Osteoporosis is a common disease affecting over 1 million Australians. Osteoporosis literally means bones with holes and it occurs when bones lose minerals, such as calcium, faster than the body can replace them. This leads to bones becoming less dense, losing strength and breaking more easily. Osteoporosis particularly affects women in their middle and later years, however men can also be affected. Thankfully, there is plenty that can be done to prevent osteoporosis occurring, or to slow and prevent further bone loss once diagnosed.
Specialised cells form bone, and like the rest of the body, bone is constantly being broken down and renewed. Just like muscle, bone is a living tissue that needs exercise to gain strength. In the early years, more bone is made than is broken down, resulting in bone growth. Bone growth is completed by the end of your teens and around 25 to 30 years of age, peak bone mass is achieved.
Sex hormones, such as oestrogen and testosterone have an important role in maintaining bone strength and bone density in men and women. When a woman goes through menopause, there is a fall in the amount of oestrogen produced which results in increased bone loss. The average woman will lose up to 10% of her total body bone mass in the first 5 years after menopause.
As bones become thinner and less dense, the risk of serious or debilitating fractures increases. Even a minor bump or fall can cause a serious fracture. Any bone can be affected by osteoporosis, but the most common sites are the hip, spine and wrist.
Osteoporosis is often called the “silent disease” as there are usually no symptoms until a fracture occurs. Osteoporosis itself does not cause pain or specific symptoms. If you think you may be at risk of developing osteoporosis, it is important to see your doctor.
Both men and women may have certain risk factors that can make them more likely to develop osteoporosis. Women are at greater risk of developing osteoporosis because of the rapid decline in oestrogen levels during menopause. Men also lose bone density as they age, however testosterone levels in men decline more gradually, so their bone mass usually remains adequate until later in life.
Other risk factors include:
- inadequate amounts of dietary calcium – adults require 1000mg of calcium per day, which increases to 1300mg per day for women over 50 and men over 70
- low vitamin D levels – your body requires vitamin D to absorb calcium, a lack of sun exposure can mean you are not getting enough vitamin D
- lack of physical activity
- excessive alcohol intake
- caffeine intake of more than 3 cups of coffee or equivalent per day
- early menopause (before the age of 45)
- loss of menstrual period if it is associated with reduced production of oestrogen, which is vital for healthy bones (the menstrual cycle can be disrupted following excessive dieting and exercise)
- weight – thin body build or excessive weight (recent studies suggest that hormones associated with obesity may impact bones)
- long term use of medication such as corticosteroids which are commonly for the treatment of conditions like rheumatoid arthritis, asthma and other inflammatory conditions
Some conditions place people at higher risk of osteoporosis, such as:
- thyroid disease or an overactive thyroid gland
- rheumatoid arthritis
- chronic liver and kidney disease
- conditions that affect the body’s ability to absorb nutrients, such as Crohn’s disease, coeliac disease and other inflammatory bowel conditions
Currently the most reliable way to diagnose osteoporosis is to measure bone density with a DXA scan, which is a short, painless scan that measures the density of your bones, usually at the hip and spine. The results of this test will show if your bones are in the range of normal, low bone density or osteoporosis.
What happens if I am diagnosed with osteoporosis?
If you are diagnosed with osteoporosis, your doctor will start you on medication to slow bone loss and reduce the risk of fracture. They will also ensure you have adequate calcium and vitamin D, and a supervised exercise program will be recommended. Your bone health will be closely monitored.
Can osteoporosis be prevented?
The short answer is yes! Your bones require calcium, vitamin D and exercise on a regular basis to stay healthy and strong. Both men and women can take steps from a young age to prevent osteoporosis by making sure that they:
- have a healthy and varied diet with plenty of fresh fruit, vegetables and whole grains
- eat calcium-rich foods
- absorb enough vitamin D
- avoid smoking
- limit alcohol consumption
- limit caffeine
- do regular weight-bearing and strength training activities
Calcium and your bones
Almost 99% of the body’s calcium is found in the bones. Calcium combines with other minerals to form the hard crystals that give your bones their strength and structure. A small amount of calcium is dissolved in the blood which is essential for the healthy functioning of the heart, muscles, blood and nerves.
