Sunday Science Marijuana and Longevity and Cancer 2026_08_23

https://youtu.be/keLg5tXPr6c

Welcome to Sunday Science, where we dive into a few recent scientific articles and their translation into our modern lives. Here is your host, Brent W. Laartz, M.D. Alright everyone, welcome to another Sunday Science expedition here as we launch on a discovery about marijuana and longevity and cancer. Here we are in Colorado, the land of marijuana, right? So I thought we've had a lot of questions about marijuana and longevity. So we're going to dive into this. We have a lot of different articles to discuss here. So we're going to get started right away. Marijuana in 2021. in the age group of 15 to 29 years of age, had approximately 35% prevalence of smoking in the past year.And at 26 plus age group, 17%. 13 to 14 years of age, about 8%.

15 to 16%. 15 to 16 years of age, 19%. And 17 to 18 years of age, which would be a senior in high school, 30% usage rate in the past year. There are a lot, and I'm going over a lot of data about adverse effects about marijuana. However, there are some data out there for the neuroprotective. and anti-inflammatory benefits, and anti-nausea benefits, and actually potentially treatment during cancer of it actually improving outcomes during cancer. But this is mainly talking about any potential adverse effects in longevity, cancer, etc. So let's delve right into the cancerSo there is an increased incidence, according to this article by Rebecca Johnson et al. This is in Academia Oncology. And what they did in this article was to show that there was an increased incidence in states with legalized marijuana between 2000 and 2019.

So basically, they took the incidence rates in the year 2000 through 2019, and it increased in those states where it was legalized, and it actually decreased or stayed the same in those states where it was not legalized. And in Canada, and this is talking about a 26% increase in breast cancer and a... 24% increase in testicular cancer in younger persons, okay? This is from age 20 to 34 in breast cancer and age 15 to 39 in testicular cancer.An even greater effect has been shown in Canada where marijuana has been legal for decades now. and 35% increase in breast cancer, and an 83% increase in testicular cancer during that time frame. All right, so let's just show, I can show you a couple of little graphs here. Let's share

All right. So all the time we have here, we have our let's share that a little bit here. This is basically showing the annual incidence and how it has increased between the years 2000 and 2020, right along with the increasing legalization by states. And here again. Also showing the increasing testicular cancer and breast cancer rate right along with the number of jurisdictions increasing their legalization.All right, so we're going to unshare momentarily because this slide that we have here is not.

That's for the next article that we're going to talk about. Okay, so next article we're going to discuss is Wang et al.'s article.

Actually, there's another article by Nargis and also basically the same kind of issues. They show that there are maybe some increased risks of other types of cancer as well. Lung, squamous cell carcinoma, and head and neck carcinoma, oral, breast, liver, cervical, laryngeal, pancreatic, and thyroid. All right, but let's go on to the next article first.

All right, so this Wang article is using Mendelian randomization, which basically takes the genetic code of cancers and brings about a causality for each of those cancers by showing that there are single nucleotide. polymorphisms that are specifically associated with that cause and showing that there is strong evidence of causal relationship for cannabis use on cervical cancer and laryngeal cancer and breast cancer all right so these are um there's not a lot of graphic anything to show here for this article but basically this article uses genetic randomization to show about that causality. The next article that we have is by Song et al and they did a meta-analysis. Showing that there's an odds ratio of 1.71 for marijuana use and testicular cancer.So if you smoke marijuana and current use that you have. 1.7 times more likelihood of having testicular cancer and if you smoke cigarettes tobacco use is an odds ratio of 1.18 okay so again a meta-analysis and i think they had um approximately let's pull up the full

article there. And they had, I think, 23 studies that showed that causality and odds ratio, at least the association between those. Okay. Next, let's go to biological aging. So we at all used both the PhenoAge and the Plumera-Dolby Biological Age, which were blood tests associating the use of marijuana and aging. Okay, so this took current versus never smoked marijuana and took the NHANES databases and they had 12,000.Persons in the database, 14% were users, and it increased during that time frame, 2005 to 2018, from 12% to 18%. And the pheno age basically added age of 0.49 years versus if you were a never user. subtracted 0.22 years during that time frame. So accelerated aging, where instead of, let's say you started out right at 2005, 2018, instead of aging 13 years, you age 13 and a half years versus subtracted 0.

22 age. According to the KDB, aging it was plus 0.21 versus minus 0.16 and it's additive if also you use tobacco and that and they also checked metal levels in this and suggesting that becausemarijuana also has cadmium and heavy metals in some samples of marijuana and it's actually a great amount potentially apparently they tested all of the heavy metals in those users that they had blood tests for And cadmium mediated about 15% and 8% of the effects of those phenol age increase. Okay, so the next article by the same author essentially did a little bit different because we have over the last five to 10 years developed this blood test called alpha-clotho, which is associated with increased aging. They checked the levels of alpha-clotho in these patients in the NHANES database.

