One in two Australian women and one in three Australian men over 60 years old will have an osteoporotic fracture. But you don’t have to become another statistic, says dietitian Caitlin Reid.
Every eight minutes, another Australian is admitted to hospital with an osteoporotic fracture. Alarming, isn’t it? Worse still, by 2021 this amount is expected to double. And once you’ve had an osteoporotic fracture, your risk of having another increases. In fact, roughly 50 per cent of fracture sufferers have a second one, with fracture risk increasing again with every subsequent fracture. This ‘fracture cascade’, as it’s called, can result in serious pain, deformity, disability and even premature death. But there’s good news: for many people, osteoporotic fracture can be prevented or at least, the risk of fracture reduced.
What is osteoporosis?
Osteoporosis is a disease in which bones become fragile and more likely to break. It is characterised by reduced bone density and quality, which causes bones to weaken and subsequently increases fracture risk.
Often referred to as the ‘silent thief’, osteoporosis can progress without any symptoms until a bone breaks. The hip, spine, humerus (upper arm), ribs or wrist are among common fracture sites, although a fracture can occur anywhere. Hip fractures impair a person’s ability to walk, while spinal fractures also have serious consequences, including loss of height, severe back pain and deformity.
Why do we get it?
It’s easy to think of bone as solid and lifeless, but it’s actually a living tissue, which is constantly being renewed. Throughout life, old bone is lost and removed by cells called osteoclasts, while new bone is built by osteoblasts; a process of removal and formation that’s usually balanced, thereby maintaining skeletal strength.
However, once we’ve reached a stage of bone development called peak bone mass (when our bones are strongest), our bone strength very slowly begins to decline. It’s this peak bone mass, and the resulting rate of bone loss, that are the major determinants of osteoporosis development.
Peak bone mass occurs around the age of 20, which explains why childhood and teenage years are critical times for bone growth and development. About 60–80 per cent of peak bone mass is genetically determined, but other factors, such as calcium and vitamin D intake, physical activity levels, hormonal status and lifestyle factors such as smoking and alcohol consumption, can all be of influence too.
Preventing osteoporosis: The Don’ts
As there is a strong predisposition to osteoporosis risk, prevention is not always possible. However, everyone has the ability to reduce fracture risk and minimise the effects, if we choose to follow a healthy lifestyle, be physically active, get enough sunlight and eat a healthy, balanced diet rich in calcium. Here are some guidelines for healthy bones.
A lifetime of dieting is likely to lead to an inadequate intake of important bone nutrients such as calcium, which increases the risk of developing osteoporosis. On top of this, maintaining a low body weight reduces the mechanical load placed on an individual’s bones, which is a cause for concern because bones respond to mechanical stress such as body weight by stimulating formation of osteoblasts – the bone-building cells – thereby improving bone strength.
The other issue with dieting involves the weight gain that invariably occurs when people cease their diet regimen. Incidentally, carrying excess weight is a separate danger, as having a BMI above 30 can increase the risk of becoming immobile, developing osteoarthritis and falling. A healthy body weight (a BMI of 18.5–24.9), achieved through a healthy, balanced diet, is best for bone health.
Don't be afraid to weight train
The myth that weight-training encourages bulky muscles makes many women hesitant to exercise with weights. In fact, weight-training not only results in a slimmer appearance and stronger muscles – it builds bone strength. When it comes to exercise, bone is exactly like muscle: it actually responds by getting stronger, resulting in increased bone mineral density in adolescents, maintained bone density in young adults and slower bone loss in older adults. According to US research, exercising regularly can reduce the risk of developing osteoporosis by 59 per cent (although it cannot reverse advanced bone loss).
Performing at least 30 minutes of weight-bearing exercise, such as brisk walking or running on most days of the week, as well as 2–3 weekly weight-training sessions, will help maintain strong bones.
