Blood Pressure and Salt

Does high salt consumption affect blood pressure?

Can high blood pressure be lowered by avoiding salt?

There is indeed a connection between salt in the body and blood pressure. The body needs certain salt concentrations, which include our table salt. The more salt there is in the body, the higher the available fluid content must be. The fluid balance is regulated by the kidneys. If too little is drunk while simultaneously consuming high amounts of salt, the cells are deprived of the water they need. When there is no water left there, thirst increases. Due to the increase in volume, a higher fluid content always leads to an increase in blood pressure.

Experiments have shown that healthy individuals can lower their blood pressure when they eat a low-salt diet and vice versa. However, whether excessive salt consumption has a long-term negative impact on the health of healthy individuals is completely unclear. Many of the studies on this topic are poorly designed, which is why concrete statements are lacking. Scientifically sound double-blind studies that investigate the long-term effects of excessive salt consumption in humans are not feasible because they are ethically very questionable. Imagine if a group of healthy participants were made to eat a high-salt diet to see if they subsequently become ill or even die earlier - unimaginable!

It is certain, however, that at least one third of the population is affected by high salt consumption influencing blood pressure. Among high blood pressure patients, the proportion of salt-sensitive individuals is even half - meaning that a lower salt diet lowers blood pressure for one third of the general population and for half of the hypertension patients. Those who are overweight, suffer from diabetes, have kidney disease, or are under too much stress often experience negative effects from too much salt in their diet.

In November 2023, the results of an American study were published, which observed the development of blood pressure in 213 participants during a week of low-sodium diet compared to a week with high sodium intake. Participants aged between 50 and 75 years with normal blood pressure, well-controlled high blood pressure, or uncontrolled or untreated hypertension took part. However, all were already consuming too much sodium with their normal diet. In the week of high sodium intake, participants received 2,200 mg of sodium daily, which they were to add to their normal diet. In the low-sodium week, the diet contained only 500 mg of sodium, but was salted with 4,500 mg of potassium as an alternative.
About 75% of all participants had blood pressure in the low-sodium week that was on average 8 mmHg lower systolically and 3 mmHg lower diastolically than in the high-sodium week. Thus, regardless of whether hypertension was present or not, a reduction in blood pressure was observed in the majority of participants. And that in the short time of just one week!

The problem with today's diet is the many hidden salts that we consume with industrially processed food without realizing it. Especially ready meals usually contain significantly more salt than one might think. In a press release from 20.02.2012, the Federal Institute for Risk Assessment (BfR) addressed the issue of high blood pressure and salt. It was recommended to reduce the salt content of ready meals in Germany. This demand is, of course, directed not at consumers but at manufacturers of ready-made products. The BfR identifies bread, dairy products (such as cheese), and meat and sausage products as particularly problematic. While there are other product groups like snacks and sauces that also contain too much salt, they are not consumed as frequently as the initially mentioned products.

This opinion was also supported by the Stiftung Warentest, which examined 74 products in the April 2012 issue of the Test magazine. The 5 grams of salt per day recommended by the German Society for Nutrition (DGE) are quickly reached and often exceeded.

Salt calculator for mineral water:

Sodium: mg/l Chloride: mg/l

Salt: 1.7 mg/l

Salt Values to Know:

Product	Salt content
Baked rolls	approx. 1.1 g
Slice of toast	approx. 0.4 g
100 g cereal	approx. 0.7 g
100 g raw ham	approx. 8.0 g
100 g cooked ham	approx. 2.3 g
Sausage	approx. 2.0 g
Wiener sausages	approx. 1.0 g
Potato dumpling (ready-made product)	approx. 1.2 g
100 g ready-made potato salad	approx. 1.0 g

These are only rough guidelines. Foods are always subject to natural variations.

Caution with Effervescent Tablets

Researchers from the Saarland University Medical Center found that supplements taken as effervescent tablets contain a lot of sodium. This applies to both over-the-counter and prescription products. The examined effervescent supplements contained an average of 283.9 mg of sodium. The leader was a vitamin C effervescent tablet that contained 564.7 mg of sodium, which corresponds to 28% of the recommended daily maximum dose of sodium. Mind you, in a single effervescent tablet.

Insights on the Dangers of Low-Salt Diets

In 2012, a meta-analysis from studies with a total of over 2,700 participants was published, which found that a low-salt diet for heart patients drastically increases mortality and the risk of death from heart failure. Stress hormones increase. A low-salt diet may result in a minimal reduction in blood pressure. Blood pressure values were reduced systolically by about 1.27 mmHg and diastolically by 0.05 mmHg. However, this is countered by a dangerous increase in some metabolic values. For example, an increase in the stress hormones renin, aldosterone, adrenaline, and noradrenaline was found. More on this in the article about the connection between stress and high blood pressure. Since older people have a lower fluid content in their bodies, there is also a faster risk of dehydration (water loss) with a low-salt diet. Such dangers far outweigh the benefit of a minimal reduction in blood pressure through reduced salt intake - this is the current expert opinion.

Recent studies from 2015, 2016, and 2020 have also not provided different statements and confirmed that a high-salt diet can promote high blood pressure.

Conclusion

Experts currently disagree on the extent to which salt has a harmful effect on the body. Both extremely low and excessively high salt consumption are considered critical. For people with high blood pressure, it is recommended not to consume more than 5 grams of salt per day, because - and experts agree on this - high salt consumption negatively affects high blood pressure.

Interesting to Know:

A Chinese study has now found that spicy food helps to reduce salt consumption. The substance capsaicin, found in peppers and chili peppers, which gives the spiciness, makes us perceive dishes as saltier as a side effect. This means that less salt is needed, which in turn can have an impact on blood pressure.

October 2020:

Researchers have found indications of an active ingredient in a study on rats that may help with salt-sensitive high blood pressure. It is known that some difficult-to-control high blood pressure is caused by excessive salt consumption. As mentioned above, not everyone reacts the same way to salt, and there are salt-sensitive hypertension patients. For this group, scientists may have found a pharmacological treatment option with the alpha1-adrenergic receptor blocker, provided the effect is confirmed in clinical studies.

Women More Salt Sensitive

A review article published in August 2022 reports on the occurrence of salt-sensitive blood pressure among different genders. Researchers found that women of all ages react more salt-sensitively than men. Especially after menopause, salt-sensitive blood pressure occurs more frequently in women and to a greater extent. It is suspected that this is an effect of hormonal changes during menopause. Hormones that likely protect women before are available in lower amounts after menopause.

Salt Substitutes, Salt Alternatives

Salt substitutes are seasoning agents that are often referred to in stores as "blood pressure salt" or "diet salt." Unlike conventional sea or rock salt, these consist not only of sodium chloride but also partly of potassium chloride. This mitigates the blood pressure-raising effect of sodium chloride. This has been investigated and proven in various studies. An article published in January 2024 in Hypertension deals with salt substitutes and suggests recommending a salt alternative for hypertension patients consisting of 75% sodium chloride and 25% potassium chloride, provided this is not excluded due to other diseases or existing potassium intake. These salt substitute products are not suitable for people with known kidney disease, as this can lead to hyperkalemia, or high potassium levels in the blood. Hyperkalemia can also be caused by excessive potassium intake and is considered dangerous, as it disrupts the electrolyte balance. Possible symptoms can include diarrhea, nausea, muscle twitching, and potentially dangerous heart rhythm disturbances.

Sources:

By Sabine Croci. This article is medically reviewed. Last updated (03/2024).
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