Pills for Bites: The Alarming Link between Drug Abuse and Eating Disorders

This is a guest post for ScienceofEDs blog. If you’re interested in research relating to eating disorders, ScienceofED is the place to go.

I recently stumbled across a disturbing post on a forum. In it, the author gushed about taking prescription stimulants to ensure weight loss and keep it off. A chorus of approval followed, with no regards to side effects and no qualms about lying to get the pills.

The association between drug abuse and eating disorders (EDs) isn’t new. Or even surprising. Since the 1970s, doctors have reported higher incidents of self-medication and drug abuse in a subset of eating disorder patients. Drugs, in this context, cover everything from laxatives, diet pills, alcohol to street drugs. What’s shocking is the extent of the problem. In a report detailing the most comprehensive review on the topic, the National Center on Addiction and Substance Abuse concluded: “Individuals with eating disorders are up to five times likelier to abuse alcohol or illicit drugs and those who abuses alcohol or illicit drugs are up to 11 times likelier to have eating disorders”.

The report is available online for free, and I highly recommend reading the entire document. However, if you’re pressed on time, here are some of their main findings.

  • The link is strong: Between 30-50% of bulimia nervosa (BN) patients and between 12-18% anorexia nervosa (AN) patients abuse or are dependent on alcohol or drugs, compared to roughly 9% of the general population. This may be an underestimation, as the rates do not include many individual with eating disorders who smoke or abuse prescription medication. Eating disorders not otherwise specified (EDNOS) and Binge eating disorder (BED) does not seem to be included in these rates, and no further explanation was given. However, the report did note that individual with BED are more likely than obese individuals to abuse illicit drugs.
  • The link is reciprocal: Up to 35% of individuals who abuse or are dependent on alcohol or drugs also have an eating disorder, compared to up to 3% in the general population.
  • The link starts young and occurs even in sub-clinical cases: Preadolescent and adolescent girls and boys with strong weight concerns are roughly twice as likely to start smoking or smoke daily than those less concerned about their weight. A similar correlation in seen with drinking, where girls who engage in unhealthy dieting behaviors (fasting, diet pills, or binging and purging) as twice as likely to begin drinking and drink considerably more than non-dieting peers.
  • The link between alcohol/illicit drug use is stronger for BN than AN. Alcohol abuse is more common in people with bulimia, who report higher rates of suicide attempts, anxiety/personality/conduct disorders and other substance dependence than non-alcoholic BN patients.  BN patients, compared to AN patients, are more likely to have abused amphetamines, barbiturates, marijuana, tranquilizers and cocaine. The highest rate of illicit drug use is associated with BN binge-purge type, some of whom use heroin to facilitate vomiting. Stimulants (cocaine, Ritalin and Adderall) are used to suppress appetite and to induce a sense of self-control. Similar results are found in a sample of women including both college students and community members, who exhibit disordered eating behaviors but do not have an ED diagnosis.
  • The report points to a rise in ED occurrence in males, athletes and racial/ethnic minorities, but did not have any data on concurrent drug abuse in this population.
  • The casual relationship between ED and drug abuse is not well understood.

EDs and substance abuse have many shared risk factors, which may explain the high rate of co-occurrence. These include:

  • Biological factors: Both disorders operate on the same reward and motivational systems in the brain, precipitating an obsessive preoccupation with a substance, intense cravings and compulsive behavior.
  • Personality risks: Both disorders may represent ways for certain people to cope with stress and transition. High-risk personality traits include low self-esteem, depression and anxiety. The strong link between BN and drug abuse may be partially explained by high impulsivity in individuals with both disorders.
  • Parental and environmental risks: Both disorders may be influenced by unhealthy parental behavior, social pressure and the advertising, marketing and entertainment industries.

It is difficult to pinpoint which risk factors are the main contributors to the development of each or both disorders. However, these shared traits may explain why in some cases ED predisposes the individual to substance abuse (and vise-versa).

The prevention and treatment of co-occurring EDs and substance abuse will have to depend on many parties, including parents, schools, health professionals, policy makers and researchers. Parents and schools are especially important in educating young individuals, by modeling and promoting messages about healthy eating and dangers of drug use. Health professionals need to recognize and screen for the co-occurrence of both disorders. Unfortunately, at the time of the report (late 2003), few effective treatment programs exist for addressing both disorders simultaneously. At the moment, the body of literature concerning this topic tends to be more descriptive (“a link exists”) than mechanistic (“this is why is exists”).

