Updated Thu. Dec. 21 2006 7:32 PM ET
CTV.ca News Staff
A new study has found that overweight adults who took daily supplements of a common dietary fat actually lost weight -- and kept it off during the holidays.
In the new study published in the International Journal of Obesity, University of Guelph applied nutrition professor Andrea Buchholz and her colleagues at the University of Wisconsin-Madison studied 40 overweight people.
"They tended to lose the weight over their abdomens, which was particularly exciting because that abdominal fat is the fat that's really metabolically active," Buchholz told CTV News.
"It's associated with an increased risk of heart disease and diabetes."
Half of the study participants were given daily supplements of 3.2 grams of conjugated linoleic acid (CLA) for a period of six months which overlapped with the holiday season.
The other half of the study participants receive placebo pills.
CLA is a naturally occurring form of fatty acid, a type of polyunsaturated fat, which is found in dairy products and meat.
Though there were no differences between the two groups in regards to calorie intake or physical activity, the CLA group still managed to trim down prior to the holiday season and didn't gain any weight even during the late-year binge.
Within the placebo group, holiday weight change was significantly greater in comparison with the pre-holiday period, Buchholz said.
During November and December, the CLA group lost weight while the placebo group gained 1.5 pounds of fat mass.
Even though both groups reported less physical activity during the holiday period, the CLA group still managed to reduce body fat mass.
Over the course of the six-month study, the CLA group lost a total of 2.2 pounds of fat, especially around the abdomen.
Peter Jones, director of the University of Manitoba's Richardson Centre for Functional Foods and Nutraceuticals, says the study is important because the holiday season is associated with weight gain and negative health markers such as cholesterol.
But he added that more human studies need to be done.
"We are putting together a national conference to try and unravel the questions around CLA in June here in Winnipeg," he said.
"We're planning to bring not just national experts but international experts, to try and understand why some of the human studies show it works and understand why some others suggest it doesn't work."
Animal studies suggest CLA is effective by turning up the body's thermostat and burning off fat cells, but human data has been inconsistent.
There are different forms of CLA and studies that mixed the two more common forms together showed the greatest promise, so the researchers decided to give their participants a mixed-form capsule of CLA.
All of the study participants had a body mass index of between 25 and 30 and were between the ages of 18 and 44.
The researchers also took blood samples at the beginning and end of the study to determine whether there were any risks from taking the supplementary form of CLA.
"We looked at effects on liver function, inflammation and insulin resistance and found no adverse effects," Buchholz said.
"It looks as though there are very few risks in taking the mixed-form supplements (which can be found in pharmacies and health-food stores) and lots to be gained."
CLA is already available in stores because it is a natural supplement.
Though the results indicate CLA could play a role in mitigating weight gain associated with the holiday season, researchers caution that the supplement has its limitations.
"Additional studies are needed before prolonged use of CLA can be recommended," the study says.
An alternative to taking the supplement is consuming the fatty acid from food sources.
"Many studies show that low-fat dairy products are helpful in maintaining low body weight, which can probably be partly attributed to the CLA," Buchholz said.
With a report from CTV's Avis Favaro and Elizabeth St. Philip