Prof. Petras Stirbys [1]
Member of the New York Academy of Sciences
“Arterial hypertension, or hypertensive disease, afflicts
many older people. The problem is extremely relevant, despite the attention
paid to it. A simple but often forgotten way to reduce arterial hypertension is
a low-salt diet.
The human body
tolerates elevated blood pressure for a long time, but over time, adaptation
mechanisms are exhausted and hypertension eventually takes over, ultimately
depleting vital resources.
Oversalted: too much salt is found not only in pickled and
salted foods, smoked meats, barbecues, salted fish, sausages, carbonated
drinks, technologically processed, canned food, but also in bread.
Arterial hypertension eventually creates an environment
conducive to the emergence of serious complications, such as hypertrophy of the
heart muscle (thickening of the left ventricle muscle), heart attack, stroke,
heart rhythm disorders, heart failure, kidney disorders, etc. Complications are
manifested by shortness of breath, swelling of the legs, heart pain, decreased
physical activity, and ultimately - a complete loss of quality of life. Sudden
death can also occur if life-threatening heart rhythm disorders develop.
It is
announced that symptoms of hypertensive disease are diagnosed in 40 percent of
the world's population over 25 years of age. This disease is believed to claim
about 10.4 million lives each year.
We will not delve into the stages of the disease, the
graduation of arterial blood pressure values, the peculiarities of pressure
control, etc., because this would take up a lot of space. It can only be said
that the human body tolerates elevated blood pressure for a fairly long time,
but over time, adaptation mechanisms are exhausted and hypertension eventually
takes over, finally depleting vital resources.
There is more than one cause of hypertensive disease, and to
summarize them, we can call it a consequence of life stresses, their cumulative
expression. This would be the primary or most important, the most common type
of hypertension, manifesting itself as a chronic progressive disease. This is a
very superficial, insignificant characteristic, just like the treatment, which
we will not examine in detail. It remains to concentrate on the diet, on the
restriction of some of its ingredients, in particular, the avoidance of table
salt consumption, which is extremely important. Scientists unanimously claim
that consuming too much salt significantly increases mortality from
cardiovascular diseases and, in general, overall mortality from many diseases,
including kidney activity disorders in the final stages of the disease.
Let's start with an impromptu sentence: it is pointless to
treat hypertension by ignoring a salt-free diet. Let this phrase emphasize the
harmful factor that spoils the life of humanity, by the way, slowly but surely.
Following this call, as we will soon see, one can really achieve a lot. It is
important to know that salt is an important, albeit non-determining ingredient
in our diet. A little, relatively little, is needed for the physiological needs
of the body. So, it is not salt itself that is evil, but its excess, excessive
consumption.
Noteworthy
Since Roman times, according to P. Rust and colleagues, salt
has been called white gold, because it could be used to effectively preserve
meat and fish. Nowadays, too much salt is found in pickled and salted foods,
smoked meats, shish kebabs, salted fish, sausages, carbonated drinks and
various technologically processed and canned food. In this regard, researchers
have recently drawn attention to bread, its products, various cereals, and this
is alarming.
In 2022, the World Health Organization (WHO) declared a goal
by 2025 reduce salt consumption globally by 30 percent, while drawing attention
to the risks that humanity faces if action is not taken warnings and recommendations. It was
emphasized that this will require joint efforts of food producers, residents
and states, first of all - to become aware of the threat of the risk factor.
Although 2025 is already halfway through, there is no information whether the
set goal has been achieved.
Mechanism of action
Excess sodium chloride, or table salt (hereinafter referred
to as salt), promotes fluid retention in the body's tissues and blood vessels,
which increases blood volume and blood pressure in the arteries. It is stated
that hypertension can sometimes be treated as a physiological response of the
body to get rid of excess salt, which is considered a defensive reaction. Age
characteristics also complicate the general situation, since at this stage the
excretory (excretory, filtration) function of the kidneys begins to
deteriorate. Increased salt concentration in the blood provokes the so-called
endothelial dysfunction - that is, the cells of the inner layer of blood
vessels can no longer function normally, as a result, the function of the blood
vessels themselves is disrupted, they cannot expand or contract properly, they
lose elasticity, which causes circulatory disorders.
Sodium is more important than chlorine for the progression
of hypertensive disease, or, figuratively speaking, for it to rage. Many modern
canned foods may not contain salt, but contain sodium compounds, which can be
in the following forms: monosodium glutamate, sodium bicarbonate (baking soda),
sodium benzoate. These preservatives act in the body in exactly the same way as
table salt and cause exactly the same effects, and this is necessary to know.
