Anyone even remotely familiar with cannabis use and its potential to cause the “munchies” would immediately assume that regular cannabis use would likely promote weight gain and, in consequence, the risk forf type 2 diabetes.
Thus, readers may well be as intrigued as I am by the work of Gerard Ngueta and colleagues from Québec, Canada, published in OBESITY, showing a rather strong inverse association between cannabis use and BMI in the Inuit.
The researchers analyzed data from 786 Inuit adults from the Nunavik Inuit Health Survey (2004), which included self-reported use of cannabis as well as measured levels of fasting blood glucose and insulin.
Not only was cannabis use highly prevalent in the study population (57%), but even after adjustment for a number of potential confounders, cannabis use was significantly associated with lower body mass index (BMI) (about 2 BMI points, P < 0.001), lower % fat mass (P < 0.001), lower fasting insulin (P = 0.04), and lower HOMA-IR (P = 0.01).
In multivariate analysis, past-year cannabis use was associated with 0.56 lower likelihood of obesity (95% confidence interval 0.37-0.84), and it was this relationship that fully explained the seemingly positive effect of cannabis use on insulin resistance (as a surrogate for diabetes risk).
It may also be worth noting that the association of cannabis use with lower BMI was only seen in past or non-smokers, but not in current tobacco smokers.
Now normally, being highly sceptical of these types of association studies, which are generally hopelessly confounded and can never prove causality, I would have dismissed this as a chance finding of little significance.
Imagine my surprise, however, when the authors go on to mention several previous studies, in a variety of populations, that have reported similar findings.
Unfortunately, the authors have little to offer in terms of a plausible biological mechanism and can only speculate on possible genetic or functional factors involving the cannabinoid system or putative effects on energy expenditure associated with the pulmonary consequences of smoking.
Thus, I can presently make little of this finding – but I will likely stay tuned.
Following a rather relaxed August, which included meeting my new grand daughter and turning my attention to jazz guitar, I spent the last week in Australia speaking at the Australian Diabetes and Diabetes Educator conference in Adelaide and visiting colleagues at the Melbourne Baker Institute and Sydney University’s Charles Perkins Centre.
Clearly, Australia has an obesity problem that easily rivals that of most “western” countries, with no real solutions in sight (as in most “western” countries).
As virtually everywhere else, much government talk (and millions of dollars) focusses on prevention, while access to obesity management within the healthcare system (public or private) remains as sparse and unfunded as everywhere else.
Whilst other countries are gradually grappling with the idea that obesity, once established, must be considered a chronic disease (and thus requires the same approach to management as any other chronic disease), it appears that government and professional agencies in Australia are particularly resistant to accepting this reality.
This is especially surprising, as some of the best and strongest evidence for the chronicity of obesity and the complex biological responses that occur to defend against weight loss and virtually guarantee weight regain (including studies published in the New England Journal of Medicine and the Lancet), come from my colleague Joe Proietto’s group Down Under.
I guess the fact that even the best science rarely translates into effective policies is not just a problem in Canada.
Yesterday, the Health Quality Council of Alberta, released a report called Overweight and obesity in adult Albertans: a role for primary healthcare, which provides an in-depth analysis of the prevalence, burden, and rates of use of a number of key healthcare services for overweight and obese individuals in Alberta. The report also provides a strong rationale for the role of primary healthcare in weight management for adult Albertans living with overweight and obesity.
In 2014, the HQCA conducted a survey of adult Albertans about their use and satisfaction with healthcare services. As part of this survey, self-reported height and weight were collected from individuals in order to calculate their body mass index. According to these findings, nearly six out of 10 Albertans over the age of 18 were either overweight or obese. The estimated provincial prevalence of adults with overweight and obesity was 35.2 per cent and 23.9 per cent, respectively. In addition, obesity was associated with an increased risk of multiple comorbidities, greater use of healthcare system services, and a lower self-rated individual quality of life.
Managing overweight and obese populations, as well as comorbid conditions, falls predominantly on primary healthcare providers. Evidence shows that diverse strategies for the management of overweight and obesity within primary healthcare are associated with benefits in weight management; however, the most effective mix of providers, interventions, and duration requires further evaluation. Moving forward, Alberta may benefit from working towards a more unified strategy for weight management that includes opportunities to engage Albertans in discussions about weight management, and to increase the use of team-based care across all weight categories.
The full report is available here.
A fact sheet is available here.
But just how much evidence is there that any of this is actually beneficial to your health (i.e. if you are not a mouse).
This question was addressed by Benjamin Horne and colleagues from Salt Lake City, Utah, in a paper published in the American Journal of Clinical Nutrition.
The researchers review the evidence on various forms of fasting from the published literature, which consists of a grand total of three randomised controlled trials, together involving about 100 participants, with durations ranging between 2 days to 12 weeks.
Although all three trials reported some benefits in terms of body weight, cholesterol and other surrogate markers, the authors failed to find any study that looked at actual clinical endpoints (e.g., diabetes or coronary artery disease].
To be fair the authors did find two observational studies in humans (both involving the first author of this study), where fasting was associated with a lower prevalence of heart disease or diabetes but, as readers should be well aware, these types of studies cannot prove causality.
I guess it would be fair to say that the popular enthusiasm about the health benefits of various forms of fasting, as far as their benefits for humans are considered, appear largely based on hope and hype – at least as far as clinically meaningful outcomes are concerned.
This is not to say that fasting, whether alternative day or otherwise, may not well have some medical benefits – fact is, we just don’t know.
Or rather, as the authors put it,
“whether fasting actually causes improvements in metabolic health, cognitive performance, and cardiovascular outcomes over the long term; how much fasting is actually beneficial; and where the threshold of hormesis resides (i.e., a balance between long-term benefit from fasting compared with harm from insufficient caloric intake) remain open questions….considerable additional clinical research of fasting is required before contemplating changes to dietary guidelines or practice.”
According to a study conducted by a team of researchers from the US, Canada, Australia and Iceland, published in Pediatric Obesity, weight-based bullying in children and youth is the most prevalent form of youth bullying in these countries, exceeding by a substantial margin other forms of bullying including race/ethnicity, sexual orientation or religion.
According to the almost 3000 participants in this study, parents, teachers and health professionals were seen as those with the greatest potential of reducing weight-based bullying.
In addition, the majority of participants (65-87%) supported government augmentation of anti-bullying laws to include prohibiting weight-based bullying.
While these findings may not strike anyone living with obesity as surprising, they should be a reminder to the rest of us that weight-based bullying, with all of its negative consequences for mental, physical and social health, is something to be taken very seriously and needs to be opposed as much as we would oppose any other forms of bullying.