Don’t stop your daily yoga or tai chi sessions, either – these non-impact exercises do not increase bone strength, but they do improve balance, posture and functional movements, which can help to decrease the risk of falls and broken bones.
Don't cut out alcohol completely
You know the saying: “everything in moderation”. And alcohol is no exception to the rule. Recent research from Tufts University in the US found that although moderate alcohol consumption is actually beneficial for bones, bone mineral density is lower in men who drink more than two standard drinks each day. Similar results have been found in women too.
So why can alcohol negatively affect bone? Too much of it interferes with bone growth and the replacement of bone tissue, which leads to decreased bone density and increased risk of fracture. During adolescence, alcohol consumption can reduce peak bone mass, producing weaker bones in adulthood. In adults, alcohol consumption inhibits the function of osteoblasts and interferes with vitamin D production, which all disrupt calcium balance. Excess alcohol also plays havoc with hormone production by reducing testosterone levels in men and oestrogen levels in females, both of which increase osteoporosis risk.
If you don’t drink, there’s no need to start now, but if you do, enjoy it in moderation: no more than two standard drinks each day and at least two alcohol-free days each week.
Don't cut out dairy
Contrary to what people may think, dairy products should only be removed from the diet if there is a medical reason, such as a cow’s milk allergy or lactose intolerance. Dairy products (or calcium-fortified soy alternatives) are extremely important for bone health: 99 per cent of your body’s calcium is stored in bones and teeth. The remaining one per cent can be found circulating in your body, where it plays a tightly regulated role in heart health, muscle and nerve contraction, and blood clotting. If we don’t eat enough calcium, circulating levels of calcium are maintained at the expense of our bones.
Optimising calcium intake early in life can reduce the likelihood of pre-pubertal bone fractures and increase peak bone mass in adults by 5–10 per cent, which has the potential to reduce fracture risk by more than 50 per cent in the later years. To optimise bone health, adults should aim for 1000–1300mg of calcium each day (for kids’ recommendations, see www.nrv.gov.au).
Don't stay inside all day
Instead of sitting in at your desk during your lunch break, go out and soak up some sun. UV rays are the best source of vitamin D – a fat-soluble vitamin that increases absorption of calcium and phosphorus in the gut, maintains calcium levels in the blood, and helps strengthen the skeleton. Without your daily dose of sun, you’re at risk of developing misshaped or thin, brittle bones, leading to deformities and fractures.
So how much sun is enough? Well, this depends on the season, the amount of skin exposed, the amount of time exposed and skin colour. In general, exposing 15 per cent of your body to the sun for 6–8 minutes a day in summer and about 20 minutes in winter, will help to ensure you reach your daily vitamin D requirements.
Preventing osteoporosis: The Do's
Do limit salt intake
Bone health is just another reason to watch your salt intake. According to research, salt (sodium chloride) intake directly affects the amount of calcium our bodies excrete in urine. And the more salt we eat, the more calcium we excrete.
For every 2300mg of sodium (or about 6g of salt) consumed, urinary calcium excretion rises by 20–60mg, which is quite alarming considering the average Australian consumes 3600mg of sodium or 9g of salt each day.
Luckily for us, our body has the ability to compensate for this form of calcium loss by increasing calcium absorption in the small intestine. But there’s a danger here if you’re not eating enough calcium – then, the amount of calcium your body absorbs will be less than needed to offset salt’s effects, so your body will take the calcium it needs from your bones instead.
So, for strong healthy bones and to reduce your risk of heart disease and stroke, limit salt intake to no more than 6g per day (2300mg of sodium).
Do add milk to your coffee
Too much caffeine can reduce bone density. This is because caffeine produces a small increase in urinary calcium excretion and a very small decrease in calcium absorption. If your calcium intake is less than 750mg per day, a daily caffeine intake equivalent to about three cups of brewed coffee is enough to promote bone loss.