In Western countries, portions of packaged food (in regular 100 g packages)
indicate that the sodium content should be less than 100 mg. It is worth noting
that some kidney diseases make it difficult to excrete sodium (specifically
sodium, not sodium chloride) through the kidneys, so it accumulates in the
blood and raises arterial blood pressure. In kidney diseases, there are
consequences even when avoiding table salt.
Excess salt promotes fluid retention in the body's tissues
and blood vessels, which increases blood volume and blood pressure in the
arteries.
The kidneys are programmed to deal with low salt
concentrations, but due to their limited filtration capacity, it becomes
problematic to excrete excess salt, especially when they have to work hard for
a long time, constantly, every day. The feeling of thirst also enters the
mechanism of increasing blood pressure, which, in order to normalize the salt
concentration in the blood plasma, encourages drinking more water or fluids,
i.e. diluting the salt, which facilitates the work of the kidneys. Although
kidney function is somewhat normalized in this way, the increased blood volume
due to the additional amount of fluids consumed increases arterial blood
pressure, and due to the increased plasma volume, overloads the cardiovascular
system, which eventually begins to signal the impending complications mentioned
above. Again, when the arterial walls are tense, the total peripheral
resistance increases, which determines the overload of the left ventricle of
the heart and the consequences arising from it, primarily, functional heart
failure. Thus, salty food pushes the body into a vicious circle, from which it
is possible to get out or try to get out only by giving up salty food. More
persistent hypertensive disease, of course, will also require appropriate
medical treatment, but giving up salt will significantly facilitate the
treatment of the disease, and the result of the treatment of the disease will improve.
This makes it clear that salt, and, above all, its excess, is a serious risk
factor that affects both the quality of life and its duration.
The links between salt and hypertensive disease
characterized here are presented in a simpler way, while the entire mechanism
of the disease is much more complex. Sodium or sodium cations play a
significantly more important role than chlorine anions. Therefore, we should
talk more about the harm of excess sodium, not chlorine. However, these are
subtle details, which, if we delve deeper, would lead us to the very complex
vicissitudes of the onset of hypertensive disease and its dynamic development
with the complex influence of sodium salt on the renin, angiotensin and
aldosterone system. By the way, sometimes there is an idle debate about whether
elevated blood pressure is a direct effect of salt or its side effect. The
increase in blood pressure is also mentioned as the body's response to get rid
of excess salt by intensifying blood filtration through the kidneys.
In order to fully understand the importance of sodium, the
peculiarities of the electrolyte-fluid relationship, we would have to delve
into the mechanism of the so-called sodium-potassium pump in the heart and
other muscle cells, and finally, the vital role of potassium, so let's accept
it a priori as a known truth, as the vital importance of the sodium-potassium
balance.
Salt regulations
The WHO
informs that when the salt content exceeds 5 g per day in food, systolic blood
pressure inevitably increases. The WHO recommended daily dose of salt is less
than 2 g, which, by the way, is valid for both people with hypertension and the
general population.
The following should be emphasized in particular: epidemiological
studies show that a small amount of salt does not pose any risk, especially
when it comes to the cardiovascular system. It is emphasized that a small
amount of salt is necessary to ensure the physiological needs of the body. This
necessary minimum of salt is found in fruits, vegetables, meat and other
natural products. This is evidenced by the long history of mankind - humanity
has successfully survived for millions of years even before salt became
established in the diet of the population.
Currently, in European countries, the average daily salt
consumption is from 7 to 13 g - which is almost scandalous. In hot climate
countries, salt is consumed more than in cold ones, perhaps due to greater
sweating and, as a result, greater sodium loss. There, a lot of salt is added
to bread, fish and spicy food products with complex ingredients. Both salt and
sugar are added to the so-called high-calorie and low-nutrient meals. On the
African continent, hypertension is prevalent precisely because of excessive
salt consumption (E. Menyanu et al.), and in some countries as much as a third
of the population is unaware of the harmful effects of salt on health. However,
the highest salt consumption is in Northern China and Japan – more than 10 g
per day. Americans consume an average of 3.4 g of salt, which is almost twice
the recommended daily dose.
People who
consume a lot of salt tend to be obese and overweight – this is explained by
the fact that saltier food tastes better, so more of it is eaten.
A look into the past
It is said that since the Paleolithic period, the processes
of human evolution have been extremely slow. As civilization progressed more
rapidly, dietary, cultural and other customs changed, including salt
consumption habits, but ancient people consumed perhaps only about 0.69 g of
sodium salt per day (L. Cordain et al.). Today, a person consumes an average of
4.9 g (M. A. Garfinkle). A dramatic change is believed to have occurred 10
thousand years ago. BC. e., with the emergence of salt extraction technologies.
