Touching Lives - December 2003
Osteoporosis: why prevention is the best cure
Cast your mind back to when you were nine years of age. Remember those heady days of running around, playing tag, catch, skipping or hopscotch or whatever your favourite game was. As well as having a good time you were providing your body with essential elements that would stand you in good stead for the rest of your life.
During puberty, girls build up 40 per cent of the total amount of bone mineral content (two and a half kilos) that is accumulated in the skeleton of a mature young woman. Young adult males have approximately three kilos of bone mineral content, and a ten-year old child has around one kilo.
These minerals that develop the bones come from calcium in the diet and the effect of exercise on the body. This process will be complete by the age of around 21 when an individual will have the maximum amount of bone mineral that they are ever going to have. And from then it’s all a downhill slide! Both men and women lose around one per cent of their bone mass each year, with women losing more at the onset of the menopause.
The biggest force to which bones are subjected is the pull of the muscles attached to them. Such strain placed on the bone — arising especially from weight-bearing exercise such as running or brisk walking — makes the bone able to resist stress and fracture.
The effect of both physical strain and calcium on bone is that it increases the total amount of mineral density and size — and this improves the bone’s strength. A study of adult tennis players has shown that the playing arm has up to 40 per cent more bone mass than the non-playing arm!
The levels of bone mineral content that any person lays down in a lifetime are decided by 70 per cent genetic factors and 30 per cent through exercise, diet and lifestyle. So there is plenty of scope for an individual to play a part in improving his or her own bone health.
Studies in adults and children have shown that taking calcium tablets alone does not have a particularly beneficial effect on bone density. Action Medical Researchers Dr Zulf Mughal, Dr Kate Ward and Professor Judy Adams believe that adequate calcium intake in conjunction with exercise will result in higher bone mineral density, and thus stronger bones. So ^popping pills is unfortunately not enough. There is no substitute for exercise!^
Elite gymnasts versus the couch potatoes
The £95,000-funded study looked at a group of 37 boys and 49 girls. There were 44 gymnasts, some of whom were of Olympic standard, and 42 others who were deemed ‘couch potatoes’ by comparison. They were then divided into two groups — some who took calcium tablets and the ‘control’ group who did not.
The gymnasts did a very impressive minimum of 13.6 hours of exercise each week, often exerting a force of up to twelve times their own body weight during some of their exercises. The couch potatoes did 5-6 hours of exercise a week, in and out of school. Exercise included things like cycling, dancing, swimming and football.
Kids today, eh?
Statistics show that many children today lead a more sedentary lifestyle in comparison to children from previous generations. The effects of lack of exercise at school, not walking to school, television and computers have all had a negative influence on children’s health.
Diet too has changed and even in young children, the bone mineral that they develop is being eroded by bad eating habits, particularly the consumption of fizzy drinks that have been shown to reduce the amount of calcium in the body. Junk food has high levels of phosphate and this can leach out calcium from the bones, making them weaker.
Using scanning techniques, the Action Medical Research team looked at the density and size of the bone in the forearm and shin. They used this data to work out a ‘strength and strain’ index to determine how much stress the bones would take before they would break.
The results showed that the gymnasts had bigger bones with an extra 10 per cent more hard bone in the shinbone and the forearm than the couch potatoes. This meant that the gymnasts’ bone was about 10 per cent stronger than the couch potatoes.
Prevention is the best cure
Dr Mughal who led the study told Touching Lives, “The focus of our study was to look at what early preventative measures can be taken to reduce the burden of osteoporosis in later life. ^Osteoporosis affects one in three women and one in twelve men and has a very high morbidity and mortality rate in older people. As childhood is the most important time for laying down reserves of bone mineral we decided to look at what factors could influence this.^
“Osteoporosis costs the NHS £750million a year and the eating, drinking and lifestyle habits of young children are really going to affect them in later life. The Government has already made some steps towards reducing the incidence in later life. They have produced a Green paper that will give relevant ministers advice on what preventative and therapeutic measures can be taken. Most of these are aimed at adults, in particular post-menopausal women, but researchers are changing towards looking more at interventions for children.”
The researchers hope that the results of their study will encourage parents, children, health practitioners and schools to improve diet and exercise opportunities for growing children so that their long-term health can be maximised.
The team are going to take follow-up measurements to see whether any effect of the supplementation is sustained. The next step would be to take the couch potatoes and put them on an exercise programme — with and without calcium supplements — to see if this is beneficial.
Jessica Beddoes is a gymnast at the Gorton Gymnastic Centre in Manchester and took part in the study. She does a very impressive 20 hours of exercise a week. Jessica, who is now 13, said, “I liked being in the study although I didn’t like taking the tablets because they were horrible — what I would call cakky! It was difficult for me to be in the scanner too because I don’t like sitting still. I have to watch what I eat as a gymnast but I still like to eat crisps!”
Jessica’s mother Jane Beddoes is a gymnastics teacher and is already aware of the benefits of having healthy bones. She told Touching Lives, “I think it is essential to raise awareness and educate parents about the benefits of building up their children’s bones when they are young.
“We thought that the Action Medical Research study sounded important so we were really pleased to be able to take part. We know how vital it is to eat a proper balanced diet so I hope that Jessica is developing nice strong bones that will last her a lifetime.”