Osteoporosis is a complex disease caused by a progressive imbalance in the activity of the cells involved in bone remodeling. Bone remodeling is the process of repairing wear related microcracks in bone.  This occurs in 10% of bone each year with the entire skeleton being rebuilt every decade. 

Resident bone cells called osteocytes are sensitive at detecting microcracks requiring repair.  The image shows these wear-related microcracks. They activate the process of remodeling first stimulating osteoclast, the cells that remove the worn area.  After 2 weeks of bone removal, osteoblasts, the cells that fill in new bone are given their turn.  This process is shown in the diagram below.  Remodeling is shown as a timeline from left to right.

The activity of the osteoclasts and osteoblasts is in balance up to about age 35.  Beyond that osteoclastic bone removal gets more active, while osteoblastic bone building declines.  This results in a gradual loss of bone mineral density (BMD) of 1-2% each year until menopause, where it accelerates to 3-5% loss per year. 

The cause of this cell imbalance is the gradual decline in estrogen which begins about age 35 with the more pronounced decline at menopause.  Estrogen limits osteoclast activity while at the same time maintaining osteoblast activity preventing bone loss in younger adults.

A key question in treatment is which type of cells should be targeted with therapy, osteoclasts or osteoblasts?  The drug therapies for osteoporosis all go after just one type of cell.  The antiresorptive drugs such as Prolia or Fosamax try to slow osteoclastic bone removal, but they do not enhance osteoblastic bone deposition.  The anabolic drugs such as Evenity stimulate osteoblastic bone deposition but do not slow osteoclastic bone removal.

I think back about the Miller Light commercials https://www.youtube.com/watch?v=argdPEmD9bI in the 1970s trying to get the point across that light beer could be both less filling and taste great.  This series involved two groups arguing about whether this new kind of beer was less filling or tasted great.  The point was it could be both.

You may be wondering what this has to do with osteoporosis.  In a way, a similar debate is occurring; is it better to inhibit osteoclastic bone removal or stimulate osteoblastic bone building. 

The answer seems to be what these commercials were implying, it is best to have both.  This is where the various nutrient therapies fit in. 

Several flavonoids from different herbs have been shown to do both tasks making them ideally suited to osteoporosis. 

The diagram shows the different herbs/flavonoids that have been shown to both inhibit osteoclastic bone removal and stimulate osteoblastic bone building.

I have a saved search on PubMed looking at the research on osteoporosis.  Each Monday I get an update of any new studies and about 100-120 appear each week.  Perhaps 4-8 are looking at natural herbs or their flavonoids as a promising therapy for bone loss.  While a few either inhibit osteoclasts or stimulate osteoblasts, most do both.  It seems like herbs/flavonoids are the light beer of osteoporosis therapy!