These two topics are often presented together, but the evidence behind them is very different. The metabolic side has a real human association that nobody can yet explain. The bone side has an appealing preclinical story, and the most-cited human study points the other way. This article separates them.
Nothing here is medical advice or a reason to change diabetes treatment. Type 1 diabetes requires insulin, always, and nothing in this article changes that. In Thailand cannabis flower is a controlled herb dispensed only on prescription form PT 33.
1. The Metabolic Finding
Penner EA, Buettner H, Mittleman MA. The American Journal of Medicine 2013;126:583-589. The authors analysed United States National Health and Nutrition Examination Survey (NHANES) data from 2005–2010: 4,657 participants: 579 current cannabis users, 1,975 former users and 2,103 never-users.
Compared with people who had never used cannabis, current users showed:
- 16% lower fasting insulin
- About 17% lower insulin resistance (HOMA-IR)
- Higher HDL cholesterol
- Smaller waist circumference
According to the authors, these associations stayed similar and statistically significant after participants with diagnosed diabetes were excluded.
The finding is real and often cited. It also fits separate epidemiological reports of lower obesity rates among cannabis users in large national surveys.
And nobody knows why. Earlier survey work had already noted a paradox: users report eating more calories, yet they tend to have a lower body mass index. Penner, Mittleman and colleagues do not claim a mechanism. In an accompanying editorial, the journal’s editor-in-chief, Joseph S. Alpert, called the findings remarkable and argued that much more basic and clinical research is needed before drawing conclusions.
What it is not. It comes from cross-sectional survey data, with self-reported exposure, no randomisation and no follow-up. It shows an association, not which way causation runs, and there are obvious alternative explanations: differences in age, activity, diet and who uses cannabis in the first place. No trial has shown that cannabis improves metabolic outcomes enough to justify clinical use, and no cannabinoid is currently licensed for any metabolic indication.
Other popular claims, and how to read them. Popular sources claim that cannabis stabilises blood sugar, reduces arterial inflammation in diabetics, prevents nerve inflammation, reduces neuropathic pain, acts as an antispasmodic, and lowers blood pressure through vasodilation. The neuropathic pain claim has the best support: diabetic neuropathy is a recognised neuropathic pain syndrome, and it fits the broader evidence on cannabinoids and neuropathic pain. The other claims are mechanistic assertions with no human outcome data behind them. The blood pressure claim in particular should be weighed against the human cardiovascular evidence, which points in an unfavourable direction.
Type 1 diabetes specifically is an autoimmune destruction of insulin-producing cells. Nothing above addresses that, and no cannabinoid replaces insulin.
2. The Bone Claim
The usual bone story rests mainly on mouse studies:
- Ofek et al., PNAS, 2006: mice lacking the CB2 receptor lost trabecular bone faster with age. A CB2-selective agonist, which is not psychoactive, reduced bone loss after ovariectomy. The authors concluded that CB2 signalling helps maintain normal bone mass.
- Idris et al., Cell Metabolism, 2009: mice lacking the CB1 receptor had higher peak bone mass but developed age-related osteoporosis, with reduced bone formation and fat cells building up in the marrow.
Some accounts go further and say that maintaining bone is “the main role” of CB2, or that cannabis itself prevents marrow fat build-up. Those stronger statements are not what these papers show.
The receptor biology is genuine. CB1 and CB2 receptors, along with the endocannabinoids anandamide and 2-AG, are present in bone and appear to be involved in regulating bone formation and remodelling.
The experimental evidence is entirely preclinical. The knockout and agonist findings come from mice. There is no human trial of any cannabinoid for osteoporosis, and no cannabinoid is licensed or recommended for bone health anywhere.
3. The Human Bone Data: The Most-Cited Study Points the Other Way
This part changes the picture, and it is rarely quoted in promotional accounts.
Sophocleous A, Robertson R, Ferreira NB, McKenzie J, Fraser WD, Ralston SH. The American Journal of Medicine 2017;130(2):214-221 (published online 2016; University of Edinburgh). This is the most-cited human study on the question. It used DEXA scanning to compare 170 regular cannabis smokers with 114 cigarette smokers who did not use cannabis. The figure of 170 comes from the university’s press release; the published paper reports 144 heavy and 56 moderate users. Heavy use was defined as 5,000 or more lifetime occasions. The average heavy user reported more than 47,000 occasions, while moderate users averaged around 1,000.
