As we begin this new decade, and the first of the Baby Boomers move through their 60s, researchers and doctors may begin experiencing the fruition of a long-held theory:
Boomer women may be more prone to osteoporosis than any other generation, due to early exposure to lead.
In 2004, researchers at the University of Rochester, supported by a grant from the National Institutes of Health, began a long-term study of the relationship between exposure to lead during childhood, and diagnosis of osteoporosis later in life.
The theory: lead in the bones can cause osteoporosis. It can also slow down healing after fractures; and skew the results of DEXA scans, which measure bone mineral density.
We've long known that early exposure to high levels of lead can slow children's physical and mental growth. What we didn't know is that it can also affect children's bone growth plates, which ultimately determine skeletal density in young adulthood - the time when our bones attain their peak density.
Long-term, exposure to lead, and absorption of lead into the bones, may be responsible for up to 10% of the lowered bone density we experience later in life. If lead stops our bones from reaching their maximum density when we're in our 20s, we're working with bones that are already "thinner" than normal once we reach our 60s.
Why is this predicted to be an issue for Boomers, more than earlier or later age groups?
Because Boomers, as a group, were routinely exposed to high levels of lead during childhood. Leaded gasoline was common, as was lead paint on the walls of your home, and lead pipes carrying drinking water to the faucet.
Today, we know lead exposure is bad. Back then, we didn't know how deadly lead could be; no one thought twice about babies chewing the lead-painted bars of their cribs, or breathing gasoline fumes, or the normal, regular flaking of lead-painted walls into the rooms where we ate, slept, and breathed.
Dr. Edward Puzas, leading the University of Rochester research team, notes that preliminary studies have shown lead disrupting the normal process of bone breakdown and buildup, causing the bones to skew more towards breakdown. Once women reach menopause, lack of estrogen speeds bone breakdown even more. So Boomer women entering menopause might be expected to lose bone at a faster rate than women not exposed to high levels of lead during childhood.
Puzas and his team are not only studying incidence of osteoporosis diagnosis in Boomer women, but how well their fractures heal, if they do break a bone. Previous animal studies have shown that lead can affect healing speed for fractures; Puzas et. al. will seek to replicate those results using human data.
Finally, it appears that lead can interfere with the chief method doctors use to determine bone density, the DEXA scan. Puzas theorizes that lead can make a person's bones appear more dense than they actually are, by a factor of up to 11%. ""It's frustrating to think that we could be helping people with osteoporosis, but we're not because the lead in their bones is masking the disease," Puzas said, in an interview on the University of Rochester Web site.
What's your takeaway here?
If you're a Boomer woman, childhood exposure to lead may make you more prone to osteoporosis than you thought.
What can you do about that?
Follow a healthy lifestyle: exercise, good diet, and the avoidance of excess alcohol and tobacco. And when your doctor says it's time to start osteoporosis screening, don't put it off. That first baseline DEXA might reveal bone loss you never suspected.