Comments on Bone Health Article in the Vegetarian Voice

The Fall 2009 issue of Vegetarian Voice magazine, the newsletter of the North American Vegetarian Society, has an article by Amy Joy Lanou and Michael Castleman, “A Whole Diet Approach to Building Better Bones.”

I will quote from the article to sum up their arguments:

“[W]e have known for at least 20 years that fracture rates are highest in areas where dairy and calcium consumption are also the highest.”

“Research shows that a low-acid diet, one that is high in fruits and vegetables and devoid of (or low in) animal protein (meats, poultry, fish, milk, eggs and cheese) helps keep calcium in bones.”

“[Osteoporosis is] actually a disease of calcium imbalance. Drinking milk and eating dairy foods provides calcium – but these foods are so high in protein that they draw more calcium out of bone then they replace.”

“We do need some calcium. The World Health Organization recommends 400 to 500 mg/day for people in countries at high risk of osteoporosis.”

“The best approach to osteoporosis prevention – the only one that makes scientific sense – is a diet very low in or devoid of animal foods and high in fruits and vegetables, combined with walking or equivalent exercise for 30 to 60 minutes a day, every day.”

If you have been following vegan nutrition advocacy for the past two decades, nothing above should be new to you. And here are the major problems I have with it:

1. Most non-vegans in Western countries get around 800 to 1200 mg of calcium per day. At this level of intake, I agree that there is little evidence that to prevent osteoporosis one needs even more calcium. However, Lanou and Castleman imply that all you need is a vegan diet containing 400 – 500 mg of calcium per day and walking for 30 to 60 minutes for strong bones. And they leave out the most important study published to date on bone health and vegans, a 2007 report from the EPIC-Oxford study which showed that vegans had a 30% higher rate of bone fractures than did meat-eaters and lacto-ovo vegetarians!

In that study, the vegans who got more than 525 mg of calcium had the same rate of bone fractures as the meat-eaters and lacto-ovo vegetarians, showing that vegans need more than 525 mg of calcium. (In the study, 32% of vegans had calcium intakes between 525 and 699 mg per day, and 24% had greater than 699 mg per day.)

This is the only study looking at the bone fracture rates of vegans.

2. Lanou and Castleman base most of their argument on the idea that animal protein leeches calcium from the bones. As I posted a few weeks ago, a meta-analysis looking at bone health and fractures found that “Overall, the weight of the evidence shows that the effect of dietary protein [including animal protein] on the skeleton appears to be favorable to a small extent or, at least, is not detrimental.”

In my opinion, the argument that a primary cause of osteoporosis is animal protein has always been on shaky ground.

3. Lanou and Castleman leave vitamin D out of their final recommendations (they briefly mention you can get it from the sun earlier in the article). Vitamin D can be a significant problem for many vegans and needs to be addressed in discussions of bone health.

4. I do not see why it is necessary to make an argument that people only need 400 to 500 mg of calcium per day, when the evidence is so lacking (and actually points in the other direction). What harm could come from encouraging vegans to get at least the low end of what is a normal amount of calcium (like 700 to 800 mg/day) in Western countries? None. But what harm could come from vegans not getting that much? Only osteoporosis!

In summary, there is no direct evidence that a vegan diet with only 400 to 500 mg of calcium per day prevents osteoporosis. The direct evidence is just the opposite.


More info on vegan diets and bone health.

24 Responses to “Comments on Bone Health Article in the Vegetarian Voice”

  1. Ginny Messina Says:

    Thanks for posting this information. I agree that the evidence linking high protein intake to osteoporosis risk is shaky at best–especially when we look at the more recent research. And there is certainly good evidence–as you pointed out–that vegans and everyone else need more than 500 mg of calcium. Vegans need to be smarter about bone health and we need to stop relying on outdated perspectives on this issue. It’s potentially harmful to vegans and that’s potentially harmful to vegan advocacy.

  2. beforewisdom Says:

    IMHO the issue with #4 is that it is politically difficult.

    It is very hard to get more than 500 mg of calcium on a vegan diet without supplements.

    “Supplements” being “artificial” which the subculture of vegans tends to have a problem with AND critics will tend to use as an argument against veganism.

    People also want to feel reassured. Even if you have access to high calcium greens, the kind you can usually find only in Asian groceries, it can be very uncomfortable to get 500 mg of calcium or more through natural foods.

