What happens when sodium levels fall?
A person with mild hyponatremia may not feel sick, but if for any reason the level of sodium in their blood drops even lower, it will cause symptoms such as difficulty concentrating, headache, nausea. In severe cases, confusion, convulsions, and even coma may occur.
Hyponatremia can occur as a result of diarrhea, vomiting, heavy sweating, certain heart or kidney problems. It often occurs during the heat, when the body releases sodium salts with plenty of sweat, which is why the number of patients with hyponatremia in the emergency department increases significantly during the summer.
Swedish scientists have discovered
Sweden and Denmark are countries that have managed to collect a huge amount of systematic medical data. Since the end of the 20th century, doctors have kept electronic records of the health cards of all citizens of their country. This provides rich material for analysis.
This study looked at data from all Swedish citizens aged 18 and over. The researchers tracked all cases of hyponatremia recorded in the patient’s medical records from October 2005 to December 2014. They plotted the results on a temperature graph for the same period recorded by the Swedish Institute of Meteorology and Hydrology.
The researchers found that the risk of hospitalization as a result of severe hyponatremia increased sharply on hot days, with the elderly over 80 being the most vulnerable part of the population and in addition, the risk of adult women being higher than that. of men. People in the 80+ age group were 15 times more likely to develop hyponatremia in hot weather compared to the risk of hyponatremia on cooler days.
It is logical that the summer months gave the highest number of victims and the fewest such cases in January.
The researchers’ calculations showed that, on average, a rise in temperature by one degree Celsius led to an increase in hospitalizations due to hyponatremia by 6.3%, while when the temperature rose by 2 degrees, the number of such cases increased by 13.9 %.
What explains this?
Dr. Jakob Skov, one of the authors of the study, says that the lack of sodium in the blood may be due to insufficient sodium intake or excessive consumption of fluids that remove it from the body. In the heat, there is a strong excretion of sodium through sweat, while a person can consume much more fluids than on cooler days.
Older people tend to have some kind of cardiovascular disease and in addition, their kidneys may not function well, which leads to fluid retention in the body. Both factors can contribute to hyponatremia.
Interestingly, the temperature limit, after which the risk of hypothermia rises sharply in Swedish citizens, is only 15 degrees Celsius.
We can assume that this limit will be higher in warmer countries, so to complete the picture, Dr. Skov and his team are going to analyze data on the association between high temperatures and hyponatremia in countries with different climates.
The advantage of the published study is the large sample size, which includes the entire adult population of an entire country. The weakness is the retrospective nature of the study, which precludes experimentation.
However, the authors of the paper recommend, taking into account their results, the careful monitoring of the condition of elderly patients in hot weather.
Will the findings have an impact on the common recommendations of dietitians to consume as little salt as possible, the body’s main source of sodium?
It’s not clear yet, but let’s remember what is known about it today.
How much salt do you need?
Most experts recommend limiting salt intake for both people with cardiovascular disease and healthy people, especially those who love fast food and processed foods. The fact that processed foods contain excessive amounts of salt, sugar, trans fats is a known fact.
Of course, it is better to exclude from your diet fast food, chips, smoked ham, sausages, frozen foods such as chicken nuggets and then the problem of excessive salt intake is likely to disappear.
However, we must remember that salt is the main source of sodium in our body and severely limiting its intake can lead to both hyponatremia and a number of other health problems.
The most common recommendation from reputable medical agencies is not to consume more than 5.8 grams (one teaspoon) of salt per day. At the same time, in the popular press, one can come across the following view: the less “white poison”, the better, and if you can completely give up salt, it will be absolutely wonderful.
Scientific studies, however, give very contradictory results.
Doctors often recommend a salt-free diet in patients with hypertension, but there are studies that show that reducing or eliminating salt intake does not always lead to an optimization of pressure and often reduces it slightly, so that the patient is not relieved of the need. take the appropriate medication.
A recent study by British scientists, which is a review of scientific papers published up to 2018 on this topic, shows that there is no conclusive evidence of the benefit of salt-restricted diets in preventing heart failure and mortality. for this reason. The authors can neither confirm nor refute the current recommendation to consume no more than 5.8 grams of salt per day.
5.8 grams of salt correspond to 2300 milligrams of sodium, since the salt is 40% sodium and the rest is chlorine.
Meanwhile, some experts recommend consuming at least 3-5 grams of sodium a day, which would be equivalent to 7.5-12.5 grams of salt.
In a 2011 Canadian study in a group of 28,880 patients with cardiovascular disease, less than 3 and more than 7 grams of sodium per day were found to increase the risk of death from heart attack, stroke and congestive heart failure.
However, there are studies (for example, this work of scientists from Harvard University) in which the reduction of salt in the diet showed a reduction in the risk of death from cardiovascular disease, so today the question of the role of salt in such diseases can not be considered closed.
In addition to the immediate symptoms of hyponatremia described above, a lack of sodium in the body can lead to other problems. One of these is insulin resistance, a metabolic disorder in which the body’s cells do not respond to the signals of the hormone insulin, which prevents cells from entering the glucose they need. This in turn leads to type 2 diabetes and heart disease.
In a 2011 Harvard study of 152 healthy volunteers, researchers found that
just 7 days of a low salt diet led to insulin resistance.
At the same time, there are scientific studies in which the authors found no link between salt restriction and insulin resistance, nor did they observe a reduction in a low-salt diet.
A number of studies have shown that reduced sodium intake is associated with increased blood levels of harmful cholesterol-low-density lipoprotein (LDL) and triglyceride fractions.
The Cochrane team of scientists in a 2003 study found that low-salt diets increased LDL by 4.6% and triglycerides by 5.9%. Their review in 2011 gives slightly different data: the reduction in salt content in the diet led to an increase in LDL and triglycerides by 2.5 and 7%, respectively.
What to guide when the scientific evidence is ambiguous?
Are you worried about any physical ailments? Then it does not make sense to worry too much about how much salt you eat, unless you live exclusively on fast food and processed products.
There are now many different diets for weight loss, including a salt-free diet. On the Internet, you can find promises that by completely eliminating salt, a person will lose 6-7 pounds in two weeks.
Cutting out salt altogether is not a healthy practice, and even more so for those whose only goal is to lose weight. In this case, it is better to choose a well-balanced diet.
If you have problems with the heart, blood vessels or kidneys, you should consult a doctor and choose a daily dose of salt that is best for you.
It is important for people with cardiovascular disease and the elderly (especially women!) To remember that in hot weather it is worthwhile to slightly increase your daily salt intake to avoid hyponatremia.
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