Bones act like a calcium bank – if you don’t get enough calcium from your diet to replace losses and maintain adequate levels in the blood, the body reacts by withdrawing from your bone bank and depositing it into the bloodstream. If your body withdraws more calcium than it deposits over a long period, your bone density will gradually decline and you may be at risk of developing osteoporosis.
The amount of calcium you need depends on your age and sex. The highest daily requirements are for teenagers (a period of rapid bone growth) and for women over 50 and men over 70.
Eating a healthy, balanced diet with a variety of foods and an adequate intake of calcium is vital to building and maintaining strong, healthy bones. Dairy foods have the highest levels of calcium, but there are many other sources of calcium including sardines and leafy green vegetables, such as spinach and almonds.
If you are unable to get enough calcium from your diet alone, you may need to talk to a health professional about calcium supplements.
Vitamin D is essential as it helps your body to absorb the calcium in your diet. We mostly obtain vitamin D from the sun. Vitamin D forms in the skin when it is exposed to UV from sunlight.
The best source of vitamin D is UVB radiation from the sun. UV radiation levels vary depending on location, time of year, time of day, cloud coverage and the environment.
There are recommendations from the Cancer Council for the amount of safe sun exposure for sufficient vitamin D production depending on your skin type, geographical location in Australia and the season.
Some people may not be able to access the sun exposure required to help them maintain their vitamin D levels. These groups may be at risk of vitamin D deficiency. They include:
- naturally dark skinned people – who need more UV exposure to produce adequate levels of vitamin D as the pigment in their skin reduces UV penetration
- people who cover their skin for religious or cultural reasons
- frail/elderly, chronically ill or institutionalised people who live mostly indoors
- people who are obese
- babies and infants of vitamin D deficient mothers
- people taking particular medications or have conditions causing poor absorption of calcium and vitamin D
- people who avoid sun exposure because they have previously had skin cancer or are at high risk of skin cancer
People in these groups should consult their doctor for advice on whether they need to take a vitamin D supplement.
Vitamin D can also be found in small quantities in foods such as:
- fatty fish (salmon, herring, mackerel)
- fortified foods such as low-fat milks and margarine
However, it is unlikely that adequate quantities of vitamin D will be obtained through diet alone, so again, talk with your health professional about vitamin D supplements if you are concerned you’re not getting enough vitamin D.
Exercise to prevent osteoporosis
Regular physical activity and exercise plays an important role in maintaining healthy bones. A sedentary lifestyle, poor posture, poor balance and weak muscles increase the risk of fractures. Weight-bearing exercise encourages bone density and improves balance so that falls are reduced.
A person with osteoporosis can improve their health with exercise in valuable ways, including:
- reduction of bone loss
- conservation of remaining bone tissue
- improved physical fitness
- improved muscle strength
- improved reaction time
- increased mobility
- better sense of balance and co-ordination
- reduced risk of fractures caused by falls
- reduced pain
- better mood and increased energy
Exercise in the prevention of osteoporosis should include:
- weight-bearing activities such as brisk walking, jogging, tennis, netball or dance – while non weight-bearing exercises such as swimming or cycling are excellent for other health benefits, they do not promote bone growth
- resistance training using free weights such as dumbbells and barbells, elastic band resistance, body weight resistance or weight training machines
- exercises to improve posture, balance and body strength such as Tai Chi, Pilates or Yoga
Ideally, weekly physical activity should include something from all 3 groups. Aim for 30 to 40 minutes, 4 to 6 times per week. Exercise for bone growth needs to be regular and have variety.
Always consult with your doctor, physiotherapist or health care professional before you decide on an exercise program.
Manage Risk Factors
Lifestyle changes can help reduce the risk of developing osteoporosis. Be guided by your doctor, but general recommendations for lifestyle changes may include:
- stop smoking
- get some sun
- drink alcohol in moderation
- limit caffeinated drinks
- exercise regularly