Even modest exercise can reduce negatve effects of belly fat
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Even modest exercise can reduce negative effects of belly fat
Thursday, April 23, 2009
A new University of Illinois study suggests that moderate amounts of exercise alone can reduce the inflammation in visceral fat—belly fat, if you will—that has been linked with metabolic syndrome, a group of risk factors that predict heart disease and Type 2 diabetes.
"In the study, the benefits of exercise were apparent, even without a change in diet. We saw improvements in insulin sensitivity, less fat in the liver, and less inflammation in belly fat," said Jeffrey Woods, a U of I professor of kinesiology and community health and faculty member in the U of I Division of Nutritional Sciences and the Integrative Immunology and Behavior Program.
Belly fat is particularly dangerous because it produces inflammatory molecules that enter the bloodstream and increase the risk of heart disease and diabetes, he said.
"Scientists now know that obesity is associated with a low-grade systemic inflammation. Obese people have higher levels of circulating inflammatory markers, such as C-reactive protein (CRP), which are produced and secreted by fat tissue. This inflammation then triggers the systemic diseases linked with metabolic syndrome, such as Type 2 diabetes and heart disease," he said.
In the study, Woods and his colleagues examined the effects of diet and exercise on the inflammation of visceral fat tissue in mice. A high-fat diet was first used to induce obesity in the animals. After 6 weeks, mice were assigned to either a sedentary group, an exercise group, a low-fat diet group, or a group that combined a low-fat diet with exercise for 6 or 12 weeks so the scientists could compare the effects in both the short and long term.
"The surprise was that the combination of diet and exercise didn't yield dramatically different and better results than diet or exercise alone," said Vicki Vieira, the lead author of the study.
"Unexpectedly, the only significant increase from 6 to 12 weeks in belly fat—the type of fat that triggers these inflammatory diseases--was in the mice who were sedentary, which suggests that exercise is an effective behavioral approach to reduce the accumulation of visceral fat even when fat in the diet is high," she said.
Woods says that is a promising finding. "The benefits of exercise were apparent even if the animals were still eating a high-fat diet. That tells me that exercise could decrease or prevent these life-threatening diseases by reducing inflammation even when obesity is still present."
"The good news is that this was a very modest exercise program. The mice ran on a treadmill only about one-fourth of a mile five days a week. For humans, that would probably translate into walking 30 to 45 minutes a day five days a week," he noted.
"Even if you struggle with dieting, we believe you can still reduce the likelihood of developing obesity-related inflammatory diseases, such as Type 2 diabetes and heart disease, by adding a modest amount of exercise to your life," said Woods.
These results were reinforced by the scientists' study of sedentary older adults published in a recent issue of Brain, Behavior and Immunity (BBI).
In that 10-month study, one group of sedentary older adults participated in three 45- to 60-minute cardiovascular exercise sessions per week, while another group focused on exercises to improve non-cardiovascular flexibility and balance for 75 minutes twice a week.
"At the end of the study, the 'cardio' group had lower levels of C-reactive protein (CRP), less belly fat, and improved general fitness than the 'flex' group," said Ph.D. candidate Vieira.
"The lower CRP levels were partially mediated by the reduction in trunk fat," she explained.
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University of Illinois at Urbana-ChampaignThanks to University of Illinois at Urbana-Champaign for this article.
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Must exercise liao.....
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Sculpting The Body With Recycled Fat
by Allison Aubrey
A doctor uses a scalpel in a liposuction surgery. Some plastic surgeons have adopted the controversial technique of transferring unwanted fat from the belly, hips and thighs of patients to the breasts and other areas. iStockPhoto.comMorning Edition, June 1, 2009 · Plastic surgeon Dr. David Broadway describes body fat as "liquid gold." He is an early adopter of a controversial technique to transfer fat from unwanted parts of the body — namely the belly, love handles and thighs — to places where it's more desirable — namely the breasts.
"We've been using it in combination with liposuction," says Broadway. "And rather than simply discard that fat, we'll inject it into the breast area."
The idea of relocating — or recycling — fat is not new. More than 100 years ago, a German physician grafted fat from a patient's lumbar region and used it in the breast. And in recent years, fat transfer procedures have been performed as part of reconstructive surgery on breast cancer patients.
Your Mileage May Vary
But pioneers in the field of breast augmentation have learned that transferring fat is complicated, and things can go wrong. The process of extracting it — or sucking it out with liposuction — can damage the fat. And once it's injected back into the body, the fat doesn't always find the blood supply it needs. As a result, only a portion of the fat survives.
"Usually we get 40 to 80 percent of the fat to take," says Broadway. And that means that patients are not entirely sure what the end result will be.
"I knew there were no guarantees," says Christina Stone, a mother of two from Loudoun County, Va., who opted for a fat transfer breast augmentation surgery. She says the idea of using her own fat was a big part of the appeal.
During her procedure, surgeons extracted fat from her abdomen and thighs. But when she woke up after the surgery her hopes of increasing her bust by two cup sizes were dashed. "Immediately I looked down and saw there was no difference — or maybe just little," Stone says. "So I was pretty sad."
Stone had a second surgery, this time to get silicone implants. She says she's now very happy with the results.
Doctors Still Unsure Of Long-Term Risks
Surgeons like Dr. Scott Spear of Georgetown University Hospital want to know more about the techniques used to transfer fat for breast augmentation.
"We're at the beginning of the learning curve," he says. He has initiated a clinical trial to answer some questions about the best way to perform the procedure and whether there are any measurable risks. To date, there are no published studies in the United States, so doctors are relying on their own clinical experience.
Some critics worry that women who opt for fat transfers to the breast may end up with calcifications — small bits of calcium in the breast tissue — that could mask or be confused with tumors. Over a woman's lifetime, the uncertainty may necessitate extra mammograms and/or biopsies, and the anxiety that comes with the screenings.
"It's not a big issue," Spear says. Reports from France and Italy, where the procedure has been performed for more than a decade, suggest that it does not interfere with the detection of breast cancer, he says.
Spear says there's another question: Can the process of injecting fat stimulate anything abnormal to happen? "There's some research that shows in certain animal models that injecting fat can actually stimulate tumor cells to grow more aggressively," he says.
This has not been demonstrated in humans, but Spear says it's an issue researchers may want to address.
The American Society of Plastic Surgeons has issued some guiding principles to surgeons who are performing fat transfer procedures. The society concludes that complication rates associated with the procedure are not "unduly" high, though reports include infection, bleeding, fat embolism and volume loss (fat not "taking").
The group recommends that physicians inform patients before the procedure that there is limited scientific evidence to verify the safety and efficacy of fat transfer procedures.
Beefing Up The 'Pecs' With Fat
Broadway and his colleague surgeon Dr. John Millard of Lone Tree, Colo., have pioneered a technique to beef up men's upper torsos by injecting fat into the muscles.
"I like to describe the augmentation of the male pectoralis muscles this way," says Millard, "we're taking filet mignon and turning it into Kobe beef." Millard and Broadway are promoting the technique by teaching other surgeons how to perform it.
According to Brad Hamilton of Toronto, who has had the procedure, the results make him look as if he's been working out for years. "It actually defines and enhances your muscles."
Hamilton says he knows these procedures are still in their infancy, and there are no guarantees that the results will last.
But he says, at 45 years old, as gravity pulls ... he's pushing back.
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I prefer not to go under the knife for weight loss.