Myth: "Nutrition has little impact on autoimmune diseases." The opposite is well-documented. Even moderately increased salt intake can raise the number of inflammatory Th17 cellsa subset of T-helper cells that drive inflammation in individuals and elevate blood pressure – simultaneously, the gut flora changes and loses protective lactobacilli ^[1]. Those striving for high performance should treat the immune system like a finely tuned engine: The fuel determines whether it operates smoothly, efficiently, and for a long time – or overheats.

Autoimmune diseases arise when the immune system mistakenly recognizes the body's own structures as foreign. Central to this is the immune balance between pro- and anti-inflammatory signaling pathways. Nutrition acts as a regulator here. Gut microbiotathe totality of microorganisms in the gut produce short-chain fatty acids like butyrate from dietary fibers, which promote Tregsregulatory T-cells that dampen excessive immune responses and stabilize the epithelial barrierprotective layer of the intestinal mucosa ^[2]. Conversely, trans fatsindustrially hardened fats and excessive salt can amplify inflammatory pathways. "Inflammation" is not an enemy but a tool – however, when chronically dysregulated, it costs energy, regenerative ability, and lifespan.

High salt consumption shifts the immune environment towards Th17 dominance, promotes vascular inflammation, and can raise blood pressure through reduced NO production in endothelial cells; concurrently, changes in gut flora occur that favor local inflammation ^{[3] [1] [4]}. A high intake of red and especially processed meat is associated with increased C-reactive protein – an inflammation marker – in randomized studies, particularly in individuals with cardiometabolic risks ^[5]. Trans fats worsen glucose metabolism, fatty liver, and intestinal inflammation more severely than saturated fats in animal models – accompanied by immunological shifts in the gut ^[6]. Insufficient dietary fiber means fewer short-chain fatty acids, fewer Tregs, and a weaker barrier – a pattern that may promote allergies and autoimmunity ^[2]. On the positive side, n-3 fatty acids modulate inflammation signals and can dampen pro-inflammatory cytokines ^[7], while fermented foods increase the diversity of gut microbiota and exhibit immunoregulatory effects ^{[8] [9]}. Vitamin D deficiency is common in several autoimmune diseases and is associated with higher disease activity; supplementation may improve symptoms in some studies ^[10].

Several lines of evidence link nutrition directly to immune regulation. Experimental and clinical studies show that high salt load promotes the differentiation of CD4 cells into pathogenic Th17 cells; in a human pilot study, Th17 cells and blood pressure increased under moderate salt load, while Lactobacillus species decreased – a clear indication of the gut-immune system axis ^[1]. Reviews summarize that salt can thus drive not only hypertension but also autoimmunity ^{[3] [4]}. Omega-3 fatty acids like EPA show reduced cytokine production through the miR-125b-5p/CREB axis in cell models, which dampens NF-κB-mediated inflammation – a plausible mechanism for their clinical effects ^[7]. In a crossover intervention in rheumatoid arthritis, a seafood-rich diet significantly altered n-3 levels in erythrocytes; the oxylipin response was heterogeneous, indicating individual metabolic pathways and dose-time effects, necessitating further research ^[11]. Concurrently, a recent systematic review suggests that higher consumption of red – particularly processed – meat increases inflammatory markers like CRP, with stronger effects without energy restriction and at ≥0.5 servings/day ^[5].

- Consume fatty fish twice a week: Plan for 2–3 servings of salmon, mackerel, or sardines to intake EPA/DHA. Aim for 1–1.5 g EPA+DHA/day from fish or certified algae/fish oil supplements, in consultation with your doctor. These n-3 fatty acids modulate pro-inflammatory signaling pathways and dampen cytokines ^{[7] [11]}.
- Rotate fermented foods daily: Use natural yogurt or kefir (without sugar), sauerkraut, kimchi, miso. Start with 1–2 small servings/day and monitor tolerance. Probiotic lactobacilli support gut microbiota, immune balance, and vitamin formation ^{[8] [9]}.
- Optimize vitamin D based on status: Get 25-OH vitamin D tested in your blood and supplement individually, especially in winter. Aim for the target range recommended by your doctor; studies indicate higher disease activity with deficiency and report symptom improvements under supplementation ^[10].
- Eliminate-test common triggers: Pause gluten-containing grains and dairy products for 3–4 weeks, then reintroduce systematically (each for 3–5 days) and document symptoms. Observational data show frequently elevated food-specific IgG in autoimmune patients; a targeted, medically supervised elimination trial can identify individual triggers ^[12].
- Consciously reduce salt: Decrease heavily processed products, salty snacks, and ready-made sauces; cook fresh more often and season with herbs. This minimizes Th17-driven effects and blood pressure spikes ^{[1] [3] [4]}.
- Avoid trans fats: Check ingredient lists for "hydrogenated/partially hydrogenated fats," and avoid fried snacks and cheap baked goods. Trans fats exacerbate intestinal inflammation and metabolic stress ^[6].
- Limit red and processed meat: Max 1–2 servings/week, avoiding processed meat whenever possible. Focus on fish, legumes, and poultry; this reduces inflammatory markers like CRP ^[5].
- Eat a fiber-rich diet: 25–35 g/day from vegetables, berries, legumes, oats, and psyllium husks. The resulting SCFAs promote Tregs, barrier function, and inflammation resilience ^[2].

Your immune system measurably reacts to every fork – leverage these levers. More omega-3, fermented foods, fibers, and vitamin D; less salt, trans fats, and processed red meat. Start today with a fresh, low-salt meal and a serving of fermented foods – your future self will thank you.