Arya M. Sharma, MD

Last week, the media erupted in reports and commentaries prompted by an article by Robert Lustig and colleagues front the University of California, published in the journal NATURE, calling on governments to regulate sugar in a fashion akin to alcohol.

Although the media referred to this piece as a ‘new study’, the article did not actually provide any new data - it was merely an ‘opinion piece’ suggesting legislative approaches to the ill-effects of eating too much sugar.

Presented as a possible solution to the obesity epidemic, the jist of the arguments more or less were as follows: worldwide sugar consumption has increased, sugar is toxic and addictive and, therefore, regulating sugar like alcohol or tobacco (including taxation and limiting access to individuals below the age of 17), would reduce obesity and prevent metabolic syndrome.

In a number of media interviews, I took issue both with the proposal to tax and ban sugar as well as the rather simplistic causal linking of sugar to the obesity epidemic.

Here is why:

1) While there is no doubt that overconsumption of sugar (like consuming too much salt (not sodium!), trans-fats, alcohol, or perhaps processed foods in general) may well promote ill health, these links may be far less robust or scientifically proven than the article suggests. More importantly, there is very little evidence from high-quality intervention studies (outside of the rather artificial setting of a clinical trial) that the proposed population measures (namely attempting to restrict sugar consumption by banning or taxing it) would have the desired effect on obesity or anything else - if there are such examples, the article certainly fails to mention them.

2) As any reader of these pages will also realize, obesity is a multifactorial complex condition driven by a myriad of socioeconomic, psychological, and biological factors - some of which do indeed make many of us prone to ‘overconsume’ salt, sugar, fats, and perhaps alcohol or illicit drugs. In the case of sugar, the article unfortunately fails to seriously delve into what exactly these socioeconomic, psychological, or biological drivers to consume more sugar may be (beyond simply suggesting that sugar is cheap, omnipresent and ‘addictive’). Unfortunately, by reducing the solution to the obesity epidemic to simply a matter of banning and taxing sugar, the article not only reinforces the widely held stereotype that obese people are obese simply because they eat too much (in this case sugar) but also that obese people, because of the damage they do to themselves and society, need to be punished and policed for the benefit of all.

3) But, even if sugar was indeed a major driver of obesity (a few years ago we would have thought it was fat, others have recently suggested it is wheat or indeed all carbs, some think it is not enough protein, others point to our industrialized meat production, or is it simply having too much variety on the shelf?), calling for interventions primarily on the demand side (making sugar less accessible and more expensive) rather than the supply side (making sugar less attractive for farmers to produce) is problematic. Paradoxically, changing demand without changing supply, at least in the short term, may well have exactly the opposite effect - sugar becomes even cheaper, thus making it an even more attractive ingredient for food producers. Reductions in the price of raw materials will likely quickly neutralize any increased cost of taxation with the net effect on consumption being zero. If, in the long run, such interventions did actually reduce sugar consumption in countries where it is regulated, we would simply be diverting streams to countries where it is not (worldwide tobacco consumption is the perfect case study for this).

4) The article is also rather cavalier about how exactly such measures would be implemented and enforced. As we well know from the hopelessly lost ‘war on drugs’, if people really want something (like sugar, assuming it is indeed as addictive as the authors suggest), they’ll find ways to get it. So making something ‘illegal’ is meaningless unless government is also prepared to enforce any such legislation. For a substance as omnipresent as sugar, this would require a rather expensive bureaucracy (I can already see food and drug inspectors raiding schools, recreation facilities, and grocery stores to ensure that no candy is sold to anyone below the legal age). I would imagine that the money required to effectively police and enforce any such new legislation would more than outweigh any potential revenues from the ’sugar tax’ thereby snuffing any hope that such revenues could perhaps be used for other efforts to reduce obesity (like building bicycle lanes).

5) Finally, it is not clear to me why the authors would chose to simply focus their attention on sugar - it would have made as much sense to include all refined carbs, as it takes very little for our digestive systems to turn a slice of Wonder Bread or pizza into glucose. Will all refined carbs (and what exactly is the definition of ‘refined’ in this context? Do we include polished rice?) be next on the list of toxic substances that require a permit? And what about other natural sources of sugar - are we going to tax cane sugar, beets, honey, or perhaps even Maple syrup? Let us also not forget that biologically there is little difference (if any) between the ample sugar in fruit juice and the sugar I add to my cup of tea.

