Higher amounts of fat in your liver, muscle and blood could lead to weakened bones, according to a new study.
Researchers from Harvard Medical School found that people with higher amounts of fat in these places also had higher amounts of fat in their bone marrow. Fat in the bone marrow has been linked in previous research to weakened bones; stem cells in bone marrow can either turn into fat cells or osteoblasts (which are cells that are integral to bone formation).
"Bone marrow fat makes bones weak," study researcher Dr. Miriam A. Bredella, M.D., who is an associate professor at Harvard and a radiologist at Massachusetts General Hospital, said in a statement. "If you have a spine that's filled with fat, it's not going to be as strong."
The study, published in the journal Radiology, involved using proton magnetic resonance spectroscopy on 106 men and women between ages 19 and 45 to gauge how much fat is in their livers, muscle and bone marrow. All the study participants were obese but healthy.
Researchers found that those with high levels of fat in their livers and muscle had more fat in their bone marrow, even after taking into account factors such as physical activity level and body mass index. And those with more fat in their bone marrow were more likely to experience a bone fracture. Meanwhile, an association was found between "good" HDL cholesterol and lower levels of fat in bone marrow.
They also found that high levels of triglycerides in the blood (which is a type of fat) were linked with higher levels of bone marrow fat.
Past research in mice has suggested that exercise could play a role in making stem cells in bone marrow turn to bone, and not fat, The New York Times reported.
And another study, conducted also by Bredella and presented in 2010 at the annual meeting of the Radiological Society of North America, showed that visceral fat (which is the fat that surrounds the organs) is linked with reductions in women's bone mineral density, MyHealthNewsDaily reported.