    I’ve tried. Even if you don’t have problems with gas you (I have) gotten very uncomfortably full eating 2 + cups of cooked greens a day.

  3. beforewisdom Says:

    Jack, Ginny;

    What about those articles people hear about concerning people in 3rd world countries who get extremely little calcium yet do okay with avoiding osteoporosis?

    Could it be that osteoporosis isn’t about calcium after a certain point, but other things like lack of adequate exercise, too much sodium( a serious problem few ever talk about ) and inadequate sun exposure?

    Assuming that were true I guess it doesn’t change much. Just like many Americans don’t like to eat many high calicum vegetables on a regular basis, increasing exercise, increasing sun exposure and reducing sodium would also be things that would be hard to get people to do.

  4. Ginny Messina Says:

    Beforewisdom, the data you are referring to doesn’t actually show lower rates of osteoporosis in countries where people consume less calcium. It shows lower rates of hip fracture. There are some big problems with this data which have caused most bone health experts to discount it more or less.

    Most importantly, many of the population groups included in this analysis were Asian, and Asians have a slightly different hip anatomy that makes it more resistant to fracture. So when we look at the actual bone density and at osteoporosis in the spine, these groups are no better off than Westerners regarding bone health. Other groups—particularly in Africa—metabolize calcium differently and tend to have more dense bones no matter what. So we can’t make assumptions about calcium requirements for people of European descent based on these findings.

  5. beforewisdom Says:

    Ginny;

    Thanks for the informative and interesting reply.

    I have seen popular articles about write ups of western studies that seemed to show no link between calcium supplementation and the prevention of osteoporosis. I know that could simply mean that supplements are a poor substitute for food. It could also mean that you and Jack are right, but that after a certain point more calcium will not help. Perhaps after that hypothetical optimal intake things like sodium, exercise, vitamin D, other bone nutrient intakes take over as issues.

    I know it is a dangerous idea, but I can’t help believing that the current DVs are inflated. Getting a gram of calcium or over with vegan foods is a practical impossibility. People must have been alright without dairy and lower calcium intakes in history. On the other hand, maybe osteoporosis has always been a fact of aging for non-dairy consuming populations and pre-dairy consuming Europe — it is just being measured now with modern science.

    I am thankful that you and Jack are speaking up about this issue.

    Some vegan health experts don’t like contradicting other vegan health experts. In my view, I feel safer when I hear a variety of opinions spoken.

  6. beforewisdom Says:

    I’m not counting on a definite answer from science any time soon about these issues. I guess the thing to do is to measure what is going on in my body and adjust.

    Are osteoporosis tests cheap, reliable and easy to get from a doctor?

  7. Jack Norris RD Says:

    I don’t think anything is cheap from a doctor (in the USA) unless your health insurance covers it. I’m not necessarily up-to-date on the various ways to assess whether someone has osteoporosis — a Google search would probably tell you. MayoClinic.org usually has good info.

  8. Flo Says:

    beforewisdom,

    If fortified foods count as supplements then I have to agree, that it is hard to get a sufficient amount of calcium as a vegan. If not there are quite a lot of fortified soy,oat,rice-milks and some juices (120mg Calcium/100ml) at least here in Germany. Also some mineral waters can contain several hundred milligrams of calcium per liter here (without fortification!). In the German Vegan Study GVS the mean calcium intake was around 200-300 mg higher than the intake of the vegans in the EPIC Oxford study, though still under the recommendations. Since the GVS was conducted (2003) more fortified foods entered the stores, so I hope the number of vegans with low calcium intakes (and some other nutrients ) will decline in future.

    I think it would be the best for vegans to get all the nutrients from normal and fortified food. For most people taking a pill is more of a problem. Sadly this is still necessary for many vegans here.
    The problem with the “a vegan diet needs supplements and is unnatural, artificial …” argument is, that few people know how unnatural the diet (and life) of an average cow, pig or chicken is. Most of the vitamins produced by the industry go into animal feed. Minerals like cobalt, iodine, selenium, calcium (for cows and laying hens) are also often added. In Germany much iodine comes from animal products but only because the animal feed is enriched. Without adding all these minerals and vitamins to the animals diet the current animal husbandry would be impossible.

