Research on rats reveals connection between binge eating, food addiction

By Chika Anekwe
Princetonian Staff Writer

The researcher

The side wall of psychology professor Bart Hoebel's office is lined with dozens of storage boxes. One is labeled "salt," another "self-stimulation," yet another "crave." Then there is the cluster of boxes resting prominently on top of a file cabinet, each labeled, "Food Addiction."

Food addiction — or more technically, "the neural basis of appetite" — has been the focus of Hoebel's research for the past 47 years. Initially looking to study brain mechanisms that control eating and are also involved in drug addiction, Hoebel's research led him to study whether food can be addictive.

What they did

Hoebel and his students placed rats on different feeding cycles, then observed their behavior in response to those cycles and subsequent changes in the brain.

"We had to create an animal model with an eating disorder that might reflect food addiction," he said.

What they found out

His research has shown that a prolonged cycle of binge feeding on sugar induces dependency in rats by causing them to become dependent on their own natural brain opiates. The experiment involved placing rats on a cycle of no food for 12 hours, followed by 12 hours of regular food plus a sugar solution. Hence, the rats were binge feeding on sugar for alternating 12-hour spans. As time progressed, the rats consumed an increasing amount of the sugar solution.

After about three weeks, the rats experienced an increase in brain receptors for opiates and dopamine. Opiates are chemical messengers that identify sweet tastes as desirable, while dopamine is a chemical messenger that works with memory to urge people to pursue sweet tastes in the future.

When an injection of an opiate-blocker was administered, the rats experienced withdrawal symptoms, including teeth chattering, body quivering and anxiety. The rats were essentially "getting addicted to their brains' own morphines," Hoebel said.

Another component of the study examined lasting changes in the behavior of sugar-addicted rats after ten days on a normal diet. Sugar whet the rats' appetite for chow more than usual, and the animals were hyperactive to amphetamine, a chemical that releases dopamine.

What they concluded

These conclusions taken together show that sugar binging can cause "lasting changes in the brain, in that sensitization remains after a period of normal feeding," Hoebel said.

Yet, as Hoebel emphasizes, "It's not just the sugar, but how and when you eat it." In rats, binge eating promotes addiction, "just like binge drinking alcohol promotes alcohol addiction."

What is said about addictions

Addiction involves three stages: increased intake of a substance, followed by withdrawal symptoms upon deprivation and signs of craving and relapse.

Why research?

Hoebel's research could reveal the reasons behind food addiction in humans and could lead to more effective treatment for people with eating disorders.

The researchers advice about not having a food addiction

In the meantime, Hoebel's advice: "If addiction runs in your family, then repeated fasting and binging on sugar or alcohol may lead to an addiction that disrupts your life. You can choose your pattern of intake now when you are young. Otherwise you may not be able to reverse the brain changes later."

And a little more of a snippet…Right now over 50% of women in Britain are on a diet. Research shows that 96% don't work.
Taken from http://www.bbc.co.uk/radio1/onelife/health/addiction/excessive.shtml

Further research by someone else...

The researcher and what he thinks

Mark Griffiths, a professor of gambling studies at Nottingham Trent University, who has researched addictive behaviour for 16 years, believes any activity can produce chemicals in the brain that give the same high as cocaine. 'We are living in the most addictive society the world has yet seen,' he said. 'Society has changed dramatically in the last few years; we're living longer than ever before, we have more spare time, more disposable income and there are more socially excessive behaviours in which we can indulge.

Some statistics

According to the Government, at least one in 25 British people is dependent on alcohol, twice as many as are dependent on drugs, while almost one in four of us boasts an addiction to shopping, a rise of more than 6 per cent in just five years.

More than 370,000 Britons are addicted to gambling, while 6 per cent of 17,251 respondents in a recent online survey met the criteria for compulsive internet use, with over 30 per cent using the net to escape negative feelings.

So are habits addictions?

Hodson is critical of the therapy industry for its open-door policy. 'It's the definition of addiction that is on the increase, not the numbers of those genuinely addicted to anything,' he said. 'It is very distressing to be a compulsive gambler, but addiction is not the right word to describe what is, in fact, a conditioned or compulsive behaviour.'

Hodson also points to the tendency of psychiatrists to classify patterns of behaviour or compulsion.

'The word addiction contains a meaning which takes away the sufferer's freedom of action,' he added. 'It is a destructive word if misapplied. If you are told that you're someone who chooses to do things that are destructive, you have more hope of recovery than if you're told you have no choice.'

'It is a doctor's job sometimes to make moral judgements. I don't care what gets called addiction, as long as we recognise that compared to a drug, alcohol or food addiction, any other compulsion is trivial.'