Building Better Bones

Unhealthy habits put today's children at extreme risk of osteoporosis. Here’s how to protect them, and yourself.

Every time a child drinks a soft drink, he’s laying the groundwork for a dangerous bone disease. No, fizzy and sugary drinks don’t cause osteoporosis. But because they’re often a substitute for a glass of milk, kids are coming up short of the calcium and vitamin D they need to build a strong skeleton. Many of them also lead a sedentary lifestyle, so they aren’t getting the bone-building benefts of vigorous exercise either. These children aren’t just in jeopardy for brittle bones and fractures decades down the road: they could be at risk of osteoporosis at a younger age than ever before.

That’s a problem everyone should be concerned about. Says Dr Leon Root, author of Beautiful Bones Without Hormones, and professor of clinical orthopaedics at Weill Medical College of Cornell University in New York, “Osteoporosis is actually a childhood disease that manifests itself later in life.” The condition causes bones to become riddled with holes, like the frame of a house that’s been attacked by termites. That can lead to broken bones, which in turn can cause deformity, chronic pain or disability.

Osteoporosis can even be fatal: 20 per cent of older people who suffer a broken hip die within a year.

Osteoporosis isn’t just your grandmother’s health threat. Although it strikes more than half of women in Australia over 60, it also menaces nearly one-third of men.

Bone loss can begin as early as 25, yet most people aren’t even aware that there’s an epidemic in the making, says Professor Nicholas Pocock, from the Department of Nuclear Medicine and Bone Densitometry at St Vincent’s Hospital, Sydney. “Awareness is the best prevention.”

There’s a new medical understanding of the best ways to protect ourselves – and our children. Simple lifestyle changes can save your bones, which can save your life, And it’s never too soon – or too late – to take action.

The Calcium Connection

Contrary to popular belief, the skeleton isn’t a rigid and unchanging structure. Each year, our bodies re-place about 20 per cent of our bones’ spongy tissue, which means that our activities at every age infuence their health. Sections of old bone break down, creating gaps to be flled by new bone. Until about the age of 30, we build bone very effciently, so making the right health moves, such as exercising and getting enough calcium, helps your skeleton reach its genetically determined peak strength.

Think of your bones as a retirement fund: the more you deposit when you’re young, the better off you’ll be in later years, when you need to draw on your reserves. But most kids don’t bank nearly enough calcium. The National Nutrition Survey found that three out of fve Australian kids are not getting the recommended daily allowance (RDA) of this bone-building material. That’s frightening, since 90 per cent of accumulated peak bone formation takes place before the age of 20. The effects of being shortchanged on calcium also go beyond an increased risk of osteoporosis in the future. There may be a price to pay much sooner: a recent Mayo Clinic study reports an alarming rise in children’s forearm fractures, compared with rates 30 years earlier. Giving kids a calcium boost may help ward off painful injuries. In a 2005 study at Ohio State University Medical Centre, doctors tracked the skeletal growth of girls ages eight to 13 over a seven-year period. All of them averaged about 800 milligrams of calcium from their diet – far less than the RDA of 1300 milligrams for their age group.

Half of the girls received calcium supplements, while the other halfdidn’t. “We saw powerful benefts to getting extra calcium, especially at puberty when children have a major growth spurt,” says Dr Velimir Matkovic, lead author of the study and director of OSUMC’s Osteoporosis Prevention and Treatment Centre. Not only did the supplemented group develop stronger bones, but they had half the fracture rate of the other girls in the study.

Do all children need supplementsf Ideally, kids and adults should get their daily calcium quota through a healthy diet. Along with milk, dairy products of all types will do the trick. Other good sources include sardines or tinned salmon with bones, leafy green vegetables, soya beans and calcium-fortifed orange juice, cereal or breakfast bars.

Encourage your children to have three to fve servings of these bone-builders daily. And if they shun milk because they think it’s fattening, let them know the latest research shows the opposite is true: kids with the highest milk consumption are also the slimmest, while those who drink the most soft drinks or other sweetened beverages, unsurprisingly, are the heaviest.

Since most people don’t consume enough calcium, supplements can fll the gap, says Dr Matkovic. “There are several types, and all of them do a good job. Flavoured, chewable tablets are more appealing to children, making it more likely that they’ll actually take them.” In his study, girls were given 1000 milligrams a day, half in the morning and half at night, since calcium is best absorbed in amounts of 500 milligrams or less at a time. That’s also a safe dose for adults whose diets are lacking in this bone-building mineral. Supplements interact with some drugs, so check with your GP or pharmacist.

