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PSA For Ladies In Particular: The heavier you are the stronger your bones.

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Scientists at the University of Auckland have been studying bones and calcium supplements, and I think it’s of interest to all women, in particular, not just for bone reasons.

Prof Ian Reid talks to Kim Hill about it here. His study has not been funded by commercial enterprise (such as Fontera, which you may well assume given the importance of the dairy industry in NZ), but by the NZ Government, which is the only sort of food research anyone should take any notice of.

If you’re taking calcium supplements — perhaps they’ve even been prescribed by your doctor — I recommend listening to the podcast for the latest research, which has yet to filter through to many GPs (as is usually the case).

Even if you already steer clear of calcium supplements, what I find interesting about this discussion is the politics of obesity. When these bone scientists found out that ‘the heavier you are, the stronger your bones’, doctors working in other areas of health were alarmed that this news might ‘promote obesity’.

Let’s all go out and get fatter now. Phew! That’s a relief. (Seriously?)

The fact is, humans naturally get fatter as we get older. For women, ‘healthy weight’ is really quite different from ‘fashionable weight’, because of this skewed era we live in. Weight gain correlates with increased age, across the world in every society, and has been the case for eons. Is it time, perhaps, to accept that there are very good evolutionary reasons for this? That our wider hips keep us balanced as we head into old age, and our increased weight in our pre-menopausal years is preparing our bones in case we make it past four score and ten?

Take away points from the interview:

  • Osteoporosis will lead to fractures in: 56% of women over 60 and 29% of men. [When we think of the big killers we think of heart attack and stroke, but ‘falls’ in the elderly can be lethal.]
  • Nearly 20% of people with hip fractures will die from related complications within one year.
  • The latest research says that calcium supplements don’t actually help bone density. They could even increase the risk of heart attacks. No one knows why exactly but data suggests people on calcium supplementation programs suffer 25% more heart attacks and 15% more strokes (which are both outward manifestations of arterial disease.)
  • Educated speculation about why calcium supplementation might lead to an increased risk of heart attack and stroke: Some of the calcium in supplements might stick to the bones but it’s just as likely to stick to the arteries. Taking Vitamin D with your supplements doesn’t really help, either. There’s nothing you can take to whack calcium into your bones and teeth, where you want it to go.
  • Extra calcium in your body is just one more thing your body needs to get rid of. You don’t want it to mineralise your soft tissues, just your bones. You don’t want calcification in your muscles or kidney stones, either. (Kidney stones occur for all sorts of reasons but giving people calcium supplements increases the risk quite considerably.)
  • Calcium from tablets is ‘not clever enough’ to know how to go into the bones and not into the soft tissues.
  • Skeletons are not like something you’d find in a cave — bones actually have a lot of fat etc — bones are complex things more similar to organs than rocks. We’re all laying down new bone and taking away old bone all the time. The skeleton is like all of our other tissues. Each year we replace about 10% of our skeleton, which is why it lasts as long as it does. We’re always losing small amounts in our sweat/urine, so you do need a bit of calcium regardless of bones.
  • Counterintuitively, calcium supplements seem to increase the risk of hip fractures. Auckland University didn’t believe their own results but 3 other groups have found the same thing.
  • There are hormones which control levels of calcium in the blood — e.g. parathyroid hormone, which stimulates the formation of osteoblasts to lay down bone and also stimulates the widening of the femoral neck which happens to all of us when we get older. This is the bit that breaks when the elderly have a fall. (We are SUPPOSED to get wide in the hips as we get older.)
  • We could get older people at risk of osteoporosis to take parathyroid hormone but it’s extremely expensive and needs to be given daily by injection. At present it’s only given to the most extreme at risk population. The Japanese are working on it. They’ve worked out how to make it a once a week injection so far.
  • Osteoporosis seems to be an inevitable part of getting old, and perhaps shouldn’t be regarded as a disease but rather as an inevitable consequence of living beyond 45-55. In women there’s a huge change at menopause which has a profound effect on bone. From menopause women progressively lose bone. Whether it results in fractures depends on how strong our bones are at the peak of adult life.
  • Don’t smoke. The evidence is strong on that, even specifically for bone health. Smokers fracture more, perhaps because smokers tend to be thinner.
  • Also don’t live too long, if you want to avoid osteoporosis. In your 80s and 90s bone loss is substantial and risk of fracture suddenly becomes high and a major public health problem. It shortens life but also substantially reduces the quality of life. Continuous back pain destroys the benefit of having a longer life, for example.
  • Women who are very thin have significantly more fractures than people who are a healthy body weight.
  • “The fatter you are, the stronger your bones.” This finding caused an incredible stir, because it was thought the bone doctors were “encouraging obesity”.
  • Alcohol is not all bad when it comes to bones. The Double Osteoporosis Study just outside Sydney found that women who have a couple of drinks per day was fine for their skeleton.
  • On the issue of ‘healthy body weight’, here’s what Dr Reid has to say: For average height women aim for a weight between 60-70kg. Being fatter makes your bones stronger because fat cells produce hormones themselves and people who are fatter also have changes in hormone levels. A number of hormones are involved, and these hormones either switch on or off the activity of the bone absorbing cells.
  • Someone who is 120kg actually has a wonderful bone density. But someone that large will be more prone to falls. [So perhaps aim for as heavy/dense as possible without it affecting your joints and balance.]
  • After a certain age it’s thought that you’re not going to get any more bone so more calcium isn’t going to help you. Prof Reid added that calcium doesn’t seem to make much difference all throughout one’s life — even in children. African children, who have a low average calcium intake, are fine in regards to bone health (excepting those with rickets).
  • Dark green vegetables are as good as dairy products when it comes to bone health, as long as the calcium is received via the diet.
  • Are calcium supplements ever useful? Prof Reid hasn’t prescribed them himself in the last 5 years because of the latest research. Certain people who have abnormalities in their calcium regulating hormones who need to have their levels maintained but for people without specific illnesses like that there seems to be no benefit.
  • The calcium you get in a supplement is not the same calcium you get in your diet. The fundamental difference is that some calcium supplements contain more calcium than you would take in all the meals of the day. Blood levels can climb above the normal range in the hours after you’ve taken a supplement and can stay up there for more than 8 hours. But if you get calcium via a meal your blood levels rise very little. Extra calcium can cause higher blood pressure and coagulate your blood which can obviously be a bad thing.
  • The dairy industry has been keen to promote the idea in the past that the more milk you drink the stronger your bones, but that isn’t true. However, the dairy industry will probably be fine with these results which show that calcium should be sourced via the diet rather than via supplementation.

People in Paleo diet world have been aware of the genuine role of calcium in good health for some time (because Paleo enthusiasts are consistently ahead of the curve from what I can see), and tend to downplay the importance of dairy for various reasons, including this one.

Current thinking in Paleo world is that magnesium is as important for bone health as calcium, but hasn’t had the same press (and when I say ‘press’ I mean, ‘advertising push from the dairy industry’). I was hoping Professor Reid was going to talk about magnesium, but it doesn’t seem to have been part of his research.

Can some government please fund that? K, thanks.

 



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