Sodium and Health, Harvard T.H. Chan School of Public Health
In most people, the kidneys have trouble keeping up with excess sodium in the blood. As sodium accumulates, the body holds onto water to dilute the sodium. This increases both the amount of fluid surrounding cells and the volume of blood in the bloodstream. Increased blood volume means more work for the heart and more pressure on blood vessels. Over time, the extra work and pressure can stiffen blood vessels, leading to high blood pressure, heart attack, and stroke. It can also lead to heart failure. There is some evidence that too much salt can damage the heart, aorta, and kidneys without increasing blood pressure, and that it may be bad for bones, too. Learn more about the health risks and disease related to salt and sodium:
Cardiovascular disease
After conducting a review on sodium research, the Institute of Medicine concluded that reducing sodium intake lowers blood pressure, but evidence of a decreased risk of cardiovascular diseases (CVD) is inconclusive. [2] It is clear, however, that high blood pressure is a leading cause of CVD. It accounts for two-thirds of all strokes and half of heart disease. [3] In China, high blood pressure is the leading cause of preventable death, responsible for more than one million deaths a year.
Chronic kidney disease
Chronic kidney disease (CKD) shares risk factors with cardiovascular disease, with high blood pressure being a major risk factor for both. Salt sensitivity is reported to be more prevalent in patients with CKD due to a reduced ability to excrete sodium, which may lead to increased blood pressure.
Osteoporosis
The amount of calcium that your body loses via urination increases with the amount of salt you eat. If calcium is in short supply in the blood, it can leach out of bones. So a diet high in sodium could have an additional unwanted effect—the bone-thinning disease known as osteoporosis. [3] A study in post-menopausal women showed that the loss of hip bone density over two years was related to the 24-hour urinary sodium excretion at the start of the study, and that the connection with bone loss was as strong as that for calcium intake. [16] Other studies have shown that reducing salt intake causes a positive calcium balance, suggesting that reducing salt intake could slow the loss of calcium from bone that occurs with aging.
Cancer
Research shows that a higher intake of salt, sodium, or salty foods is linked to an increase in stomach cancer. The World Cancer Research Fund and American Institute for Cancer Research concluded that salt, as well as salted and salty foods, are a “probable cause of stomach cancer.”
Are “natural” salts healthier than table salt?
The most widely used, table salt, is extracted from underground salt deposits. It is heavily processed to remove impurities, which may also remove trace minerals. It is then ground very fine. Iodine, a trace mineral, was added to salt in 1924 to prevent goiter and hypothyroidism, medical conditions caused by iodine deficiency. Table salt also often contains an anticaking agent such as calcium silicate to prevent clumps from forming.
Kosher salt is a coarsely grained salt named for its use in traditional Kosher food preparation. Kosher salt does not typically contain iodine but may have an anti-caking agent.
Sea salt is produced by evaporating ocean or sea water. It is also composed mostly of sodium chloride, but sometimes contains small amounts of minerals like potassium, zinc, and iron depending on where it was harvested. Because it is not highly refined and ground like table salt, it may appear coarser and darker with an uneven color, indicating the remaining impurities and nutrients.
Himalayan pink salt is harvested from mines in Pakistan. Its pink hue comes from small amounts of iron oxide. Similar to sea salt, it is less processed and refined and therefore the crystals appear larger and contain small amounts of minerals including iron, calcium, potassium, and magnesium.
Larger, coarser salt granules do not dissolve as easily or evenly in cooking, but offer a burst of flavor. They are best used sprinkled onto meats and vegetables before cooking or immediately after. They should not be used in baking recipes. Keep in mind that measurements of different salts are not always interchangeable in recipes. Generally, sea salt and table salt can be interchanged if the granule size is similar. However, table salt tends to have more concentrated, saltier flavor than kosher salt, so the substitution is one teaspoon of table salt for about 1.5 to 2 teaspoons of kosher salt depending on the brand.
The Dangers of Salt:
It’s More Than Just a Blood Pressure Problem, Journal of the American College of Cardiology
High dietary sodium may have direct effects on the brain, heart, kidneys, and blood vessels. These effects can be independent of changes in blood pressure.
Dangers of Salt | Blood Vessels
Elevated sodium levels can negatively affect the function of the inner lining of the blood vessels, called the endothelium, report Dr. Farquhar and colleagues.
And the last thing we want to do is foul up our endothelium.
