Wednesday Bubble: osteoporosis – all bets are off!

Posted by Liz on Mar 3, 2010 in bone health, estrogen | 3 comments

Which came first? The chicken or the egg?

When it comes to osteoporosis, all bets are off. Researchers are now saying that age and not estrogen decline is the primary culprit in development of osteoporosis in women. Estrogen simply acts to “accentuate” the negative results.

Aging increases what science refers to as “oxidative stress.” This means that as we age, an imbalance is created between certain molecules that freely circulate in the body (better known as free oxygen radicals) and cause major damage to cell and vessels walls and  the body’s natural ability to fight them off. Not surprisingly, oxidative stress has been linked to numerous chronic illnesses, including cancer, heart disease and diabetes.

In so far as osteoporosis goes, the loss of estrogen and androgens decrease our natural defenses against oxidative stress in bone in particular, leading to increased bone breakdown (resorption). The body also starts to overproduce certain hormones that directly affect the the vitality of the skeleton, causing bones to become brittle and more prone to fracture. However, studies also show that bone loss can begin in both women and men as early as age 30 or so, well before any major changes in sex hormone production.

The question is, what can we do about it?

Researchers have also found that there is a specific family of proteins in our bodies that act as a natural defense against oxidative stress. These proteins, better known as FOS (foxhead box transcription factors) are integral to a healthy lifespan and also, preserving bone mass. If researchers can identify what causes the decline in FOS, they may be able to devise strategies to preserve our reserves. Meanwhile, estrogen gets at least a partial reprieve this time.

Sources: Manolagas SC. Endocrine Reviews. 2010.  Ambrogini E. Cell Metabolism 2010;2:136-146.