Is IgE useful for longevity?

The utility of IgE (immunoglobulin E) for longevity is not well supported by current evidence. IgE is primarily a marker for allergic responses and parasitic infections. While some research suggests IgE may be involved in immune regulation and chronic inflammation, its direct role in human lifespan is unclear. Elevated IgE levels are associated with conditions like asthma, atopic dermatitis, and certain infections, but not with longevity per se. Consumer tests offering IgE as a longevity biomarker lack robust validation. Measuring IgE can be clinically useful for allergy diagnosis, but for longevity optimization, it is not a proven target. Evidence: unclear/mechanistic. Caveat: IgE levels vary with age, environment, and genetics; interpretation requires medical context.