KNOW YOUR BONES
I can’t say that I normally give much thought to my bones.
They’re there, just doing their thing, all 206 of them. It’s a case of ‘out of sight, out of mind’. Yes they’re important, but unless they’re broken (and I have never broken a bone!), bone health isn’t something that would normally be given priority in my mind, as a late 20’s, healthy female.
But attending a talk from Osteoporosis NZ this week has made me think twice.
Did you know that we reach our peak bone mass in our mid to late 20’s? This means that everything we do up until this point is critical for ensuring our lifetime bone health, and what we do beyond this point is a matter of trying to maintain / prevent the decline in bone mass as much as possible as we age!
It’s well known that fractures during our senior years can have a significant impact on health, sometimes even with life or death consequences. There are approximately 3,700 hip fractures in NZ every year, and 25% of these individuals pass away within 12 months of the fracture. This is why exercise for fall prevention in the elderly is so important! (Check out my balance and stability classes held in Hobsonville every Wednesday).
Here’s another neat fact - our skeleton completely replaces itself every 8-10 years. Our bones are constantly changing, re-modelling, adding new bone cells and taking away the old. This is true regardless of your age!
There are several different types of cells involved in this process:
Osteoclasts: These cells break down and absorb the old bone (a necessary part of bone healing).
Osteoblasts: These cells are laid down to form the new bone matrix.
Osteocytes: These cells control the process and maintain the overall bone health.
In our younger years, the rate of new bone being laid down exceeds that of the bone being broken down. But this changes in our mid to late 20’s. If you are under 30, now is the time to work to strengthen your bones and create the most resilient skeleton that you can! Optimise the opportunity while you can.
If you are between 30-50, now you should be working to maintain. The balance between bone addition and bone removal has switched - this means that it is being removed faster then it is being remade. But this doesn’t mean that all is lost! The more that you can do to maintain, the better you will be in future years. (For every 10% of bone mass not achieved, osteoporosis can occur up to 13 years younger!)
If you are over 50 years, particularly females, you should be thinking more seriously about your bone health. The hormonal changes that occur during menopause speed up the ‘bone eating’ process, which means that density starts declining at a faster rate (in fact, women lose 15-25% of their bone mass in the 10 years after menopause!). Note also that the same process occurs in young female athletes who go through amenorrhea - loss of their menstruation cycle - due to their extremely lean body mass. One in 3 women have osteoporosis, but it’s not only a woman’s condition - One in 5 men are also affected.
If you are over 50 and have had a fracture from a minor fall or injury, consider getting a bone health check done. There is a free online resource that you can use at https://www.knowyourbones.org.nz/ to assess your risk. It takes into account possible genetic contributions (do you have a family history of osteoporosis?) as well as lifestyle variables (exercise, smoking, alcohol, body weight).
Above 65 years, you really want to be doing what you can to keep yourself strong and fit. Balance training is also great to prevent falls from occurring and reduce your risk of fractures!
What can you do to improve bone health?
Exercise: First and foremost. Weight-bearing exercise (i.e. exercise that works against gravity, such as walking) is superior to non-weight bearing exercise (I.e. cycling, swimming) when it comes to strengthening the bones, as the bones need load to stimulate increased growth. Strength training is also great to promote bone adaptation.
Diet: Ensuring sufficient calcium in your diet. The recommended dietary intake is 500mg/ day. It is recommended to achieve these levels through FOOD as opposed to calcium supplementation, as supplements have been shown to contribute to the calcification of arteries, promoting heart attacks and strokes. This can include sources of dairy such as milk, yogurt and cheese, or non dairy options such as tofu, green vegetables such as spinach and broccoli, and nuts (almonds, Brazil nuts). Some dairy alternatives such as soy and almond milk also have added calcium.
Vitamin D: Get out in the sun! Being low in Vitamin D can impact on your ability to absorb Calcium from your diet. 15-20 minutes of sun per day is all you need, with direct exposure to the skin (sun block blocks absorption). You can also use Vitamin D supplementation to increase your levels of Vitamin D if adequate sun exposure is not possible.
Lifestyle: Limiting alcohol intake, smoking cessation, and eating a balanced diet are all helpful for maintaining bone health.
Body weight: Being underweight is a significant risk factor for osteoporosis, as the bones are not being provided with enough load to promote bone re-modelling. People with a history of eating disorders are at an increased risk! Ideally keep within a healthy BMI of 20-25.
Know your bones: 50-60% of your skeletal strength is determined by your genetics. If you are over 50, you should be giving some thought to your bone health, particularly if you have a family history of osteoporosis!