Should a specific diet be followed in cases of lupus?

Key points to remember about the diet for lupus cases.

Refined sugars cause glycaemic spikes that stimulate inflammatory cytokines.
The refined salt triggers the molecular mechanisms responsible for kidney damage and must be considerably restricted.
When taking corticosteroids, weight gain is not just a matter of calories: it is a chemical reaction. The “no salt / low sugar” duo is your best defence to limit swelling and protect your muscles.
The omega-6-rich oils and saturated fats provide the body with the components required to produce inflammatory molecules.
The ultra-processed foods contain additives that damage the intestinal barrier and promote excessive immune activity.
Alfalfa sprouts and other sprouted seeds must be completely excluded because of L-canavanine, which activates autoantibodies.
Garlic overactivates immune cells and can turn a stable phase into an acute inflammatory flare.
Theechinacea enhances the immune system’s attack signals, creating a risk of breaking tolerance and counteracting the effect of treatments.
Although gluten is not intrinsically toxic, it can compromise the integrity of the intestinal barrier and place unnecessary demands on the immune system; however, its exclusion should be confirmed by a physician to avoid any risk of deficiency.

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Food no. 1: refined carbohydrates and glycated products.

In the context of lupus, sugar is not only a problem in terms of calories; it is a systemic pro‑inflammatory agent. The consumption of carbohydrates with a high glycaemic index (> 70), such as white bread, white rice, standard pasta, pastries or breakfast cereals, induces immediate postprandial hyperglycaemia. This glucose spike forces the pancreas to release a high concentration of insulin, which can reach levels four to eight times higher than normal (between 2 and 20 mIU/L). Insulin is a hormone that, in excess, stimulates interferon signalling pathways, which are already overactive in patients with lupus.

Moreover, the consumption of fast-acting sugars promotes the formation of advanced glycation end products (AGEs) through a spontaneous chemical reaction known as the Maillard reaction. During this reaction, excess sugar molecules bind irreversibly to the body’s proteins, thereby altering tissue structure. These compounds attach to RAGE receptors on immune cells, generating oxidative stress that sustains inflammation of the joints and vascular walls. Clinical studies have demonstrated a direct correlation between high intake of fast-acting sugars and an increase in lupus activity scores (SLEDAI), suggesting that sugar acts as a fuel for pre-existing inflammation.

For a patient with lupus, replacing these foods with whole grains (quinoa, buckwheat, brown rice) can help stabilise the disease activity score.

Food no. 2: salty foods and industrial additives.

Table salt, ubiquitous in processed foods (hard cheeses, cured meats, canned dishes, stock cubes, etc.), has become a central topic in autoimmune disease research. Recent studies have shown that a high concentration of sodium chloride in the interstitial environment activates a specific enzyme (“Serum/Glucocorticoid-regulated Kinase 1”), which promotes the differentiation of T lymphocytes into Th17 lymphocytes. These cells are particularly problematic in lupus because they secrete IL-17, a cytokine responsible for direct damage to kidney tissue and for triggering inflammatory flares. This mechanism is activated as soon as intake exceeds the critical threshold of 5 grams of salt per day (equivalent to about 2,000 mg of sodium), a dose frequently reached through the hidden salt in processed foods.

Industrial and ultra-processed foods present a double trap. Beyond their excessively high content of refined salt, they often contain additives and emulsifiers that alter intestinal permeability. This increased fragility facilitates the passage of bacterial fragments into the bloodstream, creating a favourable environment for immune overactivation. These foods often contain inorganic phosphates – such as additives E338 to E343 – which are absorbed 100% by the body and overload the kidneys, a major concern in lupus. They also contain emulsifiers, such as polysorbate 80 or carboxymethylcellulose, which act by disrupting the intestinal barrier.

Limiting salt intake not only helps to protect the arteries; it also contributes to reducing immune pressure on the kidneys, an organ frequently targeted in lupus nephritis.

Food no. 3: foods rich in fats.

