Scientists find natural way to curb your greed

July 5, 2010

( -- University of Manchester scientists have discovered a naturally-occurring appetite suppressant that could be used to make a diet drug without side effects.

Professor Simon Luckman and Dr Garron Dodd believe the peptide hemopressin, which affects the reward part of the brain responsible for hedonistic behaviour, might treat some aspects of alcohol and drug abuse.

Dr Dodd, co-author of the findings published in the , explains: “It has long been known that the rewarding aspects of feeding behaviour influence our appetite, so that sometimes we eat for pleasure rather than hunger. This is because the cannabinoid system in the brain - a component of the naturally-existing circuitry responsible for reward - is affected by chemicals that are termed ‘agonists’ which bind to its receptors and increase the reward from feeding.

“One such agonist is cannabis - it hijacks the cannabinoid system and leads to what is colloquially referred to as ‘the munchies’. Similarly, when you fast, the brain causes an increase in naturally-occurring agonists. This results in increased hedonic impact so that when you do eat, food tastes better.

“Conversely when ‘’ bind to the receptors of the cannabinoid system, it decreases the reward from feeding. By reducing hedonistic feeding, it is possible to help people lose weight by quenching the desire to eat.”

A synthetic antagonist, Rimonabant, was developed six years ago and marketed as an anti-obesity treatment. As well as acting in the brain to reduce feeding it also acted in peripheral tissues to reduce fat deposition. However, despite its efficiency at reducing body weight in humans, it was later withdrawn from the market due to undesirable side effects such as depression and increased . Dr Dodd believes that naturally-occurring hemopressin may not cause such side effects.

The scientists in the Faculty of Life Sciences, gave mice hemopressin and monitored feeding and other behaviours. They found that while feeding behaviour decreased, importantly, other behaviours were not affected by the natural antagonist. With the synthetic antagonist, feeding behaviour decreased, but other non-specific behaviours, such as grooming and scratching increased. This shows that, unlike the synthetic antagonists, hemopressin specifically affected , acting to potentially reduce hedonistic behaviour without some of the “off-target” effects.

“We now plan to investigate this further,” Dr Dodd adds.

“This is a newly discovered peptide and we do not know yet exactly where it is expressed in the brain. We also need to find out whether it has prolonged actions on body weight. Finally, while our findings are an indication of safety, this cannot be immediately extrapolated to humans. This discovery does however offer new insights into how the brain controls appetite, and opens new avenues by which to manipulate this circuitry and aid the development of anti-obesity treatments.

“The existence of naturally-occurring agents, such as hemopressin, provides attractive targets for drug companies as they may be ‘safer’ in the long term. In addition, as peptides are modified quite easily there is the potential to target their uptake by the body to reduce undesirable .”

Explore further: Appetite – it’s a brain thing

More information: ‘The Peptide Hemopressin Acts through CB1 Cannabinoid Receptors to Reduce Food Intake in Rats and Mice’, Journal of Neuroscience.

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5 / 5 (5) Jul 05, 2010
I'm actually pretty upset that the title author chose to characterize excessive eating as "greed." That's just such a terribly negative way to say it. The fact is that this article demonstrates that eating too much can have little to do with virtue or vice, but merely be a chemical imbalance in the brain.
1 / 5 (3) Jul 05, 2010
The headline plays into the editors socialist bent.
This also begs a question regarding legalizing marijuana.
Some of the same people who support legalizing marijuana also support government action to tax fat and sugar in food and to restrict smoking tobacco.
Anyone else notice the irrationality here?
5 / 5 (2) Jul 05, 2010
Shavera, you are right on. Greed has nothing to do with overeating. Perhaps the author was thinking of the term gluttony. Even that is rather heavy handed to descibe overeating as it implies a moral failing. There are many causes of overeating; none of them have anything to do with a lack of morality. To imply differently is prejudice and bigotry of the highest degree. But then fat people are the last group that it is "OK" to discriminate against. I wonder if they will ever find the gene that causes arrogance?
5 / 5 (4) Jul 05, 2010
The headline plays into the editors socialist bent.
This also begs a question regarding legalizing marijuana.
Some of the same people who support legalizing marijuana also support government action to tax fat and sugar in food and to restrict smoking tobacco.
Anyone else notice the irrationality here?