Role of Vitamin D

Are you getting enough vitamin Df The required daily intake of vitamin D is between 600 and 1000 international units per day. However, there’s a growing scientifc consensus that the current guidelines are too low. That’s bad news for our bones, since this vitamin is crucial to processing calcium effciently, says Dr Robert Heaney, professor of medicine at Creighton University in Omaha. In a 2003 study, he compared the effects of giving postmenopausal women vitamin D supplements one year, followed by one year of no supplements. The result: when the women had higher vitamin D blood levels, they absorbed 65 per cent more calcium.

Dr Heaney and other experts are advocating a rise in the RDA for this nutrient. “Getting too little has been linked to many chronic disorders, from osteoporosis to type 1 diabetes and even cancer, so defciency is a huge health threat,” says the doctor, who believes that the best protection is taking 1800 international units daily.

Part of the problem is that vitamin D is found in relatively few foods, says Dr Heaney. And while people can also get the vitamin naturally, through sun exposure, that’s not always possible or even a good idea, especially if you’re prone to sunburn.

“We’ve just shown that in the northern United States, outdoor workers make plenty of vitamin D in the summer,” says Dr Heaney. “But it doesn’t last through the winter, when the sun is lower on the horizon.” Studies also show that skin production of the vitamin dwindles in older people, even if they’re sun-worshippers, suggesting that a supplement might be the best way to safeguard their bone health.

Use It or Lose It

As you age, you lose bone faster than you produce it. Over the fve to seven years after periods stop, women can lose up to 20 per cent of their bone mass due to oestrogen defciency. Paying extra attention to bone health can lessen the damage, however. Men are also affected by age-related skeletal loss, but not as dramatically, since their larger frames provide a higher peak bone mass and their hormones don’t plunge after age 50.

Our skeleton needs regular exercise at every age to stay strong. Many adults – and children – don’t do the minimum to keep their bones ft: 60 minutes of physical activity a day for kids and 30 minutes for adults. A combination of weight-bearing routines (such as walking, jogging, stair climbing or dancing, plus resistance exercises like weight-lifting) is the ideal recipe for bone health.

For children, jumping is a fun way to bone up, a 2003 study at the Univer-sity of British Columbia found. The researchers contrasted school girls who took gym classes with those who also did ten minutes of high-impact jumping exercises three times a week.

At the end of the two-year study, the exercise group had a nearly fve per cent jump in bone mass. Other weight-bearing exercises that will appeal to children include skipping, skating, tennis and team sports such as soccer.

Getting in shape pays off at every stage of life, says Dr Ethel Siris, director of the Toni Stabile Osteoporosis Centre at New York-Presbyterian Hospital/Columbia University Medical Centre. “It’s enormously valuable for kids and young adults, because they’re still building bone mass. If you’re in your 30s or 40s, it helps you hang on to what you have.”

Research shows that weight-bearing exercise, in part, can undo the bone-damaging effects of menopause.

Even at 80, when the risk of fractures is very high, exercise is still worthwhile, because physically ft older people are less likely to fall and break a hip.

To get people moving in the right direction, osteoporosis experts are challenging everyone, the public and doctors, to work together to improve bone health. Millions are at risk for fractures, and it’s all preventable. This is an epidemic that doesn’t have to happen.

A Test That Can Save Your Life

As osteoporosis often causes no symptoms at all until a fall snaps a bone, the only way to tell if you have it is via a bone-mineral density test. This procedure is advised for anyone over 50 who has suffered a fracture and all women over 65. Right now, the test involves lying on your back while the arm of a special X-ray device moves over your body to measure the thickness of various bones.

CyberLogic, a New York research frm, has developed a simpler device that’s around 23 centimetres long, runs on four AA batteries and scans bones with ultrasound.

If the portable scanner proves as reliable as X-rays, it could be a breakthrough, says osteoporosis expert Dr Ethel Siris. “A small device like this could make bone checkups part of a routine medical visit, because it’s both affordable and user-friendly.”

If testing shows you have osteoporosis, some major advances in treatment can help. While there are several effective medications on the market, including Fosamax, Etidrate and Forteo, the latest wonder drug is Boniva, the frst once-a-month pill for osteoporosis. The US FDA recently approved this drug, which works by reducing the activity in cells responsible for bone breakdown.

Should osteoporosis get severe enough to collapse a vertebra, doctors in the US have a new way to make repairs: two tiny balloons are inserted into the bone through surgical tubes and infated to push the bone back into its normal position. Bone cement is used to prevent it collapsing again.