  9. Jeff Gibson Says:

    A question for Ginny Messina:
    I clicked on your name but could not find a way of contacting you via your “The Vegan Dietitian” blog, so with apologies to Jack and the commenters here for being a bit off topic, I am interested in this comment of yours:

    “Most importantly, many of the population groups included in this analysis were Asian, and Asians have a slightly different hip anatomy that makes it more resistant to fracture.”

    As someone in the health care field I’d love to know your source(s) for this anatomical difference. If you could point me in the right direction, I’d appreciate it. Thanks!

  10. Deborah Pageau B.Sc. Says:

    There are two very significant points that must be factored into any discussion of how much calcium we need:

    1) Weight bearing exercise is what draws minerals (not just calcium!) into bones and it is a localized issue. That is to say, vigorous walking, ideally up and down hills and stairs as well as on flat land, builds bone in the lower half of our bodies. The arm, wrist and hand bones also need weight bearing exercise such as pulling and pushing. Some people like to carry light weights or use hiking poles when they walk, which helps. When walking out of doors, stopping along the route to do some push & pull-ups on playground equipment or enjoy a youthful flight on a swing adds greatly to the value of the walking for the whole body.

    2. Gluten intolerance, when undiagnosed, interfers with the absorption of various nutrients and calcium is often one of those. Vegetarians and vegans tend to consume a high proportion of their calories in wheat and other gluten-bearing grains. Although eating a plant-based diet offers most people a significant improvement in their health, those with gluten-intolerance must avoid the popular veggie dogs and burgers, breads, crackers etc based on gluten-grains. At this time, projections from control group studies indicate that there are still many people with undiagnosed gluten-intolerance eating gluten-bearing grains and suffering the consequences. The medical community is gradually becoming more aware of the need to screen patients for this but at this time, recognition of the issue still usually comes first from the patient. For more on this, there are lots of good websites on the net with the latest information on gluten-intolerance and it’s relationship to osteoporosis.

  11. beforewisdom Says:

    Deborah;

    How does one know if one is gluten intolerant?

    Are there symptoms?

    More importantly, is there a reliable medical test that you can ask a doctor for and will tell you, for sure, one way other?

    Is their medical literature establishing gluten intolerance as a medical problem and one that interferes with calcium absorption?

  12. Ginny Messina Says:

    Regarding the feasibility of getting a gram of calcium on a vegan diet, I agree that it’s difficult. But keep in mind that osteoporosis is a disease of older people and as longevity increases, we might have to change our perspective on how much calcium is enough. So the fact that people did okay in the past without high calcium intakes might not be relevent to us now. Also—although this seems counter-intuitive—childbearing reduces risk for osteoporosis. In the past, women had more children. And in some other cultures, women still have more children which may affect comparisons of bone health.

    And nutritional anthropologists says that our early ancestors had huge intakes of calcium from wild leafy greens. The cultivated greens we eat now are probably much lower (and we eat less of them) but this does suggest that in the best of all worlds, it was possible and ideal to get calcium from greens.

    Jeff, here is a reference for the hip axis length, and I’m sure there are others as well: J Bone Mineral Res 1993; 8:1211 (first author is KG Faulkner)

    And yes, it’s true that bone health is an issue in untreated celiac disease, which is glucose intolerance. But celiac disease affects only around 1 percent of the population so it’s probably not an issue for most people. A lot of people with celiac disease are undiagnosed, though.

  13. Deborah Pageau B.Sc. Says:

    Beforewisdom;

    Yes, there are many possible symptoms caused by untreated gluten intolerance. They are many and varied. To save space and time, I would ask that you refer to some of the websites specific to this topic. One of them is celiac.com.

    The word celiac refers to one of the symptoms that some people with gluten intolerance have. The word “celiac” refers to the flattening of the nutrient receptors in the small intestine. At one time, this was thought to be the one and only real symptom. Back then, an endoscopic investigation was the only recognized method for diagnosis.

    There are now a number of tests available using blood, stool or saliva. However, they are prone to false negative results. The only 100% reliable test is the DNA test. This is because gluten intolerance is caused by a genetic trait. Not all people who have the trait develop the condition but all people who have the condition, have the gene.

