Let's talk about salt — how unhealthy is it really?

Give up chips, soy sauce and frozen pizza forever? Most people can't imagine living without these salty treats. But that's exactly what German Health Minister Karl Lauterbach has been practicing largely for more than 30 years. He says he does it to take care of his health.

We know excessive amounts of salt aren't great for us. Does that mean we should all follow Lauterbach's rigid strategy?

The comforting news in advance: "No, we don't have to do that," said Matthias Riedl, nutritionist and medical director of the Medicum Specialist Center in Hamburg, Germany. "But we do need a healthy approach to salt."

Only in small amounts 

Salt is essential for life. 

To understand that, we need to take a closer look at the science behind the seasoning. Salt consists of the chemical compound sodium chloride. Our body requires sodium to regulate our water balance, ensure the functioning of nerves and muscles and to drive digestion. 

The body needs about one gram of salt to accomplish these tasks.

In other words, salt in moderation is healthy. 

"It depends, as with many other food products, on the dose," said Riedl. With salt, it could be compared to a J-shaped curve: "Too little salt is bad for you. After that there is a short, healthy section. But that can be exceeded very quickly."

One teaspoon per day

At what point do we exceed this healthy section? According to the World Health Organization (WHO), the limit is a maximum of five grams of salt per day. That's about one level teaspoon.

"We already exceed this amount with one frozen pizza," warned Riedl. The same applies to two tablespoons of soy sauce. 

According to Riedl, it’s not a big deal if this happens once in a while. But many people regularly overstep the recommended five-gram limit.

Especially in some countries in east and central Asia, people consume too much salt. In China, the average salt consumption is around 10.9 grams per day — more than double the WHO limit.

Many European countries such as Germany, Portugal and Italy, as well as the United States, Canada, Australia and New Zealand, also exceed the daily guideline. The situation is similar in Latin America — particularly in Brazil, Colombia and Bolivia. Only a few African countries have healthy rates of salt consumption.

Too much salt = high blood pressure?

But why does the WHO set this limit of five grams? Studies have shown that if this amount is exceeded, we start seeing negative health effects — especially on blood pressure. 

That’s because salt bonds with water. This bonding causes the pressure in our tissues to rise, which can increase blood pressure and lead to a higher risk of stroke or heart attack.

But salt isn’t the only thing that influences blood pressure. 

"The reality is that many different factors affect blood pressure," said Riedl. "In addition to salt consumption, other factors include physical activity, stress, preexisting medical conditions and the rest of your dietary habits."

According to Riedl, slim people from Asian countries with high salt consumption who eat an otherwise healthy and traditional diet often have fewer problems with blood pressure than people from Western countries, who often already suffer from obesity or diabetes.

Salt-sensitive and salt-resistant people 

Furthermore, only about one-third the population is salt-sensitive — this means their salt consumption impacts their blood pressure. 

The remaining two-thirds are salt-resistant. In their cases, salt consumption and high blood pressure are probably not linked. 

"With a simple blood test, you can find out which group you belong to," said Riedl. However, in many countries this can be expensive. 

But even people who belong to the salt-resistant group should adhere to the five-gram limit. That's because too much salt can have other negative consequences for our health.

Stressed kidneys 

When salt consumption is very high, our kidneys become consumed by the act of excreting the excessive salt. "This can stress the organ out," said Riedl. In the long term, it can lead to renal insufficiency.

Too much salt also affects the gut microbiome. The number of lactic acid bacteria decreases, while the number of so-called Th17 helper cells in the blood increases. Researchers assume that this interaction causes inflammation and autoimmune diseases.

Along with increasing the risk of stomach cancer and bone loss (osteoporosis), salt can even contribute to obesity — it stimulates the appetite, beckoning us to keep eating even when we aren’t hungry anymore. 

How to reduce our salt consumption

The WHO estimates that if the entire world population reduced its salt consumption to five grams per day, around 2.5 million deaths caused by strokes and heart attacks could be prevented per year. But how can we keep our salt intake in check?

Luckily, there are different strategies. Instead of using salt to increase flavor while cooking, we could opt for fresh herbs. We could also stop adding salt when eating at the table. In Bolivia, for instance, salt shakers have been banned from restaurant tables since 2015.

Watch out for hidden salt

However, in many cases the problem of our excessive salt consumption does not result from cooking or adding salt at the table. 

"The majority — about 75% — of our salt consumption is due to convenience products that contain a lot of hidden salt," said nutritionist Riedl.

This includes the classic frozen pizza, but also pastries, sausages such as salami, cheese, tomato ketchup, ready-to-eat sauces and soups, chips and canned foods. If we really want to reduce our salt consumption to a healthy level, we should try avoiding these products.

For people who already suffer from high blood pressure, so-called diet salt can be a solution. This is a seasoning that resembles ordinary table salt but contains less of the harmful sodium and more potassium.

Other types of salt such as sea salt or Himalayan salt are often claimed to be healthier. However, they have roughly the same composition as ordinary table salt — and thus the same effects on our health.

Finally, the right amount of salt is a matter of habit. If we consume a lot of salt over a long period of time, our tongue gets used to the taste — and demands saltier foods. But if we use salt carefully, even meals with hardly any salt taste great. So until we find a healthy balance, we might just need a pinch of patience.