How inflammation drives skin conditions
The skin is the largest organ and a major immune interface. Inflammatory skin conditions all share dysfunction of the barrier (the outer stratum corneum) plus an immune component. In eczema, barrier defects (often filaggrin mutations) allow allergens and microbes through, triggering a Th2-dominant immune response with IgE and IL-4/13. In psoriasis, the immune system is primarily dysregulated with Th17/IL-17 dominance, driving the rapid keratinocyte turnover that produces scaling plaques. Rosacea involves vascular hyperreactivity plus innate immune dysregulation. Acne combines hormonal sebum overproduction, follicular hyperkeratinization, C. acnes proliferation, and inflammatory cytokine release.
Underlying all of this is the gut-skin axis: systemic inflammation from gut dysbiosis or poor diet shows up on skin. CRP and IL-6 elevations track with skin disease severity in cohort studies.
Why these foods help
Omega-3 fatty acids reduce systemic and cutaneous inflammation; meta-analyses show modest benefit in eczema and psoriasis. Vitamin D from fatty fish, eggs, and fortified foods supports immune regulation in skin. Zinc from oysters, beef, and pumpkin seeds is essential for barrier function and wound healing. Polyphenols from green tea, berries, and dark chocolate protect against UV damage and quench oxidative stress. Probiotics and fermented foods improve eczema in some trials, likely via gut-skin axis effects.
For acne specifically, lower-glycemic patterns and less dairy improve outcomes in trials — though the effect size is modest and individual.