Researchers will need to work with clinicians to develop better approaches to preventing, assessing, diagnosing and treating substance abuse and eating disorders. Specific guidelines are outlined in Chapters 3 and 4 of the report.

Finally, the dangers of co-occurring drug abuse and ED cannot be overstated. ED patients often suffer hair loss, tooth decay, osteoporosis, and weakening of the heart. Stimulants, such as Adderall, Ritalin, cocaine and nicotine (found in tobacco) further stress the cardiovascular system, which can lead to high blood pressure, stroke and even heart failure. With the rise of “study drug” abuse in both students and professionals, these dangerous consequences are becoming increasingly relevant to those with EDs.

Once again, I recommend reading the full report “Food for Thought: Substance Abuse and Eating Disorders” (link here, pdf warning). I’d love to hear your thoughts: why do you think some individuals with EDs are more likely to abuse drugs? Or is substance abuse inherent in some types of EDs, as a symptom?

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Physiological responses to chew & spit – ghrelin and obestatin

This is my second guest post for Science of Eating Disorders blog. Tetyana has a lovely piece up looking at Deep Brain Stimulation as a potential therapy for intractable AN. If you haven’t seen it yet, please go check it out and join the discussion!

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Google “Yummy food”. Oh god salivating!!!

Your body responds to food long before it reaches your stomach. The taste, smell, even the mere sight of food all act to trigger a physiological response, “priming” the gut by stimulating various enzymes required for proper digestion and absorption of nutrients. This is called the “cephalic response”, and it is mediated by a part of the nervous system that’s generally not under conscious control (the autonomous nervous system). Keep in mind, the actual consumption of food is NOT necessary to trigger this reflex.

As you may have already guessed, the act of chewing and spitting out food activates this response, increasing the secretion of stomach acid, digestive enzymes and insulin as well as changing one’s metabolic rate. Which leads me to wonder – what are the changes that occur in the body during the cephalic response? Are these responses altered in patients with eating disorders who also chew and spit? If so, how? And are there any long-term consequences for engaging in chew and spit?

These are obviously very broad questions. To narrow it down, in this post I’d like to look specifically at two hormones involved in appetite control: ghrelin and obestatin. A little background first. Ghrelin and obestatin are both gut-brain hormones that are secreted (mainly) from the stomach and act on the brain. While ghrelin has many neurological functions (such as buffering against stress-induced depression), it was first identified as a hunger-promoting hormone. Ghrelin is secreted during the cephalic phase, and can promote feeding in multiple ways.

First, ghrelin travels through the bloodstream to areas of the brain involved in appetite regulation.  There it acts directly on specific receptors designed to trigger hunger and drive food-seeking behaviors. In fact, injecting humans with synthetic ghrelin was enough to produce feelings of intense hunger. Ghrelin can also make food seem more desirable. It does this by activating the reward system, causing dopamine release at the sight, taste and smell of yummy foods.  Hence, it may play a central role in conveying the pleasure and reinforcing aspects of high-calorie “rewarding” foods. Finally, ghrelin can directly act on the GI tract, blunting the stomach’s “fullness” signal and promoting overeating.

There is much less research on the recently discovered obestatin. However, it seems to directly oppose ghrelin’s effect on food intake, acting as a “brake” for the desire to feed (note, this is a MASSIVE oversimplification).

In the current paper, researchers wanted to know if patients with anorexia nervosa (AN) secret ghrelin and/or obestatin differently than control subjects when allowed to chew, taste and spit out food. To test this, they recruited 8 women with AN (both binge-purging and restrictiving) and 8 age-matched healthy female subjects. Following an overnight fast and a standardized breakfast, researchers served the women a lunch made up of 67% carbohydrates, 13%protein and 20%fat. To chew and spit in a controlled setting (in this case, called “modified sham feeding”), the women were allowed to see and smell the food for 5 minutes before chewing and spitting each bite into a napkin. Blood samples were taken before and after feeding (or chew and spit) for analysis, and the subjects were asked to fill out the Three Factor Eating Questionnare (TFEQ) to assess their eating behavior.

