Estrogen, the female reproductive hormone, plays an important role in every woman’s health. After menopause, when estrogen levels in your blood drop, your body undergoes many changes. You can develop urinary tract infections, your skin may become more fragile, and your bones can weaken, leading to an increased risk of osteoporosis, or thinning of the bones that can lead to fracture. In fact, statistics show about 20% of Caucasian women and 50% of African-American women over the age of 50 have osteoporosis, as do 20% of Asian-American women and 10% of Latina women in the same age group. But why does the loss of estrogen affect your bones and what can you do to reduce the risk of developing osteoporosis? Bone Health and Remodeling Your bones are constantly rebuilding (remodeling) throughout your lifetime. Starting at birth, old bone reabsorbs into the body as new bone is formed. Bone mass then usually peaks in the 20s, when the balance begins to change. As people get older, they lose bone mass more quickly than it is replaced. Woman have the highest risk of quicker bone mass loss and osteoporosis, mostly due to the loss of estrogen after menopause. Estrogen is essential in helping build bone mass, along with calcium, vitamin D, and other hormones and minerals. Estrogen works by stopping your body from producing an enzyme that prevents bone cells from growing. Without it, bone loss is more likely and more severe, potentially leading to bone fractures and other complications. Causes of Osteoporosis Osteoporosis has several causes, but the most common one is estrogen loss post-menopause. Post-menopause osteoporosis can occur any time in a woman’s life after she stops ovulating, whether this happens naturally with age, is caused by a medical condition, or is induced by surgery to remove the ovaries. The earlier you undergo menopause, the longer you’re left without the benefit of estrogen’s protection, which in turn raises your risk of osteoporosis. Certain illnesses can also affect your bone health, such as hyperthyroid disease, conditions that affect food absorption, and cancer, to name a few. Some types of medications can prevent bones from rebuilding, such as corticosteroids, as can medications used to treat seizures, gastric reflux, and cancer, as well as drugs that prevent transplant rejection. Osteoporosis and Estrogen Some estrogen is produced by your adrenal glands and fat tissue, but for younger women, most of the hormone is produced by the ovaries. However, after menopause, the ovaries completely stop producing estrogen. Without this hormone, bone cannot rebuild as quickly or efficiently and the lack of estrogen actually speeds up the bone loss process. During the first five to seven years post-menopause, women can lose up to 20% of their bone mass. Estrogen is considered the female hormone, but men need it to maintain bone mass as well, although their estrogen levels are not as high. Because men don’t have ovaries to produce estrogen, they don’t undergo a sudden loss of estrogen like menopausal women. Therefore, men’s risk of developing osteoporosis is lower than women’s. Women who are post-menopausal can replenish estrogen levels with hormone replacement therapy, either alone or in combination with another hormone called progestin. Hormone replacement therapy was once a standard treatment for women post-menopause to manage many symptoms, including hot flashes and mood swings. However, research has shown that hormone replacement therapy does have certain health risks. Some women taking estrogen can develop heart disease, stroke, blood clots and breast cancer. Now, current guidelines state estrogen after menopause is recommended only for women at increased risk of developing osteoporosis who can’t tolerate other types of medications to treat the condition. And although it’s recommended that women who do take estrogen start during the early stages of menopause while the bones are strongest, many experts say there are still benefits up to 10 years after menopause. Osteoporosis Prevention Osteoporosis prevention can begin early in life, by strengthening your bones as much as possible. But it’s never too late to start doing weight-bearing exercises. Weight-bearing exercises include energetic activities like aerobics, running, and dancing, but there are other exercises that also benefit your bones, such as climbing stairs, walking, yoga, and tai chi. Unlike weight-bearing exercises, strength training doesn’t improve bone strength, but if you build up muscle strength, the muscles can help protect your bones and lower your risk of falling at the same time. What you eat throughout your life is also important in preventing osteoporosis. Calcium is key for strengthening and building bones, so look for calcium-rich foods like dark green vegetables, dairy products, and sardines and salmon. Vitamin D helps your body absorb and use the calcium in your diet, so seek out foods that also include vitamin D, such as fatty fish and fortified dairy products. Osteoporosis is not inevitable, but as women go through menopause, their risk for losing too much bone mass does rise. Speak with your doctor about the best approach to reduce your risk of post-menopause osteoporosis.