Findings:
- Bone mineral density in heavy cannabis users was about 5% lower than in the 114 cigarette smokers who did not use cannabis (the university’s figure; the paper reports lower hip and spine Z-scores).
- Fractures were more frequent among heavy users than among the cigarette smokers who did not use cannabis (fracture rate ratio 2.17, 95% CI 1.59–2.95).
- Moderate users showed no difference from the cigarette smokers who did not use cannabis.
- Heavy users had lower body weight and lower BMI than the cigarette smokers who did not use cannabis. Low BMI is itself an independent risk factor for low bone density, and this fits the metabolic association in section 1. The authors’ analysis suggested that the effect on spine density worked partly through low BMI.
Limits: both groups smoked tobacco, so tobacco cannot explain the difference, but it may interact with cannabis smoke, and heavy users more often used other illicit drugs. The design is cross-sectional, cannabis exposure was self-reported, and the sample was small.
The lead researcher, Professor Stuart Ralston, said that for heavy users there is “a real concern that this may put them at increased risk of developing osteoporosis and fractures later in life.”
Other population studies have given mixed results. For example, an analysis of US NHANES 2007–2010 data on 4,743 adults aged 20–59 (Bourne D, Plinke W, Hooker ER, Nielson CM. Archives of Osteoporosis 2017;12:29) found no association between cannabis use and bone density at any level of use.
4. How to Hold Both
The receptor biology and the outcome data are not necessarily in conflict, and the most likely way to reconcile them is instructive.
CB2 signalling may well be involved in maintaining bone balance; that is the preclinical finding. But chronic exposure to cannabinoids from outside the body is not the same intervention as the body’s own endocannabinoid signalling. It may do the opposite of what the receptor’s normal role suggests: through receptor downregulation, through the low body weight that accompanies heavy use, or through mechanisms not yet identified.
The underlying error is a common one: assuming that because the body uses a signalling system, supplying a plant analogue of it at arbitrary doses must be beneficial. The fact that the body’s own system is involved in a process tells you the system matters. It does not tell you which direction an external drug will push it.
The dose threshold matters too. In the Edinburgh study, moderate users showed no bone effect. The finding is specifically about very heavy, long-term use (5,000-plus lifetime occasions), which is not the exposure of a patient on a prescribed regimen. That is a genuine limit on how far the finding applies, and it should be stated rather than dropped.
5. Summary
| Claim | Human evidence | Status |
|---|---|---|
| Lower fasting insulin, lower insulin resistance, higher HDL, smaller waist | Cross-sectional NHANES survey, 4,657 participants (Penner et al. 2013) | Real association, mechanism unknown, causation not established, no trial |
| Reduced diabetic neuropathic pain | Consistent with the broader neuropathic pain evidence | Plausible |
| Stabilises blood sugar / treats diabetes | None | Unsupported. Type 1 diabetes requires insulin |
| Prevents or treats osteoporosis | None. The most-cited human study shows lower bone density and more fractures in heavy users; a large US survey found no association | Contradicted for heavy use in the most-cited study; evidence mixed; unstudied for therapeutic use |
6. Who Should Care About the Bone Finding
Three groups, and this is the practical takeaway of the article:
Long-term heavy users. Low bone density causes no symptoms until a bone breaks. It is worth mentioning to a doctor rather than discovering at 65.
Older patients, who already have age-related bone loss and who may also have a higher risk of falls from dizziness and orthostatic hypotension. Lower bone density plus more falls is a particularly bad combination, and the two risks are rarely considered together.
Anyone with low body weight, for whom the associations add up.
7. In Thailand
Cannabis flower is a controlled herb under the Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis) B.E. 2568, issued 26 June 2025. It may be dispensed only against a prescription on form PT 33 from an authorised practitioner. Each prescription covers no more than 30 days and is single use (no refills). Diabetes and osteoporosis are not approved or licensed indications for cannabis in any major jurisdiction, and both have effective established treatments.
If you have used cannabis heavily over many years and have ever had a bone density scan, that result is genuinely useful information, and almost nobody posts it. Equally, if you have type 1 or type 2 diabetes and use a cannabinoid on prescription, did anyone check what it did to your glucose readings? The survey association is interesting, but individual monitoring is the only way to know whether it applies to you.
This article is general educational information from the Asiannabis Community. It is not medical advice. Never change insulin or diabetes medication without your doctor.