'Third-helping' hormone found

[Guest guest]

Hi All, The below I could not find in the files, so here it is.

Cheers, Al.

http://www.nature.com/nsu/020805/020805-8.html

'Third-helping' hormone found

Pills that tell the brain you're full might help to fight

obesity.

8 August 2002

HELEN PEARSON

Turning down food from

an all-you-can-eat is a

stiff test of self-control.

Now scientists claim to

have found a natural

'fullness' hormone that

could make it easier to

resist overeating, helping

to fight obesity.

Volunteers injected with

the hormone, called

PYY3-36, helped

themselves to a third less

food from a free spread,

obesity scientist

Bloom of Imperial College

London and his team

found. " It's what stops

you having the third

helping, " he says.

Levels of the hormone

rise when you're stuffed,

and remain high for the

few hours between meals.

Bloom hopes that taking tablets mimicking PYY3-36 before

meals could curb appetite: " You might stop after two

platefuls, " he says.

The treatment might best help those who have lost weight

and are fighting hunger pangs, says Schwartz, who

studies nutrition at the University of Washington in Seattle,

rather than those who want an easy way to shed pounds.

That's because hormones can be overridden by the conscious

decision to eat, which is influenced by food's taste, our

expectations and emotions. Medication won't necessarily

reverse a bad lifestyle, says Schwartz.

Hormonal hunger

Over the past ten years, researchers have discovered a

cocktail of hormones that control how much we eat. They are

thought to have evolved to help us maintain an appropriate

body weight, adjusting the amount we eat when food is

scarce or rich.

The most famous of these is leptin, which is thought to act

over the long term, telling the brain when fat stores run low

and triggering appetite. Other hormones, such as PYY3-36,

act from meal to meal, controlling when we feel hungry, and

hence when we start or stop eating.

Researchers knew that

cells lining the bowel

make PYY3-36 when it

becomes filled with food.

Bloom's team found that

a dose of the hormone

equivalent to that

released during a big

meal suppresses appetite

in mice and humans for

up to 12 hours1. They

propose that it travels to

the brain's hypothalamus,

where it shuts down

nerves that trigger eating.

Bulky, fibrous foods such

as vegetables, which

move further down the gut

before they are fully

digested, stimulate the

release of more PYY3-36

than fast foods, which are

mainly dissolved in the stomach, says Bloom. He suspects

that eating particular types of food could help to tell the

brain that you are full and also prevent overeating.

PYY3-36 is thought to work alongside a 'hunger' hormone

called ghrelin, which the stomach secretes when empty; it

acts on the same nerves in the hypothalamus. Tackling

these central brain systems " is where the obesity treatments

will come from " , says Schwartz.

References

1.Batterham, R.L. et al. Gut hormone PYY3-36

pyhsiologically

inhibits food intake. Nature, 418, 650 - 654, (2002).

[Guest guest]

--- " Alan Pater " wrote:

> http://www.nature.com/nsu/020805/020805-8.html

>

> 'Third-helping' hormone found

>

> Pills that tell the brain you're full might help

> to fight obesity.

I posted this in sci.life-extension yesterday -

it seems relevant to mention here:

I would have posted this to the CR list - but

/

....is currently down.

Here are some news articles from the last

year relating to hormones affecting hunger:

Hormone reduces appetite by a third:

http://news.bbc.co.uk/1/hi/health/2176391.stm

'Hunger hormone' identified

http://news.bbc.co.uk/1/hi/health/1862607.stm

Hunger hormone identified

http://news.bbc.co.uk/1/hi/health/1689858.stm

The Hunger Hormone?

An appetite stimulant produced by the stomach may lead to

treatments for obesity and wasting syndromes

http://www.sciencenews.org/20020216/bob10.asp

Gene for 'Hunger Hormone' Plays Role in Obesity

http://www.lifescan.com/care/news/dn082202-1.html