    So, getting the genetic test will tell you if any health issues you have may be due to eating gluten. If you have Irish or Scandanavian ancestory, the odds of you having the trait are very high. While there was a time when the 1% guess-timate was considerable reliable, that rate has been steadily rising in the past 20 to 30 years as testing has improved. Anyone with osteoporosis should be tested for gluten intolerance.

    Many people accurate identify their own gluten intolerance through trail-and-error. Withdrawing all gluten from the diet for a period of weeks, then adding it back in can tell you a great deal.

  14. jeff gibson Says:

    Thanks Ginny. My search did not turn up that exact reference, but KG Faulkner is cited in many similar papers. For anyone else interested, the gist is this: Asian women generally have a shorter hip axis length, defined in one paper as “the distance from the greater trochanter to the inner pelvis”, and shorter hip axis lengths are associated with fewer hip fractures.

  15. Maija Haavisto Says:

    “Vitamin D can be a significant problem for many vegans” – uh, getting adequate vitamin D is a significant problem for most people, except for those living near the equator (and even they can be deficient). You can’t get nearly enough vitamin D from the diet, vegan or not, fortified or not, so the diet you follow is completely irrelevant in this particular regard. Thus I find this statement highly misleading.

  16. Jack Norris RD Says:

    Maija,

    I agree that vitamin D can be a problem for many people. However, there are levels of vitamin D deficiency. The well-established, extreme deficiency that can lead to rickets or osteomalacia can be more of a problem for vegans because they do not have the traditional sources of vitamin D, which are fortified milk and fish oils. I know a number of vegans who have had severe vitamin D deficiency. When it comes to milder forms of vitamin D deficiency, I agree that vegans are in about the same category as everyone else.

  17. Deborah Pageau B.Sc. Says:

    Beforewisdom Steve;

    Even people who believe themselves well may be gluten intolerant. Symptoms can be subclinical or unrecognized initially. When symptoms are transient, they may be attributed to “having a cold”, stomach flu or stress. It can be at the root of mood disorders and infertility. It is still regrettably common for people to go for 10 years with increasing symptoms of various types before accurate diagnosis.

    When people with gluten intolerance develop osteoporosis, they typically fail to respond to treatment until 100% of gluten is withdrawn from the diet. Fortunately, the vast majority of symptoms go into rapidly remission with gluten elimination diet.

    While this may seem like too much to consider for people who already eat a vegan diet, I can assure you, it is do-able and can be necessary to provide the desired results. Anyone with certain disease trends in their family history may be wise to investigate this avenue.

  18. Rick Says:

    Beforewisdom,

    I believe that dexa bone scan (dual energy x-ray absorptiometry) is the best test for measuring bone mineral density. It is a highly accurate way to diagnosis osteoporosis or osteopenia.

    All,

    Luigi Fontana, M.D., Ph.D. (the Ph.D. is in Nutrition) at the Washington University School of Medicine conducted a study which included performing dexa on several vegans and his findings were of concern.

    He looked at four groups: standard American diet (SAD), lacto ovo vegetarian (LOV), vegan and raw food vegan (RFV). Bone density ranged from normal in SAD with progressively higher incidence of osteopenia and osteoporosis in LOV, to vegan and and worst in RFV.

    As I understand, he only published (Arch Intern Med. 2005;165:684-689.) his findings of the high incidence of osteopenia and osteoporosis in the RFV group however, because due to the small number of people in the study, the LOV and vegan groups unfortunately did not achieve a statistical power. I also believe that other indicators of bone health were normal and the osteoporosis was not associated with a higher incidence of bone fractures. http://archinte.ama-assn.org/cgi/content/full/165/6/684

  19. Kieran F. D'Souza Says:

    Hi all

    I am really confused as to where this discussion is leading to. I mean osteoporosis is the problem in the West where the daily meat eating and milk drinking food habits are most widespread. Which is why many doctors, scientists, nutritionists etc are concluding that meat eating, the acid nature of it, the excess protein could be a cause for the disease. So why is vegetarianism being blamed all of a sudden due to some strange concocted experiments?? I mean who is osteoporotic the meat eating West or the almost vegetarian Asia and Africa ? Are the majority of elderly who suffer fractures in the West vegetarians???

    before you people blame vegetarianism I think you should first properly define it, see what a proper vegetarian diet consists of, and how a vegetarian meal is prepared.

