Chronic THC users (ages 30-65) had significantly shorter leukocyte telomere length than age-matched controls, suggesting cannabis addiction may accelerate cellular aging.
Aging researchers, addiction medicine specialists, cellular biology researchers
What the researchers 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.
Why it 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 numbers in context
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 the study worked
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.
What this study cannot 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.
How to read the evidence
Preliminary: small case-control study with appropriate blinding but limited control for confounders and cross-sectional design.
When this study was published
2025 publication
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.
Questions still open
- Would cannabis cessation allow telomere recovery?
- Is the telomere shortening mediated by THC-specific oxidative stress or by the chronic stress of addiction?
Read the original research
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
Citation
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
Explore the wider topic
- Physical vs Psychological Cannabis Dependence: What Science Actually Shows
- The Gap Between Cannabis Perception and Science: Why What We Believe Outpaces What We Know
- Cannabis Use Disorder: Am I Addicted? Self-Assessment Guide
- Cross-Addiction After Quitting Weed: When One Habit Replaces Another
- Is Weed Addictive? What the Research Actually Shows
- Is Cannabis Addictive? What the DSM-5 and Brain Science Say
- Quitting Weed and Alcohol Together: What to Know About Dual Cessation
- Is Rehab Necessary for Weed? An Honest Assessment
- Signs You May Have Cannabis Use Disorder: An Honest Self-Assessment
- Weed Vape Pen Addiction: Why Vaping Makes It Harder to Quit