considered as a thing of particular value. Indeed the word “salary” is derived from the Latin word for salt. However, medically speaking, it has been touted as one of the biggest threats to cardiovascular health for many years. Is this true?

Salt is pure, white, immaculate and incorruptible

In many health controversies, a great deal of heat is often generated by spurious arguments that tend to obscure the strictly science-based position. However, the evidence is overwhelming about the fact that high salt intake has a detrimental effect on cardiovascular health and that people in developed countries have a salt intake that is much too high.

Salt = Na

Salt is a commonly occurring mineral, the technical name of which is sodium chloride. The human body needs about 500 milligrams of sodium (1000 mg sodium = 2.5 g salt) a day to survive. There is more than enough salt found naturally in fresh foods to provide this amount, so discretionary salt is not really necessary to a healthy eating plan. It is recommended that we use no more than 2400 mg of sodium (about 6 grams of salt) a day. Salt intakes across Europe are known to vary widely, ranging from 8.6 g of salt per day in the UK, to around 12g salt in Croatia. This is causing a long-term glut of cardiovascular problems.

This high salt intake is partly due to poor understanding by the patient of the fact that sodium and salt are one and the same thing. Many doctors and much of the literature available simply tell hypertensive patients to avoid salt, which the patient dutifully does, not realizing that over 75% of his salt intake comes in the form of sodium found in processed foods. Sodium is present in additives such as monosodium glutamate and sodium bicarbonate. As part of a successful cardiovascular management program, it is imperative that doctors inform their patients of this crucial difference. About 10% of dietary sodium is naturally present in foods; 15% is added during cooking or at the table (so-called discretionary salt); and 75% is incorporated during manufacture and processing. It is evident, therefore that manufactured foods provide the greatest scope for significant reduction of salt intake. Examples of high salt processed foods include soy sauce, processed meats, canned soups, peanuts, chips and stock cubes.

The best example is found in a can of soup. Canned soup contains on average about 0.4 g of sodium per 100 ml. This means that in a plate of soup (about 250 ml) contains about 1 g of sodium (2.5 g of salt), i.e. over 40% of the recommended daily maximum.

Crystal death…

Salt plays an enormous role in blood pressure regulation. It helps to maintain the concentration of body fluids at correct levels. However, the more salt we eat, the more water is drawn into the bloodstream. This raises total blood volume, which leads to increased blood pressure. With high levels of fluid circulating through the brain there is a greater chance that weaknesses in the brain’s blood vessels are exposed, and that they may burst, causing a stroke. Salt also plays a central role in the transmission of electrical impulses in the nerves, and helps cells to take up nutrients. Sodium is the major ion that accepts electrons. Sodium helps maintain the balance of electrolytes and the electrical conductivity of tissues.

In addition, salt also increases the risk of osteoporosis, particularly in women. High sodium intake can often lead to calcium loss (excreted out in urine). This loss in calcium is exacerbated if intake of calcium is low. Continued urinary calcium loss will translate to decreased bone density and increased risk for fractures in the later years.

Reductions in a minor key

A recent study in the US showed that if we reduced dietary salt intake in the USA by 3 g per day (1200mg less sodium per day), it could result in 60,000 to 120,000 fewer cases of heart disease, 32,000 to 66,000 fewer strokes and 54,000 to 100,000 fewer heart attacks.

A reduction in dietary salt of 3g per day would have approximately the same effect on reducing cardiac events as a 50% reduction in tobacco use, a 5% reduction in body mass index among obese adults or the use of statins to treat people at low or intermediate risk for CHD events.

And here’s the kicker: reducing dietary salt intakes by 3g per day would save $10 billion to $ 24 billion in annual health care costs.

In the healthcare industry, “management” is a magic word that blankets all manner of excuses and that often fails to address basic issues such as “disease education”, which is the axis on which healthcare should be balanced. There are as many definitions of disease management as there are disease management programs. The confusion is perhaps rooted in a fundamental paradox: In disease management, we really should try and manage patients, not diseases. It is as important for a doctor to educate his patients about the differences between salt and sodium as it is for him to prescribe the correct cocktail of medication. It is only through information that a doctor will truly empower his patients to take responsibility for his disease.

Uwe DIEGEL, CEO, iHealthLabs Europe