Low Salt Is Bad for Heart Health

By Dr. Mercola

The leading cause of heart attacks and stroke in the U.S. is high blood pressure. Recommendations from the American Heart Association (AHA) and other policy makers have been to reduce salt intake in order to control your blood pressure. However, research has not supported this recommendation for everyone.¹

Salt is an ionic compound made of two groups of oppositely charged ions, namely sodium and chloride. Table salt is made of one metal ion (sodium) and one non-metal ion (chloride). Your body needs both ions to function and can produce neither, so you must get them from your food.

However, not all salts are created equally. Refined table salt is almost all pure sodium chloride and 39 percent sodium. The rest are man-made chemicals.

Iodine is often added to refined salt in a public health preventive measure against iodine deficiency. A lack of iodine is the leading cause of hypothyroidism, mental retardation, autism, depression and anxiety.²

Unprocessed salt, such as pink Himalayan salt, is 84 percent sodium chloride and 37 percent pure sodium. The remainder is naturally occurring trace minerals your body also needs, including phosphorus and vanadium.³ 

Dangers of Restricting Your Salt Too Much

In a controversial study^4,5,6,7 published in the Lancet medical journal, results supported a mid-range salt intake to protect your heart and your health. While high-salt diets are not healthy for your body, it turns out that low-salt diets are dangerous as well.

According to the Centers for Disease Control and Prevention (CDC), the average American eats approximately 3,400 milligrams (mg) of salt each day.⁸ This is higher than the 1,500 mg per day that the AHA recommends, but within range of the results of this study.⁹ 

Associate professor of clinical epidemiology and lead researcher, Andrew Mente, Ph.D. finds that, "Having neither too high nor too low levels of sodium is optimal for health."¹⁰  

Mente and his colleagues analyzed four different studies covering 49 countries and using over 113,000 participants. Each study was structured in the same manner, estimating salt intake from a single-morning urine sample and then following the participant's health status for several years.

The results demonstrated that whether you suffer from high blood pressure or not, low salt intake was linked to a greater risk of heart attack, stroke and death.¹¹ The data does highlight the need to lower salt intake if you suffer from high blood pressure, but not to levels currently recommended.

Instead, the study demonstrates that eating a moderate amount of salt, near to 3,000 mg per day, was associated with the best health. Salt intake levels that were high or low carried the same risk of high blood pressure, cardiovascular disease (CVD) and stroke.

Results indicated a low-salt diet could increase your risk of heart attack by 26 percent if you don't suffer from high blood pressure, and 34 percent higher risk if you do.

Arguments Against the Study Results

Although controversial, the results of the study have been supported by the results of other studies^12,13 

A second study evaluated over 100,000 individuals and found those who consumed between 3,000 and 6,000 mg per day were at the lowest risk of health conditions, and those who ate more than 6,000 or less than 3,000 were at the highest risk.

The AHA has been critical of the study published in the Lancet, citing a reliance on incorrect sodium levels in the study.¹⁴ The claim was spot urine testing could not adequately measure salt intake in participants over the length of the study.

However, 24-hour urine collections have been standard in research studies to measure salt intake in the past.^15,16 Research has also demonstrated the accuracy of spot urine testing to adequately measure the amount of sodium intake.^17,18

Critics also object to the assumption by researchers that salt intake was consistent over the course of the study for each individual based on spot testing.

However, in both studies, participants numbered over 100,000 individuals, making the risk of the participant having an abnormally high or low salt intake for testing day relatively minor.

Imbalanced Sodium to Potassium Ratio Is the Most Important Risk Factor

One teaspoon of refined table salt contains 2,300 mg of sodium. According to the AHA, an excess of sodium in your body may cause you to retain water, putting an extra burden on your heart, blood vessels and kidneys.

Past recommendations have assumed that in some people this may lead to high blood pressure.¹⁹  But, sodium is just one-half of the ratio needed to keep your body healthy. The second half of the equation is potassium.

Your body is a complex organism, relying on the interactions and relationships between several factors. Your sodium level is important, but the ratio between sodium and potassium is even more important.

The main finding in one study showed the sodium-to-potassium ratio was more strongly associated with blood pressure changes than were either sodium or potassium individually.²⁰ 

Our modern diet is high in foods containing large amounts of salt and low in potassium-rich real foods, such as vegetables. This electrolyte mismatch has significant effects on your body and your cardiovascular health.

