On Monday, Oprah Winfrey told Piers Morgan on his new show that following the box-office bust of her 1998 film "Beloved," she sank into a "massive, depressive macaroni-and-cheese eating tailspin" and downed some "30 pounds' worth" of the salty, fatty, carb-loaded stuff.
Excessive? Yes. But logical, even -- in an extreme way -- life-preserving? Absolutely.
That we reach for greasy gloppy goodies when we're stressed (in Winfrey's case, to the point of depression) is an evolutionary necessity, wired into our brains to ensure our survival as a species. But these days, with such "comfort food" so accessible, the circuit has gone haywire. Winfrey, after all, had simply to ask her chef to whip up a massive batch of the cheesy goo.
Since at least the mid-1970s, scientists have been showing that cortisol, our primary stress hormone, activates the same reward system in the brain as cocaine, heroin and other drugs of abuse. True, the degree of activation is different, but the process is the same. Both cortisol and addictive drugs stimulate neurons in a part of the brain called the ventral tegmental area, which sits atop the brainstem, to release the neurotransmitter dopamine. The dopamine then zips via nerve fibers over to the nucleus accumbens, the so-called pleasure center of the brain. The information, "Ahh, pleasure," is then relayed to the prefrontal cortex, where it makes its way into consciousness.
Mind you, the dopamine itself is not the reward. Rather, it sparks the motivation to do the work to get the reward. The good feelings are ones of delicious anticipation. Dopamine supercharges wanting.
What we want during stress, scientists say, depends on context. The reward just has to be palatable, a natural reinforcer. Studies have shown that if a rat is stressed and a hunk of pork fat and regular chow are both within reach, it'll make a beeline for the pork fat. If cocaine is available at the push of a lever, it'll go for that. If a running wheel is the only game in town, it'll exercise its little legs off.
The food-as-drug comparison goes even further. Sweet, high-fat foods increase the release of endogenous opioids, or endorphins -- naturally occurring brain chemicals that also activate the brain's reward system. The opioids, in turn, increase the dopamine dump. The two together spur the intake of even more sweet, high-fat foods, which then increases the release of opioids, which...
It's a cycle remarkably similar to that of drug addiction. No wonder Winfrey couldn't stop at a mere 15 or 20 pounds of her mac-and-cheese fix.
Eating because of stress makes evolutionary sense beyond its tranquilizing properties. Cortisol, after all, exists to save our skins -- at least, that was its reason for being back when we were hunter-gatherers attempting, say, to spear a moose for dinner. Cortisol sparks the release of glucose, the simplest sugar, into the bloodstream from the liver and muscles. The glucose release ensured that the hunter-gatherer had plenty of accessible energy (calories) to either slay the moose or flee to safety -- and also that he had plenty of glucose to replenish energy stores once the stressor had passed. Moose carved up and hunks of meat over shoulder? Time to eat again.
The problem is, these days most of our stressors are not of the short-lived physical kind; they bubble up and take hold in our heads: when we're in traffic, or obsessing about money, or plowing through mountains of work, or caring for aging parents -- or, in Oprah Winfrey's case, when "Chucky" trounced "Beloved." We don't need that extra glucose spurt, nor do we need to replenish glucose stores once the stressor has passed, but our brain and body don't know that. And so we eat, and the added fat goes right to our belly, the worst place for it to be.
We can break the cycle. Here are two ways to start:
Learn to eat mindfully. Indiana State University's Jean. L. Kristeller, Ph.D., co-founded an entire center to educate people about mindful eating. The site includes everything from "Principles for Mindful Eating" to downloadable MP3s of presentations on topics such as "Unintentional Eating" and "Different Types of Hunger." With Kristeller's method, people first rate their level of hunger and fullness when they're ready to eat, then learn how to savor the food for part of the meal. "The process slows down eating in a manageable way and increases enjoyment," says UCSF health psychologist Elissa Epel, Ph.D., who studies the relationship between stress and obesity. "Even a few moments of being fully aware can change the quality -- and the size! -- of a meal."
Sever the stressed-digest connection. Partly what drives us to reach for, say, a boatload of mac-and-cheese when we're stressed is the memory that the stuff made us feel better last time. So rather than reaching automatically for your particular brand of comfort food, develop a new association -- to something that makes you feel better and is good for you -- before the next stressor strikes. Remember: Many activities can kick off the reward circuit. Me? I high-tail it to my swanky club, where I can watch movies on a giant flat-screen TV while I power away on the elliptical -- a wonderful treat, given that I own just a tiny box of a TV sans the cable to even get movies.