Not all fats are equal, and their impact on lupus depends on their molecular structure. Vegetable oils rich in omega‑6 fatty acids – such as sunflower, maize (corn) or grape seed oil – are the precursors of arachidonic acid. While a healthy physiological balance relies on a 3 to 1 (omega‑6 / omega‑3) ratio, excessive intake often leads to an alarming ratio exceeding 15 to 1, creating a biological environment in which chronic inflammation is no longer regulated. In a person with lupus, this acid is converted into prostaglandins and leukotrienes, molecules that orchestrate pain and joint swelling. In contrast, saturated fatty acids (fatty meats, cured meats, butter) saturate cellular receptors and increase membrane rigidity, making immune cells more reactive.

To protect the cardiovascular system, which is already weakened by systemic inflammation, it is preferable to limit these sources in favour ofoils with an anti-inflammatory profile, such as olive oil for cooking, or linseed, hemp and camelina oils for seasoning.

Food no. 4: alfalfa, garlic and echinacea – powerful immune stimulants for patients with lupus.

While most foods act indirectly, alfalfa is one of the few that has a direct triggering mechanism. This plant, often found in “health” salads, vegetarian sandwiches or certain food supplements, contains L-canavanine. This is a non-protein amino acid that is structurally similar to arginine. The body mistakenly incorporates it into its own proteins, thereby altering their structure. The immune system, no longer recognising these modified proteins, launches a massive attack against its own tissues. In a patient with lupus, consumption of alfalfa sprouts or mung bean sprouts can worsen autoantibody activity. It is essential to avoid these foods, as clinical observations have shown that they can reactivate native anti-DNA antibodies and trigger severe joint pain, even during a phase of stable remission.

While alfalfa is contraindicated in patients with lupus because it contains L-canavanine, garlic (Allium sativum), by contrast, should be avoided for the opposite reason: its stimulating effect on the immune system is too strong. Garlic contains sulphur compounds, notably allicin and thiosulphates, which have powerful immunostimulant properties. In a healthy person, these molecules strengthen natural defences, but in a patient with lupus they exacerbate the imbalance of the immune system. By stimulating the activity of macrophages and T lymphocytes, garlic increases the production of autoantibodies and can turn a stable phase into an acute inflammatory flare.

This vigilance extends beyond fresh garlic cloves: garlic powder and garlic extracts found in ready-made dishes and so‑called “detox” food supplements are also affected.

In a similar vein to garlic, echinacea is a medicinal plant whose natural reputation conceals a danger for patients with lupus. Often consumed as herbal teas, capsules or mother tinctures to prevent colds, it acts by increasing the production of pro-inflammatory cytokines (TNF-α, IFN-γ). Clinical observations have shown that echinacea can not only interfere with immunosuppressive treatments by cancelling out their effects, but also trigger a resumption of autoimmune activity in patients who were previously stable. By driving lymphocytes to multiply, it risks disrupting the patient’s fragile immune tolerance and precipitating the body into a new flare.

Food no. 5: gluten and its impact on immune balance.

The link between gluten and lupus is a subject of debate within the scientific community. The main idea is that gluten stimulates zonulin, a molecule that increases the permeability of the intestinal wall. When this barrier becomes less tight, external elements can pass into the bloodstream, which may place additional strain on an immune system that is already hyper‑reactive. However, it is crucial to emphasise that eliminating gluten is not a universal rule. According to recent studies, adopting a gluten‑free diet without a medical diagnosis of coeliac disease may be counterproductive. Gluten remains an important source of protein; removing it unnecessarily could lead to nutritional deficiencies in patients who are already weakened by the disease. Avoidance of gluten should therefore only be considered if a genuine sensitivity has been confirmed by a doctor.

An analytical study recalls that the risk of coeliac disease remains low in patients with lupus. It emphasises that a gluten-free diet should only be followed on medical advice, in order to avoid unnecessary financial burden and the risk of malnutrition.