Helping Teenagers Build Strong Bones

Drink milk to help your bones!

Teenagers, both boys and girls, are in the prime position to look after the future of their bones. At this stage of their life, many aspects of their bodies are changing rapidly - and bone density is no different.

A diet rich is calcium and plenty of weight bearing exercise helps ensure that bone density growth is maximised, providing them with the best chance to prevent osteoporosis later in life. But although most adults are aware of the need for calcium and exercise, many teenagers shun the facts and don't adequately exercise or consume enough calcium.

Read on to find out some of the reasons why and how you can help encourage them to act now.

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Why is calcium so important for teenagers?

During the teen years, bone density is built up to its maximum level. According to CalorieKing.com.au dietitian Allan Borushek, "By age 16, 80% of peak bone mass is reached." After 30 years of age, a gradual loss of bone begins, decreasing even more rapidly for women during menopause. By age 80, a woman may have lost up to as much as two-thirds of her skeleton!

As each generation of teenagers gets taller, their leg bones are also becoming longer. Now, more than ever, it's important to ensure that these bones are strong enough to support their bodies throughout their lives. Weak, calcium-deficient bones can only lead to problems with hips, pelvises and painful fractures as they age.

The key to preventing osteoporosis and other problems later in life is to build strong, healthy bones in the teenage years. Although this fact is well known, a CSIRO study has shown that only one out of every three Australian girls is getting the recommended daily intake of calcium.

Factors causing low-calcium intake for teenage girls

Although osteoporosis does affect men, women are at a higher risk. They generally have about 30% less bone than men and experience greater bone loss during menopause when oestrogen levels drop.

So why aren't teenage girls taking more notice of the facts and doing everything they can to prevent these problems? Here are some of the many factors that could be contributing to low calcium intake for teenage girls.

Parental/Guardian influence. According to New Zealand research, more than three-quarters of the children in their study who habitually avoided milk had a family member who also avoided milk. This finding highlights the often-underestimated influence of role models on young people's nutrition.

What parents can do: Be a positive role model and make sure you're getting plenty of calcium in your diet too. Encourage your daughter to drink a glass of milk at breakfast by doing the same.
The myth that 'dairy products are fattening'. Many Australians mistakenly remove dairy products from their diet when trying to lose weight, and teenage girls are no different. At a particularly body-conscious age, many girls spend much of their teenage years dieting and skipping meals. If these diets involve missing breakfast or cutting out dairy products, their bones are heading for trouble. Contrary to the myth, university researchers in America have found that regardless of how active their female participants were, those who consumed higher levels of calcium lost more weight than those with low-calcium diets.

What parents can do: Encourage your teenager to eat breakfast. A quick bowl of cereal topped with milk and yoghurt is a great start to the day. Alternatively, make them a smoothie to drink on the way to school. Offer teenagers low-fat dairy options, these usually contain the same or more calcium per serve as full-fat products, and still allow them to watch their weight.
Carbohydrate-free dieting. With low-carbohydrate dieting comes the issue of avoiding milk and most dairy products due to the carbohydrate content. If teenagers are avoiding these products they are putting themselves at risk of osteoporosis later in life, by building weak bones during their formation years.

What parents can do: Encourage teenagers to eat a healthy balanced diet, rather than restricting certain foods. Help your child with weight issues by providing the whole family with nutritious, low-fat meals and encouraging participation in active family activities.
Soft drinks preferred over milk. As drink choices become more varied, teenagers are often choosing soft drinks and juices over milk. These other beverages are often high in calories or sugar, compared with milk. As well as calcium needs, it has been shown in a US study that children who avoid milk tend to be fatter than those who drink milk.

What parents can do: Encourage your teenager to drink flavoured milk rather than soft drinks. Choose milk drinks that are reduced-fat and have less added sugar or additives. Lactose-intolerant or vegetarian teenagers can use soy drinks, such as So Good and So Natural. Check to make sure that the label says 'calcium-enriched'.

Exercise a key factor

Exercise during the teenage years has been shown to be extremely important in building strong bones.

In a ten-year study, over 80 teenage girls were studied to determine the affects of exercise, calcium intake and oral contraceptives on bone strength. It was found that exercise had the largest impact by far, with those girls who regularly participated in sport having significantly stronger bones. Surprisingly, calcium intake and oral contraceptives were found to have no significant impact on bone growth or density. However, this doesn't mean that calcium intake is not important, with the study researchers quick to point out that teens should not miss out on the benefits of calcium.

These finding are likely to also be applicable to teenage boys, however the study concentrated only on females.

More fruits and vegetables?

Although calcium and exercise are the most beneficial ways to prevent bone loss, a recent study of US girls has shown that eating at least three servings of fruit and vegetables every day can help limit the body's excretion of calcium from the bones.

Even though the study was small and has not produced definitive evidence, the indications are that adding extra fruit and vegetables certainly can't hurt!

References :

This article was compiled in consultation with CalorieKing.com.au experts and in reference to the following sources:

Allan Borushek's Calorie and Fat Counter 2004 - 'Osteoporosis Guide & Calcium Counter'

Osteoporosis Australia

CSIRO, 1999, Dairy Foods in the Australian Diet results from the National Nutrition Survey 1995 - 96

Norton, A. 'Fruits and vegetables may strengthen girls' bones.' Reuters Health, 16 March 2004

McKinney, M., 'Exercise boosts teen girls' bones.' Reuters Health, 23 June 2004

'The Latest News in Weight Loss: Eat More Calcium' TUFTS University Health and Nutrition Letter, July 2001

Black, R.E., et al., 'Children who avoid drinking cow milk have low dietary calcium intakes and poor bone health.' American Journal of Clinical Nutrition, 2002, 76:675-80 Cited In: Australian Dairy Corporation Nutrition News, Issue 11, November 2002

Australian Dairy Corporation Nutrition News, Issue 10, September 2002

Last updated: July 19th, 2004