Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sugar on the brain: Study shows sugar dependence in rats

21.06.2002


Denied sugar, bingeing rats suffered withdrawal



It’s a common refrain: "I’m addicted to sugar." Now a study by Princeton University psychologists suggests that such urges really may be a form of addiction, sharing some of the physiological characteristics of drug dependence.

Although the term "sugar addiction" often appears in magazines and on television, scientists had not demonstrated that such a thing as sugar dependency really exists, said neuroscientist Bart Hoebel, who led the study. Hoebel and colleagues studied rats that were induced to binge on sugar and found that they exhibited telltale signs of withdrawal, including "the shakes" and changes in brain chemistry, when the effects of the sweets were blocked. These signs are similar to those produced by drug withdrawal.


Sugar, said Hoebel, triggers production of the brain’s natural opioids. "We think that is a key to the addiction process," he said. "The brain is getting addicted to its own opioids as it would to morphine or heroin. Drugs give a bigger effect, but it is essentially the same process."

Hoebel emphasized that there are more elements to addiction than bingeing and withdrawal, and that further studies will be needed to complete the picture. Also, it is not clear how closely the findings might apply to humans, he said.

The greatest value of the research, Hoebel said, is that it provides an animal model of sugar dependency, allowing scientists to probe more deeply the connections between food cravings and brain physiology.

As far as the plight of the many people who feel powerless in the face of sugar, it also is not clear how the findings will help, he noted. "Unfortunately, it’s very difficult to treat addictions," he said. "But it does change the way the person might look at it. It puts it in the realm of an addictive disorder rather than a failure of willpower."

Hoebel’s research was published in the June issue of Obesity Research. His co-authors are former undergraduates Carlo Colantuoni, Joseph McCarthy, Caroline Patten and Andrew Chadeayne, visiting researcher Pedro Rada and graduate student Nicole Avena.

"I think the results are interesting and exciting and provide a new way of looking at overeating," said Harry Kissileff, a psychologist and specialist in human food intake at Columbia University. Kissileff agreed that Hoebel’s rats offer an important model system, but said he would be cautious about using them to put sugar in the same category as drugs.

"There is some overlap between the systems that control food intake and addiction," Kissileff said. "I am not sure they necessarily make food addictive."

In their experiments, Hoebel and colleagues in his lab started rats on a pattern of bingeing by withholding food for 12 hours when the rats were sleeping and through breakfast time, then giving them nutritionally balanced food plus sugar water. The animals gradually increased their daily sugar intake until it doubled, consuming most of it in the first hour it was available.

When the researchers suddenly removed the sugar portion of the rats’ diet, the animals exhibited teeth chattering, a common sign of withdrawal. For some animals, the researchers removed the sugar and also administered a dose of a drug that blocks the opioid receptors in the brain. In addition to teeth chattering, those animals showed anxiety and a reversal in the usual balance of neurochemicals in the brain’s motivation system.

Animals that binged on normal food with no sugar and received the opioid blocker did not show these withdrawal signs. Animals that were given a steady diet of food and sugar water without binging also did not show signs of withdrawal.

"The implication," said Hoebel, "is that some animals, and some people, can become overly dependent on sweet food, particularly if they periodically stop eating and then binge. This may relate to eating disorders such as bulimia."

Hoebel noted that his rats should be termed "sugar-dependent" rather than addicted, because he has not yet proven that they exhibit all the elements that make up the definition of addiction, which is three-fold: a behavioral pattern of increased intake and changes in brain chemistry; then signs of withdrawal and further changes in brain chemistry upon deprivation; and third, signs of craving and relapse after withdrawal is over. Experiments in Hoebel’s lab so far have shown the first two points, while ongoing experiments are investigating craving and relapse in the rats.

Steven Schultz | EurekAlert!

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>