But in the end, my main criticism would be that, as so often, the authors have chosen to focus on the ‘what’ (eating to much sugar) rather than on the far more complex issue of the ‘why’ (why is this happening?). That of course would have been a very different paper requiring some very uncomfortable and complex analyses of the very core of how industrialized societies operate.

While the article is no doubt well intended, I sincerely fear that these rather simplistic and superficial ‘one-size-fits-all’ solutions to the obesity epidemic based on principles of shame, blame, tax, and ban, merely distract us from having a value-driven and non-judgemental discussion about the true drivers of the societal (e.g. industrialization and centralization of food production), psychological (e.g. stress, lack of sleep, emotional deprivation) and biological (e.g. fetal imprinting, endocrine disrupters) changes that have led to this epidemic, we will fail to even remotely begin to reverse this problem.

AMS
Ottawa, Ontario

Lustig RH, Schmidt LA, & Brindis CD (2012). Public health: The toxic truth about sugar. Nature, 482 (7383), 27-9 PMID: 22297952

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As not everyone may have a chance during the week to read every post, here’s a roundup of last week’s posts:

• Obesity and Mental Health: Complicated and Complex
• Obesity and Mental Health: Beyond Pharmacotherapy
• Treating Obesity in the Mentally Ill
• Metabolic Syndrome Risk in Children Treated with Second-Generation Antipsychotics
• Antipsychotic Prescriptions to Children - Too Much Too Soon?

Have a great Sunday! (or what is left of it)

AMS
Edmonton, Alberta

You can now also follow me and post your comments on Facebook

Prof. Raymond Négrel, Director of the Faculty of Sciences, University of Nice-Sophia Antipolis.

Following our 1999 report on the existence of a local renin-angiotensin system in human adipose tissue, we thought it appropriate to write a review on the now rapidly accumulating evidence from human and animal studies on the physiology and potential health-related effects of this system, especially in relationship to cardiometabolic problems (although this term had yet to coined).

So, in 2000, I invited Raymond Negrel from the Centre de Biochimie, Université de Nice-Sophia Antipolis, Nice, France, to join Stefan Engeli and myself in co-authoring this paper for HYPERTENSION.

At the time, renin-angiotensin system had already long been recognized as an important regulator of systemic blood pressure and renal electrolyte homeostasis. In addition, it had become evident that local renin-angiotensin systems in a wide range of tissues, including the heart, blood vessels, and the brain, may play a role in pathological changes of organ structure and function by modulating gene expression, growth, fibrosis, and inflammatory response.

With regard to the function of this system in adipose tissue, we reviewed the literature on the emerging evidence for a role in adipogenic differentiation and in the regulation of body weight.

We also discussed how such changes in adipose-tissue renin-angiotensin could affect systemic activity of this system, thereby influencing blood pressure.

We concluded our review by noting that:

“..future studies with more carefully described phenotypes are necessary to conclude whether obesity (by stimulation of adipogenic differentiation) and hypertension are associated with changes of renin-angiotensin system activity in adipose tissue. If so, the physiological relevance of this system in animal models and humans may warrant further interest.”

Stay tuned for future posts on this topic, as my lab began addressing some of these ideas in subsequent studies.

According to Google Scholar, this paper has 312 citations to date.

AMS
Edmonton, Alberta

Engeli S, Negrel R, & Sharma AM (2000). Physiology and pathophysiology of the adipose tissue renin-angiotensin system. Hypertension, 35 (6), 1270-7 PMID: 10856276

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To round up my posts on the obesity articles of the January issue of the Canadian Journal of Psychiatry, I would like to briefly highlight some of my comments published in an editorial I wrote for this issue.

Reader will by now be familiar of the many links between obesity and mental health problems. With regard to this relationship, I write:

“Thus, while it is not complicated to appreciate the fact that mental health is an important determinant of body weight, it is also important to recognize that this relationship is complex.

While the links between mental illness and weight gain can be as simple as the induction of ‘hedonic hyperphagia’ with the use of ‘atypical’ antipsychotics, they can be as complex as the link between early childhood trauma and binge eating disorder or the recurrence of addictions following bariatric surgery.”

I conclude with what I have said often enough:

“It is therefore of considerable importance that mental health practitioners familiarize themselves with the complexity of obesity and its management whilst, by the same notion, anyone attempting to manage obesity requires at least basic competencies in the art and science of assessing mental health.

