The three major health fears that plague women as they get older are developing breast cancer, becoming demented, and breaking a hip.
For context, the risk of a woman dying of breast cancer by her 85th birthday is 1 in 43 while dementia is now the leading underlying cause of death in Australian women.
As for hip fractures (strictly speaking, these are fractures of the femur, or thigh bone, rather than the hip itself), the risk rises steeply with age:
But current medical science offers little of value to women (or men) who want to keep their bones strong.
- Bone mineral density scans are next to useless for identifying people who are at increased risk of fracture (see my article The great osteoporosis scam).
- Osteoporosis drugs such as Fosamax do not prevent fractures in women with low bone density but no previous fractures and are only of marginal benefit to women who are at greatly increased risk of fracture density; their side effects include an increased risk of fracturing the shaft of the femur, oesophageal reflux and cancer, and osteonecrosis of the jaw (see my article 5 reasons to think twice before taking osteoporosis drugs).
- The new kid on the osteoporosis treatment block, Prolia (denusomab), is of uncertain benefit for fracture prevention but does increase the risk of infection.
- Eating more calcium in your diet, or taking calcium supplements, does not reduce the risk of suffering a bone fracture and may even increase it (see my article For strong bones, avoid excess calcium!), while also increasing your risk of heart attack, acute abdominal conditions and in the elderly, death (see my article 5 reasons to think twice before taking calcium pills.
- Vitamin D supplements are unlikely to prevent hip or other fractures, while high dose vitamin D supplements increase the risk of falls and fractures in older women.
So what’s a concerned older individual supposed to do, to protect his or her bones? Exercise!!!!! Never was the adage ‘use it or lose it’ more true, than in the case of bone.
Wolff’s law, formulated in the 19th century by German anatomist and surgeon Julius Wolff, states that bone grows and remodels in response to the forces that are placed upon it.
Remove the force of gravity from bone and it atrophies, as we see in astronauts, who lose 1-2% of their bone mass for every month they spend in space.
Remove the force of muscles pulling on bone, as we see in people who are confined to bed rest due to surgery, serious illness, or complications of pregnancy, and bone loss – especially in the leg bones – occurs almost as rapidly as in astronauts.
However, providing resistive exercise equipment to astronauts not only prevents bone loss; they actually return to Earth with higher bone density than when they went into space.
And training programs involving jumping exercises prevent bone loss from prolonged bed rest.
Two important studies highlighting the role of exercise in bone health have been published recently.
The first, a Cochrane review titled ‘Exercise for preventing falls in older people living in the community‘, found that exercise reduces the number of falls by 23%.
The second, a cohort (population follow-up) study title ‘Association of Physical Activity and Fracture Risk Among Postmenopausal Women‘, found that higher total physical activity was associated with lower total and hip fracture risk, but sedentary behaviour was associated with a higher risk of fracture.
Let’s unpack the Cochrane review first. Falls are a major risk factor for hip fracture, as well as causing significant pain and suffering in older people who bruise more easily and have poor wound healing. Any intervention that decreases the risk of falls in this vulnerable population is worth doing.
The review summarised the results from 108 randomised controlled trials which involved a total of 23 407 participants (75% women; average age 76) from across 25 countries.
The effect of exercise on falls prevention was dramatic: compared to a norm of 850 falls in 1000 people in this age group over the course of one year, exercise would result in 195 fewer falls.
Regardless of whether participants in these trials were judged to be at an increased risk of falling or not, exercise also reduced the number of people who fell one or more times in a year, by 15%.
The best exercises for falls prevention were those that involved balance and functional training, while programs that combined multiple types of exercise – such as balance, functional exercise plus resistance exercises – were judged to probably reduce falls, and Tai Chi was rated as a ‘maybe’ for reducing falls.
There was insufficient evidence to determine whether exercise programs that were mainly comprised of resistance exercises, dance, or walking were effective at preventing falls, while there was no evidence to determine the effects of flexibility or endurance exercise on falls.
Now let’s look at the study on exercise and fracture risk. This one followed over 77 000 postmenopausal women (aged 50 to 79 years) enrolled in the Women’s Health Initiative prospective cohort study for an average of 14 years, tracking their activity level and incidence of bone fractures.
They found that total physical activity was inversely associated with the risk of suffering a hip fracture – that is, the more activity the women did, the lower their risk.
Walking, mild activity, moderate to vigorous activity and yard work were all found to reduce the risk of hip fracture.
Mild activity was also associated with lower risks of clinical vertebral fracture (that is, a spinal fracture that causes symptoms) and total fractures (hip, spine, wrist and other sites combined).
On the other hand, sedentary time was positively associated with total fracture risk – that is, the more time women spent sitting down each day, the higher their risk of breaking a bone, although having a higher total activity level offset this risk to some extent.
On the minus side, women who were the most active had a higher risk of knee fracture and moderate to vigorous activity (e.g. running) was positively associated with wrist or forearm fracture.
Falls are a major risk factor for both of these types of fractures, highlighting the importance of balance and functional training – as discussed in the Cochrane review – in older people. As we age, the sensory systems which help us maintain our balance decline; hence, even physically fit older people should engage in balance training to prevent falls.
The results of the Women’s Health Initiative study add to an already substantial body of research indicating that exercise is by far the most effective strategy for reducing the risk of bone fracture as we age. They echo the findings of an earlier Cochrane review, ‘Exercise for preventing and treating osteoporosis in postmenopausal women‘, which found that while 11 women out of 100 who did not exercise had a fracture, only 7 women out of 100 who exercised had a fracture.
The bottom line: Exercise, and in particular combination exercise programs that incorporate balance, resistance/strength training, functional training – that is, whole body workouts that build muscles that you use in everyday life and enhance your ability to perform daily life activities such as getting out of a chair – and walking, is the most effective strategy that we have for preserving bone strength and reducing fracture risk. And perhaps most importantly, it’s completely within your control and its ‘side effects’ are almost entirely good ones, such as improved mood, easier weight control and better sleep.
If you have been inactive for a long time, have suffered an injury, have never done strength or balance training before, or have any other condition that affects your ability to exercise, find an exercise physiologist – EPs are specifically trained to help you exercise safely and effectively, no matter what health conditions or limitations you are currently suffering.
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