Search Results for "food addiction"
Is Obesity an Addiction?
Regular readers of these pages are well aware of the close link between addictions and some forms of overeating. This topic is now nicely addressed in a commentary by Valerie Taylor (McMaster, Hamilton), Claire Curtis and Caroline Davis (both York University, in this week’s edition of CMAJ. As they discuss, “The concept of food addiction, which more accurately may reflect addiction to specific components of food, can be described in much the same way as other addictive behaviours. Both food and drugs induce tolerance over time, whereby increasing amounts are needed to reach and maintain intoxication or satiety. In addition, withdrawal symptoms, such as distress and dysphoria, often occur upon discontinuation of the drug or during dieting. There is also a high incidence of relapse with both types of behaviour.“ To further support their arguments, they cite the many imaging studies showing that specific areas of the reward or mesolimbic system, such as the caudate nucleus, the hippocampus and the insula, are activated both by drugs and by food. Thus, the easy accessibility of highly palatable foods together with our innate preferences for such foods, can increase the likelihood that vulnerable people will “misuse” food, in much the same way that addicts misuse other drugs to blunt negative emotional states, such as depression, anxiety, loneliness, boredom, anger orinterpersonal conflict. While the concept of addiction should not negate the role of free will and personal choice, it does provide a rationale for the including addiction screens as a routine part of assessment for obesity. It may also help explain the success of lifestyle programs that incorporate pharmacotherapy or behavioural strategies specifically designed to address the addictive component of this illness. Thus, as pointed out by Taylor and colleagues, there is not only considerable overlap among the medications shown to interfere with food and drug abuse in animal models, but the many behavioural interventions developed for managing addictions (motivational interviewing, cognitive behavioural therapy and 12-step programs), are increasingly recognised as also being helpful in managing obesity. Health professionals and decision makers charged with tackling the obesity epidemic would do well to familiarise themselves with the science of addictions and utilize learnings from addiction management in their counseling of patients presenting with excess weight. AMS Edmonton, Alberta
Addiction Gene Linked to Common Obesity
Hedonic hyperphagia (overeating controlled by reward rather than need for calories) often underlies excess caloric intake. As the reward centres that regulate drug and other forms of addiction are the same that are stimulated by highly palatable foods, it is not surprising that genes associated with substance and other addictions may also be linked with obesity. This assumption finds new support in a study published this month in PLoS Genetics by Nancy Heard-Costa from Boston University School of Medicine on behalf of the CHARGE (Cohorts for Heart and Aging Research in Genome Epidemiology) consortium . The researchers performed genetic analyses on more than 30,000 subjects participating in 8 large cohort studies, including the Age, Gene/Environment Susceptibility-Reykjavik Study (AGES- Reykjavik Study), the Atherosclerosis Risk in Communities Study (ARIC), the Cardiovascular Health Study (CHS), the European Special Population Network consortium (EUROSPAN), the Family Heart Study, the Framingham Heart Study, Old Order Amish (OOA), and the Rotterdam Study (RS). Genetic loci studied included those identified in previous studies as well as new candidate loci for abdominal fat deposition. In addition to confirming significant associations with the previously reported FTO and MC4R genes, the researchers found a novel locus in the NRXN3 gene associated with waist circumference, BMI and obesity. NRNX3 has previously been associated with addiction (alcohol dependence, cocaine addiction, and illegal substance abuse) and is part of a family of central nervous adhesion molecules, which are highly expressed in sub-cortical regions of the brain in involved with learning and reward training. Although the odds ratio for obesity per copy of the implicated G Allele was only 1.13, this small effect at a population level can be substantial. More importantly, this finding clearly supports the notion that some individuals may be more susceptible to obesity because of an increased genetic predisposition to reward-seeking behaviours, that obviously include seeking out highly-palatable (addictive) foods. Punitive approaches to drug addictions have not worked – neither will punitive approaches to obesity resulting from hedonic overeating. AMS Edmonton, Alberta
Another Addiction Drug for Obesity?
