Benefits of Physical Activity

Written by Isobel Pugh Jun 12, 2009 at 08:23 AM We have recently read the following study, which we thought of great interest, here is the reference:

Mavroeidi, A., Stewart, A.D., Reid, D.M., & Macdonald, H.M. (2009). Physical Activity and Dietary Calcium Interactions in bone mass in Scottish postmenopausal women. Osteoporosis International, 20: 409 - 416.

The study looked at 1847 women aged between 60 and 82. It found that, with regard to bone density, physical activity particularly had beneficial results in individuals that had a low to medium calcium intake.

Throughout the study, a number of interesting points were made. Here are a few quotes:

"It is now well accepted that in addition to genetic factors, environmental influences, such as diet and lifestyle, are also important contributors to the population variance in bone mineral density"

"Bone mineral density is limited, but not controlled by diet, and regulated by mechanical loading"

In particular:

"It has been postulated that the reduction in habitual Physical Activity, a product of the increased mechanisation of everyday life, could be one of the main reasons for the doubling of hip fracture rates in both sexes, over the past 30 years in the UK."

We say: This was an encouraging study. We'd also add that exercise reduces fracture risk in other ways than by simply increasing bone density - by improving an individuals balance, co-ordination, and flexibility, for example. It is still the case that over 90% of osteoporotic fractures occur after a fall, so if you can reduce the risk of falling, you dramatically reduce the problems associated with osteoporosis. See more news items...

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Vitamin B12 Vitamin B12 is important for bone health:

http://onlinelibrary.wiley.com/doi/10.1359/JBMR.041018/full

The subject is still being researched: and as far as we can tell, the mechanism by which B12 affects bone density is yet to be understood.

It seems to us that this information is most important for people who have conditions which may affect their ability to absorb the vitamin - it seems that having low levels of Vitamin B12 in the bloodstream may be linked to lower bone density.

We think that the vegetarian society has a good article about B12 - particularly because reliable sources of B12 are only available from animal produce (vegans need to ensure that they eat fortified foods, or supplement). This article tells you how much B12 you need per day:

http://www.vegsoc.org/info/b12.html

Here is a list of foods that contain Vitamin B12, and the amoung of B12 they provide:

http://ods.od.nih.gov/factsheets/vitaminb12.asp#h3

Apparently soil contains quite a lot of Vitamin B12 (We're certainly not going to recommend people stop washing their vegetables though!). ...read more

Vitamin D Update Very important...

July's edition of Osteoporosis International included essential updates aboutVitamin D, fracture risk, and health:

Increasing evidence shows that the current mainstream guidelines for vitamin D intake are inadequate.

If you have had a bone density test with us, before July 2010, it is very important that you familiarize yourself with these updated guidelines. In fact, we recommend ALL women (and men!) living in the UK do so... and also be aware that we STRONGLY suspect over the next few years these guidelines will be revised - in an upward direction! This is certainly NOT a situation where the recommendations are set in stone!

Let's get started. The link below is particularly important for the over 60s; it is the International Osteoporosis Foundations' (known as the IOF) position statement for Vitamin D requirements for older adults:

Dawson-Hughes, B., Mithal., A., Bonjour, J.-P., Boonen, S., Burckhardt, P., Fuleihan, G.E.-H., Josse, R.G., Lips, P., Morales-Torres, J., & Yoshimura, N. (2010). IOF position statement: vitamin D recommendations for older adults. Osteoporosis International, 21: pp.1151-1154.

Link to news release here:

http://www.iofbonehealth.org/news/news-detail.html?newsID=327

Next: This large, heavyweight, review article, put forward a strong case for much higher intakes of vitamin D - even compared to the new IOF guidelines:

Bischoff-Ferrari, H.A., Shao, A., Dawson-Hughes, B., Hathcock, J., Giovannucci, E., Willet, W.C. (2010). Benefit-risk assessment of vitamin D supplementation . Osteoporosis International, 21: 1121-1132

Link to the article here: http://www.ncbi.nlm.nih.gov/pubmed/19957164

Here are a few key points from the benefit-risk assessment article:

Our analysis suggests that mean serum 25(OH)D levels of about 75 to 110nmol/l (30 - 44ng/ml) provide optimal benefits for all investigated endpoints without increasing health risks. These levels can be best obtained with oral doses in the range of 1,800 to 4,000 IU of Vitamin D per day (45 - 100µg per day); further work is needed, including subject and environment factors, to better define the doses that will achieve optimal blood levels in the large majority of the population.
The reliable evidence that excess vitamin D can cause hypercalcemia [excessive calcium in the bloodstream, sometimes seen as a sign of Vitamin D toxicity or overdose] comes from daily intakes of Vitamin D greater than 100,000 IU [!] which are far higher than those necessary to achieve benefits.