Again, 13,000 in this database, 2007 to 2016, these were 45 to 59 years of age. So in the middle-aged persons.They had 6,600 who had both complete alpha-clotho test and substance use questionnaires and show the decreased levels of alpha-clotho in current use of marijuana and a trend in ever users versus never users. Okay, so and it was independent of tobacco use. There was a negative beta coefficient, and it was logarithmic. So basically, a 10% decrease in alpha-clotho in those patients who were current users of marijuana versus those who had never used, okay? Another study. by Hernandez and Cortero took epigenetic clocks. These are basically looking at DNA methylation in 93 persons between 51 and 56 years of age.

They showed that there was an increased methylation and a significant difference from never versus to both former and current users of marijuana for every unit. of joint year smoke, there was a plus 0.92 year increase in the DNA age. So that's the methylation. So that's, so if you smoked one joint per day per year, so if you smoke for 20 years, that's 20. So Potentially, you would age at least two years more if you smoked one joint per year for 20 years. Cigarette smoking, there was eight years difference. Marijuana, 4.1. years difference. So a little bit less for marijuana versus smoking in that time frame. Okay.The next study, we'll get to more about the hormones because of the potential use of... Oh, one more article by... This is by...

This is another article on epigenetic risk, showing that there was DNA methylation increase. And this is... This is the Hernandez and Cortero article, and the chronicle, and so they were basically this DNA, M-age skin blood was trained solely on chronological age.

One more thing here, they did also try to adjust for FEV1 over FVC, which is a lung function, and there was no, basically, association or quantification over that. And we do have this share here, where we can share this.

this is just showing the never former and current use and showing that overall p test p less than 0.01 comparing the dna age of a current smoker versus a never smoker again in the dna mfino age showing the significant difference there. Okay. So, all right. So let's get to the next article. This is we, let's go to some of the hormonal differences. And this could be one of the reasons why testicular and breast cancer are such a big deal here is because of this.

I have so many articles here that it's hard to keep track of them. There's like 12, I think 14 articles we're talking about today. Okay, so this article is by Meyer et al.And this article suggested that there is an increase in aging and polysubstance use. And so this took the DNA age and the phenotype age, but also did some other types of biological age based on their financial preparedness, their health preparedness. Suggested that if you were a lifelong non-user versus tobacco versus ethanol versus a midlife recreational user versus quitters, the composite age was plus 0.7. There was a significant decrease in brain age. a slower gait, older facial age, there was less health preparedness, financial preparedness, and social preparedness, and it was worse than long-term ethanol use. And after adjusting for tobacco, ethanol, and other illicit drugs, the effect was actually greater for marijuana use than any of these combined. All right.So again, this is kind of a lifetime users. And so could be something. different from somebody who was a user in older age. And again, this is talking about people who are lifetime users and not necessarily regarding those people who used for a particular reason, a short-term reason in, let's say, the treatment of cancer.

All right, so this article by Texera, let's go through this article about, they took 316 infertile men and they tested their testosterone, their steroid hormone binding globulin, prolactin, and their estradiol and assessed what that showed in these infertile men whether they smoked marijuana or not. And marijuana usage had no effect on testosterone or testis volume or semen parameters. However, it did have a positive effect on estradiol and aromatizing. And so therefore, your estradiol, your beta, was I had a beta coefficient of negative 11.1. So essentially for every unit increase in marijuana, you decreased your estradiol by 11.1, which is actually a very significant amount. And it increased the prolactin levels and hence why there are some behavioral and or other issues with marijuana. It elevated the steroid hormone binding.

globulin and the testosterone over estradiol was also increased. So increased potential testosterone versus estradiol. Obviously, if you decrease your estradiol, you're going to increase that ratio and therefore have an abnormal ratio, which would affect potential fertility, et cetera. All right. So let's go on to this was a Swiss test. This was a Swiss study by Galmish and at all, they used liquid chromatography and they just had 47 persons who were non versus current users, and they included in that chronic versus occasional, and there was increased androgen levels in those persons who had a current use of marijuana. All right, so that's in the GALMISH study.

There is a study by Lowe et al. that just had some review on the impact of cannabinoids on pregnancy and reproductive health and outspring outcomes. And they basically just showed that there was a an impact on male and female fertility, and it has been associated with altered reproductive hormones, menstrual cyclicity, semen parameters, and erectile dysfunction, abnormal spermatogenesis, and testicular atrophy. It does cross the placenta. And has been detected in breast milk and has been shown to have some effect on gestational age. term birth, fetal neurodevelopmental consequences and imperatives, offspring, social, behavioral, and cognitive development. So there is some evidence for that. While it's not robust, there is some evidence for that. Okay. So let's go through, let's get off the... Hormone health and let's get to lifespan again here.

