-- 25 maja 2011, 18:57 --
In 2008, Nicole Avena published data stating that sugar affects opioids and dopamine in the brain, and thus might be expected to have addictive potential.
Sugar and the taste of sweet stimulate the brain by activating beta endorphin receptor sites. These are the same chemicals activated by heroin and morphine.
Recent behavioral tests in rats further back the idea of an overlap between sweets and drugs. Drug addiction often includes three steps. A person will increase his intake of the drug, experience withdrawal symptoms when access to the drug is cut off and then face an urge to relapse back into drug use. Rats on sugar have similar experiences. Researchers withheld food for 12 hours and then gave rats food plus sugar water. This created a cycle of binging where the animals increased their daily sugar intake until it doubled. When researchers either stopped the diet or administered an opioid blocker the rats showed signs common to drug withdrawal, such as teeth-chattering and the shakes. Early findings also indicate signs of relapse. Rats weaned off sugar repeatedly pressed a lever that previously dispensed the sweet solution.