Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientist shows link between diet and onset of mental illness

14.12.2010
Changes in diet have been linked to a reduction of abnormal behaviors in mentally ill people or animals, but a Purdue University study shows that diet might also trigger the onset of mental illness in the first place.

Joseph Garner, an associate professor of animal sciences, fed mice a diet high in sugar and tryptophan that was expected to reduce abnormal hair-pulling. Instead, mice that were already ill worsened their hair-pulling behaviors or started a new self-injurious scratching behavior, and the seemingly healthy mice developed the same abnormal behaviors.

"This strain of mouse is predisposed to being either a scratcher or a hair-puller. Giving them this diet brought out those predispositions," said Garner, whose results were published in the December issue of the journal Nutritional Neuroscience. "They're like genetically at-risk people."

Garner studies trichotillomania, an impulse-control disorder in which people pull out their hair. The disorder, which disproportionately occurs in women, is thought to affect between 2 percent and 4 percent of the population.

Mice that barber, or pull their hair out, have been shown to have low levels of serotonin activity in the brain. That neurotransmitter is known to affect mood and impulses. Garner hypothesized that increasing serotonin activity in the brain might cure or reduce barbering and possibly trichotillomania.

Serotonin is manufactured in the brain from the amino acid tryptophan, which is consumed in diets. The problem is that tryptophan often doesn't make it across the barrier between blood and the brain because other amino acids can get through more easily and essentially block the door for tryptophan.

Garner modified a mouse diet to increase simple carbohydrates, or sugars, and tryptophan. The sugars trigger a release of insulin, which causes muscles to absorb those other amino acids and gives tryptophan a chance to make it to the brain.

Using eight times as much sugar and four times as much tryptophan, Garner observed a doubling of serotonin activity in the brain. But the mice that barbered did not get better.

"We put them on this diet, and it made them much, much worse," Garner said.

A second experiment divided the mice into three groups: those that were seemingly normal, others that had some hair loss due to barbering and a group that had severe hair loss. All the mice soon got worse, with conditions escalating over time.

"Three-quarters of the mice that were ostensibly healthy developed one of the behaviors after 12 weeks on the new diet," Garner said.

Some of the mice developed ulcerated dermatitis, a fatal skin condition thought to be caused by an unidentified pathogen or allergen. Garner saw that the only mice that contracted the condition were the scratchers.

"What if ulcerated dermatitis, like skin-picking, another common behavioral disorder, is not really a skin disease at all?" Garner said. "We now have evidence that it may be a behavioral disorder instead."

When taken off the new diet, the negative behaviors stopped developing in the mice. When control mice were switched to the new diet, they started scratching and barbering.

Garner's study raises questions of how diet might be affecting other behavioral or mental illnesses such as autism, Tourette syndrome, trichotillomania and skin-picking. He said that before now, a link between diet and the onset of mental disorders hadn't been shown.

"What if the increase of simple sugars in the American diet is contributing to the increase of these diseases?" Garner said. "Because we fed the mice more tryptophan than in the typical human diet, this experiment doesn't show that, but it certainly makes it a possibility."

Garner next wants to refine the experiments to better imitate human dietary habits, including the amount of tryptophan people consume. Internal Purdue funding paid for his work.

Abstract on the research in this release is available at: http://www.purdue.edu/newsroom/research/2010/101213GarnerTryptophan.html

Brian Wallheimer | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Health and Medicine:

nachricht Rabies viruses reveal wiring in transparent brains
19.01.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht On track to heal leukaemia
18.01.2017 | Universitätsspital Bern

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>