But research shows that this effect can be negated with a diet containing adequate calcium, as the body can balance out caffeine’s effects by reducing calcium excretion later in the day. To help ensure adequate calcium intake, try drinking your coffee with milk and limit caffeine consumption to no more than 300mg per day (equivalent to six teas, three instant/plunger coffees, or one to two regular espressos).
Do eat protein
Some studies have shown that increasing protein intake can sometimes increase urinary calcium excretion, potentially resulting in weaker bones.
But that’s no reason to avoid protein – particularly when these studies have generally been conducted with pure protein rather than dietary sources such as milk, which contain other bone-friendly components such as phosphorus.
In longer-term studies, protein’s negative effect on bone is not seen, which suggests it simply may take a while for the body to adjust its response to a change in protein intake. According to 2007 research, high protein intakes were found to be associated with higher bone mass, as long as calcium intakes were above 600mg each day.
Studies in the elderly have also linked low protein intake to increased bone loss.
For healthy bones, make sure you include protein in your diet, along with sufficient calcium.
Do stop smoking
Despite the majority of Australians being non-smokers, 25 per cent of men and 21 per cent of women are still risking their bone health by lighting up. In fact, smokers have been found to have significantly lower bone mass than non-smokers. It’s thought the cadmium in cigarettes lowers bone density.
According to research, smoking is estimated to increase lifetime fracture risk by 31 per cent in women and 40 per cent in men. According to research published in the Journal of American College of Nutrition, a diet with more than 750mg of calcium per day may slightly lower this risk. For the strongest bones however, the best advice is not to smoke at all.
Calcium supplements and heart disease
Many studies have suggested that women with higher calcium intakes not only have improved bone health but also a lower risk of cardiovascular disease. However, two recent studies have raised questions about the protective effect of calcium supplements on cardiovascular disease. Research published in theBritish Medical Journal found that more heart attacks occurred in post-menopausal women (average age 74 years) who took calcium supplements, while a study published earlier this year found the same results in women aged 52–62. However, a similar study of calcium supplementation has shown no increase in heart disease risk in women taking calcium supplements. While more research is needed, what remains vital for the health of elderly women is balancing this potentially detrimental effect against the likely benefits of calcium supplements on the bone. At present, calcium supplementation guidelines remain the same, but as with any health issue, it’s important to consult your doctor to determine what’s best for you.
How to manage your osteoporosis
If you’ve been diagnosed with osteoporosis, there are three important steps to take. Firstly, you will be placed on medications to prevent further bone loss and fractures. Then, appropriate exercise can be prescribed by an Accredited Exercise Physiologist. Lastly, a healthy balanced diet, focusing on the essential bone nutrients, will be prescribed. Increasing calcium intake, getting more vitamin D, and reducing alcohol and salt intake are all important dietary changes to make for people with osteoporosis. For people who can’t get enough calcium through their diet, a calcium supplement of 500–1000mg is often recommended. It’s also important to get at least 400–600IU of vitamin D each day, however if you cannot get this, a vitamin D supplement of at least 400IU per day is recommended. But before taking any supplements it’s best to consult your doctor.
Are you at risk? Take our quiz
Do you have a small frame and low body weight?
Have you broken a bone as an adult?
Have you taken long-term medications or drugs?
Is your diet low in dairy products or other calcium rich foods?
Are you a post-menopausal woman?
Have you experienced early menopause?
Do you get less than 20 minutes of sunlight every day?
Are you physically inactive?
Do you smoke?
Do you drink excessive amounts of alcohol?
Answered ‘yes’ more than three times? See your doctor.
Expert comment: Don’t be a statistic
“There are some scary statistics out there on osteoporosis… people don’t realise how much it affects lives. It’s the major reason for people going into nursing homes. Every Australian should be doing more to keep their bones healthy.”
Caryl Nowson, Professor at Deakin University and scientific advisor to Osteoporosis Australia.
Fast fact: Osteoporosis literally means 'porous bones'.