Junk Food Addiction



   More Than Meets The Eye

When it comes to processed food, excessive amounts of sugar and hydrogenated fats is the rule rather than the exception. It is no secret anymore that there is a very distinct thread linking the increased consumption of such foods, coupled with relentless advertising campaigns and the epidemic proportions of diabetes and obesity in all age groups on a global scale. In fact, if current trends continue, it is estimated that by 2030, more than 86% of Americans will be either overweight or obese. For some people, this picture looks dreadful enough already, but the truth is that it barely scratches the surface of the problem.

Neurobiology research has shown that food can cause serious addiction, the kind that addictive drugs do. Dr Nicole Avena and her colleagues from the department of Psychiatry, University of Florida, report that the consumption of sugar not only alters brain function and behavior, but it also elicits the same type of withdrawal symptoms like opiate drugs do. In other words, sugar affects the opioid receptors in the brain, which are recognized by natural (endogenous or not) opioid substances. On the other hand, foods rich in fat seem to affect the brain in a different way, although they cause withdrawal-type symptoms as well. Many studies show that there is a unique relationship between emotional balance and fatty acids.


For example, a study published in The Journal of Clinical Investigation in 2011 tested the effects of fat consumption in healthy people while experiencing experimentally induced sad feelings. Within minutes the sad feelings were significantly alleviated and the subjects reported improved mood, while MRI scans confirmed the expected brain response. This study is important because it shows that fat actually does not even have to be properly digested in order to modify brain functions. The mere presence of fat in the gut triggers the release of gastrointestinal hormones, which regulate neurological and emotional responses within very few minutes.

The above studies prove that junk food, high in fat and sugar, is so much more than excessive calories. It truly creates addiction on a biochemical and neurological level. It would be naive to believe that the richness of junk food in these specific compounds is an accident. Michael Moss explains in his incredible book "Salt, Sugar, Fat: How the Food Giants Hooked Us" that the amount of secretive research invested by Big Food giants in finding the right combinations of the cheapest and most addictive ingredients for their products, is tremendous.

What neuroscience is only now starting to understand and elucidate, food companies knew it all along. And they have capitalized hard on it by selling processed food especially designed to bypass appetite control and neurological security valves of any unsuspected victim. Due to the complexity and interconnectedness of the biological functions in the human body, the overall impact of processed food on human physiology, health, life expectancy and quality of life in this generation is still hard to estimate.

But again the full extent of this slow, but efficient, genocide cannot be not fully appreciated if the impact on the future generations is not assessed as well. Latest research shows that the diet during pregnancy has a significant impact on the nutritional choices of the offspring. It is now confirmed that when the expectant mother follows a high-fat diet, her baby shows a measurable preference for sugar. However, this is not just a behavioral trait casually passed on to the next generation by means of mimicking the behavior of adults. On the contrary, as a result of the maternal diet, the DNA and subsequent expression of genes encoding opioid and dopamine receptors in the brain of the child is altered in a manner that promotes addiction.

Studies prove that the junk food, rich in fat and sugar, much more than the excess calories. It really creates a dependency on the biochemical and neurological level.

This is no surprise, since repeated use of certain drugs has been well documented to cause enzymatic DNA modifications (epigenetic changes) which disrupt neuronal gene programs and support addictive behavior. This scientific fact explains why the kids of obese mothers are heavier with increased fat mass and have elevated insulin and glucose levels in their blood in comparison with control groups. Experiments show that the genetic disruption induced by maternal junk food consumption during pregnancy has long-term effects on the child's behavior and neurological responses.

In a twisted way, the new generation is genetically pre-programmed to be addicted to junk food, even before they are born. This perfect self-feeding loop guarantees long-term profits for the food corporations and chronic debilitating disease for humans, for generations to come. By designing and selling addictive, low quality and disease-promoting products, Big Food has achieved the unthinkable: to create a dedicated army of health-compromised, addicted fans, whose cognitive, biochemical and even genetic potential to break free of their addiction is hijacked before birth.


   Born to Be Junk Food Junkies

When you’re pregnant, that bag of cookies or chips can look pretty irresistible. But resist anyway. A new study  suggests that eating a junk food diet during pregnancy may alter not only your own brain chemistry, but also the developing brain of your baby. As a result, your child’s brain may be prewired for later junk food addiction.

It’s the latest—and some of the strongest—evidence that junk food addiction is all too real. Recently, I had a chance to chat with Beverly Muhlhausler, PhD, study coauthor and head of the Metabolic Health Unit at the University of Adelaide’s FOODplus Research Centre in Australia. Here’s what she told me about how a junk food junkie is born.