This article was adapted from Stress Less: The New Science That Shows Women How to Rejuvenate the Body and the Mind, by Thea Singer (Hudson Street Press, 2010).
Sources:
Adam TC, Epel ES. Stress, eating and the reward system. Physiol Behav. 2007 Jul 24;91(4):449-58. Epub 2007 Apr 14. Review.
Brydon L, Wright CE, O'Donnell K, Zachary I, Wardle J, Steptoe A. Stress-induced cytokine responses and central adiposity in young women. Int J Obes (Lond). 2008 Mar;32(3):443-50. Epub 2007 Dec 4.
Dallman MF, Pecoraro NC, la Fleur SE. Chronic stress and comfort foods: self-medication and abdominal obesity. Brain Behav Immun. 2005 Jul;19(4):275-80. Review.
Dallman MF, Pecoraro N, Akana SF, La Fleur SE, Gomez F, Houshyar H, Bell ME, Bhatnagar S, Laugero KD, Manalo S. Chronic stress and obesity: a new view of "comfort food." Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11696-701. Epub 2003 Sep 15.
Dallman MF, Warne JP, Foster MT, Pecoraro NC. Glucocorticoids and insulin both modulate caloric intake through actions on the brain. J Physiol. 2007 Sep 1;583(Pt 2):431-6. Epub 2007 Jun 7. Review
Dallman MF, Pecoraro NC, La Fleur SE, Warne JP, Ginsberg AB, Akana SF, Laugero KC, Houshyar H, Strack AM, Bhatnagar S, Bell ME. Glucocorticoids, chronic stress, and obesity. Prog Brain Res. 2006;153:75-105. Review.
Dallman MF, Akana SF, Pecoraro NC, Warne JP, la Fleur SE, Foster MT. Glucocorticoids, the etiology of obesity and the metabolic syndrome. Curr Alzheimer Res. 2007 Apr;4(2):199-204. Review.
Daubenmier J, Yglecias L, Kuwata M, Maninger N, Jhaveri K, Purnell D, Kristeller J, Hecht F, Kemeny M, Epel E. Effects of mindfulness meditation training on eating behavior, cortisol and body fat distribution. Abstract presented at American Psychosomatic Society, Baltimore, MD; Mar 12-15, 2008.
Epel E, Jimenez S, Brownell K, Stroud L, Stoney C, Niaura R. Are stress eaters at risk for the metabolic syndrome? Ann N Y Acad Sci. 2004 Dec;1032:208-10.
Epel E, Adler N, Ickovics J, McEwen B. Social status, anabolic activity, and fat distribution. Ann N Y Acad Sci. 1999;896:424-6.
Epel E, Lapidus R, McEwen B, Brownell K. Stress may add bite to appetite in women: a laboratory study of stress-induced cortisol and eating behavior. Psychoneuroendocrinology. 2001 Jan;26(1):37-49.
Epel ES, McEwen B, Seeman T, Matthews K, Castellazzo G, Brownell KD, Bell J, Ickovics JR. Stress and body shape: stress-induced cortisol secretion is consistently greater among women with central fat. Psychosom Med. 2000 Sep-Oct;62(5):623-32.
Foster MT, Warne JP, Ginsberg AB, Horneman HF, Pecoraro NC, Akana SF, Dallman MF. Palatable foods, stress, and energy stores sculpt corticotropin-releasing factor, adrenocorticotropin, and corticosterone concentrations after restraint. Endocrinology. 2009 May;150(5):2325-33. Epub 2008 Dec 23.
Gesta S, Tseng YH, Kahn CR. Developmental origin of fat: tracking obesity to its source. Cell. 2007 Oct 19;131(2):242-56. Review. Erratum in: Cell. 2008 Oct 17;135(2):366.
Gibson EL. Emotional influences on food choice: sensory, physiological and psychological pathways. Physiol Behav. 2006 Aug 30;89(1):53-61. Epub 2006 Mar 20. Review.
Grigson PS. Like drugs for chocolate: separate rewards modulated by common mechanisms? Physiol Behav. 2002 Jul;76(3):389-95. Review.
