Source: DGNews  |  Posted 1 year ago

By Louise Gagnon

TORONTO -- October 19, 2010 -- A high-protein diet wards off bone loss in
postmenopausal women who are not yet osteoporotic, concludes a study presented
here at the American Society of Bone and Mineral Research (ASBMR) 2010 Annual
Meeting.

“There are various factors that lead to loss of bone when are you losing
weight, including a decrease in insulin-like growth factor and a decrease in
calcium absorption,” explained presenting author Deeptha Sukumar, MSc, Rutgers
University, New Brunswick, New Jersey, speaking at an oral presentation here on
October 15. “These 2 factors are affected by higher protein intake,” said
Sukumar. “We were asking the question if there is an increase in protein intake
during weight loss, if that can prevent the weight-loss-associated loss of bone
mass.”

Sukumar and her fellow researchers enrolled 47 women in a 1-year study and
placed them on either a high-protein diet, where protein made up 24% of
calories, or a normal-protein diet, where protein represented 18% of total
daily calories. Both groups of women had a fat intake of 28% of total calories,
explained Sukumar, noting patients received equal amounts of calcium and
vitamin D.

Investigators conducted statistical analysis to find greater loss of bone
mineral density at several sites in women who ate a normal-protein diet
compared with their counterparts who ate a high-protein diet. There was a
statistically significant difference in bone resorption favouring women who
consumed a high-protein diet compared with those who consumed a normal amount
of protein.

In addition, investigators observed bigger increases in insulin-like growth
factor-1 and insulin-like growth factor binding protein-3 in women who consumed
more protein.

“The clinical takeaway message is that if you are a postmenopausal woman and
dieting, if you can take 24% of your total calories as protein, and have
adequate calcium and vitamin D, you can prevent the bone loss that is typically
associated with weight loss,” said Sukumar.

Sukumar noted that increased protein intake in this study came from animal
sources and not plant sources.

Funding for this study was provided by the National Institutes of Health.

[Presentation title: Insulin Like Growth Factor and Bone Mass Is
Influenced by Higher Protein Intake During One Year of Caloric Restriction.
Abstract FR0432]