Obese people appear to have fewer brain receptors for dopamine, a chemical that helps to produce feelings of pleasure and satisfaction. This abnormal brain circuitry has also been found in people addicted to cocaine, alcohol and other drugs as it leads to what is known as the brain reward system.
Scientists have discovered a brain chemical linked to drug addiction, which could contribute to obesity. The discovery could also lead to new ways to suppress food cravings in obese individuals.
In addition, the detection suggested that obese people might use food to trigger a drug-like effect on the brain's dopamine "pleasure" centers as they had fewer dopamine receptors. In effect, eating pays off by providing the brain with a reward system, i.e. feeling good. Thus, the more you eat, the quicker you experience your feel-good reward.
It was unclear whether some people might have a naturally low number of dopamine receptors that predisposed them to overeating or if they had lost the receptors due to "chronic overstimulation" from a lifetime of overeating. It was possible that the eating patterns of obese people had sent their dopamine levels so high that their brains compensated by "closing the receptors".
Wang and his colleagues at the Brookhaven National Laboratory in Upton, New York, compared brain scans from 10 obese subjects with those from 10 normal-weight participants. The team discovered that obese people had fewer dopamine receptors. The heavier the individual, the fewer the receptors.
Previous research has indicated that the food intake could influence dopamine levels and addictive drugs were known to boost dopamine concentrations thus creating their characteristic "high".
The Lancet (2001; 357:354-357) added that some scientists believed that the high rate of drug use and smoking among people with eating disorders could be partly explained by their increased need for dopamine.
Information provided is courtesy of and compiled by the Academy of Anti-aging Research staff, editors, and other reports.
The mesolimbic dopamine system, or brain reward system, controls your response to any pleasurable experience such as social interaction, sex, and of course, food, by releasing dopamine. Dopamine is a "feel good" hormone, and unfortunately, many people are addicted to the rush they get from it. Thus they tend to want to repeat the experience and associate it with, for example, eating. Ergo, the more you eat, the more dopamine is produced, and the better you feel until the dopamine levels go down once more. This causes a vicious cycle that is a form of addiction, that is, the addiction to feeling good due to the dopamine release. In effect, the more you eat, the more your brain’s reward system pays you with your feel good fix.
Dopamine, however, is the precursor to norepinephrine and epinephrine, the hormones responsible for the "flight or fight mode" your body goes into every time it encounters stress. This stress could be either psychological or physiological in origin.
Dopamine is produced in the brain but synthesized by the adrenal glands to produce norepinephrine and epinephrine. Together with cortisol, they take care of the body’s stress combating mechanism, i.e. the NEM stress response.
With the eating in order to experience the dopamine "high", the body is put under constant stress, and the levels of these hormones fluctuate constantly. Finally, the body reaches a state of constant, heightened awareness, i.e. stress, with consistent high cortisol levels. Because the adrenal glands are not able to keep up with this demand, however, your system finally crashes and you go into what is known as adrenal fatigue. The symptoms associated with this can be debilitating.
Obesity is a disease and an addiction, much like a drug addiction. Make no mistake about it.
The reason why 95 percent of dieters fail is because of the failure to recognize this very important fact. Like any addiction, successful treatment takes time. Allowing one to two years to shed excessive weight should be the norm. Exercise is known to elevate dopamine levels, and very few successful diet programs can be sustained without a concurrent exercise program. Additionally, the high cortisol output that ultimately leads to the adrenal glands being compromised regarding their functionality results in a negative result that compromises the entire system.
