Does Sodium Increase Inflammation in the Body?

January 6, 2026 •

5 min read

Recent studies in both human and animal models have shown that a high salt intake can trigger inflammatory responses in the body, with one study indicating that an extra gram of sodium beyond daily recommendations can increase eczema flare-ups by 22%. This evolving scientific consensus is moving beyond the well-known link between sodium and blood pressure to explore its impact on broader immune function and chronic inflammatory conditions.

Quick Summary

A high-sodium diet can promote a pro-inflammatory state by disrupting the immune system and gut microbiome, influencing the severity of conditions like autoimmune disease and IBD. The mechanisms involve specific immune cell activation and alterations in gut bacteria, highlighting the role of dietary salt as an environmental trigger.

Key Points

High sodium can activate pro-inflammatory immune cells: Excessive salt intake can prompt immune cells like Th17 cells and M1 macrophages to become overactive and release inflammatory cytokines.
The gut microbiome is negatively affected: High-salt diets can cause an imbalance in gut bacteria, depleting beneficial species like Lactobacillus and promoting a pro-inflammatory environment.
Links exist to autoimmune diseases: The activation of inflammatory Th17 cells by high sodium is a potential environmental trigger for autoimmune conditions, including MS and IBD.
Vascular inflammation and oxidative stress are exacerbated: In addition to increasing blood pressure, high sodium intake can cause low-grade inflammation and oxidative stress that damages blood vessels and contributes to atherosclerosis.
Reducing sodium can help decrease inflammation: Adopting a diet lower in processed foods and high in whole foods is a simple, effective strategy to reduce inflammation and related health risks.
The impact can be localized, not always systemic: Not all systemic inflammation markers (like CRP) show consistent changes in response to high sodium, suggesting the inflammatory effect may be more localized in specific tissues, such as the gut and skin.
Excessive and insufficient sodium can be problematic: Maintaining a balanced intake is crucial, as both excessively high and very low sodium levels have been shown to have pro-inflammatory effects in some contexts.

The Direct Impact of High Sodium on the Immune System

Beyond its effect on blood pressure, mounting evidence suggests that excessive sodium directly influences the immune system, primarily by modulating immune cell function and differentiation. A high salt concentration can create a hypertonic environment in tissues, altering how immune cells behave and potentially leading to an overactive, pro-inflammatory state.

Sodium's Effect on T Cells and Macrophages

Research has identified several ways sodium affects immune cells:

Th17 Cell Activation: High salt levels promote the differentiation of T cells into pathogenic Th17 cells, which produce inflammatory cytokines like IL-17. These cells are known mediators of autoimmune diseases and are implicated in chronic inflammation. In autoimmune diseases such as multiple sclerosis (MS) and inflammatory bowel disease (IBD), increased salt concentrations can cause a stable induction of these inflammatory Th17 cells.
Macrophage Polarization: Excessive sodium pushes macrophages, a type of white blood cell, toward a pro-inflammatory M1 phenotype. This shift increases the production of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1β, while suppressing the anti-inflammatory M2 phenotype. This macrophage activation can lead to tissue inflammation and damage.
Glucocorticoid Regulation: High salt intake has been shown to increase circulating levels of glucocorticoids, hormones known to inhibit certain immune cells like granulocytes. While cortisone (a glucocorticoid) is used to suppress inflammation, this salt-induced increase can paradoxically weaken the immune system's ability to fight bacterial infections, as observed in a University of Bonn study.

The Gut Microbiome: A Key Link to Inflammation

The gut microbiome plays a critical role in regulating immune homeostasis, and high sodium intake has a significant and detrimental impact on this delicate balance. The typical Western diet, which is high in ultra-processed foods, is rich in salt and has been linked to microbiome disruption and a rise in inflammatory conditions.

How High Sodium Affects Gut Health

Reduced Beneficial Bacteria: Studies, primarily in mice but corroborated by human findings, have shown that a high-salt diet can deplete beneficial gut bacteria, particularly Lactobacillus species. These bacteria produce anti-inflammatory compounds like short-chain fatty acids (SCFAs), and their reduction can weaken the body's anti-inflammatory defenses.
Dysbiosis and Pathogenic Flora: The decrease in beneficial bacteria can lead to gut dysbiosis, an imbalance where potentially harmful bacteria thrive. This shift can promote local inflammation in the gut, contributing to diseases like IBD. In IBD patients, low-salt diets have been shown to induce remission, highlighting the significant role of sodium in exacerbating intestinal inflammation.
Increased Inflammatory Mediators: High salt intake can alter the intestinal environment, prompting an increased production of inflammatory cytokines and altering the immune response. This gut-level inflammation can contribute to systemic inflammation throughout the body.

The Connection to Specific Diseases

Autoimmune Diseases

Research has increasingly linked high sodium intake to an increased risk and severity of autoimmune diseases. The mechanism involves the overstimulation of Th17 immune cells, which attack the body's own tissues. Examples include multiple sclerosis, rheumatoid arthritis, and psoriasis. Reducing salt intake is being explored as a simple, proactive strategy to manage symptoms and lower the risk of flare-ups.

Cardiovascular Disease

High sodium intake is a well-established risk factor for cardiovascular disease (CVD), primarily through its effects on blood pressure. However, inflammation is now recognized as another contributing factor. High salt intake triggers oxidative stress and low-grade vascular inflammation in target tissues, damaging blood vessels and accelerating the process of atherosclerosis.