Kelley AE, Bakshi VP, Haber SN, Steininger TL, Will MJ, Zhang M. Opioid modulation of taste hedonics within the ventral striatum. Physiol Behav. 2002 Jul;76(3):365-77. Review.
Kuo LE, Czarnecka M, Kitlinska JB, Tilan JU, Kvetnanský R, Zukowska Z. Chronic stress, combined with a high-fat/high-sugar diet, shifts sympathetic signaling toward neuropeptide Y and leads to obesity and the metabolic syndrome.Ann N Y Acad Sci. 2008 Dec;1148:232-7.
Kuo LE, Kitlinska JB, Tilan JU, Li L, Baker SB, Johnson MD, Lee EW, Burnett MS, Fricke ST, Kvetnansky R, Herzog H, Zukowska Z. Neuropeptide Y acts directly in the periphery on fat tissue and mediates stress-induced obesity and metabolic syndrome. Nat Med. 2007 Jul;13(7):803-11. Epub 2007 Jul 1. Erratum in: Nat Med. 2007 Sep;13(9):1120.
Lutter M, Sakata I, Osborne-Lawrence S, Rovinsky SA, Anderson JG, Jung S, Birnbaum S, Yanagisawa M, Elmquist JK, Nestler EJ, Zigman JM. The orexigenic hormone ghrelin defends against depressive symptoms of chronic stress. Nat Neurosci. 2008 Jul;11(7):752-3. Epub 2008 Jun 15.
Naleid AM, Grimm JW, Kessler DA, Sipols AJ, Aliakbari S, Bennett JL, Wells J, Figlewicz DP. Deconstructing the vanilla milkshake: the dominant effect of sucrose on self-administration of nutrient-flavor mixtures. Appetite. 2008 Jan;50(1):128-38. Epub 2007 Jul 18.
O'Hare E, Shaw DL, Tierney KJ, E-M K, Levine AS, Shephard RA. Behavioral and neurochemical mechanisms of the action of mild stress in the enhancement of feeding. Behav Neurosci. 2004 Feb;118(1):173-7.
Pani L, Porcella A, Gessa GL. The role of stress in the pathophysiology of the dopaminergic system. Mol Psychiatry. 2000 Jan;5(1):14-21. Review.
Pecoraro N, Reyes F, Gomez F, Bhargava A, Dallman MF. Chronic stress promotes palatable feeding, which reduces signs of stress: feedforward and feedback effects of chronic stress. Endocrinology. 2004 Aug;145(8):3754-62. Epub 2004 May 13.
Rosmond R. Role of stress in the pathogenesis of the metabolic syndrome. Psychoneuroendocrinology. 2005 Jan;30(1):1-10. Review.
Russell SJ, Kahn CR. Endocrine regulation of ageing. Nat Rev Mol Cell Biol. 2007 Sep;8(9):681-91. Review.
Shively CA, Register TC, Clarkson TB. Social stress, visceral obesity, and coronary artery atherosclerosis: product of a primate adaptation.Am J Primatol. 2009 Sep;71(9):742-51. Review.
Sinha R. Chronic stress, drug use, and vulnerability to addiction. Ann N Y Acad Sci. 2008 Oct;1141:105-30. Review.
Teegarden SL, Scott AN, Bale TL. Early life exposure to a high fat diet promotes long-term changes in dietary preferences and central reward signaling. Neuroscience. 2009 Sep 15;162(4):924-32. Epub 2009 May 22.
Teegarden SL, Bale TL. Effects of stress on dietary preference and intake are dependent on access and stress sensitivity. Physiol Behav. 2008 Mar 18;93(4-5):713-23. Epub 2007 Nov 28.
Wand GS, Oswald LM, McCaul ME, Wong DF, Johnson E, Zhou Y, Kuwabara H, Kumar A. Association of amphetamine-induced striatal dopamine release and cortisol responses to psychological stress. Neuropsychopharmacology. 2007 Nov;32(11):2310-20. Epub 2007 Mar 7.
Warne JP, Dallman MF. Stress, diet and abdominal obesity: Y? Nat Med. 2007 Jul;13(7):781-3.
Zellner DA, Loaiza S, Gonzalez Z, Pita J, Morales J, Pecora D, Wolf A. Food selection changes under stress. Physiol Behav. 2006 Apr 15;87(4):789-93. Epub 2006 Mar 6.