Is the low salt diet healthy?

Is the low salt diet healthy?

In many developed countries salt has been considered as a primary cause of high blood pressure and heart disease. Now, lots of studies are warning about the dangers of the low salt diets.

The Japanese paradox – highest life expectancy and highest salt intake

It is well known that the Japanese have the longest life expectancy rates in the world. It is less known however, that they also have the world’s highest rates of salt consumption.

According to the World Bank, after Hon Kong, Japan has the second-highest life expectancy of 84.67 years in the world. In Sweden – 82.41, in Canada – 81.75, in UK – 80.90, and in US – 77.28.

But you probably don’t know that Japan also has one of the world highest levels of salt intake of 11g per day; most “salt-friendly” people in the world. Whereas European and North American health authorities recommend the maximum salt consumption per day of 6g – that’s around 1 teaspoon. It’s partly due to the use of soy sauce.

Maybe the low salt diet is a myth?

Salt is essential for your health

Salt is essential to the health nutrient even your heart won’t beat without it. Actually, no mineral is more essential to human survival than sodium.

Salt is one of the five basic taste sensations. Sodium ions are vital for generation of nerve impulses, for maintenance of electrolyte balance and fluid balance, for heart activity and certain metabolic functions. It helps your muscles stay strong, and keeps your cells and brain functioning. Actually, no mineral is more essential to human survival than sodium. However, our body cannot produce it, and therefore it must be consumed with our diet.

Salt daily intake

According to the new guidelines of the World Health Organization, salt daily intake is 5g (1 teaspoon) for adults. It is recommended that adults should consume less than 2,000mg of sodium (which is contained in 5g of salt) and at least 3,510 mg of potassium per day.

Health risks of a low salt diet

The researchers from McMaster University and Hamilton Health Sciences have found that, contrary to popular belief, low-salt diets may not be beneficial and may actually increase the risk of cardiovascular disease and death compared to average salt consumption. A large worldwide study that involved more than 130,000 people from 49 countries showed that regardless of whether people have high blood pressure, low-sodium intake is associated with more heart attacks, strokes and deaths compared to average intake. They looked specifically at whether the relationship between sodium (salt) intake and death, heart disease and stroke differs in people with high blood pressure compared to those with normal blood pressure.

Studies also show that excessively low salt intake (below three grams of salt per day) is associated with an increased mortality and higher risk for cardiovascular disease.

The study published in the Journal of the American Medical Association revealed the results of eight years of investigation of 3,681 middle-aged healthy Europeans that were divided into three groups: low salt, moderate salt, and high salt consumption. It was found that the less sodium excreted in the urine (a marker of salt consumption), the greater the risk of dying from heart disease. The risk for heart disease was 56% higher for the low-salt group than for the group who ate the most salt!

Sodium / Potassium Pump

Sodium is the most prominent cation in extracellular fluid: the 15 liters of it in a 70kg human have around 50grams of sodium, 90% of the body’s total sodium content.

The distribution of sodium ions are mediated by Na+/K+-ATPase, which is an active transporter pumping ions against the gradient, and sodium/potassium channels. By means of this enzyme, living human cells pump three sodium ions out of the cell in exchange for two potassium ions pumped in; comparing ion concentrations across the cell membrane, inside to outside, potassium measures about 40:1, and sodium, about 1:10. In nerve cells, the electrical charge across the cell membrane enables transmission of the nerve impulse – an action potential – when the charge is dissipated; sodium plays a key role in that activity.

The problem is that currently most people consume too much sodium and not enough potassium. Processing reduces the amount of potassium in many food products.

Potassium-rich foods include: beans and peas (1,300mg of potassium per 100g), nuts (600mg/100g), vegetables such as spinach, cabbage and parsley (550mg/100 g) and fruits such as bananas, papayas and dates (300mg/100g).