Here’s what they found:

1)   Patients with AN had higher levels of ghrelin before and after chew and spit compared to controls. Both groups showed a spike in ghrelin secretion within 30 minutes of chew and spit, but AN women showed a much higher peak than controls.

2)   AN women had higher obestatin levels compared to control women, and showed a much sharper DECREASE in blood obestatin levels 30 minutes after chew and spit.

3)   Blood sugar levels didn’t significantly change after chew and spit – there was also no difference in blood sugar levels between AN and control women both before and after chew and spit.

4)   Ghrelin levels after chew and spit correlated with TFEQ factor 2 in all women, and TFEQ factor 3 in women with AN.

So what does this mean?

In healthy women, chew and spit can cause an increase in ghrelin and a simultaneous decrease in obestatin. As mentioned above, ghrelin promotes hunger and food seeking, while obestatin may counteract its effect. Together, these hormonal changes may represent the body’s normal response to the presence of palatable food, promoting the initiation of food intake. To support this idea, increased ghrelin levels correlated with TFEQ factor 2, which measures the tendency to lose control over eating.

In AN patients, base levels of both ghrelin and obestatin were increased, and the hormonal responses to chew and spit were significantly enhanced. This amplification of ghrelin increase and obestatin drop might result in an amplified signal of hunger for at least 30 minutes after chew and spit. This is supported by the eating behavior data in AN patients that shows a correlation between enhanced ghrelin levels with TFERQ factor 3, which measures hunger. Hence, it is conceivable that chew and spit may increase hunger levels in AN patients, leading to feelings of a lack of control over eating. This may counteract the patients’ rigid control over food intake and promote more chewing and spitting (or binge eating), resulting in a downward spiral.

While this is an interesting study, there are some problems with it. First, subjects may have swallowed food unconsciously  – a nurse monitored their chew and spit session, but a more subjective measure would be to look at cholecystokinin levels (released by the small intestine), which increases during feeding but stays stable during chew and spit. Second, the number of subjects is quite small, hence I’m not sure how generalizable it is to a greater population. And finally, note that this study looks at AN patients undergoing chew and spit in a controlled setting – they did not ask whether these patients engaged in chew and spit outside the experiment. It is conceivable that chronic chew and spit may alter the body’s response somewhat.

Nevertheless, this study shows that AN patients have enhanced ghrelin and obestatin responses after chew and spit, and this may be a strong factor in promoting hunger and loss of control over eating, ultimately leading to more chew and spit sessions and/or binging behavior.

ResearchBlogging.org
Monteleone P, Serritella C, Martiadis V, & Maj M (2008). Deranged secretion of ghrelin and obestatin in the cephalic phase of vagal stimulation in women with anorexia nervosa. Biological psychiatry, 64 (11), 1005-8 PMID: 18474361

Méquinion, M., Langlet, F., Zgheib, S., Dickson, S., Dehouck, B., Chauveau, C., & Viltart, O. (2013). Ghrelin: Central and Peripheral Implications in Anorexia Nervosa Frontiers in Endocrinology, 4 DOI: 10.3389/fendo.2013.00015
This is a recent review on ghrelin in AN in general, and a good read for those interested in exploring the subject further. Note the authors argue that AN can be viewed as an addictive disorder – I’m not fully on board.

Chewing and spitting – a neglected symptom?

This is a cross-post from the wonderfully informative Science of Eating Disorders blog. ScienceofED covers a broad range of peer-reviewed research articles related to all aspects of eating disorders. Head over and check it out!

Eating disorders come in all shapes and sizes, but all of them are characterized by the same goal: to avoid weight gain or induce weight loss. While behaviors such as food restriction, purging and laxative abuse are relatively well studied, chewing and spitting (CHSP) is a  less studied symptom. A simple Google search, however, reveals over 1.5 million results for the term “chewing and spitting..  Results often links to blog posts or Tumblr pages where CHSP sufferers confess their guilt, disgust and obsession with the behavior.

What is chewing and spitting? How does it relate to other disordered eating behaviors, such as restrictive eating or binge eating?

Guarda AS et al. Chewing and spitting in eating disorders and its relationship to binge eating. Eating Behaviours 5 (2004) 231-239

What is CHSP?

