Best Supplements for Healthy Aging Ranked by Evidence Strength

As global life expectancy rises, the focus of longevity research has shifted from adding years to life toward preserving functional quality during those years. This 2026 narrative review by Kurtz et al. addresses a critical gap: synthesizing human evidence on dietary supplements that target the recognized hallmarks of aging—mitochondrial dysfunction, oxidative stress, chronic inflammation, loss of proteostasis, and deregulated nutrient sensing—with emphasis on clinically meaningful functional outcomes rather than cosmetic or surrogate endpoints.

The research team conducted a structured literature search across PubMed, Scopus, and Web of Science covering 2010–2025. Thirty-two human studies met inclusion criteria, supplemented selectively by animal studies for mechanistic context. Evidence was qualitatively graded as strong, moderate, or emerging based on study design, sample size, and reproducibility across populations. Studies were excluded if they focused on clinical pathologies unrelated to aging, lacked control groups, had sample sizes under 10 (except for mechanistically unique pilot data), or reported outcomes irrelevant to the defined aging hallmarks.

The most robust finding was that heavy resistance training combined with whey protein supplementation was the only intervention in a 208-participant RCT that simultaneously preserved muscle mass and increased strength in older adults. Protein and collagen supplementation alone showed more modest effects on musculoskeletal outcomes. The probiotic Weizmannia coagulans BC30 added to plant protein improved postprandial amino acid appearance in blood, suggesting enhanced digestibility. Multi-strain probiotics (~10⁹ CFU/day for 4–12 weeks) showed preliminary support for immune function and gut microbiota composition, though results were highly strain-, duration-, and population-specific.

GlyNAC (glycine + N-acetylcysteine) emerged as one of the most compelling mitochondrial-targeted interventions, with 16–24 week supplementation in older adults improving glutathione levels, mitochondrial efficiency, oxidative stress markers, inflammation, endothelial function, gait speed, grip strength, cognition, and body composition. These findings are rated moderate given their origin in smaller pilot trials. NMN (250 mg/day for 10 weeks) improved muscle insulin signaling and insulin sensitivity in postmenopausal women with prediabetes. Resveratrol (150 mg/day for 30 days) reduced liver fat, triglycerides, glucose, and inflammatory markers in obese males, also rated moderate. Several compounds including NR, MitoQ, and standalone NMN in healthy aging cohorts were excluded due to inconsistent or insufficiently aging-specific evidence.

The review's authors emphasize that no single supplement is sufficient and advocate for personalized, integrative strategies combining targeted supplementation with resistance exercise and balanced nutrition. Key caveats include high heterogeneity across study designs, supplement formulations, dosing protocols, and population characteristics, limiting generalizability. The authors call for future research to standardize dosing, investigate synergistic nutrient combinations, and evaluate long-term safety and efficacy across diverse older populations.