  20. Jack Norris RD Says:

    Kieran,

    What “strange concocted experiments” are you referring to?

    You might want to read the follow up to this post — click here.

  21. beforewisdom Says:

    Hi Kieran;

    I’m not a health or medical expert of any kind.

    I don’t think anyone is blaming veganism for osteoporosis ( I’ve been a vegetarian for 30 years and a vegan for about 15 ).

    IMHO, the discussion is about people interested in nutrition trying to to conclude the most from very limited information.

    A problem that has to be frequently solved in science is separating correlation from causation. Just because one thing always happens with another thing, does not mean it is a cause. Finding the true cause is often crucial to solving the problem.

    Getting back to bone health there have been a number of articles showing that consumption of cows milk and calcium supplements doesn’t seem to be reducing osteoporosis.

    Does that mean calcium intake is irrelevant? In my opinion. No. It just means, possibly, past a certain point other factors are an issue. So, vegans shouldn’t consider calcium to be a non-issue for their health.

    I guess what I am trying to explain and not doing a good job at doing it briefly and clearly is that we aren’t dissing diets we are trying to figure out if particular conclusions are true.

    You do that in part by bringing up, reasoning out and eliminating other possibilities. You do that so you get correct information and advice that WORKS instead of hurting people.

    Virginia Messina’s earlier comment is an excellent example.

    Many people read about the Vietnemese Buddhist Nuns having fewer hip fractures and only ingesting a few hundred grams of calcium a day. Many people, including myself, were quick to conclude “Aha, I don’t need more calcium to prevent a broken hip”.

    Virginia mentioned a study that showed that Asian women have slightly differently shaped hip bones, which makes their hips less likely to break. She wasn’t dissing veganism. She was mentioning one of those other possibilities so that people wouldn’t alter their dietary practices in a potentially harmful way.

    I became a vegan because I have a high value on the truth. Many things are known and unknown. Truth isn’t a static thing. I would be a hypocrite to what made me go vegan if I avoided discussions about the merits of a vegan diet because comments that are not 100% ringing endorsements might surface.

  22. Kieran F. D'Souza Says:

    Beforewisdom:

    I agree we must seek the truth and IMHO what makes it so difficult is that the truth has to be first uncovered from layers of deliberate disinformation, vested interests, ignorance, big business, you name it, before you recognize it as THE truth. In the mean time generations have suffered and are suffering, myself included, due to misinformation that abounds.

    As a seeker of truth and knowledge I have to ask these questions:

    Why is man such a special species that he has to depend on the cow for the health of his bones. Doesn’t that reduce us to sort of semi parasites – that is to say, if one day cows disappear then our bones will also come crashing down? What if cows behaved and thought like us – then they would believe mere grass is insufficient for their massive bones: They would have to drink elephant milk!!

    What is the physiology of man? It has been well established by our bunched up grinding teeth, our chewing motion, our long complex digestive tract, weak hydrochloric acid etc that we are vegetarians and fruit is our optimum food so it does not need to be cooked in most cases at least.

    Why do we look down upon vegetative sources of calcium which have better combination of magnesium, potassium, other minerals and is better absorbed than calcium of milk as well as without the casein?

    I feel people in general have been influenced in their thinking by Big Business so they blindly conclude that the best source of calcium is cow’s milk, best protein is steak etc. That is why I say it is difficult to get to the truth nowadays, because it has been made a casualty of Big Business.

  23. Vegan Says:

    I appreciate keeping this conversation honest. I’m a young vegan, who has been eating minimal or no dairy for almost 10 years. I recently had a DEXA scan as part of a study I was in, and my bone density was two standard deviations below the norm. Are insufficient weight-bearing exercise and small frame factors? Absolutely. But I’m not going to stick to ideology over my health. I make sure to take 1 g Ca/day through supplements.

    If not for this scan, I would have continued pretending it was okay my Ca was low, because I ate lots of greens. But as mentioned above, I haven’t borne any children or breastfed, I don’t have to exercise for my job–things are just different than in the past and my bones are at risk.

  24. Norris: Vegans Aren’t Automatically Protected Against Osteoporosis Says:

    […] between bone health and animal protein intake. His conclusion: The take home message, which I’ve written about before, is that not eating animal protein does not protect you from osteoporosis. Make sure you […]

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