Chewing and spitting describes the pathological eating behavior where the individual chews a variety of enjoyable foods, and spits it out to avoid undesirable consequences of weight gain (Mitchell et al, 1988). This seemingly “smart” workaround allows them to enjoy the taste of foods they usually deny themselves. However, CHSP is described as “driven and compelling,” often leading to uncontrollable episodes in which the individual chews and spits out large quantities of food. This type of behavior often results in social isolation, severe food obsession and financial difficulties.

Given the phenomenological similarities between CHSP and binge eating, CHSP was previously mostly examined in the context of bulimia nervosa (BN). While chew and spit is fairly common in patients with BN (64.5% of 275 patients with BN over the course of their lifetime), few patients engaged in the behavior continuously (Mitchell, 1985). In fact, chew and spit was considered an intermittent purging behavior used in place of self-induced vomiting or laxative abuse. A more recent survey  of individual with anorexia nervosa (AN), BN and eating disorder not otherwise specified (EDNOS) revealed that chew and spit was not limited to patients with BN (Kovacs, 2002). Patients who reported engaging in this type of behavior in the AN and EDNOS group demonstrated more disturbed eating behavior than their non-chewing and spitting counterparts.

In a study by Guarda and colleagues, , the authors set out to evaluate the prevalence and frequency of chew and spit in patients with AN, BN and EDNOS, and compare psychometrics between individuals who have this behavior compared to those who do not. Self-report questionnaires included the Beck Depression Inventory (BDI), which measures depressive symptomatology, and the Eating Disorder Inventory-2 (EDI-2) questionnaire, which measures eating disorder symptomatology. Overall, 301 patients were surveyed.

So what did they find?

Results:

1)   Overall prevalence: 34% admitted to one episode of CHSP in the month prior to admission, with 19% engaging in the behaviour several times a week (CHSP+).

2)   Overall, compared to patients who did not CHSP or did so once a week or less (CHSP-) CHSP+ patients were younger, significantly more likely to abuse diet pills, engage in excessive exercise, skipping meals and restrict fat and calories. The authors further examined if this difference in disordered eating occurred in all groups (AN, BN and EDNOS), and found that it was seen only in the AN group,. In other words, AN patients who engaged in CHSP reported more of the above behaviors than AN patients who did not. On the other hand, CHSP did not significantly alter eating behaviors in BN and EDNOS groups.

3)   Overall BDI scores were not different between CHSP- and CHSP+ patients, although CHSP+ patients were more likely to have considered suicide.

4)   There were no significant differences in mean length of stay as an inpatient, race or current employment between CHSP groups.

5)   There were no significant differences in BDI or EDI-2 in CHSP+/- patients who also engaged in binge eating.

Making sense of these results:

Contrary to previous belief, chewing and spiting is not limited to BN patients, but appears in similar frequency in patients with eating disorders in general. AN patients who engaged in CHSP tend to be more pathological in their disorder than AN patients who did not. CHSP did not influence eating behaviors of patients with BN or EDNOS. Surprisingly, CHSP is more commonly associated with other restricting eating behaviors than binging and purging.

However, as the authors noted, a limitation of this study is that they did not assess the amount of food consumed during each chew/spit episode or associated loss of control. Patients generally choose sugary or high fat food to chew and spit, hinting at a reward system deregulation that is also found in patients with binge eating disorder.  Future studies should address the macronutrient composition and amount of food consumed in a sitting as well as the individual’s state of mind to characterize this frequent eating disordered behavior and its reinforces.

References:

Mitchell J et al. 1985. Characteristics of 275 patients with bulimia. American Journal of Psychiatry, 142, 482-485.

Mitchell J et al. 1988. Chewing and spitting out food as a clinical feature of bulimia. Psychosomatics, 29(1), 81-84.

Kovacs D 2002. Chewing and spitting out food among eating-disordered patients. International Journal of Eating Disorders, 32, 112-115.

ResearchBlogging.org
Guarda AS, Coughlin JW, Cummings M, Marinilli A, Haug N, Boucher M, & Heinberg LJ (2004). Chewing and spitting in eating disorders and its relationship to binge eating. Eating behaviors, 5 (3), 231-9 PMID: 15135335