A study published in Clinical Endocrinology in 2020 showed that an increase in salt consumption leads to a rise in cortisol levels in your urine and lower cortisol levels in your bloodstream. What does this potentially mean? Restricting your sodium intake may lead to higher levels of circulating cortisol.

Salt is often vilified, and many physicians instruct their patients to adopt a low-sodium diet for health reasons. However, not consuming enough of it may interfere with the removal of cortisol from our bloodstream. Sodium helps flush the stress hormone from the body, and avoiding it may ultimately lead to chronically elevated blood cortisol levels. If left untreated, high cortisol levels can lead to a variety of bothersome symptoms and potentially serious complications. Most people are experiencing some symptoms of elevated or dysregulated cortisol from life stressors, and abstaining from salt may be exacerbating the situation.

What Is Cortisol?

Cortisol is an essential steroid hormone the adrenal gland produces in response to stress. It is often referred to as the stress hormone because the body releases it in higher amounts during the fight-or-flight response to a stressor. Cortisol helps release stored glucose from our cells so we have the energy to run away from a perceived threat.

The stress hormone has many vital functions, including regulating blood sugar levels, managing metabolism, controlling inflammation, and assisting with your sleep and wake cycle. It is an important hormone, however, high cortisol levels over a prolonged period of time can negatively affect health—including weight gain, high blood pressure, and weakened immune function.

The Difference Between Salt and Sodium

People often use the words salt and sodium interchangeably, but there is a marked difference between the two. Sodium is a mineral found in many foods and is essential for our bodies to function properly. Salt is a combination of sodium and chloride. It is a chemical compound comprised of 40 percent sodium and 60 percent chloride, hence its moniker. Ultimately, sodium is one of two elements that salt is made from.

Sodium is an essential mineral that helps regulate the body’s fluid balance and maintain normal nerve and muscle function. It is also involved in the absorption and transportation of nutrients throughout the body. Essential means your body cannot make it, and you must get adequate amounts from the food you eat. What is our primary source of sodium? Salt.

The Salt and Cortisol Connection

The findings of the 2020 study are not new. A separate study published earlier in the same year found that, “On a high-salt, as compared with a low-salt, diet, urinary aldosterone excretion decreased, whereas urinary cortisol and cortisone excretion increased.” In 2013, a study published in Cell Metabolism determined that “[A] high-salt diet increases cortisol excretion in humans.”

A study published in The Journal of Clinical Endocrinology and Metabolism in 2003 stated, “In healthy subjects, dietary salt loading increases and sodium restriction decreases urinary free cortisol excretion” and “​​changes in cortisol metabolite excretion after salt loading were accompanied by a decrease in plasma cortisol concentration.”

Prior to that, a 1998 study concluded, “This study supports the notion that sodium restriction decreases urinary cortisol excretion.”

Although more research is needed to fully understand the relationship between salt intake and cortisol excretion, the 2020 study raises a few points. Increased dietary sodium intake may cause false positives in urinary-free cortisol excretion tests, and low-sodium diets may make cortisol blood tests inaccurate. Additionally, a low-sodium diet may raise cortisol, and incorporating high-quality sources of sodium into your diet comes with benefits in terms of cortisol regulation.

The Type of Salt Matters

When it comes to salt consumption, the type of salt matters. Table salt is the most commonly used salt. It is heavily processed and stripped of many of its natural minerals. Chemicals are often added to keep it from caking in humidity.

Kosher salt is pure sodium chloride and contains no trace minerals, iodine, or unhealthy additives.

Foods That Can Help Lower Cortisol

In addition to high-quality salt, the best foods for lowering cortisol are those that are anti-inflammatory. Any foods that lower inflammation will, in turn, lower cortisol levels. Several foods can help reduce cortisol levels in the body, including:

• Dark chocolate: Dark chocolate contains flavonoids and studies have shown it can reduce cortisol levels.
• Berries: Berries are rich in antioxidants, which can help reduce inflammation and lower cortisol levels.
• Fatty fish: Fatty fish such as salmon and tuna contain high levels of omega-3 fatty acids. Research has shown that omega-3s can reduce cortisol levels.
• Nuts: Nuts are a great source of magnesium, which can help lower cortisol levels.
• Leafy greens: Leafy greens such as spinach and kale are also rich in magnesium and antioxidants and can help reduce inflammation and lower cortisol levels.
• Fermented foods: Fermented foods, including kimchi and sauerkraut, contain probiotics. Probiotics have been shown to help reduce cortisol levels.
• Herbal teas: Research supports that herbal teas, such as chamomile and lavender, have calming properties that can help reduce cortisol levels.
• Ashwagandha: A plant that has been used for centuries in traditional Ayurvedic medicine, ashwagandha is believed to reduce cortisol levels in the body. It has treated a variety of conditions, including stress, anxiety, fatigue, and depression.

Some studies suggest that ashwagandha also has anti-inflammatory and immune-boosting properties. However, ashwagandha can be unsafe for some people and should be discussed with a physician.