Health check: How to have stronger bones
It’s not possible to prevent the loss of bone density as we age, but there are ways to reduce the risk of developing osteoporosis. In the second instalment of our pre-conditions series, Healthy Food Guide senior nutritionist Rose Carr looks at ways to promote stronger bones.
Osteopenia is an early sign of bone loss. It’s the term used to describe less than normal bone density, which is not so low as to be diagnosed as osteoporosis. But not everyone with osteopenia will develop osteoporosis, and there are things that can be done to help avoid further deterioration of your bones.
The make-up of our bones
We all know bones can break and although we know bones can also mend, it’s easy to think of them as being solid, in the way we might think of a frame for a house. But, just like the rest of our extraordinary body, our bones are alive and the cells are always working.
Bone is, in fact, a specialised type of connective tissue. Bones have both blood vessels and nervous tissue servicing them, and our bones are constantly being remodelled. This makes sense when we’re still growing, as they need to grow with us, or when we break a bone and it needs to be mended. But even as adults, our bone cells carry on remaking our bones throughout our lives. Unfortunately, as we get older, we start to lose more bone cells than we can make, so our bones gradually become weaker.
Bone density as we age
We have most of our bone mass by about 20 years old, with around 5-10 per cent still being added during our 20s. So, by the time we’re 30, we reach the highest bone density we’re going to achieve in our lives. How high that is depends on our genetics and general health, but also on our diet and exercise. And we don’t stay at this peak for long. From around 35-40 years old we lose bone density. And for women, after menopause there is a 5-10-year phase where bone loss is more rapid because of the drop off in oestrogen.
Effect of lifestyle
The right diet and exercise help to maximise both our peak bone mass and minimise bone loss as we age. Conversely, smoking, too much alcohol or caffeine, along with being under or overweight are all detrimental to bone health. If we’re past 30, we can’t go back, but we can help minimise future bone loss.
Can you measure density?
A DEXA scan can be used to check bone mineral density, usually measured at the hip and spine, but this is normally only done when the result will have an impact on treatment. So, we don’t need to wait to get to that point before we think about our bone health and how to maximise it.
What can I do to promote bone density?
Get plenty of calcium
Milk or dairy products are the best source of easily absorbed calcium. Aim for two or more serves each day, choosing low-fat varieties, where possible, to limit saturated fat. Also include other foods containing calcium.
If you need to avoid dairy, go for calcium-enriched dairy alternatives, such as soy milk.
Sardines and canned salmon are high in calcium – it’s in the bones. Tofu can be a good source too, but check it’s produced using calcium. Smaller amounts of calcium are also found in nuts, figs, legumes, tahini, spinach, broccoli and grainy bread.
A daily dose of vitamin D
We produce our own vitamin D through skin exposure to the sun. Keep safe between September and April by taking a daily walk outside of high UV times.
Foods that contain small amounts of vitamin D include oily fish, milk and dairy products, eggs and liver.
This will give us plenty of magnesium and potassium, and 50-60 per cent of our body’s magnesium is in our bones. You can find magnesium in nuts, seeds, legumes, wholegrain cereals and dark leafy greens, as well as in dairy products.
Higher potassium intake is believed to reduce calcium excretion in our urine, but high sodium intake has the opposite effect. Minimise sodium by holding the salt when cooking, and choosing processed foods with lower sodium. Vitamin C is involved in making collagen, found in skin and muscles as well as bones. So eat vegetables, such as capsicum, broccoli and cauliflower, as well as citrus fruits.
Add some meat, shellfish or eggs
Include these to ensure you’re getting enough zinc and vitamin K. Thirty per cent of our zinc is in our bones. Zinc is found in meat, oysters, mussels, eggs, legumes, nuts, seeds and dark leafy greens. Growing evidence suggests getting enough vitamin K2 is needed too. Find vitamin K2 in meat, eggs and dairy foods, especially cheese and yoghurt as they’re fermented. It’s found in other fermented foods too.
Exercise dem bones
Weight-bearing exercise that puts some pressure onto bones is key. Include exercise, such as resistance training, jogging, or even dancing or fast walking. Swimming and cycling are great for overall health, but they don’t help strengthen our bones.
What’s my risk?
You are more likely to develop osteoporosis if you:
- Are aged 65 years-plus for women; 75 years-plus for men
- Have a BMI (body mass index) less than 20
- Have a family history of osteoporosis
- Use glucocorticoids
- Go through early menopause
- Drink more than two alcoholic drinks daily
- Have a history of falls
- Have rheumatoid arthritis
- Have a history of eating disorders.
See Health check: Turn the tables on hypertension for the first instalment of our pre-conditions series.