Bone Health – Why It's So Important
We often overlook our bone health until a devastating fracture occurs, putting our life on hold, robbing us of our independence.
But with a few simple lifestyle interventions, we can strengthen our skeleton and keep our bones strong for life.
Our bones provide the structural framework for locomotion, respiration, and organ protection and act as a reservoir for calcium, phosphorus, and carbonate.
Bone is only formed during the first few decades of life.
For example, half of total body calcium stores in women are made during puberty, with the peak rate (the greatest mass our bones will ever reach) in our early twenties, but it’s important to remember that genetics also plays a role.
Over the course of a decade, your skeleton is completely replaced.
But unfortunately, over the age of 40, bone mass will start to decline. We start to lose more bone than we make, and the risk of various bone disorders and fractures is correspondingly increased.
Approximately, as many as one in two women over the age of 50 suffer with osteoporosis in the UK. This is a condition where bone density, mass, strength and structure decrease, often alarmingly.
This puts us at a greater risk of bone breakage, increased bone fragility and fracture risk. As a result, our risk of falls increases, which could, in some cases, result in death.
Osteoporosis is a “silent disease” because there are typically no symptoms until a bone is broken.
Therefore, time is of the essence as there is a very limited window in which we can take action to maximise our bone mass before skeletal growth is complete.
During childhood and adolescence our bones are rapidly growing. We can significantly increase this by optimising our nutrition, exercise, and lifestyle choices.
Factors such as smoking, inactivity, excessive alcohol, sodium and caffeine consumption and poor nutritional choices will all decrease our peak bone mass. But other chronic illnesses like anorexia nervosa can jeopardise our bone mass acquisition and can have devastating consequences in later life which may not be reversible.
Therefore, it is critical we receive proper, well-balanced nutrition during our adolescent years, paying close attention to not only Calcium and Vitamin D intake, but Iron as well.
Iron Deficiency and Bone Health
The physiological timing of skeletal growth occurs simultaneously with the occurrence of a young girl’s monthly cycle, as well as an increasing desire for independence. This may result in adolescents choosing foods and lifestyle choices independent of parental input, meaning their bone health could be in jeopardy as studies have suggested that adolescents have a very limited understanding of the components needed for building healthy bones.
On average, girls start having menstrual periods at the age of 12, and having a regular period is vital for bone health because it indicates that sufficient oestrogen is being produced and peak bone mass is achievable.
Oestrogen is a hormone that improves our calcium absorption. However, the loss of Iron through menstruation may result in an iron deficiency, especially if the menstrual period is heavy.
Iron deficiency anaemia affects approximately 446 million women of childbearing age. Iron is an essential mineral for cellular growth and function, and it is, therefore, unsurprising that a deficiency would negatively affect bone metabolism.
More specifically, iron deficiency can disrupt osteoblast and osteoclast function (specific cells which help bones grow and develop), which can ultimately result in bone loss, osteopenia, or osteoporosis.
Females between the ages of 11 and 50 (pre-menopause) should aim to consume 14.8mg/day of iron.
Remember - there are 2 types of iron found in foods:
Heme iron - found in meat, fish and poultry. This is easily absorbed by the body.
Non-heme iron - found in eggs beans, lentils, nuts and seeds, wholegrains and vegetables, but where it is not absorbed as effectively.
The addition of foods high in vitamin C like red/yellow/green peppers, citrus fruits, broccoli, kiwis and strawberries will help the absorption of more non-heme iron from foods.
Exercise and Bone Health
Regular weight-bearing exercise like walking, dancing, jogging, and lifting weights can really help us to achieve optimal bone health as these activities exert forces on our bones to promote healthy growth.
To promote good bone health, adults need at least 30 minutes of weight bearing activity (such as a brisk walk), 4 or more days per week. Muscle-strengthening activities on at least 2 days of the week are also recommended.
However, a fine balance needs to be drawn. Over-exercise, resulting in an increased energy output, combined with inadequate nutrition, intentional or otherwise, can result in amenorrhea - the loss of regular periods. This results in lower estradiol and androgen levels, putting bone health at risk as skeletal development is halted. As a result, the body will compensate by reabsorbing the calcium deposited within the bones, and bone mass will decline.
Adolescent girls with an oestrogen deficiency due to the loss of periods could experience a bone mass loss of 3% to 5% per year.
Calcium and Bone Health
Calcium is a mineral which helps with bone growth and with the development and structure of the skeleton. It helps the blood to clot, digestive enzymes to work, and our muscles to contract.
As adolescent women, we should aim to consume at least 700mg of calcium a day to protect bone health, and sufficient vitamin D levels in order to absorb it.
A deficiency in calcium puts you at greater risk for both osteomalacia and osteoporosis. If you’re not getting enough calcium through your diet, your body can begin to leech it from your bones, causing them to weaken.
It’s important to space your intake of calcium out throughout the day to ensure optimal absorption.
It’s important to remember that dark leafy greens like spinach and broccoli are high in calcium, but also oxalates. Oxalates bind to minerals like calcium, lowering calcium absorption. A way to minimise this is by eating the vegetables cooked.
Vitamin D and Bone Health
It’s important to make sure that you get enough vitamin D, as it can increase calcium and phosphate absorption by as much as 50%.
It’s recommended that we get 10ug a day, and supplementation is often necessary. This is especially the case in the winter months as most of the vitamin D is synthesised by the skin when the body is exposed to sunlight. A deficiency in vitamin D would increase our risk of both osteoporosis and osteomalacia.
Zinc and Bone Health
Zinc is a micronutrient which aids in bone growth and mineralisation, helping to keep our skeleton strong and stable. The recommended daily amount for adolescent girls and women is 9mg.
The take-home messages:
Prevention is key and identifying risk factors associated with poor bone health in early adolescence can help to maximise bone mass in later life.
Remember, it’s never too late or early to start thinking about bone health.
Eat a well-balanced diet, rich in calcium, iron, and vitamin D.
Participate in regular weight-bearing exercise to enhance bone density and microarchitecture during adolescent development. Things like walking, dancing, jogging and weightlifting.
Reduce alcohol consumption and avoid smoking
References
https://www.ageuk.org.uk/information-advice/health-wellbeing/conditions-illnesses/osteoporosis/
https://theros.org.uk/latest-news/women-s-health-strategy-needs-to-go-big-on-osteoporosis-emergency-affecting-one-in-two-women-over-50/#:~:text=Osteoporosis%20affects%20women%20much%20more,a%20bone%20because%20of%20it
https://www.contemporarypediatrics.com/view/bone-health-adolescents
Heaney RP, Abrams S, Dawson-Hughes B, et al. Peak bone mass. Osteoporos Int. 2000;11(12):985-1009.
Bishop N, Braillon P, Burnham J, et al. Dual-energy X-ray absorptiometry assessment in children and adolescents with diseases that may affect the skeleton: the 2007 ISCD Pediatric Official Positions. J Clin Densitom. 2008;11(1):29-42.
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https://www.healthlinkbc.ca/healthy-eating-physical-activity/food-and-nutrition/nutrients/iron-foods#:~:text=Heme%20iron%20is%20found%20in,in%20foods%20with%20added%20iron
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Loud KJ, Micheli LJ, Bristol S, Austin SB, Gordon CM. Family history predicts stress fracture in active female adolescents. Pediatrics.2007;120(2):e364-e372.
https://www.bbdiet.com.au/post/8-dairy-free-calcium-rich-foods-for-preventing-osteoporosis