Fighting Fat: New Frontiers
Five groundbreaking wieght loss weapons
(Depicted from the Reader's Digest July 2007 cover story)
For the past 20 years, experts have searched for ways to reverse weight gain.
The reasons we gain and lose are complicated, they've learned, and involve
more than just diet and exercise.
Drug can help, of course. Two are currently approved for long-term use:
Reductil works in the brain to suppress appetite; Xenical blocks the
absordption of fat- with unpleasant gastrointestinal side effects for some.
And there's surgery, which is increasingly done laparoscopically but still
has risks. We're all hoping though, for a magic bullet. Biotech and pharma
company are spending millions to develop more powerful pills, gadgets
and procedures to put an end to the condition that can trigger a host of
serious disease- obesity.
This quest isn't easy. "We're finding that many behaviours we don't think
of as genetic often have a genetic basis," says Dr Susan Yanovski, an
obesity expert at the National Institute of Diabetes and Digestive and Kidney
Diseases. "Some people get hungrier sooner than other; some fill up less
quickly." Some binge; others are emotional eaters. And as more research is
done, specific treatments may be discovered to deal with the various causes
of obesity.
"The future is really bright for the development of better, safer and
effective drugs," says Dr Yanovski. "We're going to have more choices to treat
obesity. And they'll be more specific, so you can target the medication to the
patient, as we do in the treatment of high blood pressure," Here, some of the
most exciting advances.
THE GET-THIN PILL
Ask doctors what their biggest hop is for the near future and many will home
in rimonabant. Sanofi-Aventis, the pill's maker, is awaiting approval from the
US Food and Drug Adminnistration; the drug is already available in Europe.
Rimonabant stifles hunger and cravings by targeting the endocannabinoid system,
which plays a role in regulating weight. Cannabinoid receptors throughout the
body are thought to stimulate the cravings; rimonabant blocks the receptors,
knocking out cravings. It also lowers triglycerides and improves HDL- the
good cholesterol.
Experts are excited about the drugs, but agree it's not cure-all. "You can
eat your way through rimonabant- and all obesity treatments," says Dr Mehmet
C. Oz, director of the Cardiovascular Institute at Columbia University Medical
Center in New Yoek City and co-author of You: On a Diet. On the other hand,
one study found that following a healthy diet and exercising regularly, in
conjunction with obesity drugs, made them more effective.
Plus, you can't just take a pill, lose the weight and stop. "You've got to
take obesity medications for a long time, if not for life," says Dr Samuel
Klein, director of the Center for Human Nutrition at Washington University
School of Medicine in St. Louis. "You don't lower your blood pressure with
medication and then say, 'Ok, now I'm going to stop,' If you lose weight and
stop the treatment, it will bounce right back up again. That's been proved
over and over again."
In any case, obesity drugs are reserved for people with a body mass index (BMI)
of 30 and above, or a BMI of 27 or higher with diabetes, high blood pressure or
another complication of obesity. They're not for the "gotta lose those last five
kilos" dieter. And a review of studies found that rimonabant usually only leads
to a five-kg weight loss a year on average.
THE OBESITY VACCINE
Rimonabant is one of dozens of drugs being studied. But the medications that
target the stomach may also be helpful, says Dr Oz. "I think the best drug
will be those that work on the hormones in the gut. By the time you're working
on the brain, it's a little bit late. The stimulus is already coming from the
gut. The best way to influence the gut's signal to the brain to eat." he says.
"That way, you affect all the chemicals in the brain the way they're supposed
to be affected."
To that end, researchers are looking at a hormone called ghrelin, scourge of
yo-yo dieters. When you diet, your body goes into survival mode and ramps up
ghrelin production, which may slow your metabolism, encourage eating and force
your body to retain fat.
A team of scientists at the Scripps Research Institute have found that keeping
ghrelin from reaching the brain may prevent weight gain. When they injected
rats with the so-called obesity vaccine, rats ate normally but gained less
weight and had less body fat than rats that didn't get the vaccine. Of course,
the rats weren't on our high-fat, high-calorie diet.
The vaccine is far from being tested on humans, but it would be intended for
the seriouslt overweight, and might have to be taken for life, says Kim Jinda
PhD, one of the researchers who developed it.
Drugs are promising, but still, regulating your food intake is complicated,
says Dr Klein, since there are so many pathways involved. And even when the
pathways are working, and you eat enough to feel satisfied (not overly full)
, there are environmental triggers like the sweet aroma of fresh-baked cookies
that may lead you to eat though you're not hungry.
"Ultimately, it may take multiple drugs blocking multiple pathways to work,"
he says.
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