Chronic Cannabis Users Had Shorter Telomeres, Suggesting Accelerated Biological Aging

Chronic THC users (ages 30-65) had significantly shorter leukocyte telomere length than age-matched controls, suggesting cannabis addiction may accelerate cellular aging.

Hassan, S et al.·La Clinica terapeutica·2025·Preliminary Evidenceobservational-study
RTHC-06644Observational StudyPreliminary Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
observational-study
Evidence
Preliminary Evidence
Sample
N=60

What This Study Found

Among 30 chronic THC users and 30 age-matched controls (ages 30-65), cannabis users had significantly shorter leukocyte telomere length (LTL) (t(58)=-4.25, p<0.001). Interestingly, there was no significant correlation between age and LTL within either group, which the authors suggest may indicate that cannabis use exerts an effect on cellular aging independent of chronological age.

Key Numbers

60 participants (30 per group); ages 30-65; significantly shorter LTL in cannabis users (p<0.001); no age-LTL correlation in either group; THC levels significantly different between groups (p<0.0001)

How They Did This

Case-control study of 60 individuals (30 chronic THC users, 30 healthy controls) aged 30-65. Leukocyte DNA isolated from blood samples; telomere length assessed by quantitative PCR. THC metabolites confirmed by enzyme immunoassay. Lab personnel blinded to group allocation.

Why This Research Matters

Telomere length is a biomarker of biological aging and has been linked to age-related diseases and mortality. If chronic cannabis use accelerates telomere shortening, this adds a new dimension to the long-term health consequences of heavy cannabis use.

The Bigger Picture

Telomere shortening has been associated with other substance use disorders (tobacco, alcohol) as well as chronic stress and inflammation. Cannabis may accelerate aging through similar oxidative stress or inflammatory pathways.

What This Study Doesn't Tell Us

Small sample size. Cross-sectional design cannot determine if shorter telomeres preceded or followed cannabis use. Cannot control for all confounders (diet, exercise, stress, other substances). Single timepoint measurement. The absence of an age-LTL correlation within groups is unusual and may reflect small sample rather than a true biological finding.

Questions This Raises

  • ?Would cannabis cessation allow telomere recovery?
  • ?Is the telomere shortening mediated by THC-specific oxidative stress or by the chronic stress of addiction?

Trust & Context

Key Stat:
Evidence Grade:
Preliminary: small case-control study with appropriate blinding but limited control for confounders and cross-sectional design.
Study Age:
2025 publication
Original Title:
Assessment of leukocyte telomere length as a cellular aging marker through a quantitative PCR-based technique in individuals with a chronic addiction to the psychoactive drug delta-9-tetrahydrocannabinol. (Case control study).
Published In:
La Clinica terapeutica, 176(6), 789-795 (2025)
Database ID:
RTHC-06644

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

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Cite This Study

RTHC-06644·https://rethinkthc.com/research/RTHC-06644

APA

Hassan, S; Mehanna, Mohamed; Alwaseef, Mohammad AbdElhameed; Metwally, M; Abdelmonem, M; Alzarea, E; Gandor, N; Abd Elwahab, M; Abd Elwahab, M; Gouda, Ahmed Salah; Saadeldain, A; Sajanlal, R; Elsherbiny, A; Zeid, M; Akef, A; Ahmed, H; Rezk, A; Hashish, A; Assem, A; Hegazy, H; Omar, A; Ibrahim, D; Gomaa, K. (2025). Assessment of leukocyte telomere length as a cellular aging marker through a quantitative PCR-based technique in individuals with a chronic addiction to the psychoactive drug delta-9-tetrahydrocannabinol. (Case control study).. La Clinica terapeutica, 176(6), 789-795. https://doi.org/10.7417/CT.2025.5299

MLA

Hassan, S, et al. "Assessment of leukocyte telomere length as a cellular aging marker through a quantitative PCR-based technique in individuals with a chronic addiction to the psychoactive drug delta-9-tetrahydrocannabinol. (Case control study).." La Clinica terapeutica, 2025. https://doi.org/10.7417/CT.2025.5299

RethinkTHC

RethinkTHC Research Database. "Assessment of leukocyte telomere length as a cellular aging ..." RTHC-06644. Retrieved from https://rethinkthc.com/research/hassan-2025-assessment-of-leukocyte-telomere

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.