Research has shown that women who eat a higher amount of potassium-rich food also have a lower risk of cardiovascular disease and stroke, as well as all other causes of mortality, especially women who were not hypertensive.²¹

The protective effects of potassium are associated with the actions of nitric oxide release, which increases the relaxation of your arterial system and lowers blood pressure.²²

Impact of Your Sodium to Potassium Ratio

The separate roles of sodium and potassium, and their relationship to heart health, have been studied over the years. Researchers have also evaluated the relationship between a combination of sodium and potassium and heart health.  

In findings published in the Journal of the American Medical Association (JAMA), researchers determined that your sodium-potassium ratio is associated with a higher risk of cardiovascular disease (CVD) and all causes of mortality.²³

Several studies have suggested that the ratio of sodium to potassium is a more important risk factor for hypertension and CVD than either of the risk factors alone.^24,25,26

Data from over 12,000 individuals participating in the 3rd National Health and Nutrition Examination found higher sodium was associated with an increased risk of death, while a higher potassium level was associated with a lower rate of death from any cause.²⁷

An imbalance of potassium in your body is linked to more than just CVD and stroke risk. A low potassium level is also a contributing factor in the development of:

The Best Way to Balance Your Sodium and Potassium

Low potassium levels are related to low intake of potassium-rich foods, but also to losing potassium from other conditions, such as:²⁸

The best way to balance your sodium and potassium ratio is to increase your intake of foods rich in potassium, while maintaining a moderate amount of sodium intake. However, it's important to look at all the nutrients foods rich in potassium will provide.

For instance, white potatoes are high in potassium but also high in carbohydrates, raising the risk of spiking your insulin levels. So loading up on white potatoes to balance your sodium to potassium ratio would not be in your best interest. Whole foods naturally high in potassium and low in sodium include:^29,30

Choose Your Salt Wisely

Your body needs salt to regulate blood pressure, help your brain communicate with your muscles and support the function of your adrenal glands. However, it isn't the processed table salt your body needs to perform optimally.

Instead, I recommend pink Himalayan salt. This salt is higher in potassium than any of the other natural, unprocessed salts, helping you to maintain a balanced potassium-salt ratio. The salt is very flavorful and tastes delicious on your food. You'll find that you'll need less than you do of table salt, but you'll get more flavor and more mineral content.

It isn't just the additional minerals in Himalayan salt that makes it a better choice, but rather the lack of processing. Table salt undergoes considerable processing, and chemicals detrimental to your health are added. Table salt is what's used in canned and processed foods, which is yet another reason why they're best avoided.

I recommend eating as much real food as possible, using Himalayan salt to taste, and to increase your potassium by including ample amounts of potassium-rich foods. When ordering at a restaurant, ask your food be prepared without salt, and that your vegetables be steamed. Many restaurants now offer sea salt at the table, but if they don't you can always bring your own from home.

Salad dressings and sauces can be served on the side so you can limit the amount you use. If your food comes to the table too salty, send it back. Avoid fast food restaurants where you can easily reach your daily intake of sodium in one meal.

In an effort to reduce salt intake, the State of New York has passed a National Salt Reduction Initiative, requiring all chain restaurants to add a warning icon next to foods on their menu containing more than 2,300 mg of salt^.31 When you do eat foods high in salt, be sure to watch your diet the rest of the day and include real foods high in potassium to balance your salt-to-potassium ratio.

Optimize Your Salt to Potassium Ratio for Good Health

Interestingly, the idea that too little salt might not be good for you is not new. In an article published in the New England Journal of Medicine in 1985, the authors evaluated the dietary intake of our Paleolithic ancestors to find they naturally consumed about 11,000 mg of potassium and 700 mg of sodium.³² Today that ratio is reversed where the daily potassium intake averages 2,500 mg and sodium 3,400 mg.

This imbalance may explain why high-sodium diets affect some people more negatively than others. Another study from 2011 found that people who ate too much sodium and too little potassium had a greater risk of CVD and stroke.³³

Remember, the more you can move toward a diet of whole organic foods the healthier you'll be — whether it's veggies, meat, dairy products, or salt. Given that salt is absolutely essential to good health, I recommend switching to a pure, unrefined salt like Himalayan crystal salt.