Just to put this in perspective, 100,000 IU of vitamin D is 500 times the current RDA for the under 50s, and over 160 times the RDA for individuals over the age of 60. In other words, if you want to overdose on Vitamin D, you've really got to make an effort to do it!

Another heavyweight study here:

Leidig-Bruckner, G., Roth, H.J., Bruckner, T., Lorenz, A., Raue, F., Frank Raue, K. (2010) Are commonly recommended dosages for vitamin D supplementation too low? Vitamin D status and effects of supplementation on serum 25-hydroxyvitamin D levels-an observational study during clinical practice conditions.Osteoporosis International, June 17^th - Epub ahead of print.

Even if you simply read the last few sentences of the abstract, you get the idea - again, 2,000 - 3,000IU of Vitamin D per day are necessary to obtain a meaningful benefit:

Linkto abstract here: http://www.ncbi.nlm.nih.gov/pubmed/20556359

We say:

There are 5 different D vitamins: Vitamin D3 is synthesized endogenously (i.e., it is the one you make in your body). The other name for Vitamin D3 is cholecalciferol. Some supplements contain Vitamin D2, also known as ergocalciferol. There is some debate as to whether Vitamin D3 is ‘better' or more effective in supplement form - at the moment it would appear that both D3 and D2 can be beneficial in improving your Vitamin D status.

It is a BIG shame that ‘Vitamin' D is so called; it makes it very hard to stop thinking of it as something you obtain in sufficient quantities in your diet. Better to give it its other name, cholecalciferol.

Let's think of cholecalciferol as a chemical, or more accurately, a hormone, that your body produces when it is exposed to sunlight (rather like plants photosynthesize in sunlight). Diet is NOT a sufficient source of cholecalciferol.

Having a sufficient intake of cholecalciferol (through sunlight or supplement), and optimal levels of vitamin D in your bloodstream (known as optimal serum 25(OH)D, or serum 25OHD, 25-hydroxyvitamin D), will provide other benefits, as well as reducing your risk of fracture. There are also strong associations with bowel cancer, other nasty, killer, cancers, multiple sclerosis, depression and other mental health problems - to name but a few.

As it is unadvisable to obtain the revised quantities of cholecalciferol from food (Well - at a stretch you could - but after all of the pints of milk and portions oily fish you had eaten, you would either be fat and/or deficient in other vitamins and minerals - you wouldn't be able to eat much else), you need to make the decision: Sunlight, or supplement? Or (probably best) both?

TAKE ACTION:

How much sun exposure?

When humans (and nearly all known life on this planet) evolved, they evolved in the sun. Outdoors. We spend an unprecedented amount of time indoors - and our vitamin D status is poor as a result.

Here is a useful calculator that you can use to help you decide how much sun exposure you should be aiming for (NB! Sunscreen dramatically reduces or even stops vitamin D production):

http://zardoz.nilu.no/~olaeng/fastrt/VitD-ez_quartMED.html

We think that these guidelines are pretty conservative - note that they say ‘minimum sun exposure'. Furthermore, you need to commit to doing this regularly, and for life. Pretty difficult in our climate, particularly if you work full time.

Conversely, avoid excessive sun exposure - this simply means: don't let yourself burn. That will increase your risk of skin cancer (There is evidence that excessive sun exposure increases your risk of the less deadly, nonmelanoma skin cancers (usually these are easily treatable) - but maybe not the deadly skin cancer, melanoma - interesting, eh). Be aware that it takes a few hours AFTER your sun exposure before you can tell how much you have 'caught' the sun, so don't wait until you burn before you get into the shade! Adequate cholecalciferol will reduce your risk of some of the nastiest cancers there are - for example, bowel cancer. We think it is worth the increased risk of non-melanoma skin cancer, in order to reduce your risk of the really dangerous cancers. There is more information about this in Holick's book 'The Vitamin D solution' - see below for more details.

Recommending what supplements to take, and how much, is out of our area of qualification; however, we can soon recommend some important and fascinating books by experts on the subject. In fact, until mainstream guidelines catch up, we consider it an essential requirement to read at least one of these books:

The Vitamin D Solution - Michael Holick PhD, MD. This book also has useful guidelines for sun exposure. A ‘bigger' read than ‘Power of Vitamin D' - lots of statistics, facts and figures. The Question and Answer section at the back of the book is very good, we think worth the price of the book itself! Michael Holick is Professor of Medicine, Physiology and Biophysics and director of the General Clinical Research Center at Boston University Medical Centre.

