Plant-derived functional foods for anti-inflammatory activity in the elderly: A systematic review

Background: Aging is associated with “inflammaging”, a state of chronic, low-grade systemic inflammation that contributes to sarcopenia, cognitive decline, and cardiovascular disease. Objective: This systematic review, conducted with reference to PRISMA 2020 guidance, evaluated the evidence on plant-derived functional foods in modulating inflammatory biomarkers and functional outcomes in adults aged 60 years and older. Search Strategy/Methods: PubMed and ScienceDirect were searched for research articles published up to November 2025, supplemented by a search for literature indexed in Scopus and Embase through June 2026, with forward and backward citation tracking. A design-matched risk-of-bias appraisal (Cochrane RoB2 for trials, and Newcastle-Ottawa Scale for cohort and cross-sectional studies) was applied to all included studies, findings were synthesized narratively, and certainty was rated using GRADE principles. The review protocol was not prospectively registered. Primary human studies (randomized controlled trials, cohort, cross-sectional, and other clinical or observational designs) in adults aged ≥60 years that examined plant-derived functional foods, botanical extracts, or plant-based dietary patterns and reported inflammation-related biomarkers or related functional outcomes were included. Reviews, protocols, case reports, editorials, conference abstracts without full data, animal and in vitro studies, and non-English publications were excluded. Results: Fifty-two studies met eligibility criteria, comprising 29 randomized controlled trials, 5 prospective cohort studies, 15 cross-sectional studies, and 3 other designs. Plant-based diets and specific functional extracts, including blueberries, tart cherry juice, and curcumin, were associated with reductions in pro-inflammatory markers such as NF-κB and IL-6 in several trials. Whole-food interventions and traditional dietary patterns were associated with better quality of life and cognitive performance, while isolated carotenoid supplements, resveratrol–curcumin, n-3 fatty acid, and low-anthocyanin interventions showed limited or null effects. Short-duration trials and cross-sectional studies dominate the evidence base, and the certainty of evidence was rated low to moderate. Conclusion: Plant-derived functional foods show promise as adjunctive modulators of inflammation in older adults and may support geriatric nutrition strategies aimed at mitigating inflammaging. Given the heterogeneity of the included studies and the low-to-moderate certainty of the evidence, they should complement, not replace, established medical treatment, and longer, adequately powered trials are needed. Novelty of the Study: This review is among the first to integrate evidence across the musculoskeletal, neuro-inflammatory, and metabolic-vascular domains of inflammaging within a single design-matched risk-of-bias and GRADE-informed certainty framework, restricted to adults aged ≥60 years, while explicitly mapping the age-related bioavailability and adherence barriers that determine whether plant-derived bioactives translate into clinical benefit in older adults. Keywords: Inflammaging; Polyphenols; Gut microbiota; Bioavailability; Geriatric nutrition; Cognitive decline