Can the pill make women's bones stronger?

Dr. Judith Reichman 'Today' show contributor • Profile • E-mail

Good bone development is the best way to fight the onset of osteoporosis, but with the news that 40 percent of women with fragile bones are destined to suffer fractures, we don't seem to be winning the battle. Gynecologist and contributor Dr. Judith Reichman was invited to appear on "Today" to discuss a study which looked at the possible link between birth control pills and the prevention of osteoporosis.

Women continue building their bones until the age of 30. This engineering feat of both growing and strengthening our body’s support system is dependent on nutrition, calcium, exercise and our estrogen levels.

Most of us think that osteoporosis is an old person’s disease, but doesn’t it start in childhood and adolescence?
Yes. Bones amass 90 percent of their mineral content by the time we are 18. This is done through an extremely active breakdown and building process which occurs in three-month cycles. Bone eating cells called osteoclasts drill small cavities that are then filled and expanded by bone-building cells called osteoblasts. With proper nutrition, calcium and good estrogen production, the filling of these cavities outpaces the drilling, and our bones increase their density until we are 30; this is the age of peak bone density and the baseline from which our bones will support us in the future. From here, filling may not compensate for drilling due to declining osteoblast function and gradual loss of bone mass. In our 40s, this occurs at a rate of 0.5 percent per year. Add to that the estrogen loss of menopause, and bone loss accelerates to 2 to 3 percent per year for the first five to 10 years post menopause. 

Those children, adolescents and young women who both had, and did, everything right — good bone genes, proper nutrition, adequate calcium, exercise and appropriate estrogen levels — will reach a personal best that will allow them to withstand this later, inevitable bone loss. They are not likely to suffer from osteoprotic fractures as they get older. But those who begin their 30s with a low bone density will be among the 40 percent of women whose fragile bones are destined to fracture.

What can we do to ensure that our children appropriately build their bones?
We have to make sure they’re getting the right nutrition from infancy, and that includes good sources of calcium. Too many people believe that this mineral is important only as we get older.  Studies have shown that children who are milk avoiders and who have a low calcium intake have a 2.5-fold increase in fractures during childhood when compared to children who are milk consumers. This break-bone factor continues and “grows” as they grow old. So once we’ve stopped breast feeding, (a great source of calcium) we either need to make sure our children drink calcium-fortified formula, cow's milk or calcium-fortified soy milk, or take calcium supplements. 

The National Osteoporosis Foundation suggests that we get the following amounts of calcium according to our age:

Recommended calcium amounts, milligrams/day
Birth to 6 months                         210
6 months to 1 year                       270
1 to 3                                        500
4 to 8                                        800
9 to 18                                      1,300
19 to 30                                     1,000
31 to 50                                     1,000
51 to 70                                     1,200
70 or older                                  1,200

Remember that when calcium supplements are given, no more than 500 or 600 milligrams can be absorbed at once, so if you’re not getting enough calcium through your food and you decide to supplement, don’t try to do it all in one dose. 

What are the risk factors for osteoporosis during those bone-building years?

Eating disorders; excessive exercise; low body weight: All of these conditions are correlated with very low body fat and low production of estrogen, which often is clinically noticeable as a lack of a period (for longer than six months or at very irregular cycles).

Only on TODAY.MSNBc.com! Dr. Judith Reichman addresses your questions about women's health. LAST WEEK: Will removing my ovaries prevent cancer? GO TO ALL HEALTH TUESDAY COLUMNS

Cigarette smoking: This decreases the laying down of new bone in young individuals and increases the breakdown and reabsorption of bone as we get older. A 30-year-old who has smoked since her teens ages her bones by at least a decade and reaches menopause with 10 percent less bone mass than nonsmoking women. This translates to a 45 percent increase in future risk of fracture. If she continues to smoke, this increase may become as high as 250 percent. 

Use of steroids: There is increased risk for osteoporosis for those who use steroids for more than three months or for those with a chronic use of steroid inhalers.

Other factors:

• Calcium deficient diet
• High caffeine intake. This is most worrisome when caffeinated drinks replace milk
• A petite body frame
• Family history of osteoporosis
• Medical conditions such as overactive parathyroid or mal-absorption or Cushing’s disease 

What about birth control pills, which help supply the body with estrogen?  Can the pill help prevent osteoporosis?
In the past, doctors felt that the pill would actually help combat low bone density mass, especially when given to girls who have late puberty, miss their periods, were very thin, athletic and/or had eating disorders. We know that estrogen helps activate the bone-building cells (osteoblasts). One of the major reasons for our bone loss in menopause is indeed lack of this estrogen. When it’s low in the early years of life, it may result in even more disastrous changes. When the pill was given to these young women with low estrogen levels, they became regular and it was felt that this helped their bones. Even if the pill was used for the usual reasons; birth control, cramps or heavy bleeding, there was little concern about any negative effect on bone building. On the contrary, doctors felt it would provide hormone bone protection and extra bone endurance for the future. But new findings from the Women’s Health Initiative (WHI) appear to contradict the “pills are good for our bones” assumption.

Tell us about this study.
The WHI is best known for its reports on hormones. But that was just a small portion of the research. Much of this observational study was designed to address the impact of biological lifestyle, biochemical and genetic factors, as well as cancer, heart disease and osteoporosis in large numbers of women between the ages of 50 and 79. They followed more than 80,000 women in 40 centers in the USA for two and a half years. These women were asked at the onset of the study whether they had ever taken birth control pills, from what age and how long. The incidence of fracture in these women was then assessed annually. Those women who had used birth control pills during their reproductive years did not have a decreased risk of fracture or osteoporosis years later when they were menopausal. As a matter of fact, there was a small, but statistically significant, increased risk of fracture among previous birth control users.

Do researchers know why birth control pills increase risk of menopausal fractures?
No. Reports on oral contraceptive use and actual bone mineral density have been conflicted. Some studies suggest that when birth control pills are used in younger women (age 20 to 30), they inhibit bone mineralization and the positive effect of exercise on bone mineral density. When given to older women who no longer are building bones (30 to 50), oral contraceptives may decrease bone turnover, i.e. there is less drilling and formation of small cavities, and these women are less likely to be adversely effected and may even end up with a higher bone mineral density. The WHI researchers suggested that the study results may also be somewhat affected by the fact that women who had hormonal problems and irregular periods, and hence lower pre-menopausal bone mineral densities, were more likely to use the pill to “regulate” their periods. This may have made it appear that the pill, not their underlying condition, was at fault for a mild increase in their fracture risk years later.

Dr. Reichman's Bottom Line: Should women be considered at risk for fracture if they’ve used birth control pills? No. But they and their doctor should not assume that previous birth control pill use would strengthen their bones or decrease their future incidence of fracture. Each one of us needs to assess our risk from childhood up to our senior years, and if these risks are worrisome, have bone density studies and treat low bone density and osteoporosis under current guidelines.

Birth control pills give us contraceptive and cycle support, but we can’t rely on them to support our bones. We have to do that with nutrition and exercise, by not smoking, and if necessary, with appropriate medications.

Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," which is now available in paperback. It is published by William Morrow, a division of HarperCollins.

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