Indeed, nowhere are mental and physical health closer related to one another than in the context of the mental health and obesity epidemics – close enough perhaps to consider them close cousins, if not siblings. While reducing the burden of mental health on Canadians may well go a long way in improving their physical health, reducing the burden of obesity on Canadians without also addressing their often underlying mental health problems will prove virtually impossible.”

I do hope that this issue of the Canadian Journal of Psychiatry, will draw more attention to this relationship and will hopefully receive feedback on this from my readers and colleagues.

AMS
Edmonton, Alberta

p.s. Readers in Edmonton may be interested in attending a CIHR Café Scientifique: Is Canada ignoring obesity in men? Wednesday, February 15, 2012, 5:00 p.m. to 7:00 p.m. Edmonton City Hall (Hosted by the CIHR Institute of Gender and Health and the Canadian Obesity Network).

Valerie Taylor, MD, PhD, Psychiatrist-in-Chief, Women’s College Hospital and Head, Division of Women's Mental Health, University of Toronto

Now that we’ve discussed some of the links between obesity and mental illness, we turn to another article by Valerie Taylor and colleagues from the January issue of the Canadian Journal of Psychiatry, which looks at the treatment options for obesity management in those with mental health problems.

The article begins with a discussion of various psychological interventions to assist with behaviour change - many of which have also been shown to be effective in individuals without mental illness.

These include, Cognitive behavioral therapy (CBT), well researched and empirically effective approach to address dysfunctional, negativistic thinking characteristic of depressive disorders. In relationship to better managing obesity, short-term effects have been consistently positive, however, long-term success has been variable.

The strongest evidence for the use of CBT in weight management probably exists for binge eating disorder (BED), where CBT consistently results in greater treatment effects than do other interventions after both short- and long-term follow-up.

Components of successful CBT for obesity treatment include: 1) identifying readiness for change and goodness of fit between patient and treatment, 2) self-monitoring by tracking weight and food behaviours, 3) cognitive restructuring via challenging maladaptive cognitions and 4) problem solving by developing system of alternate food behaviours.

Other forms of psychological interventions with promising results include Mindfulness Therapy, Dialectical Behavioural Therapy, Interpersonal Psychotherapy, and Motivational Interviewing. As with CBT, all these interventions require trained and experienced practitioners and may therefore not be readily available to most patients.

The paper then briefly discusses the rather limited options for pharmacological obesity treatments, noting that many agents that act centrally are currently under investigation as obesity drugs.

Finally, the Taylor and colleagues look the outcomes of bariatric surgery on patients with co-morbid mental health issues. As noted before, a large proportion of patients seeking surgical obesity treatment have concomitant mental illness, with Axis 1 disorders ranging from 20-60%, with mood and anxiety disorders being most common, and with Axis II disorders in approximately 25% of surgical candidates.

How these underlying mental health issues affect post-surgical outcomes remains a matter of debate with studies (largely consisting of case series) showing mixed results. In fact, there is currently no accepted consensus as to appropriate mental health screening that should be utilized prior to bariatric surgery, although most weight loss surgery programs require some type of mental health evaluation prior to surgery.

“A primary objective of mental health screening is to identify and exclude patients with a significant, poorly controlled psychiatric illness or active substance dependence. Mental health evaluation may also identify addressable barriers to weight management.

Contraindications to bariatric surgery include current drug or alcohol abuse, severe uncontrolled psychiatric illness, and lack of comprehension of risks, benefits, expected outcomes, alternative, and lifestyle changes required with bariatric surgery.”

Importantly, the authors note that:

“Bariatric surgery is not a treatment for depression and is not a panacea to improve dysfunctional interpersonal relationships or psychosocial stress. It is important that patients clearly understand what can be altered with this procedure and what requires different types of treatment, preferably prior to engaging in a life changing surgical procedure.”

Also, there are consistent reports of increased risk of suicidality and ‘accidental’ deaths following bariatric surgery, a relationship that remains poorly understood both in its aetiology and incidence.

Finally, the article discusses some of the challenges of pharmacological treatment post bariatric surgery, which potentially affects the absorption of psychiatric medications.

Thus, while many patients seeking obesity treatments may also have mental health problems (but by no means everyone), these can and should be addressed through multidisciplinary interventions utilizing the full spectrum of available psychological, pharmacological and (if necessary) surgical treatments.

AMS
Lethbridge, Alberta