SOUNDBITESAustralian farmers better get milking. Their dairy exports to China are set to skyrocket after a recent study showed that Chinese 11 year olds who drank only 330ml of milk a day grew significantly taller and acquired more bone mass than a control group who didn't drink milk.
Despite the belief that the Chinese people are milk-intolerant, they can usually drink up to 300ml (more than half a pint) a day without problems. Since their annual dairy per capita consumption is only 6.4kg, they have a bit to go before they catch up with the world average of 105kg.
These findings might be making the headlines in China but they're not that unusual in the western world, where study after study show that children who habitually avoid milk have low calcium intakes and poor skeletons.
In the Journal of the American Dietetic Association, a recent study has, for the first time, linked the avoidance of milk with increased bone fractures in children. The results show that nearly one in three of the young milk-avoiders had broken a bone before the age of eight, frequently from slight trauma such as a minor trip or fall.
Hand over those soft drinks kids - you're sweet enough without them!
Obviously diet is a critical factor in forming healthy bones. The mineral calcium, primarily found in milk, cheese and yoghurt, is deposited in bones and teeth. An adequate calcium intake at all stages of life (coupled with an active lifestyle) will help ensure that bones are as strong as possible.
This is particularly important during childhood, adolescence and early adulthood, when bones are developing. Children and adults need approximately three servings a day, whereas stretching adolescents need five. A serving is a glass of milk or a match box size of hard cheese or a carton of yoghurt.
In milk and dairy products calcium is readily available, but it is usually less available from plant foods. Calcium is sometimes bound by phytates (found in wholegrain cereals and pulses) and oxalates (found in spinach and rhubarb), which makes it unavailable for absorption by the body.
As vegans do not eat dairy products, they should take particular care that their diet contains sufficient calcium. Many soya products, such as tofu and soya drinks, are fortified with calcium and so can be a useful source for vegans.
Vitamin D is also important for healthy bones because it's needed for the absorption of calcium from food. Vitamin D is made in skin that is exposed to sunlight. Most people obtain sufficient vitamin D this way but some groups, such as the housebound or those who wear clothes that cover most of their body, need to be sure that their diets contain enough vitamin D.
Few foods contain large quantities of vitamin D. Fish liver oils have very high levels and oily fish, such as sardines and tuna, are also rich sources. Egg yolk, liver and butter contain smaller amounts of vitamin D. Margarine is fortified by law with vitamin D, and many low fat spreads and some breakfast cereals are also fortified.
If your bones aren't the problem but your joints are, you can eat more oily fish, take Cod Liver Oil, or try a combination of both.
Several studies claim that mild relief can be obtained from omega 3 fatty acids contained in fish oils, which reduce the activity of enzymes that are responsible for damaging the protective cartilage. These fatty acids switch off the chemical processes that cause pain and inflammation in conditions such as arthritis.
There is also strong evidence that diets low in antioxidants - particularly vitamins A, C and E may predispose some people to joint problems. So supplement your diet with additional fruits and vegetables if necessary.
Some studies claim that following a vegetarian diet and losing any extra weight you're carrying can relieve several of the symptoms of arthritis.
On the subject of supplements, glucosamine sulphate is a substance formed naturally in the body and is involved in cartilage production. It appears to be at least as effective as ibuprofen in reducing pain and has fewer side effects. It may even help regenerate cartilage but this is as yet unclear.
Finally, in your spice rack you'll find one of the oldest natural anti-inflammatory treatments - ginger. But if hot ginger tea isn't your thing, don't worry. Ginger is prized more for its culinary qualities rather than for its medicinal properties.
Bone strength is affected by:
Genetic factors - some ethnic groups may have stronger bones in general than others.
Sex - men tend to have a greater bone mass than women.
Diet - calcium and vitamin D, in particular, are important for strong bones.
Physical activity - regular exercise is important for strong bones.
Body weight - heavier people have stronger bones.
Hormones - irregular or loss of menstrual periods can cause bone loss.