Can Education Offset The Genetic Risk For Obesity?
Obesity is a highly heritable condition with considerable penetrance, especially in our obesogenic enviroment. However, as I have pointed out before, having a genetic predisposition for obesity (like having a genetic predisposition for other diseases such as diabetes or high blood pressure) does not mean your fate is chiseled in stone. Lifestyle changes can significantly reduce the risk, but those with a stronger genetic predisposition will have to work a lot harder at not gaining weight than those who are naturally slender. That said, a new study by Liu and colleagues from Harvard University, published in Social Science & Medicine, shows that better education may offset a substantial proportion of the genetic risk for obesity and/or diabetes. The researchers created genetic risk scores for obesity and diabetes based on single nucleotide polymorphism (SNPs) confirmed as genome-wide significant predictors for BMI (29 SNPs) and diabetes risk (39 SNPs) in over 8000 participants in the Health and Retirement Study. Linear regression models with years of schooling indicate that the effect of genetic risk on both HbA1c and BMI was smaller among people with more years of schooling and larger among those with less than a high school (HS) degree compared to HS degree-holders. As one may expect, estimates from the quantile regression models consistently indicated stronger associations for years of schooling and genetic risk scores at the higher end of the outcome distribution, where individuals are at actual risk for diabetes and obesity. In other words, the greater the genetic risk for diabetes or obesity, the greater the positive impact of finishing high-school or college. In contrast, having less than a high-school education augmented the genetic risk for these conditions. From these findings the authors conclude that, “Our findings provide some support for the social trigger model, which speculates that the social environment can attenuate or exacerbate inherent genetic risks. Furthermore, it suggests social stratification may shape how genetic vulnerability is expressed. Social hierarchies based on socioeconomic status determine the health status of individuals. According to fundamental cause theory, policies and interventions must address social factors directly to have a population-level impact on disease risk . Our results show how education, a fundamental cause of health and disease, can serve as a valuable resource that offsets even innate biological risk. Education increases an individual’s ability to adapt, modify, and use surrounding resources. As such, polices that reduce disparities in education may help offset… Read More »
Call For Abstracts: Canadian Obesity Summit, Toronto, April 28-May 2, 2015
Building on the resounding success of Kananaskis, Montreal and Vancouver, the biennial Canadian Obesity Summit is now setting its sights on Toronto. If you have a professional interest in obesity, it’s your #1 destination for learning, sharing and networking with experts from across Canada around the world. In 2015, the Canadian Obesity Network (CON-RCO) and the Canadian Association of Bariatric Physicians and Surgeons (CABPS) are combining resources to hold their scientific meetings under one roof. The 4th Canadian Obesity Summit (#COS2015) will provide the latest information on obesity research, prevention and management to scientists, health care practitioners, policy makers, partner organizations and industry stakeholders working to reduce the social, mental and physical burden of obesity on Canadians. The COS 2015 program will include plenary presentations, original scientific oral and poster presentations, interactive workshops and a large exhibit hall. Most importantly, COS 2015 will provide ample opportunity for networking and knowledge exchange for anyone with a professional interest in this field. Abstract submission is now open – click here Key Dates Notification of abstract review: January 8, 2015 Call for late breaking abstracts open: Jan 12-30, 2015 Notification of late breaking abstracts and handouts and slides due : Feb 27, 2015 Early registration deadline: March 3, 2015 For exhibitor and sponsorship information – click here To join the Canadian Obesity Network – click here I look forward to seeing you in Toronto next year! @DrSharma Montreal, QC
Healthy Obesity: More Questions Than Answers?
