6 Little-Known Dangers of Restricting Sodium Too Much

Written by Hrefna Palsdottir, MS on February 27, 2020 — Medically reviewed by Atli Arnarson BSc, PhD

This article discusses sodium restriction in the general population. If you have been prescribed a low-sodium diet by your healthcare professional, or need to adhere to a low-sodium diet to manage a condition, the following information may not apply to you.

Sodium is an important electrolyte and main component of table salt.

Too much sodium has been linked to high blood pressure, and health organizations recommend that you limit your intake (1, 2, 3).

Most current guidelines recommend eating less than 2,300 mg per day. Some even go as low as 1,500 mg per day (4).

However, even though too much sodium causes problems, eating too little can be just as unhealthy.

Here are 6 little-known dangers of restricting sodium too much.

1. May increase in insulin resistance

A few studies have linked low sodium diets to increased insulin resistance (5, 6, 7).

Insulin resistance is when your body’s cells don’t respond well to signals from the hormone insulin, leading to higher insulin and blood sugar levels.

Insulin resistance is believed to be a major driver of many serious diseases, including type 2 diabetes and heart disease (8, 9).

One study involving 152 healthy people found that insulin resistance increased after only 7 days on a low sodium diet (5).

Yet, not all studies agree. Some have found no effect, or even a decrease in insulin resistance (10, 11, 12).

However, these studies varied in length, study population, and degree of salt restriction, which may explain the inconsistent results.

2. No clear benefit for heart disease

It’s true that reducing your sodium intake can reduce your blood pressure.

However, blood pressure is only a risk factor for disease. What’s really significant is hard endpoints like heart attacks or death.

Several observational studies have looked at the effects of low sodium diets on heart attacks, strokes, and the risk of death (13, 14, 15).

One study found that less than 3,000 mg of sodium per day is linked to an increased risk of dying from heart disease, including heart attacks and strokes (14).

Disturbingly, another study reported a higher risk of dying from heart disease at the lower sodium levels that many guidelines currently recommend (15).

However, other studies have reported conflicting results, so this matter is far from settled (16, 17, 18).

In a 2011 review, reducing sodium didn’t reduce the risk of dying from heart attacks or strokes, and it increased the risk of death from heart failure (19).

3. Increased risk of death from heart failure

Heart failure is when the heart is not able to pump enough blood around the body to meet its needs for blood and oxygen.

This doesn’t mean that your heart stops working completely, but it’s still a very serious health issue.

Interestingly, low sodium diets have been linked to an increased risk of death in people with heart failure.

One review found that for people with heart failure, limiting sodium intake increased the risk of dying (19).

In fact, the effect was strong — people who restricted their sodium intake had a 160% higher risk of death. This is concerning, as people with heart failure are often told to limit their sodium intake.

Yet, the results were strongly influenced by only one study, so more research is needed.