Interesting, although when I recently went to a Brazilian steakhouse I couldn't eat that much meat.
http://www.alphagalileo.org/ViewItem.aspx?ItemId=169704&CultureCode=en
A common end-product of digested protein – phenylalanine – triggers
hormones that make rodents feel less hungry and leads to weight loss,
according to a new study presented today at the Society for
Endocrinology annual conference in Brighton. A better understanding of
the mechanism by which protein diets cause weight loss could lead to the
development of drugs and diets that tackle the growing obesity
epidemic.
Hormones drive our appetite by telling us when we are hungry, and
when we are full. Ghrelin is a hormone that tells us when we are hungry.
In contrast, high levels of the hormone GLP-1 tell us when we have had
enough food and tell our bodies to stop eating. Understanding the
mechanisms by which hormones affect our feeding patterns may help
identify new ways of treating or preventing obesity. Previous studies
have shown that protein-rich diets encourage weight loss by making
people feel fuller, though these diets are difficult to adhere to and
the mechanisms by which this happens is unknown.
In this study, researchers Mariana Norton and Amin Alamshah from
Imperial College London ran a number of experiments on both mice and
rats. In the first experiment, they gave 10 rats and mice a single dose
of phenylalanine, a chemical produced in the gut when our body breaks
down protein-rich foods, such as beef, fish, milk and eggs. In the
second experiment, diet-induced obese mice, which are typically used as a
model of human obesity, were given phenylalanine repeatedly over seven
days. Both experiments compared their results to the same number of
rodents that were not given phenylalanine.
The researchers found that the single-dose of phenylalanine reduced
food intake, increased levels of GLP-1 and decreased levels of ghrelin.
Repeated administration also caused weight loss in the obese mice. The
researchers also observed that the rats were moving around more, which
might encourage them to lose weight.
To understand the mechanisms by which phenylalanine might be
stimulating these hormones, the researchers carried out a final
experiment by studying gut cells in a petri dish. They found that
phenylalanine interacted with a receptor called the calcium sensing
receptor (CaSR), and that it was CaSR in turn causing levels of GLP-1 to
increase and appetite to decrease.
“Our work is the first to demonstrate that activating CaSR can
suppress appetite,” said lead author of the study Mariana Norton. “It
highlights the potential use of phenylalanine or other molecules which
stimulate CaSR – like drugs or food components – to prevent or treat
obesity.”
According to Miss Norton, the precise mechanisms by which
phenylalanine suppresses appetite and body weight still need to be
determined, and there are likely to be additional mechanisms which are
also involved in the beneficial effects of a high protein diet.
The researcher’s next steps will be to establish whether
phenylalanine can produce the same effects in humans as in mice, and to
further confirm the importance of CaSR in our response to protein-rich
foods.
No comments:
Post a Comment