Without food, a person can persist for ten days or even dozens of days; without water, a person can live for 7 days; but if a person is completely deprived of oxygen, it only takes 3 minutes to die of brain death.
In the human body, the "brain" is the organ that requires the most oxygen. The weight of the normal human brain only accounts for 2% to 3% of the body weight, but the oxygen consumption accounts for more than 20% to 30% of the total oxygen consumption of the human body.
Recently, a study published in the authoritative medical journal Cell Reports found that a high-salt diet leads to a decrease in blood flow in deep areas of the brain, triggering a local hypoxia microenvironment.
And the "eat too salty" diet, you may be doing it every day.
"Life Times" (weChat search "LT0385" can be followed) combined with the study to interview experts, tell you how eating too much salt damages the body, and teach you to control salt scientifically.
Experts interviewed
Yang Jing, Director of the Department of Hyperbaric Oxygen Medicine, Beijing Chaoyang Hospital affiliated to Capital Medical University
Puhong Zhang, Deputy Director of the George Institute for Global Health (China) and Associate Professor of the University of New South Wales School of Medicine
Eating too salty makes your brain slowly lack oxygen
Scientists have found in previous studies that when intracranial neurons are activated, the arterioles in their areas expand, increasing blood flow, a process known as "neurovascular coupling."
Previous studies of neurovascular coupling have focused on superficial regions of the brain (such as the cerebral cortex).
In the new study, the research team at Georgia State University in the United States used neuroimaging technology to reveal for the first time the relationship between neuronal activity and blood flow in the deeper parts of the brain (such as the thalamus), as well as the effect of salt intake on the brain.
Salts are chosen because the body precisely controls sodium levels, and there are even cells in the body that specifically monitor blood sodium levels. When salt is ingested, the brain activates a series of regulatory mechanisms that cause sodium levels to drop.
Surprisingly, the researchers found that, contrary to the conclusions observed in previous studies, acute salt load gradually increases the firing of hypothalamic "vasopressin" (an antidiuretic hormone that maintains a reasonable concentration of blood sodium), causing vasoconstriction and reducing local blood flow.
That is, with the activation of hypothalamic neurons, blood flow decreases, and this unique neurovascular coupling pattern leads to a local hypoxic microenvironment.
Researchers refer to this phenomenon as "reverse neurovascular coupling," and reduced blood flow will further lead to excessive hypoxia of the brain.
Study corresponding author Javier Stern, a professor at Georgia State University, said: "If the body consumes a lot of salt for a long time, the neurons that stimulate the release of vasopressin will become overactive. This mechanism can lead to excessive lack of oxygen in the brain and even damage to brain tissue. ”
Eat too much salt, and the damage spreads throughout the body
The dietary guidelines for Chinese residents recommend that the daily salt intake of adults should not exceed 6 grams (about the amount of a beer bottle cap).
But in fact, the salt intake of adults in China has seriously exceeded the standard, and the northern residents have reached 11.2 grams.
A high-salt diet is extremely harmful to health, in addition to damaging the brain, it will also raise blood pressure, cause calcium loss, and hurt the kidneys, stomach and respiratory system.
Raises blood pressure
Eating too salty will increase the salt content of the blood, which will slowly lead to an increase in blood pressure. High blood pressure will increase the incidence of stroke and heart and kidney diseases.
Induces osteoporosis
The salty taste of table salt comes from sodium, and there is a competitive relationship between sodium and calcium in the process of renal tubular reabsorption in the human body, and increased sodium intake will correspondingly reduce the reabsorption of calcium and increase urinary calcium excretion.
Causes kidney stones
Studies from the University of Parma in Italy found that higher salt intake was associated with hypercalciuria and low citrateuria, which are the main risk factors for calcareous kidney stone formation.
Increases the risk of stomach cancer
High salt intake can damage the stomach wall, increasing the likelihood of infection with Helicobacter pylori and exacerbating the infection. A British study showed that 24% of stomach cancer cases were associated with a daily intake of more than 6 grams of table salt.
Aggravates asthma
Asthmatics on a low-salt diet can exhale more air than those on a high-salt diet, have far fewer inflammatory markers in their sputum, and require bronchodilators less frequently.
It's time to make up your mind to reduce salt
Salt reduction is the most cost-effective public health measure recommended by the World Health Organization. Scientific salt control not only protects the brain and blood vessels, but also prevents cancer.
1
Use a salt-limited spoon
With the help of the "salt limit spoon", you can control the amount of salt in the cooking call and gradually get used to the light taste.
If there is no salt limit spoon, use a beer bottle cap, flat fill a lid, that is equivalent to 5 to 6 grams of salt.
2
Improve the taste with sauces
In general, 20 ml of soy sauce contains 3 grams of table salt, and 10 grams of yellow sauce contains 1.5 grams of table salt. If soy sauce and sauce are added to the dish, reduce the amount of salt used accordingly.
You can use more sour sauces such as vinegar and lemon juice, or replace some salt and soy sauce with chili pepper and garlic to improve the taste of food.
3
Add salt near the pan
To achieve the same salty taste, the amount of salt used to put salt later is less than that used to put salt early. You can add salt when the dish or soup is about to come out of the pot to ensure the taste and reduce the amount of salt used.
4
Steam more and fry less
Mostly use cooking methods such as steaming and stewing, and when making cold dishes, put less salt.
5
Develop the habit of looking at food packaging
Pay attention to reducing the intake of high-salt foods, such as biscuits, instant noodles, etc. When buying food, make it a habit to read the nutrition facts list and eat less packaged foods with high salt content.
6
Try to eat at home
Eat less or no pickled foods and eat less eaten out or order takeout as much as possible. If you choose to eat outside, be sure to inform in advance and ask for less salt and lightness.
7
Eat less salted staples
Such as a variety of salty cakes, noodles made with salt and alkali and ramen, etc. If you really want to eat a fast food such as ramen, don't drink soup and drink extra tea or white water. ▲
Editor of this issue: Zheng Ronghua
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