Back before we knew much about the chemistry of addiction, Karl Marx declared religion the opiate of the people. It's a fun metaphor to toss around during December's holiday frenzy, but it isn't all that apt. As a sedative, religion is more like Nyquil: something that gets you through the night without too many thoughts about the exploitation of class by class. The true opiate of the people -- the seducer that fools you into feeling it's your friend, that changes your gut, rewires your brain, hooks you, hurts you and won't let you go -- turns out to rich, sweet food - aka holiday treats.
. . .or so accumulating evidence indicates. Bit by bit, experimenters, along with their sacrificial mice and rats, have built up a strong case for equating the effects of gorging on sweet, fatty fare with the effects of hard drugs.
Most recently, at the Society for Neuroscience's annual meeting, Paul Johnson and Paul Kenny of Scripp's Research Institute in Jupiter, FL, presented findings that junk food both used and altered the opiate pathways of lab rats just like, well, opiates. In controlled experiments, the animals that binged on fast foods like Ho-Hos and sausages:
(1) wanted more and more (showing habituation)
(2) needed more and more to feel "normal" levels of pleasure (showing acclimatization)
(3) held out for the hard stuff, refusing nutritionally balanced rat chow even if hungry (showing distorted priorities)
(4) kept gorging on treats while receiving electric shocks to their naked little feet (showing the self-destructive over-motivation drug addicts experience)
(5) took a long time to recover their dietary equilibrium, some never making it all the way back (indicating that their neural networks -- like hard-drug addicts' -- had been radically rewired).
At the University of New South Wales in Australia Margaret Morris found that "comfort food" actually does relieve stress and reduce stress-hormone receptors in the brain. Traumatized, stressed rats who gorged on sugar initially felt a lot calmer. And, last year, mice at the National Academy of Sciences when taken off a binge diet of sugary, fat-rich food experienced a 70% elevation in of corticotrophin-releasing factor (CRF) -- a chemical linked to narcotic addiction and withdrawal. Add these two infobits together and you can see how those of us who seek relief from holiday stress by eating comfort food are particularly vulnerable to sweet-treat addiction.
If you feel like you know all this already, you sort of do. Bartley Hoebel's research on neurological links between sugar and drug rewards goes back to his binge-and-purge research of the ‘80s, and continues through more recent studies at Princeton with Nicole M. Avena et al. In 2008 they showed that rats addicted to a 10% sugar solution (soft drink) "showed both behavioral and neurochemical signs of bingeing, withdrawal and craving. They also found signs of cross sensitization and the gateway effect - higher vulnerability to other addictive drugs - in the sugar addicted rats.
If loading up on sweet, rich food was merely addictive, we'd be fine, but, alas, excessive sugar intake also facilitates the onset
, and not only heart-taxing weight-gain itself but, especially when combined with fat, the metabolic propensity to pack on extra pounds
: Jeffrey I Gordon, M.D. director of the Center for Genome Sciences at Washington University recently recreated a human environment in the guts of "clean" (germ-free) mice, and found that switching half the mice from a plant-based diet to a fat-and-sweet "Western" one changed the animals' intestinal flora within days. Mice with the changed intestinal mix gained weight faster, even back on a low-fat diet.
Both pleasurable taste and systemic presence of sugar and fat appear to be active addictors, so science's cheery holiday message is: Eat holiday fats and sweets in small portions, balanced by other great food. Most importantly, don't fast so that you can gorge later. The one thing you don't want from sweet, fatty treats is for them to storm your Winter Palace and seize your means of production.