   What do we already know about how junk food affects brain chemistry?

Beverly Muhlhausler, PhD:  Junk food has the same effect on the brain as addictive drugs and alcohol. When you eat junk food, it switches on part of the brain known as the mesolimbic reward center. This causes opioids to be produced and released, and the opioids initiate a series of reactions that ultimately lead to the production of the feel-good chemical dopamine. And this, in turn, creates a pleasurable feeling that’s equivalent to the high experienced from a drug—although obviously in a milder form!

Consuming excessive amounts of junk food for long periods changes your brain in the same way as addictive drugs and alcohol do. As a result, you need to consume larger amounts of junk food to get the same high—and you experience withdrawal symptoms when you can’t get it.


   Which components of junk food have this effect?

Dr. Muhlhausler:  We still don’t know exactly what it is that switches on the reward center, because junk food is made up of a lot of different ingredients. Studies have shown that just feeding fat or sugar to animals is enough to activate the reward system. But it’s unlikely that fat or sugar can cross the blood-brain barrier and reach the reward center directly. We think that a hormone that increases in response to junk food, such as insulin or leptin, acts as a middleman. It’s actually the hormone that binds directly to brain cells in the reward center.


   What did you do in this particular study, and what did you find?

Dr. Muhlhausler:  In our study, we fed pregnant and lactating rats either normal rat food or a “cafeteria” diet, which consisted of a range of human junk foods, including potato chips and chocolate cookies. Then we studied the effect on their pups.

In a previous study, we had shown that pups born to junk food-fed mothers were fatter and ate more fat than their control counterparts. The part of the brain that controls reward and addiction had developed differently in those pups as well. In this experiment, we tested whether the response of pups to a drug that blocks opioid signaling in the reward center differed between the two groups.


We found that pups whose mothers had been fed a junk food diet were less responsive to the drug. This tells us that their reward system was less sensitive to the effects of opioids—and therefore to natural rewards, such as junk foods, which activate the same system. That means these pups probably would have to consume more junk food to get a feel-good effect. Consequently, they might be more prone to overindulge in this type of food.


 
   What does your research show about the addictive power of junk food?

Dr. Muhlhausler:  Our study supports the results of other research showing that junk foods do indeed have addictive properties. Eating too much junk food over a long period of time can literally cause us to become addicted. We probably all know people who have withdrawal symptoms when they can’t get access to chocolate or chips—and what our research shows is that this really is a biological response.




References:

Avena N., Gold J., Kroll c., Gold M. 2012. Further Developments in the Neurobiology of Food and Addiction: Update on the State of the Science. Nutrition. 28(4): 341–343. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3304017/


~  Van Oudenhove L, McKie S, Lassman D, Uddin B, Paine P, Coen S, Gregory L, Tack J, Aziz Q. 2011. Fatty acid-induced gut-brain signaling attenuates neural and behavioral effects of sad emotion in humans. The Journal of Clinical Investigation. 121(8):3094-9. http://www.ncbi.nlm.nih.gov/pubmed/?term=21785220


~  Ong Z. Y. and Muhlhausler B.S. 2011. Maternal "junk-food" feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring. FASEB Journal. 25(7): 2167–2179. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3114523/


~  Vucetic Z, Kimmel J, Totoki K, Hollenbeck E, Reyes TM. 2010. Maternal high-fat diet alters methylation and gene expression of dopamine and opioid-related genes. Endocrinology. 151(10):4756-64. http://www.ncbi.nlm.nih.gov/pubmed/20685869


~  Page KC, Malik RE, Ripple JA, Anday EK. 2009. Maternal and postweaning diet interaction alters hypothalamic gene expression and modulates response to a high-fat diet in male offspring. American Journal of Physiology. Regulatory Integrative Comparative Physiology. 2297(4):R1049-57. http://www.ncbi.nlm.nih.gov/pubmed/19657097


~  Moss M. 2012. The Extraordinary Science of Addictive Junk Food. New York Times. Available online at: http://www.nytimes.com/2013/02/24/magazine/the-extraordinary-science-of-junk-food.html?pagewanted=all&_r=1&


~  Vucetic Z, Kimmel J, Reyes TM. 2011. Chronic high-fat diet drives postnatal epigenetic regulation of μ-opioid receptor in the brain. Neuropsychopharmacology. 36(6):1199-206. http://www.ncbi.nlm.nih.gov/pubmed/21326195


~  “A Maternal ‘Junk-Food’ Diet Reduces Sensitivity to the Opioid Antagonist Naloxone in Offspring Postweaning.” J.R. Guguseff et al. FASEB Journal, 2013, vol. 27, pp. 1275-84.






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