Dietary oil may need help in avoiding any side effects of weight loss...

http://www.physorg.com/news126958040.html

Dietary oil may need help in avoiding any side effects of weight loss

An oil made of natural fatty acids that is sometimes used as a weight-loss
supplement may need to be paired with hormones or other substances to
prevent health problems that can follow rapid weight loss, a new study
suggests.

Conjugated linoleic acid (CLA), a compound naturally found in some meat and
dairy products, can reduce body fat in some studies in humans. But a recent
study in mice found that the hormone leptin adds an element of protection
against side effects that can accompany fat loss with CLA.

Without leptin, fat loss occurs in mice eating a diet containing CLA, but
the mice also become insulin resistant. When mice are fed CLA and given
leptin, the same fat loss occurs but insulin resistance does not develop.

So though leptin is not essential to the fat loss, it has important
protective effects to maintain insulin sensitivity, said Martha Belury, lead
author of the study and associate professor of human nutrition at Ohio State
University.

"Fat loss is not dependent on leptin but if we didn't have leptin, CLA could
have some short-term effects on insulin resistance," Belury said.

The study appears in a recent issue of the Journal of Lipid Research.

CLA is an essential fatty acid found naturally in trace amounts primarily in
beef, lamb and milk. Synthetic forms of CLA are marketed as supplements that
help reduce body fat.

But continuing research shows that there are consequences associated with
the loss of fat. Because fat in the body is energy, it has to go somewhere
if it is not burned away by metabolism. When CLA is driving fat out of fat
tissue, the fat tends to end up in the liver or in muscles. If that fat
can't
be used, insulin resistance results. So Belury and colleagues are trying to
find out precisely how CLA works to reduce body fat and how to prevent any
associated side effects.

"You can reduce body fat, which is a good thing for a person trying to avoid
diabetes. But if that body fat is lost too rapidly, the fat has to go
somewhere else and in mice, it creates insulin resistance," Belury said.
Sometimes, insulin resistance can lead to Type 2 diabetes.

In the animal study, Belury and colleagues tested the effects of leptin by
using mice genetically engineered so they have no leptin in their bodies.
These mice consume a lot of food and their metabolism is disrupted, so they
tend to be quite overweight and are called fatty mice.

"Our thinking was that if you lower body fat, you also lower leptin levels.
So if we have a mouse that has no leptin, what does CLA do then?" Belury
said.

To create controls for comparison, the researchers gave leptin back to some
of the fatty mice. Then they fed regular diets or diets containing CLA to
all of the mice to observe the effects of CLA and regular diets with and
without leptin present.

Finding that CLA diets can result in weight loss with or without leptin was
a new finding. But more significant to understanding the mechanism, the
study showed that insulin sensitivity was restored when CLA was fed with
leptin present.

That finding answers just one of many questions about possible side effects
associated with CLA-induced loss of body fat. The role of fat tissue in
regulating metabolism is complex. It stores energy in the form of fat and
also produces hormones essential to the metabolism, or burning, of the fat
tissue.

In addition to continuing animal studies on CLA's interaction with hormones
and other conditions associated with metabolism, Belury is leading parallel
human clinical trials on the effects of CLA. So far, the research has shown
that CLA can reduce body fat in postmenopausal women with Type 2 diabetes.
Another trial is investigating whether CLA can suppress weight gain in
people who are gaining weight because of a drug they take for diabetes
management.

"People can safely take CLA, but we don't know the most effective dose for
weight loss and how long people should take it. We think there are probably
some subpopulations that shouldn't take it, but we don't know for sure yet,"
she said.

Source: Ohio State University

--

Ken

"Buddhism elucidates why we are sentient."
"Buddhism follows thought throughout the Universe."
"Karma means that you don't get away with anything."