RESEARKA

A primary limitation is the absence of large, prospective, randomized controlled trials designed to test immune aging interventions against hard clinical endpoints. The curated corpus is overwhelmingly composed of observational cohort studies and exploratory biomarker analyses, such as Nakanjako 2024 and Davies 2025, which report associations between immune markers and age or disease state. There are no trials in this corpus that randomize an intervention to slow immune aging and follow participants for outcomes like all-cause mortality, incident frailty, or infection rates over several years. Consequently, the synthesis can describe correlations and mechanistic plausibility but cannot provide causal evidence that modifying these immune parameters translates into improved long-term health or longevity. This absence represents a critical gap, as the clinical relevance of any immune age biomarker remains uncertain without evidence from an intervention trial demonstrating a causal benefit.

Citation Support

• source_1 Jongsma 2023
• source_2 Xie 2025
• source_3 Wallen 2024
• source_4 Hoang 2025
• source_5 Boudhabhay 2026