This is an article by Nain. It's actually more of a review, but the article by Nain is a review and it showed basically some increased lifespan with CBD oil for. some worm and Drosophila, which is the fruit fly, and it promotes autophagy in those species potentially. And that is completely different from what we've been talking about. This is in a lab and a test tube and animal studies. So there is a review on animal studies by Nain et al. And that is included in our bibliography here of what we have been going through here. So again, okay, let's talk about brain health. Thayer has one study here showing basically no difference in older adult users versus non-users in cognition or brain volume. So these are people potentially who had used less number of years.

They were approximately 66 to 69 years of age. They did have 23 years of regular cannabis use on average. So they did have potentially at least a certain amount of use. but there was, did show greater regional volume of the left putamen and lingual cortex. And, but in general, there was no significant difference between groups in brief computational cognitive battery, et cetera. That differed a little bit from actually the same articles With Stypolsky and Thayer showing that long-term recreational cannabis use was associated with lower executive function and processing speed in a pilot sample of older adults. And these were persons who had a lot of more use, basically. And they were 60 and older, but they were primarily recreational users, and they had a lot more long-term use.

Greater than 19 years was at least half of the users. Non-users scored significantly higher than long-term users in executive function. short-term users scored significantly higher than long-term users in executive function, processing speed, and general cognition. So potentially this would be a pilot sample of basically showing that, you know, if you are 60-something years of age and you're using it for a specific reason, which there are a lot of specific reasons, reasons why at an older age you might use these substances. Additionally, a greater recent cannabis use frequency was negatively associated with work. memory in this study, okay? All right, so really let's go over the good. Obviously, cancer treatments, there is potential inhibition of cancer cells and apoptosis that has been shown in test tubes, and there is anti-inflammatory effects that can be found for potentially

issues and then also anti-anxiety that might be a benefit to certain people for treatment okay so let's not gloss over this really significant increase in the good of marijuana use and cbd use thc use in these patients potentially for cancer treatments again there is increased and improved outcomes in cancer with marijuana use and there is also improved outcomes because of the increase in the quality of life measures during treatment of cancer, for example, chemotherapy, immune therapy, or radiation therapy, which is significant. And I cannot really gloss over that less by mentioning it so many times. And again, Could it be that there is some confounding in any of these studies because the underlying reason for the medical use or recreational use, or if it's an unregulated recreational use, there might be other combined substances in the marijuana.

And some of those substances could be illicit substances. Some of them could be pesticides, herbicides, fungicides. And some other medications prescribed concomitantly could be at play. So let's say somebody is on it for nausea and they're taking it because they need it for nausea or anxiety. They could be on some other medications, which could be different from other persons, which might not have been assessed and confounded in these. Okay, so since we know there is sex hormone abnormality with cannabis, it would stand to reason that potentially there would be maybe an increase and or causality of these substances, THC and cannabinoids with testicular and breast cancer, since those are hormone sensitive cancers. dosage, duration, and reason for use. Younger use may be associated with other psychiatric issues and or other issues and behavioral issues.

issues as to why those people might have less either brain health or less longevity. All right, so again, that's Sunday Science. I guess it is relatively quick here. I thought it was going to take me longer than this to go through all these. I really did whiz through all of these without a lot of detail on them.But again, This is a sensitive issue. There are, you're either on one side or the other. And it is, if people, I remember talking to somebody. who absolutely said that there is no harm in some of these, let's say, synthetic marijuana compounds, which we know medically as physicians, because we see it every day in the emergency room of psychosis being found from synthetic.

cannabinoids that are stronger hundreds of times stronger sometimes than some of the compounds that we just get naturally from let's say marijuana use okay so There are people who just, you know, are blindly thinking that there is no health consequences to even some of the compounds that we see every day in the ER. So, and again, some people are on the other side, and obviously we have also dealt with. a major amount of misinformation from the other side saying that marijuana is 100% bad, you know, the reefer madness, etc. So let's all think about this on a scientific basis. Look at these articles. I encourage everyone to look at through these articles. Again, everything is in the show notes. all of these articles are there, some links that you can take to look at some of these articles yourself. Look at it and study it and decide for yourself what is beneficial. It is somewhat beneficial in certain studies. And again, We'll see you on next Sunday. Love that you're here with me. I love that we are getting to the bottom of everything. And we'll see you very soon.

This site and any information communicated within it are not intended as medical advice. The information herein is not intended as medical care, diagnosis, or treatment of any medical condition. No component of this content, including discussion or comments, shall be construed or implied as establishing a doctor-patient relationship. Before you translate or copy any of the information, diet, exercise, or products utilized herein or on any social media post to your own practice, consult your own research, physician, therapist, or nutritionist for your own health. No warranties or claims are made as to the benefits or risks of any treatments, diet, exercise, or products herein. Research any treatments, diet, exercise, or products thoroughly before trying for yourself. Referral, affiliate, or advertising fees may be garnered by this site.