Regular readers will be well aware of the evidence that a subset of people living with obesity can be remarkably healthy despite carrying a rather large amount of body fat. This issue of “healthy obesity” was the topic of the 13th Stock Conference of the International Association of the Study of Obesity, the proceeding of which are now published in Obesity Reviews. As the authors note, “The ‘healthy obese’ phenotype was described in the 1980s, but major advancements in its characterization were only made in the past five years. During this time, several new mechanisms that may be involved in health preservation in obesity were proposed through the use of transgenic animal models, use of sophisticated imaging techniques and in vivo measurements of insulin sensitivity. However, the main obstacle in advancing our understanding of the metabolically healthy obese phenotype and its related long-term health risks is the lack of a standardized definition.” The latter is a real problem because finding people with obesity, who are truly metabolically and otherwise healthy becomes harder the higher the BMI gets – this makes the study of this phenomenon rather challenging. Nevertheless, “One of the most consistent characteristics of metabolic health in obesity across studies in humans is reduced liver lipid. This is likely the consequence of increased capacity for storing fat coupled with improved mitochondrial function in adipose tissue and decreased de novo lipogenesis in liver. This can also result in decreased deposition of lipids, including bioactive species, in skeletal muscle. Decreased adipose tissue inflammation with decreased macrophages and a unique T-cell signature with an anti-inflammatory circulating milieu were also suggested to characterize metabolic health in obesity. Anecdotal data support a possible role for healthier lifestyle, including increased level of physical activity and healthier diet. It remains to be established whether a favourable metagenomic signature is a characteristic of metabolic health in obesity.” Finland’s, Dr Kirsi Pietiläinen explained that, “..three energy dissipation pathways, oxidative phosphorylation, fat oxidation and amino acid catabolism showed preserved pathway activities in subjects who are MHO at a level similar to their lean counterparts. In contrast, these pathways were significantly down-regulated in adipose samples from obese twins with metabolic disturbances. Another potential hallmark of metabolic health, a favourable inflammatory profile of the adipose tissue was also observed in the MHO twins. Also, the fat cells of the MHO twins were smaller with evidence of more active differentiation processes within the… Read More »
In Memorium: Albert (Mickey) J Stunkard
As I spend my days at the 9th Canadian Obesity Network’s Summer Bootcamp for young trainees from Canada and around the world, I was saddened to learn of the passing of Mickey Stunkard, clearly one of the biggest names in obesity research – at a healthy age of 92. With well over 500 publications to his name, Mickey is perhaps best known for his twin studies showing that the body weight of adopted identical twins reared apart resembles each other and that of their biological parents rather than the weight of their adoptive parents. This work helped establish the basis for much of the genetic work on obesity that followed, clearly showing that differences in body weight between two individuals are much more accounted for by their difference in genetics than by differences in their “lifestyles”. These findings were often misused in “nature vs. nurture” debates, an issue that serious scientists have long laid to rest in light of our current understanding that the two cannot be discussed separately, simply because genes and lifestyle interact on virtually every level – from molecules, to cells, to behaviours. Here is what one obituary had to say about Mickey: “He surveyed obesity treatment studies in the late ’50s and found that the nation’s diet programs could claim only a 2 percent success rate. He was an early advocate for the use of bariatric surgery to induce weight loss. He also published the first modern account of binge eating in obese individuals.” I have had to pleasure to often hear him speak at conferences. He will be dearly remembered. @DrSharma Kananaskis, AB
4th Canadian Obesity student Meeting (COSM 2014)
Over the next three days, I will be in Waterloo, Ontario, attending the 4th biennial Canadian Obesity Student Meeting (COSM 2014), a rather unique capacity building event organised by the Canadian Obesity Network’s Students and New Professionals (CON-SNP). CON-SNP consist of an extensive network within CON, comprising of over 1000 trainees organised in about 30 chapters at universities and colleges across Canada. Students and trainees in this network come from a wide range of backgrounds and span faculties and research interests as diverse as molecular genetics and public health, kinesiology and bariatric surgery, education and marketing, or energy metabolism and ingestive behaviour. Over the past eight years, since the 1st COSM was hosted by laval university in Quebec, these meetings have been attended by over 600 students, most presenting their original research work, often for the first time to an audience of peers. Indeed, it is the peer-led nature of this meeting that makes it so unique. COSM is entirely organised by CON-SNP – the students select the site, book the venues, review the abstracts, design the program, chair the sessions, and lead the discussions. Although a few senior faculty are invited, they are largely observers, at best participating in discussions and giving the odd plenary lecture. But 85% of the program is delivered by the trainees themselves. Apart from the sheer pleasure of sharing in the excitement of the participants, it has been particularly rewarding to follow the careers of many of the trainees who attended the first COSMs – many now themselves hold faculty positions and have trainees of their own. As my readers are well aware, I regularly attend professional meetings around the world – none match the excitement and intensity of COSM. I look forward to another succesful meeting as we continue to build the next generation of Canadian obesity researchers, health professionals and policy makers. You can follow live tweets from this meeting at #COSM2014 @DrSharma Waterloo, Ontario
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