Tuesday, November 22, 2011

Soda Begets Zombies

Okay, not likely.  But the sugary variety might well be causing depression in those vulnerable to fructose malabsorption.  Have a look at my previous post on the subject.

Today I have a mere observational study that adds to a pile of evidence that soda ain't the best thing in the world to be drinking, behaviorally speaking. "The Twinkie Defense: the relationship between carbonated non-diet soft drinks and violence perpetration among Boston high school students."

Here's an appropriate song (right click in new tab to open):  Kiss With a Fist

Some bad news about behavior and soda, associatively speaking:  In Norwegian adolescents, soda consumption correlated with poor mental health.  Among American college students, those who drank more soda were less likely to be social, less able to understand emotional cues, and more likely to favor individualism (is that bad?).  There are several reasons soda might cause problems - the sugar could lead to a low blood sugar "crash" which is associated with violence (as I discussed in this post).  In addition, soda is a pretty poor source of nutrition other than straight-up calories, so if it replaces more nutritious food in the diet, big soda-drinkers could end up with micronutrient deficiencies.  And yeah, micronutrient deficiencies could lead to more violence.  No one measured if anyone was a fructose malabsorber.

The experimental design of the Boston study was pretty simple - Boston public high school students were randomly selected and asked to answer a survey.  Those who answered that they drank five or more cans of non-diet soda every week comprised 30% of the sample.  They controlled for a bunch of covariates (but I can think of several million more).  Alcohol, age, gender,  race, sleep, smoking, family dinners.

Heavy soda drinkers had similar BMIs to less heavy soda drinkers, and were no more likely to have less than 6 hours sleep.  White, Black, and Hispanic kids are all equally likely to be heavy soda drinkers, but Asians were significantly less likely to be quaffing 5 or more cans a week.

Heavy soda users were far more likely to smoke or drink alcohol, and were far more likely to carry around a knife, have been violent with a sibling, a date, or another young person. When the sample was split into 4 quartiles rather than two, the violence link remained linear, suggesting a dose response relationship.

And that's pretty much it.  A rather limited self-report study with some statistical crunching, no causal relationship can be inferred; though there are some sensible physiologic explanations as to why soda could make you knife your sister, it isn't proven here.  Brain-eating was not examined.

More posts this week!  I need to answer js290 regarding the whole linear glucose thing, and I figured it would warrant a short post rather than a comment.  Jamie has sent me a few papers, and I pulled some reviews on inflammation, atopy, and behavior.


  1. Nice post as always.

    This might also be relevant?

    Chronic sugar intake dampens feeding-related activity of neurons synthesizing a satiety mediator, oxytocin.


    (And, oxytocin is not only a satiety mediator..)

  2. Hi Emily,

    I've been following your blog for a couple of months but I was really excited to see this article, which led me to the trail of articles before it. You do a really great job of presenting all of the arguments for the effects of high carbohydrate diets on mental health.

    From personal experience, I do really well on a VLC. I was diagnosed with 'carbohydrate sensitivity', a form of hypoglycemia, by a Harvard psychiatrist, where I am a postdoc, after coming to her with symptoms of anxiety, irritability, and depression. When I'm eating VLC, my symptoms totally disappear. But when I eat refined carbs, I get an initial rush of euphoria but that quickly reverses to anxiety and depression. I'm also super productive on a VLC and feel unmotivated when I eat refined carbs.

    I'm also Mexican-American. Latino communities, for example, have higher rates of diabetes (insulin link) and depression. I was wondering if maybe there is a link between carbohydrates and mental disorders in minority populations? That maybe VLC work really well for minority populations but the Wurtman high-carb diet wouldn't? I ask based on personal experience and the very interesting study you posted about the Peruvian population that had low blood sugar and high rates of aggression. Very interesting!

  3. I recently posted some notes from the book "Biological Influences on Criminal Behavior," which mentions the connection between hypoglycemia and violence:
    • A study found that a low sugar diet reduced antisocial behavior in incarcerated juveniles by 48%.
    • A study measured both blood sugar and serotonin levels and was able to predict which subjects were repeat, alcohol-abusing, violent offenders and impulsive fire-setters in 84.2% of cases.

  4. I know you have an interest in the role of inflammation and it's impact on various mental health issues. I have recently encountered a description on 'Endorphin Deficiency Syndrome'. It is very real and definitely has a link to inflammation. Inflammation also has a role in the HPA axis (and stress).

    I honestly believe that for those with bipolar and especially for those labelled with some kind of personality disorder, that EDS can really explain a lot. Also, think of 'refractory depression'. The people that do not respond to typical treatments.

    There is a lot of research to be had in regards to endogenous opioid receptors with the accompanying public fear associated with any 'opiate' drug link. The only reason why this receptor which is naturally produced by our own body is even called 'opioid' receptor is that it does share similar characteristics with the illicit drug opiates. Other than that, it should not be stigmatized because there are a lot of people out there suffereing (and causing suffering to others around them) due to lack of effective treatment, inappropriate 'step-child' type names for diagnosis such as 'Borderline Personality Disorder' etc.

    I also feel that in these populations, a ketogenic diet would be especially effective. To target both dopamine, GABA, and endorphin levels, seems to be a good approach in helping this population.

  5. Hello Dr Deans,

    Just thought I'd check in. No soda (diet or otherwise) since August 15th when I embarked upon my Low Reward experiment based on Stephan's thoughts. 3.5 months later I can't say that I still do not crave a soda at times, particularly emotionally driven, but I have managed to stay the course.

    Hope you are off the sauce too :-)



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