As part of the study, the research team set up bottles containing a water solution with HFCS in various cages. The animal models had unrestricted, round-the-clock access to the sweetened solution. The bottles were removed after about a month of voluntary drinking. The researchers observed that exposure to the HFCS solution had an impact on the animals' neural and behavioral responses to oxycodone, a variety of opioid and an active ingredient that induces pharmacological effects such as analgesia, euphoria, and feelings of relaxation. According to the experts, these changes may relatively affect both drug-taking and drug-seeking behaviors.
The scientists observed that the high sugar diet inhibited the oxycodone-induced release of dopamine and therefore stymied the feelings of reward associated with the substance. This may then prompt the body into consuming higher doses of oxycodone. According to the research team, the results demonstrate that nutrition may play a central role in opioid response. Likewise, the findings suggest that preventing unhealthy diets may not only stem obesity but may also help combat environmental factors that spur opioid dependence, the experts stated.
Data from the US National Survey on Drug Use and Health has revealed that about 27.9 million people aged 12 or older used oxycodone products. Statistics have also shown that 4.3 million people in the said age group have misused oxycodone-containing products in the previous year.
A previous study carried out by researchers at the Queensland University of Technology has cautioned that excessive sugar consumption itself should be considered an addiction. The researchers have also warned that excessive, long-term sugar intake may trigger the onset of eating disorders and may cause adverse effects on the behavior. As part of the study, the scientists examined the effects of high sugar intake on animal models and found that a sugary diet resulted in a significant increase in levels of dopamine, a hormone responsible for regulating the brain’s reward and pleasure centers. (Related: Sugar junkie? Study suggests excessive sugar intake is similar to drug addiction.)
The research team has noted that the repeated increases in dopamine levels show a similar mechanism in which the body processes drugs and substances of abuse such as cocaine, morphine, and tobacco. However, the scientists have observed that the body experiences an opposite effect in the long run as dopamine levels start to dwindle. This means that the body may require higher doses of sugar to compensate for the loss of the rewarding feeling, the scientists explained. According to the experts, artificial sweeteners have also yielded a similar addictive effect on animals.
"We have also found that as well as an increased risk of weight gain, animals that maintain high sugar consumption and binge eating into adulthood may also face neurological and psychiatric consequences affecting mood and motivation. Like other drugs of abuse, withdrawal from chronic sucrose exposure can result in an imbalance in dopamine levels and be as difficult as going ‘cold turkey’ from them,” researcher Dr. Selena Bartlett stated in a Science Daily article.
"Our study found that Food and Drug Administration (FDA) approved drugs like varenicline, a prescription medication trading as Champix which treats nicotine addiction, can work the same way when it comes to sugar cravings," Professor Bartlett added.