Date: 4 Apr 2020
Dr Candice Chin, MD, BSc Major in Biology.
For many women, when they think of menopause, they also think of bone loss. Menopause is a phase all women go through, but bone loss isn’t something that women necessarily have to experience.
Our bones constantly change through-out life. Bones are broken down, resorbed, renewed or reformed. When bone resorption occurs more quickly than formation, osteoporosis occurs which leads to a loss of bone strength and density, becoming fragile and fracturing easily.
After menopause, there is increased risk of osteoporosis. A loss of ovarian function during menopause has a profound impact on bone health. Peak bone mass occurs on average between 20 to 30 years of age, when the skeleton has stopped growing and bones are their strongest. After the age of 30, we expect more breakdown than buildup. Poor diet, family history and lifestyle are additional risks for increased bone breakdown.
Looking at the 10-year timeframe around menopause, most bone loss occurs during the year before and 2 years after a woman’s last period, hence these 3 years are paramount.
Osteoporotic fracture risk and bone mineral density varies by race and ethnicity. Bone mineral density values are typically lower in Asian women, intermediate in Caucasians and highest in African-American women.
Oestrogen helps preserve calcium in the bone and prevents bone breakdown. Decline in progesterone associated with anovulation, which is evident during perimenopause may represent an additional mechanism for bone loss independent of the circulating oestrogen.
Usually there is no sign of osteoporosis until a fracture occurs, hence it is called the silent disease. For example, osteoporosis of the spine causes loss of height and gradual appearance of rounded and stooped posture.
Therefore, it is important to boost your bone health early. The stronger the bones are early on, the better off women are when bone density declines.
There are ways women can reduce the risk factors for bone loss, thus, preserving bone density. Women don’t know exactly when their last period will take place, so it is best to get started early.
Have a well-balanced diet with fruits, vegetable, whole grains, lean protein, nuts, legumes and low-fat dairy.
Cut down on sugar and processed food.
Cut down on salt. Salty foods lose calcium and increase bone loss.
Caffeine should be taken in moderation. Caffeine causes the body to excrete calcium more quickly. Tea has no adverse effect on bone health.
Cessation of smoking.
Avoid excessive alcohol intake. Alcohol lowers the body’s ability to absorb calcium.
Calcium plays a role in muscular, neurologic and endocrine (hormone) systems. It plays an essential role in building strong bones.
According to National Osteoporosis Foundation, the recommended daily intake for women 19-50 years old is 1000mg of calcium per day and for menopausal women, or over 50’s, it is 1300mg daily. Approximately 60% of calcium intake comes from dairy products. The other 40% comes from bread, cereals, fruits and vegetables. There should be 3 serves of dairy each day (1 serve=250mL milk, 1 tub yoghurt).
Vitamin D needs to be maintained as it helps with calcium absorption and limits bone breakdown. We can get adequate Vitamin D from 5-15 minutes of sunlight mid-morning or mid-afternoon. Vitamin D can also be sourced from fish, beef liver and eggs.
Suggested supplementation is 600IU of Vitamin D for younger than 50 years old and 800IU of Vitamin D for older than 70 years old.
When oestrogen declines, Vitamin K function in the bones also reduces. Vitamin K has a role in bone protein formation, promoting the framework for bones. Vitamin K is sourced from aged cheese, soy beans, dark leafy vegetables such as kale and spinach.
Weight bearing exercises and resistance training
Weight bearing exercises are performed whilst on your feet and are excellent ways to build bone density. Examples include running, walking, dancing, aerobics or tennis. Vigorous exercises give the greatest benefit, such as walking at a fast pace.
Resistance or strength training using weights, machines or dumbbells to create resistance helps build muscle mass and places extra load on limb bones. Swimming is also good as it involves the body moving against the resistance of water.
Physical activities improve muscle strength, balance and fitness and reduces the risk of falls and fractures. A minimum of 30 minutes most days produces stronger, denser bones. The mechanical force of these resistance training exercises encourages growth of new bone cells.
Hormonal transition can increase physical and emotional stress. Stress causes the release of cortisol, the ‘fight and flight hormone’. It may lead to increased cellular death in bone building cells. Over the years, cortisol can weaken bones. Extreme fluctuations of hormones can be damaging and can cause menopausal symptoms. Women can reduce menopausal symptoms by introducing certain herbal supplementation or hormonal replacement therapy.
Bone loss and osteoporosis can be diagnosed by a bone mineral density scan which uses a specialised x-ray technique called dual energy x-ray absorptiometry (DEXA). DEXA is, to date, the most widely available and validated modality for measurement of bone mineral density (BMD) and continues to be the preferred method for assessing osteoporosis.
The National Osteoporosis Foundation (USA) recommends BMD testing for women in the menopausal transition if there is a specific risk factor associated with increased risk such as poor fragility facture. BMD is not indicated if it will not influence treatment decisions. There is currently no recommendation for osteoporosis screening in healthy perimenopausal women.