For years, experts have thought that obesity actually prevented osteoporosis. The reasoning seemed very plausible and the research seemed very sound. But lately, some new research is debunking this dogma using new scientific technology.
In the past, scientist quantified obesity in terms of the body mass index. Those that had a higher BMI did not seem to get osteoporosis. Scientist explained this by showing that fat tissue was a source of estrogen and became a primary source in post-menopausal women. Estrogen protects the bones; so in turn, fat tissue which makes estrogen protects the bones too. Right? Wrong.1
Lately, with new imagery technology, obesity is now being quantified by percent body fat and patterns of distribution. Now, researchers are discovering that fat and osteoporosis have an inverse relationship; the more fat, especially around the waist, the higher the risk of osteoporosis. The more fat in the bone marrow, the higher the risk of osteoporosis; obesity does not seem to be that protective after all.2
Well, this startling discovery has had researchers baffled. Fat tissue is still a major source of bone-protective estrogen, yet that does not seem to matter in some people. The missing link that has been uncovered is inflammation. The levels of inflammation are much higher in many obese people3 because of a syndrome called: metabolic syndrome. Scientists can now measure the level of inflammation in the blood. Those with higher levels of inflammation have a higher incidence of osteoporosis.4 As currently understood now, inflammation has a larger impact on the bones than estrogen.
The link between inflammation and osteoporosis is really nothing new.5 A condition called "inflammatory bone loss" is well known to exist in those with inflammatory diseases like rheumatoid arthritis.6 However, this bridge between osteoporosis and obesity is new and inflammation paves the way between these two problems. Because metabolic syndrome is now known to be a root cause of inflammation, obesity as a component of metabolic syndrome can now considered a risk factor for bone loss. This is quite the opposite of what was previously thought. This update information might someday lead to newer treatments for osteoporosis like more selective bisphosphonates that target inflammation and protects the bones from its wake.7
As science progresses, it is not unusual for theories to evolve and truths to be proven false. That's why it is so important to stay current with the latest information. Now, obesity is considered a risk factor for osteoporosis because obesity promotes inflammation. This debunks what was once thought to be a rare, major benefit of being overweight. It is not surprising that inflammation is the primary culprit contributing to osteoporosis because inflammation has been linked to many problems like heart disease, Alzheimer's and cancer. Ten years from now, who knows what the latest research will show about osteoporosis, obesity and inflammation. One thing is for sure, maintaining good health will continue to prove beneficial for all systems, including the bones.
- Diabetes Metab Syndr Obes. 2011; 4: 273-282
- Curr Osteoporos Rep. 2011 Jun;9(2):67-75
- Nutr Metab Cardiovasc Dis. 2004 Oct;14(5):228-32
- Endocr J. 2011;58(2):87-93
- Curr Osteoporos Rep. 2012 Jun;10(2):101-8
- Nat Rev Drug Discov. 2012 Mar 1;11(3):234-50
- Am J Ther. 2012 May;19(3):228-46