Note that Holick and Zaidi do not agree on calcium requirements. We concur with Zaidi - mainly because of concern that excessive calcium intake might increase heart disease risk ; we'll let you read the books though.

We have ordered a couple of other books on the subject - we'll post any that we feel are of value! If you have found anything informative, do let us know!

A question Tracey and I are often asked is: do we take any supplements?

The answer is - yes, for the past few months! We both take between 3,000 and 5,000 IU of Vitamin D per day - unless we are outside for a few hours in the day, or on holiday in a sunny climate (in other words, we're taking these supplements practically every day!)

We also take a multi vitamin and mineral tablet every day - A ‘complete' one - there are all sorts of brands on the market, e.g., Sanatogen ‘Gold', Centrum one a day. Isobel is currently taking one that Tesco manufacture - most main supermarkets have a cheaper ‘rival'!

We have yet to find a ‘complete' supplement that contains anything but a small fraction of the cholecalciferol required - so don't think you have adequate serum 25(OH)D status simply because you're taking a multivitamin! Further, there is no chance that the Vitamin D in the multivitamin will tip us into the ‘overdose' level. Also, check the label of any supplements you are taking to ensure that you DON'T overdose on Vitamin A - that IS toxic in excess (bone resorption, and therefore weakening, being one of the main problems!). When it comes to Vitamin A, don't go over 100% of the RDA when you supplement. ...read more

Adequate Vitamin D... ... IS VERY important for bone health!

Please read the update about Vitamin D as well!

You may be aware that vitamin D is one (of many) important micronutrients that your body uses to build and maintain your bone strength. Fewer people are aware that having low levels of vitamin D in the bloodstream can also lead to impaired balance (known more specifically as 'body sway' in scientific circles). Most osteoporotic fractures happen as a result of a fall; therefore, if an individual is vitamin D deficient, their fracture risk is increased in two very important ways. Here are a couple of articles on the subject:

http://jama.ama-assn.org/cgi/content/abstract/291/16/1999

https://www.thieme-connect.com/ejournals/abstract/eced/doi/10.1055/s-2001-14831

http://cat.inist.fr/?aModele=afficheN&cpsidt=1398002

Concerned? For a general overview about what to do, the relationship between vitamin D and bone health, and in particular, which populations are at increased risk of deficiency, we think that this article is very comprehensive:

http://www.nof.org/prevention/vitaminD.htm

An important thing to note here (and this is true for any vitamin or mineral), is that it is never a case of 'the more you take, the better' - or that 'everyone needs to take supplements!'Rather, it is a matter of ensuring that your intake is adequate. If you have any disorders of 'malabsorption' - in other words, problems absorbing whatever you are eating, e.g. Crohn's disease, Celiac disease (And other conditions mentioned in the above article), or, for example, you avoid the sun altogether, it is important to ensure that your vitamin D status is not compromised, and you take measures to counteract it. ...read more

Our promise to you Our aim is to help to reduce the prevalence of fractured bones in the UK.

When it comes to the advice that we give individuals who have a bone density scan with us, we promise to act with honesty, and professional integrity. In order to do this, we also promise to keep our knowledge of osteoporosis and fracture prevention up to date.

Why has this post come about?

In the past, we have been contacted by individuals who are keen to use our service to help them promote supplements or nutritional 'aids'. In the past we received these calls only rarely and we tended to ignore them; more recently, we have noticed an increase in this type of interest - we thought we had better set the record straight!

1. We do not accept commission - from anyone - for promoting or supporting any product, whether or not it has been proven to have an effect on bone density. We have a strong stance on this, because we believe that it may compromise the advice we give you. We do promote certain products, books, and services - but only because there is an extensive body of evidence that demonstrates that whatever we are promoting has a valid chance of either increasing bone density or reducing fracture risk.

2. In the overwhelming majority of places we test, it is the establishment that takes a small fee for having us. This is a modest amount which is solely to reimburse the establishment for the use of their space, and for making their members or employees aware of our impending visit. A number of establishments have wanted 'more money' for hosting us - we politely decline these arrangements.

3. If you are interested in promoting a medication or supplement, and using us to help you do so - don't give up just yet: before you contact us, make sure that you have an extensive body of evidence to support that whatever it is that you are promoting will reduce fracture risk. If you can provide us with peer reviewed journals, we will look at them and decide whether there is evidence enough for us to work with you. One journal will not be enough - ideally your product or service will have support from either a large meta analysis (As found in, for example, the Cochrane Collaboration) or approval from the F.D.A.; or be recognised as an effective treatment by N.I.C.E.

