Apple peel compound boosts calorie burning, reduces obesity in mice

June 20, 2012

Obesity and its associated problems such as diabetes and fatty liver disease are increasingly common global health concerns. A new study by University of Iowa researchers shows that a natural substance found in apple peel can partially protect mice from obesity and some of its harmful effects.

The findings suggest that the substance known as ursolic acid reduces obesity and its associated health problems by increasing the amount of muscle and brown fat, two tissues recognized for their calorie-burning properties.

The study, which was published June 20 in the journal , was led by Christopher Adams, M.D., Ph.D., UI associate professor of and a Faculty Scholar at the Fraternal Order of Eagles Diabetes Research Center at the UI.

"From previous work, we knew that ursolic acid increases muscle mass and strength in healthy mice, which is important because it might suggest a potential therapy for muscle wasting," Adams says. "In this study, we tested ursolic acid in mice on a high-fat diet -- a of obesity and . Once again, ursolic acid increased skeletal muscle. Interestingly, it also reduced obesity, pre-diabetes and .

"Since muscle is very good at , the increased muscle in ursolic acid-treated mice may be sufficient to explain how ursolic acid reduces obesity. However, we were surprised to find that ursolic acid also increased brown fat, a fantastic calorie burner. This increase in brown fat may also help protect against obesity."

Until quite recently, researchers believed that only infants had brown fat, which then disappeared during childhood. However, improved imaging techniques have shown that adults do retain a very small amount of the substance mostly in the neck and between the shoulder blades. Some studies have linked increased levels of brown fat with lower levels of obesity and healthier levels of blood sugar and , leading to the suggestion that brown fat may be helpful in preventing obesity and diabetes.

The UI team, which also included Steven Kunkel, Christopher Elmore, Kale Bongers, Scott Ebert, Daniel Fox, Michael Dyle, and Steven Bullard, studied mice on a high-fat diet over a period of several weeks. Half of the animals also received ursolic acid in their high-fat food. Interestingly, mice whose diet included ursolic acid actually ate more food than mice not getting the supplement, and there was no difference in activity between the two groups. Despite this, the ursolic acid-treated mice gained less weight and their blood sugar level remained near normal. Ursolic acid-treated mice also failed to develop obesity-related fatty liver disease, a common and currently untreatable condition that affects about one in five American adults.

Further study showed that ursolic acid consumption increased skeletal muscle, increasing the animals' strength and endurance, and also boosted the amount of brown fat. Because both muscle and brown fat burn calories, the researchers investigated energy expenditure in the mice and showed that ursolic acid-fed mice burned more calories than mice that didn't get the supplement.

"Our study suggests that ursolic acid increases and brown fat leading to increased calorie burning, which in turn protects against diet-induced obesity, pre-diabetes and fatty liver disease," Adams says. "Brown fat is beneficial and people are trying to figure out ways to increase it. At this point, we don't know how ursolic acid increases brown fat, or if it increases brown fat in healthy mice. And, most importantly, we don't know if ursolic acid will benefit people. Our next step is to determine if ursolic acid can help patients."

Explore further: Findings in mice have potential to curb obesity, Type 2 diabetes

More information: dx.plos.org/10.1371/journal.pone.0039332

Related Stories

Findings in mice have potential to curb obesity, Type 2 diabetes

July 5, 2011
Scientists at the National Institutes of Health have uncovered a pathway in mice that allows white fat – a contributor to obesity and type 2 diabetes – to burn calories in a way that's normally found in brown fat ...

Orexin: A hormone that fights fat with fat

October 4, 2011
The fat we typically think of as body fat is called white fat. But there's another type—known as brown fat—that does more than just store fat. It burns fat. Scientists used to think that brown fat disappeared after ...

Calorie-burning brown fat is a potential obesity treatment, researchers say

June 6, 2011
A new study suggests that many adults have large amounts of brown fat, the "good" fat that burns calories to keep us warm, and that it may be possible to make even more of this tissue.

A new candidate pathway for treating visceral obesity

May 6, 2012
Brown seems to be the color of choice when it comes to the types of fat cells in our bodies. Brown fat expends energy, while its counterpart, white fat stores it. The danger in white fat cells, along with the increased risk ...

Recommended for you

Nearly 4 in 10 U.S. adults now obese (Update)

October 13, 2017
(HealthDay)—Almost forty percent adults in the United States are now obese, continuing an ever-expanding epidemic of obesity that's expected to lead to sicker Americans and higher health care costs.

Tenfold increase in childhood and adolescent obesity in four decades, new study finds

October 10, 2017
The number of obese children and adolescents (aged 5 to 19 years) worldwide has risen tenfold in the past four decades, according to a new study led by Imperial College London and the World Health Organization (WHO). If current ...

Working night shifts may widen your waistline

October 4, 2017
(HealthDay)—Workers who regularly pull overnight shifts may be more prone to pack on the pounds, a new analysis suggests.

Weight loss for adults at any age leads to cost savings, study suggests

September 26, 2017
Helping an adult lose weight leads to significant cost savings at any age, with those savings peaking at age 50, suggests a new Johns Hopkins Bloomberg School of Public Health study.

U.S. pays a hefty price for obesity

September 26, 2017
(HealthDay)—A U.S. adult who is "healthy" but obese could eventually cost society tens of thousands of dollars in medical care and lost wages, a new study estimates.

Living near fast food outlets linked to weight gain in primary school children

September 11, 2017
Children with greater access to fast food outlets are more likely to gain weight compared to those living further away, new research suggests.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.