Current Research:'Are Sugary and Fatty Foods Addictive?'
The Problem: The science on food addiction has now determined that low-nutrient, high-calorie, intensely sweet, salty, and/or fatty foods - those that make up the majority of the Standard American Diet produce the exact biochemical effects in the brain that are characteristic of substance abuse. Junk food is available everywhere, is legal, cheap, and socially accepted; therefore, it becomes the drug of choice for many of us. Obese humans are known to have fewer dopamine receptors (called D2 receptors) compared to lean individuals –their reward response from food is not as sensitive and it is thought that they compensate by overeating. Yes, our psychological state and our individual genetics affect how susceptible we are to addictive behaviors. But also it is true that sugary and high-fat foods have physiologically addictive characteristics that may prompt almost anyone to lose control of their consumption. "Just one bite" doesn't work because that single bite activates the dopamine reward system, causing the brain to demand more. Willpower, logic, and common sense are no match for addictive drives. The intense sweetness of sugar may surpass the addictive characteristics of cocaine. People don't tend to binge on bananas; it is perhaps the reason we are more likely to supersize soda than sweet potatoes. And we are less likely to overeat yellow corn than we are to overeat candy corn. The over consumption of sugar sweetened diets has often been compared to drug addiction, though this parallel was based, until very recently, more on anecdotal evidence than on solid scientific grounds.
But now we have Positron emission tomography (PET) scans, imaging technology that can measure the brain activity. The imaging showed decreased dopamine sensitivity in obese individuals. And, the heavier they were, the less responsive they appeared to become.
Dopamine is considered the neurotransmitter primarily involved in the pleasure and reward center of the brain. It helps to motivate our drive for things like food, water, and sex, all necessary for perpetuation of our species.
We see the same thing in cocaine addicts and alcoholics. This would suggest that a reduction in dopamine receptors is associated with addictive behavior irrespective of whether it is due to food, as in this study, or to addictive drugs as seen in substance abusers. When considering food and drug reward, there appear to be overlapping circuits in human obesity and addiction.
The food industry, like the tobacco companies and the drug lords, have sought to come up with products that tap Into that same dopamine reward system. American Journal of Clinical Nutrition, 2012. Now we know that fat has similar effects in the brain as well. Fat intake modulates cerebral blood flow in homeostatic and gustatory brain areas in humans. Diabetes, Obesity and Metabolism, 2011. You feed people some yogurt packed with butterfat and within 30 min. you can start to see the same changes in brain activity that you get when you drink sugar water. People who regularly eat ice cream, sugar and fat, have the deadening dopamine response in their brains. In this study 151 healthy weight adolescents underwent MRI during receipt of a milkshake. Frequent ice cream consumption, independent of body fat, was related to a reduction in activity in the reward- region (the pleasure center of the brain).
Once we have so dulled our dopamine response, deadened our responsivity of reward circuitry, this may promote subsequent overconsumption in an effort to achieve the degree of satisfaction experienced previously, which contributes to unhealthy weight gain.
So now, there has been interest in calling obesity an official mental disorder in the Diagnostic Manual of Mental Disorders, DSM V. After all, both obesity and addiction share the inability to restrain behavior in spite of an awareness of detrimental health and social consequences. The substance use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance. Redefining obesity as an addiction, a psychiatric disease, would be a boon to drug companies that are already working on many substances that alter our brain chemistry such as opiate blockers like Naltrexone which may be used for opiate addiction to block the effects of the drug. When taking naltrexone people eat significantly less cheese as the opiate receptors are blocked by the drug.
Comments: Natural plant foods are not as intensely sweet, salty, or fatty as the processed junk foods that are purposely engineered to excite our reward systems. Eating whole, natural foods provides enjoyment of taste without activating addictive drives. Rather than taking drugs though, we can prevent the deadening of our pleasure center in the first place by sticking to foods that are naturally calorie dilute, like whole plant foods. This can help to bring back our dopamine sensitivities such that we can again derive the same pleasure from the simplest of foods like strawberries. This is not just for people who are obese. Yes, when we regularly eat calorie dense animal and junk foods like ice cream, we can blunt our pleasure center, and overeat to compensate; but when our brain down regulates dopamine receptors to deal with all these jolts of fat and sugar, we may experience less enjoyment from other activities as well. That is why cocaine addicts may have an impaired neurological capacity to enjoy sex. This may also be why smokers also have impaired ability to respond to positive stimuli. Since these all involve the same dopamine pathways, what we eat can affect how we experience all of life's pleasures. So, to live life to the fullest what is the solution? Some addiction experts say that the food industry should be given incentives to develop low-calorie foods that are more attractive, palatable, and affordable so that people can adhere to diet programs for a long time. But there is no need for this because mother nature beat them all to it, with the wide array of wonderful whole plant foods. So, there is no doubt that excess sugar and fat in our eating plan is injurious to our health and is physically and psychologically addictive. Try a whole food plan based (WFPB) eating plan to correct this.
REF:
Zahler, William, Have we 'Gone To Pot?, Online, April 27, 2014.
William Zahler, 2016