Skin Inflammation (Eczema)

A recent study found that elevated sodium levels, specifically stored in the skin, can heighten the risk of eczema. The researchers observed that consuming just one extra gram of sodium per day increased the chances of an eczema flare-up by 22%. This discovery provides a new, tangible link between dietary habits and inflammatory skin conditions.

Comparison of Inflammation Triggers


Feature	High Sodium Intake	High Sugar Intake	High Saturated Fat Intake
Primary Mechanism	Immune cell dysregulation, gut microbiome disruption.	Advanced glycation end-products (AGEs), insulin resistance.	Activation of TLRs, adipose tissue inflammation.
Immune Cells Affected	Th17 cells, macrophages, granulocytes.	Monocytes, macrophages, endothelial cells.	Macrophages, adipose tissue-resident cells.
Effect on Gut Health	Disrupts microbiome balance (reduces Lactobacillus).	Disrupts bacterial balance, feeds inflammatory species.	Can alter gut permeability and flora composition.
Inflammatory Biomarkers	IL-17, TNF-α, IL-6.	CRP, TNF-α, IL-6.	TNF-α, IL-6, CRP.
Typical Associated Diseases	Autoimmune diseases, hypertension, IBD.	Diabetes, cardiovascular disease.	Heart disease, metabolic syndrome.

Reducing Sodium for Anti-Inflammatory Benefits

Since a high-sodium diet can exacerbate inflammation, reducing intake is a practical strategy for improving health, especially for those with inflammatory or autoimmune conditions. The American Heart Association recommends aiming for no more than 1,500 mg of sodium daily, far below the average American intake of 3,400 mg.

Actionable Steps to Lower Sodium

Read Labels: Be vigilant for hidden sodium in processed foods, canned soups, condiments, and fast-food meals, as many high-sodium items do not taste noticeably salty.
Focus on Whole Foods: Prioritize fresh fruits, vegetables, whole grains, and lean proteins, which are naturally low in sodium.
Use Herbs and Spices: Flavor foods with a variety of herbs, spices, citrus, and salt-free seasoning blends instead of relying on salt.
Cook at Home: Preparing meals yourself gives you complete control over the amount of sodium used.
Choose Low-Sodium Versions: Opt for low-sodium or salt-free versions of products like broths, sauces, and crackers.

The Complex Picture: Research and Context

While a strong link exists, the relationship between sodium and systemic inflammation is complex and not fully understood. Some studies have shown inconsistent effects on systemic inflammatory markers like C-reactive protein (CRP), potentially due to methodological differences or the impact of other dietary factors. The pro-inflammatory effects may be more pronounced locally, such as in tissue macrophages or the gut, rather than consistently reflected in circulating blood biomarkers. Furthermore, extremely low-sodium diets can also be pro-inflammatory for some individuals, pointing to the need for balanced intake rather than severe restriction.

Future Research Directions

Large-Scale Human Trials: More large-scale, well-designed human trials are needed to clarify the causal relationship between sodium intake and systemic inflammation markers.
Mechanistic Studies: Further research is required to fully elucidate the specific molecular pathways and immune cell interactions by which high salt induces inflammation in humans.
Genetics and Personalized Nutrition: Studies exploring how genetic variations and individual health conditions influence the inflammatory response to sodium are needed to tailor dietary recommendations.

Conclusion

Scientific evidence confirms that high sodium intake can increase inflammation in the body through complex mechanisms involving the immune system and gut microbiome. While research is ongoing to fully understand the intricate relationship and its implications for human health, limiting excessive salt consumption is a prudent and proven strategy for reducing inflammation and mitigating the risk of various chronic diseases, including cardiovascular and autoimmune conditions. By adopting a diet rich in whole, unprocessed foods and being mindful of hidden sodium, individuals can proactively reduce inflammation and support their overall well-being.

Frequently Asked Questions

Yes, for many people, especially those with inflammatory or autoimmune conditions, reducing high salt intake can help lower inflammation. This is because excessive sodium promotes pro-inflammatory immune responses and harms the beneficial bacteria in your gut.

Sodium is a mineral and electrolyte found in foods and table salt. Salt is the crystal-like compound sodium chloride (NaCl). While the terms are often used interchangeably, sodium is the component that affects blood pressure and inflammation.

No, while processed and fast foods are major sources of high sodium, many items that don't taste salty can still contain significant amounts, such as canned goods, sauces, and condiments. It's important to read nutrition labels to track your intake accurately.

High dietary sodium can disrupt the delicate balance of microorganisms in the gut. It tends to reduce the population of beneficial bacteria like Lactobacillus species, which can lead to gut dysbiosis and increased intestinal inflammation.

Research suggests that even in healthy individuals, high salt intake can trigger pro-inflammatory immune responses and weaken the immune system's ability to fight off certain infections, though effects can vary.

The American Heart Association recommends an ideal limit of 1,500 mg of sodium per day, while other health organizations suggest keeping intake below 2,300 mg. The average American consumes far more than these recommendations.

Yes, using salt substitutes that replace sodium with potassium can be an effective strategy. Some studies show that this can help reduce blood pressure and potentially contribute to lower inflammation.