WASHINGTON (AFP) – Physical exercise can reduce a genetic predisposition to obesity by an average of 40 percent, a new study showed.

The research challenges the notion that an inherited propensity to obesity is impossible to overcome and boosts the case for the benefit of more exercise for anyone looking to shed some weight.

The study, published in this week’s Public Library of American Science Medicine journal, is based on examination of 20,430 people living in Norwich, Britain.

It found most of the study’s participants inherited between 10 and 13 genetic variants known to increase the risk of obesity, with some inheriting as many as 17 variants, and others as few as six.

Using modelling techniques, the researchers found that each genetic variant was linked to an increase in body mass index (BMI) — a measure of body size based on both height and weight.

“Each additional genetic variant in the score was associated with an increase in BMI equivalent to 445 grams (1.6 ounces) in body weight for a person 1.70 meters (5.7 feet),” the study said.

For physically active individuals, the increase was just 379 grams (13 ounces).

That was “36 percent lower than in physically inactive individuals in whom the increase was 592 grams (21 ounces) per variant,” the research found.

Each additional variant also raised the individual’s chances of obesity 1.1-fold, but in physically active individuals, “the increased odds per variant for obesity risk were 40 percent lower.”

Ruth Loos of Britain’s Medical Research Council Epidemiology Unit, who carried out the research, said the study “challenged deterministic view of the genetic predisposition to obesity.”

“Our findings further emphasize the importance of physical activity in the prevention of obesity,” Loos said.

TUESDAY, Aug. 31 (HealthDay News) — Certain types of exercise
may help ease stiffness and pain in dogs with arthritis, a new study
suggests.

Using a special treadmill and a computer program, Austrian researchers
examined the movements of joints in the front and back legs of dogs as
they did three types of exercises: walking uphill, walking downhill and
walking over low obstacles.

They concluded that walking downhill doesn’t appear to provide much
benefit but walking uphill and climbing over low obstacles could both help
dogs with arthritis.

Walking uphill may improve the flexibility of affected joints,
particularly of the hip, while walking over low obstacles may improve the
bending of the joints in the front and rear limbs, said the team at the
University of Veterinary Medicine in Vienna.

Researchers caution that dogs who have recently undergone surgery to
the tibia, however, should probably avoid walking over obstacles since
that could potentially strain the tendon that joins the knee to the
shin.

They added that the exercises don’t require expensive equipment, are
simple and can easily be supervised by dog owners.

“These types of exercises are often recommended to improve the
flexibility of joints in arthritic dogs. Nobody has yet taken the trouble
to test whether they work but we are happy to report that they are of real
benefit to the animals,” researcher Barbara Bockstahler said in a
university news release.

The study appears in the current issue of the American Journal of
Veterinary Research.

More information

The U.S. National Institute of Arthritis and Musculoskeletal and Skin
Diseases has more about arthritis.

TUESDAY, Aug. 31 (HealthDay News) — Exercise can reduce a
person’s genetic predisposition to obesity by 40 percent, finds a new
English study.

Researchers looked at 20,430 people in Norwich and focused on genetic
variants known to increase the risk of obesity. Most people had inherited
10 to 13 of these variants from their parents, but some had more than 17
while others had fewer than six.

The participants also provided information about their levels of
physical activity.

Overall, each additional obesity-related genetic variant was associated
with an increase in body mass index (BMI) equivalent to 445 grams (0.98
pounds) for a person 1.70 meters (5 feet, 6 inches) tall. BMI is a
measurement that takes into account a person’s height and weight.

However, this effect was greater in sedentary people than in active
people, the researchers found. For those with a physically active
lifestyle the increase was 379 grams (0.84 pounds) per genetic variant.
That’s 36 percent less than the increase of 592 grams (1.3 pounds) per
genetic variant for inactive people.

The researchers also found that each additional obesity susceptibility
variant increased the odds of obesity by 1.1-fold. But this risk was 40
percent lower for active people compared to inactive people, the findings
revealed.

The study shows that adopting a healthy lifestyle can benefit people at
increased genetic risk of obesity, the authors explained.

“Our findings further emphasize the importance of physical activity in
the prevention of obesity,” Dr. Ruth Loos, of the Medical Research
Council’s epidemiology unit in Cambridge and colleagues wrote in the
article published online this week in PLoS Medicine.

More information

The U.S. National Heart, Lung, and Blood Institute offers a guide to physical activity.