I have often blogged on the close link between certain forms of obesity and addiction. Not only do many patients battling with obesity openly admit to a “food addiction”, several drugs targeting obesity such as rimonabant (a CB-1 receptor antagonist) or contrave (a combination of buproprion and naltrexone) specifically target the neurocircuitary of the brain’s addiction system. A new addition to this approach may be Gaba-vinyl-GABA (GVG) or vigabatrin, an epilepsy drug currently undergoing Phase II trials for patients with cocaine and methamphetamine dependence. In a study published by Amy deMarco and colleagues from Brookhaven National Laboratory, Upton, NY, in the journal Synapse last week, vigabatrin resulted in a dose-dependent 12-20% reduction in body weight in Sprague Dawley and adolescent and adult Zucker fatty rats. Vigabatrin is an irreversible inhibitor of gamma-aminobutyric acid transaminase (GABA-T), the enzyme responsible for the catabolism of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the brain. The mechanism of action of vigabatrin is attributed to irreversible enzyme inhibition of GABA-T, and consequent increased levels of the inhibitory neurotransmitter, GABA. Vigabatrin is sold as Sabril in Canada by Ovation Pharmaceuticals Inc for the adjunctive management of epilepsy which is not satisfactorily controlled by conventional therapy. Its major neurological side effects include somnolence, impairment of peripheral vision and risk for seizures. Increases in liver enzymes have also been reported. No doubt, it will be interesting to see how the clinical trials of this compound for obesity pan out. Apparently, Brookhaven Labs have licensed out the compound to Catalyst Pharmaceutical Partners, (Coral Gables, Florida), who plan to test it for binge-eating disorder (BED). I am not sure why exactly the researchers (and Catalyst Pharmaceuticals) believe that BED is the best population to test this in, as this disorder (as blogged before) readily responds to CBT and does not actually present with typical features of addiction. In fact one of the key features of BED, the sense of dispair and failure that follows a binge episode is the exact opposite of a “high” experienced by drug users. In any case, to me, patients with BED seem the least likely obese population to respond to an addiction drug – but who knows, we’ll find out soon enough (always happy to eat my words). AMS Edmonton, Alberta
Addiction Drug for Obesity?
This week, Orexigen, a biopharmaceutical company in La Jolla, CA, announced that it won a patent covering its obesity drug Contrave. Contrave actually consists of a sustained-release version of two older drugs: bupropion, which is currently used as an antidepressant and smoking cessation aid, and naltrexone, which is used for opioid addiction and alcoholism. Contrave is currently undergoing Phase III trials for obesity and the company hopes to file for FDA approval in late 2009. Why is Contrave, a combination of two drugs that have been around for a while, novel? Firstly, there is no doubt that depression is a common problem in treatment-seeking obese individuals, many of whom are “self-medicating” with food – i.e. eating highly palatable foods that increase serotonin levels in the brain to improve their mood (albeit temporarily). There is indeed evidence that buproprion may help some people lose weight. Secondly, many patients with obesity will be the first to admit that for them eating is akin to an addiction – a statement that is not surprising given that opioid-mediated reward mechanisms may play an important role in the hedonic aspects of ingestive behaviour and that this behaviour may well involve exactly the same neurocircuitary that plays a role in other addictions. So the idea of combining two drugs that address depression and addiction, respectively, is certainly one with merit and may well prove to be highly effective in obese patients in whom depression and hedonic eating are significantly contributing to hyperphagia. I have not seen data from these trials and have no relationship with Orexigen. I do however, like the concept of this drug and can’t wait to try it on some of my patients, who I can well imagine would benefit. Obviously, we need to await the results of the Phase III program and certainly need to very carefully look at the side effect profile of the two drugs used in combination. But I do think that this could indeed be a useful drug for some patients battling obesity – although it is unlikely to be the “magic bullet” for everyone. Remember, obesity is a highly complex and heterogeneous disorder and there is absolutely no reason why any one treatment should work for all. AMSEdmonton, Alberta
Guest Post: Even if Oprah Can’t, Maybe You Can?
Today’s guest post is a response to my recent post about Oprah and her weight-loss struggles. The post comes from Dr Vera Tarman, MD, FCFP, ABAM, and author of Food Junkies: The Truth About Food Addiction and Mike MacKinnon a fitness trainer (Fit in 20). Oprah’s experience of losing and regaining her weight on a regular basis, alongside Sarah, the Duchess of York and Kristie Allie – all spokespersons for weight loss programs ‐ certainly send us a dismal message. Sure, weight loss can occur but keeping it off is the challenge that trips up 90% of people who have tried these and other programs. So, isn’t it more compassionate to dissuade people from the inevitable yo‐ yo lifestyle and accept their current obese weight? But … what if there are actually many success stores that we are not hearing about? As an addictions physician I witnessed patients who have lost an average of 60 to 100 pounds and have kept that weight off for years. They are food addicts in recovery from their addiction. They have adopted a radical diversion from the traditional bariatric or eating disorder menu recommendations: Rather than ‘learning’ how to eat all foods in moderation, these people have identified and abstained from the trigger foods that spur their addictive eating. Sobriety, food serenity and long term weight loss result – on a consistent basis. Look to the recovery circles and addiction treatment programs. Here you will unearth people who have succeeded where Oprah has not. We don’t hear about these victories because many have pledged anonymity in the church basements where they meet, strategize and buffer the messages that we are saturated with by our food‐obsessed culture. Because there is no money to be made with the simple abstinence of sugar, flour or processed foods, and no drugs, herbs or patented food packages to sell – no one is advertising or promoting this approach. Abstinence. Here is the story of one clinician who has found long ‐ term weight loss. His is a case in point: Weight loss for 13 years and counting. He is not a “rare’” individual who has achieved the impossible. He and his clients have simply applied the solution to the underlying problem of their obesity – an undiagnosed food addiction. I’m a strength and nutrition coach who specializes in helping people lose weight. My typical clients are female, age 35 and… Read More »
