Taking magnesium supplements in middle age could help protect bones, a study suggests. The pills may hold the key to reducing rates of the most preventable cause of disability in middle-aged and elderly people, UK scientists said. Researchers discovered middle-aged men who had high levels of magnesium in their blood nearly halved their chances of breaking a bone over the next 25 years. They believe the same effect might apply to women – although the study only included men – as magnesium helps to strengthen bones in the same way in both sexes. Although magnesium is known to be important for bone health, it is thought this is the first study to show how it could prevent breaks. Lead researcher Dr Setor Kunutsor, of Bristol University, said, “The findings are quite clear – there is quite a substantial reduction in risk of fractures.” He recommended doctors consider screening older people to check their magnesium levels and treat problems before their bones weaken. He added, “As people get older it becomes harder to absorb magnesium. But they don’t show any symptoms until they break a bone. Screening for magnesium levels could be one way to go in the future. Then perhaps they could be prescribed magnesium pills to increase levels if they have gone too low.” In the UK, around half of women and a fifth of men over 50 will break a bone at some point. Around 3 million Britons, the majority women, suffer from osteoporosis – a disease which weakens bones and can cause painful breaks from relatively minor falls. Fractures can be debilitating and lead to other complications, which can ultimately be fatal for elderly people. Most people get the magnesium they need from their diet as it is found in many foods including green leafy vegetables, fish, meat, dairy, nuts, brown rice and wholegrain bread. But supplements can help people with a poor or restricted diet. For the study, researchers at Bristol University and Eastern Finland University followed 2,245 Finnish men aged between 42 and 61 from the mid-1980s. The participants’ magnesium levels were measured when they signed up to the study. Around 25 years later, they were checked to see how many had broken bones in the intervening years. In total, the men suffered 123 fractures. Men with lower blood levels of magnesium had an increased risk of fractures, particularly of the hip. The risk of suffering a fracture was reduced by 44 percent in men with higher blood levels and none of the 22 men who had very high magnesium levels had any fractures at all. But the study found the reduction in risk was only caused by having higher levels of magnesium in the blood. Taking more magnesium in the diet to boost levels appeared to have little or no effect, as the kidneys usually filter out any of the mineral the body thinks it does not need. Dr Kunutsor said a supplement could help people reach the recommended daily allowance of magnesium – 300mg for men and 270mg for women – if they were not getting it from their diet. He said people taking magnesium should also take calcium and vitamin D for maximum effect and it was unlikely a magnesium supplement would have any effect on its own. In order to increase blood levels of magnesium, the researchers said it was important to treat any underlying problems which prevented it from being absorbed properly.