Inflammation and Nutrition: What Research Shows

Acute vs. Chronic Inflammation

Inflammation is a natural response of the immune system. When you cut your finger, acute inflammation ensures that immune cells reach the wound, pathogens are fought off and healing begins. Redness, swelling and warmth are signs of this process. Within a few days, the reaction subsides. This is healthy and necessary.

Problems arise when inflammatory processes remain permanently active. In chronic inflammation, the immune system continuously sends out pro-inflammatory signalling molecules (cytokines) even though there is no acute threat. This state can gradually damage tissue and organs. Calder et al. (2011) describe this mechanism as a central factor in the development of numerous chronic diseases.

Silent Inflammation: The Invisible Danger

Chronic low-grade inflammation is referred to as “silent inflammation”. It does not cause obvious symptoms such as pain or fever. Instead, it runs in the background for months and years.

Galland (2010) identified several risk factors for silent inflammation:

• Excess weight: Adipose tissue produces pro-inflammatory cytokines such as TNF-alpha and interleukin-6.
• Lack of exercise: Regular physical activity has been shown to have anti-inflammatory effects.
• Chronic stress: Persistently elevated cortisol levels can promote inflammatory processes.
• Sleep deprivation: Less than 6 hours of sleep per night increases inflammatory biomarkers.
• Diet: A Western diet high in sugar, trans fats and processed foods promotes inflammation.

The challenge is that because no acute symptoms occur, silent inflammation often goes undetected for years.

CRP and Other Biomarkers

Science uses various biomarkers to measure chronic inflammation. The most important is C-reactive protein (CRP), which is produced in the liver in response to inflammation.

Biomarker	What it measures	Normal range
hs-CRP	High-sensitivity CRP, low-grade inflammation	< 1 mg/L optimal
IL-6	Interleukin-6, pro-inflammatory cytokine	< 7 pg/mL
TNF-alpha	Tumour necrosis factor, inflammatory mediator	< 8.1 pg/mL
Fibrinogen	Acute-phase protein	200-400 mg/dL

An hs-CRP value between 1 and 3 mg/L is considered an elevated risk. Values above 3 mg/L indicate active inflammation. These values can be influenced by dietary changes.

Pro-Inflammatory Foods

Certain foods and dietary patterns can amplify inflammatory processes in the body. Research shows consistent associations between the following foods and elevated inflammatory markers:

• Sugar and high-fructose corn syrup: Stimulate the production of pro-inflammatory cytokines. A study by Aeberli et al. (2011) showed that even moderate amounts of fructose can raise CRP levels.
• Trans fats: Industrial trans fats (partially hydrogenated fats) increase inflammatory markers and are associated with a higher risk of cardiovascular disease.
• Refined carbohydrates: White flour products with a high glycaemic index can promote inflammatory responses.
• Processed meat: Regular consumption of processed meats correlates with higher CRP values.
• Excessive alcohol consumption: Chronic alcohol consumption promotes inflammation, particularly in the liver.

Anti-Inflammatory Foods

On the other hand, there are numerous foods whose regular consumption is associated with lower inflammation levels:

Berries and Dark Fruits

Berries contain anthocyanins, which have demonstrated anti-inflammatory properties. Blueberries, strawberries and cherries are among the best-studied sources.

Dark Leafy Greens

Spinach, kale and Swiss chard provide vitamin K, folate and numerous polyphenols. Epidemiological studies show an association between high vegetable intake and lower inflammatory markers.

Nuts and Seeds

Walnuts are particularly rich in alpha-linolenic acid (ALA), a plant-based omega-3 fatty acid. A handful of nuts per day is associated with lower CRP values in observational studies.

Fatty Fish

Salmon, mackerel and sardines provide the omega-3 fatty acids EPA and DHA. Calder et al. (2011) documented that these fatty acids can promote the production of anti-inflammatory mediators (resolvins and protectins).

Turmeric and Ginger

Curcumin, the active compound in turmeric, inhibits the NF-kB signalling pathway, a central regulatory mechanism for inflammatory responses. However, the bioavailability of curcumin is low and is improved by combining it with black pepper (piperine).

The PREDIMED Study: Mediterranean Diet as a Model

The PREDIMED study (Prevención con Dieta Mediterránea) is one of the largest and most important nutritional studies on the anti-inflammatory effect of an entire dietary pattern. Estruch et al. (2018) published the revised results in the New England Journal of Medicine.

Study design:

• Over 7,400 participants with high cardiovascular risk.
• Three groups: Mediterranean diet with olive oil, Mediterranean diet with nuts, control group (low-fat diet).
• Observation period: median 4.8 years.

Key results:

• The Mediterranean diet reduced the risk of major cardiovascular events by approximately 30% compared to the control group.
• Subanalyses showed significantly lower inflammatory markers (CRP, IL-6) in the intervention groups.
• The combination of various anti-inflammatory foods was more effective than individual foods.

The PREDIMED study shows that it is not individual superfoods but the overall dietary pattern that matters. Olive oil, nuts, fish, vegetables, fruit and legumes work synergistically.

Practical Recommendations

Based on current research, concrete steps can be derived:

1. More vegetables and fruit: At least 5 portions daily, focusing on variety and dark colours.
2. Choose healthy fats: Olive oil as the main fat source, regular nuts and seeds.
3. Increase omega-3 fatty acids: 2-3 portions of fatty fish per week or plant-based sources such as flaxseeds and walnuts.
4. Reduce processed foods: Fewer ready-made products, processed meats and sugary drinks.
5. Use spices: Integrate turmeric, ginger and cinnamon regularly into cooking.
6. Eat fibre-rich foods: Legumes, whole grains and vegetables promote a healthy gut flora, which also regulates inflammation.

Conclusion

Research clearly shows that nutrition influences inflammatory processes in the body. Chronic low-grade inflammation is a serious risk factor that can be influenced by food choices. The PREDIMED study and numerous other investigations demonstrate that a plant-focused dietary pattern based on the Mediterranean model can have anti-inflammatory effects.

This does not mean that individual foods cure diseases. It means that daily nutrition is an effective tool for regulating chronic inflammatory processes and supporting long-term health.

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Sources:

• Calder PC et al. (2011). Dietary factors and low-grade inflammation in relation to overweight and obesity. British Journal of Nutrition.
• Galland L (2010). Diet and Inflammation. Nutrition in Clinical Practice.
• Estruch R et al. (2018). Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. New England Journal of Medicine.
• Aeberli I et al. (2011). Low to moderate sugar-sweetened beverage consumption impairs glucose and lipid metabolism and promotes inflammation in healthy young men. Diabetes Care.