This suggests that human genetic and genomic evolutionary processes
significantly lagged behind the pace of nutritional changes, so humans did not
have time to adapt to changes, to salty food. This is how humanity encountered
the so-called diseases of civilization. Hypertension is one of them, the
development of which is clearly influenced by salt.
Treatment nuances
Reducing salt in the diet alone is considered a
cost-effective step in the treatment of hypertension. This applies, first of
all, to drug-resistant forms of this disease. Thus, efforts to reduce high
blood pressure by eliminating the salt factor can reduce drug costs, make it
possible to abandon one or more medications, which makes hypertension more
manageable. All this reduces the risk of potential cardiovascular
complications, saves on medications, and is an economic factor. Finally,
reducing medications relieves the work of the liver and kidneys, since these
organs bear the main burden of breaking down, utilizing, neutralizing, and
eliminating chemical compounds. Let's not forget that when blood pressure is
normalized, the heart and its activity find themselves in a privileged position
- after all, it is the heart that suffers most from high blood pressure. Thus,
reducing salt consumption has many advantages.
As for
serious, comprehensive treatment of hypertension, it is complex, including not
only dietary restrictions, but also lifestyle changes, including daily physical
activity, stress avoidance, pharmacological measures (antihypertensives,
sedatives, diuretics), full sleep and rest, refusal of night shift work,
avoidance of conflict situations, etc. The totality of the listed measures is
needed when we are faced with forms of the disease that are difficult to treat.
Thus, it becomes clear that the importance of a low-salt
diet is relevant in two aspects. First, it is important for the prevention and
prophylaxis of high blood pressure. Second, it effectively contributes to
stopping the progression, spread and complications of an already started
disease. All this applies not only to the so-called salt-sensitive group of
individuals, but also to the entire population.
Excessive salt consumption significantly increases mortality
from cardiovascular diseases and, in general, overall mortality from many
diseases.
Reducing is harmless
It should be emphasized that if we completely eliminate
salt, along with sodium, we would encounter problems of a different nature,
because sodium, by the way, like potassium (they are also called electrolytes),
are important for the irritability, excitability, maintenance of tone,
contractile properties of muscles, heart rhythm, propagation of impulses
through the cardiac conduction system, nerves, etc. Thus, the other extreme is
to completely avoid salt, eliminating it from the diet would also be harmful.
Interestingly, epidemiological studies, according to Prof. G. S. Youssef, show
that diets low in sodium, does not cause any side effects.
You just
need to know that all products from which food is made (and, for example,
potatoes, beets, groats, not to mention unsalted meat) contain salt, albeit in
small amounts, but it practically satisfies human needs, and this is
scientifically justified.
Going back to history, salt was incorporated into the diet
as a food preservative so that food would last longer without spoiling, and not
because of nutritional needs. Therefore, humanity lived and survived
successfully for many millennia until it discovered salt and applied it to
preserve food supplies.
Practical aspects
What would be the recommendations from the information and
considerations provided in the text about what food is most rational to eat? In
order to limit salt, it is advisable, if possible, to focus on home-cooked
meals and fresh fruits, which means that you yourself should regulate the
amount of salt, giving preference to a salt-free diet.
When
regulating the amount of salt, it is enough to rely on your own taste, it is
not necessary to scrupulously chase the normative grams.
After all, we often hear from housewives preparing food: too
much salt, salty, a little too little, just the right amount of salt, etc. Such
regulation of salt in the household is sufficient, especially the observation
that there is a rarely too little salt, so it is not necessary to dose the salt
by weighing in grams.
In current
public catering establishments, salt is added to soups at the discretion of the
staff working there, and it would be possible to entrust this regulation to the
customers themselves. For this, it is enough to update the previous practice -
to put a salt jar on the table, and serve the soup unsalted.
Perhaps something similar could be done with hot meat
dishes. It is a good practice to serve a small slice of bread, because bread,
as is advertised, contains a lot of salt. In supermarkets, you can often find
delicious, aromatic pieces of bread fried in oil. Such bread, treated with
fragrant garlic, is characterized by a unique, bewildering saltiness. Salt
simply reigns there, and if desired, and with the use of irony, you can
extract... salt in the desired quantities from that loaf of bread. Those who
eat it and do not yet feel the symptoms of hypertension should know that excess
salt with each passing day puts the nails in the coffin of those who enjoy
saltiness, and with age this process accelerates. The solution to the problem,
as already mentioned, is quite simple, primitive and effective: let fruits,
vegetables and home-cooked dishes with a minimum saltiness that you have set
yourself, which should not even be felt, shine on the dining table. Of course,
it is not easy to implement such a recommendation every day. Let this be a
guideline and an aspiration, let the food be less tasty, but health-enhancing,
prolonging life. As much as possible, let us avoid canned food, store food in
the refrigerator as much as possible.”