Almost all tissues depend on a blood supply, and the blood supply depends on endothelial cells.
The endothelium introduces all kinds of chemicals, like nitric oxide, which control how well our blood vessels expand and contract. Put simply, we want blood vessels with good elasticity; without it, they can’t stretch well with each pulse. They stiffen, making it harder for the heart to pump blood throughout the body. Eventually, the heart wears out. It’s called heart failure.
One of the endothelium’s other key jobs is releasing factors that cut down on platelet stickiness, which helps ensure that our red blood cells flow smoothly, like traffic on an unclogged freeway.
When the endothelium is malfunctioning, the result of too much salt as well as other lifestyle-related factors like high insulin levels, high LDL (bad) cholesterol, and high blood glucose, it becomes a breeding ground for inflammation, cholesterol plaque build-up, and cardiovascular diseases.
Dangers of Salt | Heart
High blood pressure is a major risk factor for left ventricular hypertrophy, which is enlargement of the muscle tissue that makes up the wall of the heart’s main pumping chamber.
But research has found that high sodium intake may increase left ventricular wall thickness independent of high blood pressure. For example, in a study of healthy adults with normal blood pressure or minimal hypertension, those with the highest sodium excretion had significantly greater diagnoses of left ventricular hypertrophy.
Having left ventricular hypertrophy can lead to multiple heart-related problems, including arrhythmia (abnormal heart rhythm), heart attack, sudden cardiac arrest (sudden loss of heart function), and heart failure (inability of the heart to pump enough blood throughout the body).
Dangers of Salt | Kidneys
One of the ways doctors assess how well our kidneys are working is with a test called glomerular filtration rate. Glomeruli are tiny sieves in the kidneys that filter waste from the blood. The higher our glomerular filtration rate, the better our kidneys are at getting rid of waste.
Studies have found that a high salt intake, even with only a minimal rise in blood pressure, can lead to decreased rates of glomerular filtration, which are a sign of chronic kidney disease, and, if not checked, kidney failure.
What Is Pink Himalayan Salt? Healthline
Pink Himalayan salt is a pink-colored salt extracted from the Khewra Salt Mine, which is located near the Himalayas in Pakistan.
The Khewra Salt Mine is one of the oldest and largest salt mines in the world.
The pink Himalayan salt harvested from this mine is believed to have been formed millions of years ago from the evaporation of ancient bodies of water.
The salt is hand-extracted and minimally processed to yield an unrefined product that’s free of additives and thought to be much more natural than table salt.
Like table salt, pink Himalayan salt is mostly comprised of sodium chloride.
However, the natural harvesting process allows pink Himalayan salt to possess many other minerals and trace elements that are not found in regular table salt.
Some people estimate it may contain up to 84 different minerals and trace elements. In fact, it’s these very minerals, especially iron, that give it its characteristic pink color.
To sum up, Pink Himalayan salt is harvested by hand from the Khewra Salt Mine in Pakistan. It’s minimally processed to provide a natural alternative to regular table salt.
Natural sea salt consumption confers protection against hypertension and kidney damage in Dahl salt-sensitive rats, Pubmed
Although sea salts are widely available to consumers nowadays, whether its consumption over refined salt has any real health benefits is largely unknown. This study was conducted to compare hypertension-inducing propensity of natural sea salt (SS) to refined salt (RS) in a well-established animal model of hypertension. Five groups of male Dahl salt-sensitive rats were fed rat chow diet supplemented with various amounts of salt for 15 weeks. The groups were: control (CON, n = 10), 4% RS (RS4), 4% SS (SS4), 8% RS (RS8), 8% SS (SS8) (n = 12 for each group). After 15 weeks, both SS4 and SS8 groups had significantly lower systolic (SBP) and diastolic blood pressure (DBP) compared to RS4 and RS8 rats, respectively. RS8 rats had markedly higher SBP and DBP compared to all other groups. Echocardiography just prior to sacrifice showed abnormalities in RS4, SS8 and RS8 hearts, while CON and SS4 hearts displayed normal measurements. Plasma renin and aldosterone levels of high salt groups were lower than those of CON, and serum electrolytes were similar amongst all groups. Abnormal kidney pathology and high glomerulosclerosis index scores were seen in RS4 and RS8 rats, but SS4 and SS8 kidneys showed relatively normal morphology similar to CON kidneys. Our findings show that consumption of natural sea salt induces less hypertension compared to refined salt in the Dahl salt-sensitive rat.