Be warned! We are also avid readers of Quackwatch! Even if you do have an extensive reference list to support you, we will not accept payment for promoting your service, but we may accept payment for providing tests free of charge to a population who will benefit from what you provide.

4. In many cases we will accept advance payment for providing bone density tests to an organisation. A number of council offices, universities, and schools have paid, or subsidized, us to provide their staff with low cost or free bone density tests. This is fine, as the organisation is not a 'vested interest' group and our accepting payment to provide the tests to the staff for free will not compromise the advice that we give the individuals that we test.

5. If you are a gym, fitness, leisure or health centre, we may well be interested in working with you, because there is longstanding evidence to support exercise for the reduction of fracture risk. We sing the praises of many of the health centres that we work with - in particular, some of the ladies only health franchises (even though there is often some healthy rivalry between those franchises!) offer an invaluable service to their members and quite literally transform the lives of some of the ladies that have had the good sense - or fortune - to join. We don't need to accept payment to say this - if you go along to some of the places we have tested (check out future events for more), you can speak to the members yourself!

We really hope that this clarifies our position. If you've read this and would like to arrange a day with us, great - we look forward to working with you! Go to Hosting a Day for more info. ...read more

Beer for Bone Health? In moderation!

Tucker, K.L., Jugdaohsingh, R., Powell, J.J., Qiao, N., Hannan, M.T., Sripanyakorn, S., Cupples, L.A., & Kiel, D.P. (2009). Effects of beer, wine and liquor intakes on bone mineral density in older men and women. American Journal of Clinical Nutrition, 89(4):999 – 1000.

This study looked at the alcohol intake, and bone density at the hip and spine, in 1182 men, 1289 post-menopausal women, and 248 pre-menopausal women. The participants were aged between 29 and 86. The difference between this study and other studies looking at bone density and alcohol, was that this study looked at different types of alcohol, and attempted to determine whether one type of alcohol was more beneficial than another for bone density.

The study results showed that men tended to be more likely to drink beer, whereas women tended to drink wine (But we knew that already, didn’t we!). Interestingly, bone mineral density at the hip was 3.4 – 4.5% greater in men who consumed 1-2 drinks of alcohol or beer compared to non-drinkers, however, men than drank more than two drinks per day had significantly lower hip and spine bone mineral density (3 – 5.2% lower than those that drank 1-2 drinks per day) – seemingly cancelling out the beneficial effect of the first drink!

Bone mineral density at the hip and spine was significantly greater in postmenopausal women consuming more than 2 drinks per day of total alcohol or wine (5.0 – 8.3% greater than in non-drinkers).

The researchers adjusted the data to see whether it may be the silicon content of the beer that was causing the improvement in bone density. The adjustment reduced the benefits of beer on bone density, suggesting that perhaps it is the silicon content of the beer that is causing the improvement in bone density in beer drinkers. However, this did not explain the improvements in bone density seen by the wine drinkers. The researchers suggested that there may be another compound (or other compounds) in other alcoholic drinks, yet to be defined, that is the reason for the benefit in other types of alcoholic drink.

The pre-menopausal women did not seem to benefit from any type of alcoholic drink.

Other studies have suggested that there may be a benefit to supplemental silicon intake, particularly where calcium intake is insufficient:

http://www.ncbi.nlm.nih.gov/pubmed/19034393?ordinalpos=4&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum

We say: Something is causing an improvement in the bone density of people that drink alcoholic beverages (in moderation!), but it may not be the alcohol!

The researchers did not look at the possible role of the mineral boron in this study. Wine is a good source of boron. There has been a certain amount of research surrounding this area, with mixed results – but enough to know that boron has a role in bone health. Boron is also found in fruit and vegetables, something that we know many people in the UK don’t get enough of. It may be that the boron in the wine was replacing that which should have been found in the fruits and vegetables of the participants!

Many people will be amazed how small a ‘moderate’ amount of alcohol is. A 125ml glass of wine contains 1.6units of alcohol – so in other words, a glass of wine this size on a daily basis may give benefits to bone, but any more will likely be counterproductive! It’s worth measuring out 125 ml of water and pouring it into the wine glass you usually use at home – stand back and be amazed how little it is.

Be very careful before taking a boron supplement (or any type of supplement) though. Many of these micro-nutrients can be very toxic in excess. We would always suggest that you try to increase your intake of these minerals through your diet, unless you are under GP advice.

Finally, the bones of the pre-menopausal women did not benefit from the inclusion of alcoholic drinks in their diet. Looks like younger ladies will have to stick to the healthy lifestyle!! Sorry girls! ...read more

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