When considering a diet to help build and maintain healthy bones, the essential mineral that comes to mind is calcium. This is the most important nutrient for bone density, as there is just over 1 kg calcium in the body, 99% of which is present in the bones.
There are other nutrients involved in bone metabolism and it is important to realise that a well-balanced diet comprising all food groups is important. A poor nutritional status increases the risk of osteoporosis, as many elderly patients admitted to hospital with hip fractures are malnourished.
Calcium and beyond
A good intake of calcium is required during the years of bone development to attain peak bone mass and thereafter to reduce the amount of bone loss.
Recommendations for calcium intake take into account that, on average, only 30-40% of the calcium taken into the body is absorbed for use in the bone, blood and nerves.
Recommendations for calcium intake The National Osteoporosis Society recommends an increase in calcium intake as we get older due to decreasing absorption of the mineral. The society recommends 1000 mg calcium a day for premenopausal women and for those on hormone replacement therapy (HRT), 1200 mg/day for menopausal women and 1500 mg/day for postmenopausal women, not on HRT. It is recommended that men take similar amounts of calcium. |
For those who dislike milk, suffer from lactose intolerance or are concerned about the reported adverse effects on health, there are many other good calcium sources.
Nutrients with beneficial effects on bone
You may have heard of the recommendation to have a milky drink at night. This makes good sense as when there is not enough calcium in the diet, our body will move calcium from the bone back into the bloodstream. This process occurs overnight when we are fasting. The calcium in the milky drink before bedtime will help to meet the overnight calcium needs of the blood and nerves, reducing the nightly calcium loss from bones.
Other good food sources of calcium will have a similar effect.
Soya isoflavones
The value of soya isoflavones in the diet has been observed from South east Asian populations, where soyabeans are a staple food.
These populations have a higher intake of isoflavones from the diet, and a lower incidence of osteoporosis and hip fractures.
A great deal of research is being conducted to determine the effect of naturally occuring isoflavones on bone, which are structurally similar to the synthetic Ipriflavone discussed in Treatments section. Isoflavones, present primarily in soya based foods and legumes, are also known as phytoestrogens. They exert a weak oestrogenic effect, a very mild form of HRT, and research is showing their potential for inhibiting bone resorption.
There are components of the diet that can have a deleterious effect on bone, if consumed in excess.
Food components with adverse effects on bone, when consumed in excess
In reality, the average UK diet has a minimal effect on the loss of calcium in this way, as the main sources in the diet are dairy products. These have a high calcium to protein ratio which actually favours calcium retention, promoting bone mass.
A well balanced diet plays an essential role in helping to prevent and minimise the severity of osteoporosis.
20/05/2009