Socialist bent? Marijuana? How is this relevant?

"some of the same people" doesn't sound like a lot. Of course you would have some people who would act irrationally, this is seen in every movement and group.

Secondly, the views are not irrational. Many people want to legalize marijuana to get if off the streets, away from cartels, and TAX it for revenue. Taxing it would be in agreement with taxing alcohol, tobacco,sugar, and fat. So I am not seeing the contradiction here.
3 / 5 (1) Jul 05, 2010
So how exactly does a side effect of a popular recreational drug equate to a socialist plot? I'm confused here.
3 / 5 (1) Jul 05, 2010
overeating and greed are rather related when one looks at a being as a biological entity.

Monetary greed is financial gluttony.

I believe there should have been some work at linking the two behaviors at their root behavior, as written the piece leaves vague a crucial connection which is easily interpreted as offensive.

Monetary greed could be seen as a misapplication of an ancient food consumption mechanism.
not rated yet Jul 05, 2010
There always seems to be some idiot crying socialism for just about everything i thought the idea of legalising mary jane and taxing it would both save and make the govt heaps of cash keep peeps outts prison and reduce organised crime and yet this is socialist?? watcht out for the reds... i mean boogeyman under the bed guys.
But back on topic id like to know what this 'naturally' ocurring compound is found in if its a food what is it if it works how can we try it? or do we have to wait ten years and give hundreds of millions of dollars to drug companies first?
1 / 5 (3) Jul 05, 2010
Pay attention all. If MJ induces cravings for junk food high in fat, sugar, and salt, all being banned around the country, and, smoking is being banned around th given all the negative consequences: junk food and smoking.
Sounds like too many are smoking MJ already given such illogical.
not rated yet Jul 05, 2010
It sounds like he has found a way to invoke 'the reverse munchies' - to fit in socialism/capitalism is something of a non sequitor.

Is counteracting the effects of a drug is bad thing, even or especially if the drug is of dubious legality, I am going to have to revisit my definition of 'bad things'.

But I do not think it is revolutionary.
5 / 5 (1) Jul 06, 2010
Look, I see food, recreational drugs, and many other things as this: One has inclinations to consume certain products, or pursue certain actions, but they must balance those desires against health considerations. The inclinations are often largely a function of neurochemical predisposition, and I think that we, as a society should be a little more understanding with those predispositions, the same as we should be for any neurochemical "abnormality" (defining normal to be a statistical mean, not a moral judgement).
5 / 5 (1) Jul 06, 2010
However, when the pursuit of these inclinations becomes unhealthy (alcoholism, obesity, addiction) people should be persuaded to curb those chemical triggers. I think that this needs to happen through education, legislation, and medical care as appropriate for the situation.
This being said, I'd like to point out that cannabis is not physically addictive like alcohol or tobacco, and has no recorded case of overdose (cf. alcohol poisoning); as such, cannabis is an inclination that has less physical harm than other things we accept in society.
not rated yet Jul 06, 2010
Personally if i was to associate the act of eating when not hungry with a sin i would not have chosen greed as greed is where you take more of something just because you want more than your due. Gluttony fits better although its a poor fit.

Anyway on topic i think this little discovery is a good tool for fighting addiction and helping people eat better. But it is just a tool and to solve these social problems [overeating and drug abuse] more will be needed.

Netherless nice work!
not rated yet Jul 11, 2010
I suggest focusing on the core concepts in this article rather than being distracted by semantics or political agendas. The authors have discovered a mechanism which affects appetite through natural means. Behaviour modification is a preferred option but for some individuals it may not be enough. My question is, are there foods which contain this peptide or stimulate it's production?

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