Reducing dietary sodium is widely recognized as a crucial
part of managing hypertension, but it's not the only factor, nor does it
necessitate a completely salt-free diet for everyone
.
Here's why and what to consider:
Sodium's Impact:
High sodium intake can significantly contribute to high blood pressure by
causing the body to retain fluid, thereby increasing blood volume and pressure
within arteries.
Benefits of Reduction: Lowering
sodium intake has been proven to significantly reduce blood pressure, even in
those already on medication for hypertension. Reductions can be comparable to
those achieved with common blood pressure medications. A low sodium diet can
also enhance the effectiveness of antihypertensive medications.
Not for Everyone:
Salt-Sensitivity: While many
individuals benefit from sodium restriction, not everyone's blood pressure is
equally sensitive to salt intake. Some studies suggest only about 30% of
patients are salt-sensitive.
Moderation is Key: Completely eliminating
salt isn't necessary for most and can potentially lead to adverse effects, as
the body requires some sodium for essential functions.
Recommended Sodium
Intake:
General Population: The American Heart Association
recommends limiting sodium intake to no more than 2,300 mg per day for most
adults.
High-Risk Individuals: For those with
high blood pressure, heart disease, or other related conditions, the ideal
limit is no more than 1,500 mg per day.
Sodium Sources:
It's important to be mindful that the majority of sodium comes from processed,
packaged, and restaurant foods, not just the salt added at the table.
Other Lifestyle
Modifications: Alongside sodium restriction, other lifestyle changes are also
important for managing hypertension, including:
Maintaining a
healthy weight.
Regular
physical activity.
Following a
healthy dietary pattern like the DASH diet.
Limiting
alcohol consumption.
Quitting smoking.
Managing
stress.
Getting enough
sleep.
In summary, reducing sodium intake is a highly effective and
recommended strategy for controlling hypertension and promoting cardiovascular
health. However, it's not the sole factor, and the ideal approach involves a
holistic management plan, which may or may not include medication, based on
individual needs and in consultation with a healthcare professional.
1. Stirbys Petras
Prof. of Biomedical Sciences, Habil. Dr., Cardiosurgeon.
“Born on February 4, 1948 in Šiuraičiai, Klaipėda district.
Petras Stirbys studied at Skomantai eight-year school
(Klaipėda district) in 1955–1963, at Švėkšna (Šilutė district) secondary school
in 1963–1966 (now Švėkšna “Saulė” gymnasium), and at Kaunas Institute of
Medicine (now Kaunas University of Medicine) in 1966–1972. In 1981, he defended
his Ph.D., in 1988 habilitated doctoral dissertations, in 1991 he was awarded
the title of professor.
The cardiac surgeon completed an internship at the Klaipėda
Republican Hospital in 1972–1973, worked at the Klaipėda Medical School by
appointment in 1973–1974, worked at the Kaunas Medical School as a research
fellow in 1974–1978 at the Kaunas Medical Institute, and in 1978–1983 at the
Kaunas Clinics. In 1983 he returned to the Kaunas Medical Institute. In
1989–1991 he was the Vice-Rector for Treatment of the Kaunas Academy of
Medicine (now Kaunas University of Medicine), from 1992 he was the Head of the
Cardiac Electrostimulation Clinic, and from 1995 he was also a physician and
cardiac surgeon at the Cardiology Clinic of the Kaunas University of Medicine.
During his work experience, P. Stirbys implanted more than 5,000 pacemakers.
Member of the Lithuanian and European Cardiological
Societies, Full Member of the New York (USA) Academy of Sciences (since 1990),
Member of the North American Society of Cardiac Electrostimulation and
Electrophysiology (since 1988), International Cardiovascular Society (since
1990), International Society for the Study of Unsaturated Fatty Acids and
Lipids (since 1995).
He has developed implantable electrodes, electrostimulation
methods and instruments alone and with others. The professor is the author or
co-author of fifteen inventions, 150 scientific publications, and 80 newspaper
articles. Co-author of the book “Programmable Cardiac Electrostimulation” (with
others) (1989), the brochure “You and Your Cardiac Electrostimulator” (1992),
the chapter “Electrical Cardiac Stimulation and Cardioversion – Defibrillation”
of the cardiology textbook “Heart Diseases” (2001), the educational book “Heart
electrostimulation with optimal energy parameters” (2003). Author of the poetry
book “Autumn deceived thoughts” (2009).
Literature:
A. What is what in Lithuania 2009. Kaunas: “Neolitas”, 2009,
p. 1 167.”
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