Bone Health in Menopause
I bet you know someone who has low bone density, or perhaps you have it yourself. In Australia 66% of the population over 50 has Osteoporosis or Osteopenia. That’s a huge number of people who are at increased risk of breaking a bone, and the majority are women, with Menopause having a large role to play. Estrogen has a big role to play on the ability of our bones to regenerate. When we start to lose Estrogen, our bones ability to regenerate declines. A female’s bone mass starts to reduce in their 30’s, however this is at an increasing rate in the first 1-2 years after Menopause. Females are at a greater risk of Osteoporosis and Osteopoenia (the first stage of Osteoporosis), see below.
Firstly, some stats - 1 in 2 women over the age of 65 will have an Osteoporotic fracture at some point in their lives. 50% of people who have one fracture will have another. If it is a hip fracture, there is a big increase in mortality risk, 1 in 4 people over the age of 65 will die within 1 year of having a hip fracture (3,4). Folks, this is not good!
Secondly, some definitions. Osteoporosis is when bone becomes weaker and less dense and is therefore at greater risk of breaking. Osteopenia is when bone density is less than normal but not as severe as Osteoporosis.
Bone is metabolically active and is in a constant state of renewal. Old or damaged bone is removed and then replaced with new bone. Approximately 10% of our bones are turned over each year in this way. In our younger years, our bodies make bone faster than old bone is broken down which culminates in our peak bone mass being achieved in our mid to late 20s. From here our bones will gradually lose mass as we age - this is normal age-related bone loss. For females, Estrogen deficiency after menopause accelerates the loss of bone. In the 5-6 years around Menopause, women can lose 10-20% of bone (1). This is why Post-Menopausal women are particularly susceptible to Osteoporosis or Osteopenia.
So how do you know if you have Osteopenia or Osteoporosis? To answer this, you would normally have a Duel X-ray absorptiometry (DXA) scan. This is a relatively quick and easy scan that measures the bone density of your spine and hip. The DXA scan will give you a T-score and if your score is below -2.5 you would be diagnosed as having Osteoporosis. If the T-score is between -1 and -2.5 a diagnosis of Osteopenia would be given. Your doctor will use your T-score along with other information to determine your fracture risk and from here an appropriate treatment plan can be put into place.
So now let’s discuss treatment, and this is where exercise really shines. The right exercise has a loading and growth effect on bone so it can supplement where your Estrogen reduction might be letting you down. Not all exercise is equal however when looking at improving bone strength. For exercise to be effective it needs to act against gravity and be weight bearing, this means that swimming and cycling will have no discernible impact on bone density. Walking, interestingly, also has little to no effect on bone (2). Research to date gives us two clear types of exercise that DO improve bone health. The first is weight bearing impact exercise and the second is resistance training.
Weight bearing impact exercise may involve jumping, hopping and bounding, but there are also lower impact options such as marching, heel drops, stair climbing and stomping. If you are a beginner, the more effective high impact options are obviously a more advanced exercise, however you could even just start with 1-2 jumps on the spot and work up from there. Sports like tennis, netball and others that have some impact and are stop start in nature may also help. If you have joint pain or injuries (including pelvic floor dysfunction) this can also add complexity however a skilled exercise professional such as an Exercise Physiologist would easily be able to assist you with an appropriately prescribed and graded program, specific for you.
Resistance training is exercise to strengthen muscles, and can be performed using weights, resistance bands or your bodyweight. As your muscles get stronger and pull on your bones during resistance training, the bones will respond by becoming stronger themselves. The key is to ensure the weights become progressively heavier, so that the muscles and bones continue to become stronger and stronger. Evidence suggests high intensity weight training (ie heavy weights and lower repetitions) has a much greater effect on bone density than light loads. A simple check here might involve a load you might only be able to lift 6 times (with maybe 1-2 reps to spare) but is very hard, compared to a load you might be able to lift 10-15 times. But you dont start with this, you work up. Again, an Exercise Physiologist can assist with an appropriate and graded program for you.
A third type of exercise should always be included for those with low bone density. Balance. Balance training won’t improve bone density, but it will help reduce falls and resulting fractures.
Other things you can do is ensure you get enough Calcium, Vitamin D (which helps your bones absorb Calcium) and Protein (Protein helps your muscles stay strong and powerful so the loading on your bones is optimal). Females are often deficient in all 3.
In summary, exercise can help in the management and treatment of osteoporosis or osteopenia by reducing your likelihood of falling (and fracturing) through improved muscular strength and balance. Exercise can also increase the strength of bones which will also make them less likely to fracture. Exercise can have a growth and loading effect which can supplement your declining Estrogen. For females, the health of your bones when you are young and leading into Menopause can make a massive difference on how much you lose when you are Post-Menopausal. If you have young females, have them starting the right type of exercise and bone health lifestyle while they are young as research shows it starts there.
References:
1. Meng-Xia Ji and Qi Yu Primary osteoporosis in postmenopausal women. Chronic Dis Transl Med 2015 Marl 1(1): 9 – 13
2. B. Beck et al. Exercise and Sports Science Australia (ESSA) position statement on exercise prescription for the prevention and management of osteoporosis. J Sci Med Sport. 2017 May;20(5):438-445
3. Arthritis NSW. Osteoporosis statistics. https://www.arthritisnsw.org.au/osteoporosis/osteoporosis-statistics/#:~:text=1%20in%202%20women%20and,an%20osteoporotic%20fracture%20in%20Australia.
4. Australian Institute of Health and Welfare. Hip Fracture Care Pathways. https://www.aihw.gov.au/reports/chronic-musculoskeletal-conditions/hip-fracture-care-pathways-in-australia/summary
