Tuesday, December 18, 2012

Eating fatty foods  makes you anxious?

Maybe it does if you are a mouse but since fat people are usually seen as jolly,  it seems unlikely that this generalizes to humans.  The normal diet of mus musculus is vegetable matter whereas humans are big meat eaters so a lack of generalization is hardly surprising.  We may be able to handle what mice cannot

The research team feed one group of mice a low-fat diet and a high fat diet to a second group over six weeks, monitoring how the different food affected the way the animals behave.

Fat represented 11 per cent of the calories in the low-fat diet and 58 per cent in the high-fat diet, causing the waist size in the latter group to increase by 11 per cent - not yet obese.

Next, the team used a variety of techniques to evaluate the relationship between rewarding mice with food and their resulting behaviour and emotions. They also looked at the brains of the mice to see how they had changed.

Mice that had been fed the higher-fat diet exhibited signs of being anxious, such as an avoidance of open areas. Their brains were also physically altered by their experiences.

One of molecules in the brain that the researchers looked at is dopamine. It enables the brain to reward us with good feelings, thereby encouraging us to learn certain kinds of behaviour. This chemical is the same in humans as it is in mice and other animals. Certain genes involved in the production of dopamine are controlled by the CREB molecule.

'CREB is much more activated in the brains of higher-fat diet mice and these mice also have higher levels of corticosterone, a hormone that is associated with stress. This explains both the depression and the negative behaviour cycle,' Dr Fulton said.

'It's interesting that these changes occur before obesity. These findings challenge our understanding of the relationship between diet, the body and the mind.

'It is food for thought about how we might support people psychologically as they strive to adopt healthy eating habits, regardless of their current corpulence.'


Ground-breaking anti-depressant eases symptoms in just over an HOUR

Sounds hopeful.  Side effects and habituation may be issues

An experimental drug has been found to lift depression in just over an hour in people who haven't responded to other treatments.

The findings open up the prospect of developing a new fast-working type of anti-depressant.

In a new study, a third of participants responded to the treatment within one hour and 20 minutes, seeing at least a 50 per cent reduction in their symptoms compared to a 15 per cent reduction in those who took a placebo.

This was significant as these patients had failed to improve in seven past antidepressant trials.

However, while their were minimal side-effects the dramatic improvements were short-lived with patients finding relief for an average of just half an hour.

The current range of treatments work through the brain's serotonin system, building up levels of this 'happy' hormone over a period of weeks. This can cause great distress to severely depressed patients as many are at high risk of suicide.

However, the latest drug called AZD6765, acts by preventing the binding of a brain chemical called glutamate to nerve cells.

It acts in a similar way to the Class C drug ketamine, but without the serious side-effects such as hallucinations.

Scientists at the National Institutes of Health, who conducted the study, said this could be because the new drug doesn't block glutamate binding as completely as ketamine.

In the trial half of the 22 patients received the drug through an IV drip, while the other half took a placebo. All of them completed a survey assessing their depressive state immediately after taking the drug and a few days after treatment. The two groups then switched the agent they took and went through the same assessment.

The patients reported only minor side effects, such as dizziness and nausea, when taking AZD6765, which were not significantly different from those experienced with the placebo.

Research leader Dr Carlos Zarate, said: 'Our findings serve as a proof of concept that we can tap into an important component of the glutamate pathway to develop a new generation of safe, rapid-acting practical treatments for depression.'

The team reported their results online in the journal Biological Psychiatry. They now want to do further trials, testing whether repeated infusions a few times per week or higher doses might produce longer-lasting results.


No comments: