What to watch with IgG and stress?

The question about IgG and stress is complex. IgG antibodies are often linked to food sensitivities (IgG4), but the scientific evidence for a direct connection with stress is weak. Stress can modulate the immune system – chronic stress tends to lower immunoglobulin production, while acute stress may temporarily increase it. However, IgG is not an established biomarker for stress. Direct measurements of cortisol, alpha-amylase, or heart rate variability are more appropriate. Moreover, commercial IgG food sensitivity testing is controversial: medical guidelines advise against it because it often leads to unnecessary elimination diets. Without medical supervision, this can cause nutritional deficiencies and undue anxiety. When considering IgG tests, be cautious of overclaiming marketing. For stress assessment, consult a healthcare professional using validated methods. Evidence grade: unclear/mechanistic.