Johnson, Rebecca H., et al. “Emerging Evidence Links Cannabis Use to Increased Risk of Breast and Testicular Cancer in Young Americans.” Academia Oncology, vol. 2, no. 2, Academia.edu Journals, 2025, doi:10.20935/AcadOnco7758.

Nargis N, Westmaas J, Orr E et al.Cancer risk and legalisation of access to cannabis in the USA: overview of the evidence.  The Lancet Public Health, 2024; 10, e160-e164.

https://www.cancer.org/cancer/supportive-care/integrative-medicine/cannabis.html

Huang, P., Zhang, P. F., & Li, Q. (2023). Causal relationship between cannabis use and cancer: a genetically informed perspective. Journal of Cancer Research and Clinical Oncology, 149(11), 8631–8638. https://doi.org/10.1007/s00432-023-04807-x 

Song, A., Myung, N. K., Bogumil, D., Ihenacho, U., Burg, M. L., & Cortessis, V. K. (2020). Incident testicular cancer in relation to using marijuana and smoking tobacco: A systematic review and meta-analysis of epidemiologic studies. Urologic Oncology: Seminars and Original Investigations, 38(7), 642.e1–642.e9. https://doi.org/10.1016/j.urolonc.2020.03.013 

Nain S, Singh N, Schlag AK, Barnes M. The impact of cannabis use on ageing and longevity: a systematic review of research insights. J Cannabis Res. 2025 Jul 29;7(1):52. doi: 10.1186/s42238-025-00267-x. PMID: 40731362; PMCID: PMC12309070. 

Wei K, Chen X. Current marijuana use is cross-sectionally associated with accelerated biological aging among U.S. adults: exploring mediating effect of blood cadmium. J Nutr Health Aging. 2026 Mar;30(3):100778. doi: 10.1016/j.jnha.2026.100778. Epub 2026 Jan 14. PMID: 41538955; PMCID: PMC12835599. 

Wei K, Chen X. Current marijuana use is associated with lower circulating α-Klotho levels in US adults even after adjusting for tobacco use: A national cross-sectional analysis of NHANES. Tobacco Induced Diseases. 2025;23(July):104. doi:10.18332/tid/208001. 

Meier M, Caspi A, Ambler A et al. Preparedness for healthy ageing and polysubstance use in long-term cannabis users: a population-representative longitudinal study. The Lancet Healthy Longevity, 3, e703-e714

Hernandez Cordero, Ana I. et al. Cannabis smoking is associated with advanced epigenetic age. Eur Respir JVol 63(5).  2024/05/02

Teixeira TA, Iori I, Andrade G, Saldiva PHN, Drevet JR, Costa EMF, Hallak J. Marijuana Is Associated With a Hormonal Imbalance Among Several Habits Related to Male Infertility: A Retrospective Study. Front Reprod Health. 2022 Feb 17;4:820451. doi: 10.3389/frph.2022.820451. PMID: 36303626; PMCID: PMC9580681.

 Galmiche, M., Meister, I., Zufferey, F. et al. Cannabis consumption is associated with altered steroid metabolism in young men. Commun Med 6, 224 (2026). https://doi.org/10.1038/s43856-026-01469-x 

Lo JO, Hedges JC, Girardi G. Impact of cannabinoids on pregnancy, reproductive health, and offspring outcomes. Am J Obstet Gynecol. 2022 Oct;227(4):571-581. doi: 10.1016/j.ajog.2022.05.056. Epub 2022 May 31. PMID: 35662548; PMCID: PMC9530020. 

Reece AS, Hulse GK. Epigenomic and Other Evidence for Cannabis-Induced Aging Contextualized in a Synthetic Epidemiologic Overview of Cannabinoid-Related Teratogenesis and Cannabinoid-Related Carcinogenesis. Int J Environ Res Public Health. 2022 Dec 13;19(24):16721. doi: 10.3390/ijerph192416721. PMID: 36554603; PMCID: PMC9778714. 

Rachel E. Thayer, Sophie L. YorkWilliams, Kent E. Hutchison, Angela D. Bryan. Preliminary results from a pilot study examining brain structure in older adult cannabis users and nonusers, Psychiatry Research: Neuroimaging, Volume 285, 2019, 58-63, ISSN 0925-4927, https://doi.org/10.1016/j.pscychresns.2019.02.001.

Stypulkowski K, Thayer RE. Long-Term Recreational Cannabis Use Is Associated With Lower Executive Function and Processing Speed in a Pilot Sample of Older Adults. J Geriatr Psychiatry Neurol. 2022 Sep;35(5):740-746. doi: 10.1177/08919887211049130. Epub 2021 Sep 28. PMID: 34583547; PMCID: PMC8958184.