Podcast Episode 63 Transcript – Bone Health & Nutrition

Aidan (00:08):

The Ideal Nutrition Podcast. My name is Aidan Muir, and I am here with my co-host Leah Higl. And this is episode 63, which we are going to be doing on bone health and nutrition. And to me, it’s an interesting topic for two reasons. One of them is that I’ve got a bit of a mild interest in longevity. It’s nothing too crazy, but it’s something that I do have an interest in. And obviously bone health plays a role in that because you can maintain independence for longer. You can stay active for longer, all of those things, and the carryover effects of staying active and stuff like that, too. And the other reason, which is something that both Leah and myself have in common, is that we both did research projects on calcium and bone health.

Leah (00:50):

Oh, you did one, too?

Aidan (00:51):

Yeah, I did. Yeah. So when you were saying that before, I was like “I didn’t even know that.” Yeah. So in university, we had to do research projects. For me, it was just as part of my fourth year. For Leah, that was part of honors, so that’s cool, too.

Leah (01:03):

Yeah. I had no idea you did the same kind of topic. Cool.

Aidan (01:07):

Yeah. So for me, mine was on calcium supplementation and vitamin D supplementation and the prevalence of bone fractures after taking those.

Leah (01:16):

Yeah. And mine was on calcium intake in Asian populations and bone health and how that all related to one another. And so that’s super interesting. But starting off with the basics, so the recommended daily intake for calcium is 1,000 milligrams per day for most adults. That does increase as you get a bit older. So for post-menopausal women, it does go up to 1,300 milligrams per day and also men over the age of 70 as well. So we do get that increase in recommended daily intake as we age. But then comparing that to the average kind of calcium intake in Australia, is around 850 milligrams per day. So for the most part, on average, we’re a little bit below the recommended daily intake for calcium.

And then if you are below average, you’re probably pretty far under that recommended daily intake, which could absolutely have quite a significant impact on your bone health and longevity. A longitudinal study on dietary calcium intake and hip fracture risk found that increasing calcium intake from lower levels to around that 750 milligram per day intake level did actually reduce the risk of hip fractures. But going higher than that doesn’t seem to provide too much of a benefit. So at least if we’re kind of hitting that 750 milligram mark, we’re kind of getting somewhere with that. Any study though that is looking at just one kind of aspect of a pretty complex topic, so what we’ll get into with bone health is it’s pretty complex. There’s a lot of different interplaying factors that affect your bone health, especially when it comes to nutrition.

So when we’re looking at just one element of that, this time being calcium, it’s pretty hard to draw really conclusive conclusions from just that thing alone. So there’s a lot of different things that are going to impact it. So yes, calcium is an important part of when we’re talking about bone health. I think we all grew up learning about that. But it’s definitely not the only thing, and there are other things that can impact our calcium absorption even when we’re talking about nutrition. So things like your protein intake, your sodium intake, all those things have an interplay. So when it comes to these studies, looking at how much calcium we need for bone health, those other confounding variables not always taken into consideration, so it’s just something to consider.

Aidan (03:49):

Yeah, awesome. Yeah. I found the 850 milligrams is the average stat kind of interesting. That was a stat that I also found. And I don’t know, it surprised me because in a previous job, I had to do nutrient analysis of clients’ diets. And what I would say there was the average calcium intake seem to be 400 to 600 in the group of people I was working with. But we know self-reported data has issues, so it’s hard to tell based off of that.

Leah (04:16):

Do you know where that number kind of came from? Was that from a national survey?

Aidan (04:22):

I do have it written down somewhere.

Leah (04:24):

Yeah. It’s just because it seems high. Hey, I thought the same thing when I saw it, is that it just seems higher than I would expect and pretty close to the recommended daily intake for adults where, yeah, in practice, I see a lot of people consuming far below that. In saying that though, I do work with a lot of people that avoid dairy and are vegan. So that definitely plays a role there. But even outside of that.

Aidan (04:48):

Yeah. So that just came from nrv.gov, the nutrient reference values. They just say that, and then they don’t provide a reference for it anywhere, but yeah.

Leah (04:56):

Okay. But I mean, they do their research, so I feel they gotten it from somewhere hopefully reputable.

Aidan (05:02):

Yeah, for sure. Other interesting stuff, so have we talked about supplementing with calcium in terms of-

Leah (05:07):

No, I haven’t touched on supplementation.

Aidan (05:09):

Yeah, cool. So that was obviously the biggest topic of my systematic review. Pretty much all the supplemental calcium studies showed an increase in bone mineral density, but that didn’t always translate to a reduction in fracture’s risk, which is, obviously there’s overlap between the two, but clearly you need to see a more powerful impact for it to actually carry over to reducing fractures. But what was interesting in all of that was the dosage that seemed to be the most effective was 1,200 milligrams, which, if we go back to the recommended daily intakes of 1,000 to 1,300, depending on the category, obviously is quite a high dosage because that’s in addition to people having whatever dietary intake they’re going to be having. But the difficulty of that is you can only really absorb so much calcium at once. So a way that typically has to be done when you’re supplementing is you have to have it at morning and night. You’ve got to have two dosages per day.

But that’s also a bit of a barrier because calcium supplements are quite large. People refer to them as horse tablets. And also, having to have it morning and night is a lot harder than just having it once per day. And I know, it sounds like I’m being soft and being like, “Oh, that’s hard,” when it’s like, I don’t know, it’s just having a tablet twice in a day. But when you look at the studies, the compliance rates drop off a cliff when people have to do something twice per day. And it’s not a medication. It’s just a supplement. And if you jump just to the bottom of the research, just the conclusion, there was a lot of studies I found where they said it wasn’t that effective for improving bone mineral density and reducing fracture’s risk. But when you go through and look at the people who actually took the supplements, it was quite effective, which is very interesting.

Leah (06:44):

Yeah. People kind of suck at taking supplements, especially when it’s something they have to do multiple times per day. And especially when it doesn’t have that, it’s not an in the now benefit. It’s like a longitudinal benefit. So yeah, the motivation to take it, maybe not so good.

Aidan (06:57):

Yeah, for sure.

Leah (06:59):

Something else to touch on in regards to calcium is also talking about the dairy component. Obviously, whenever you think of calcium, your mind usually goes straight to dairy. What I want to talk about here is more, just a little controversy around dairy. So there is a Harvard study that was done on milk in 1997 that showed no link between higher milk consumption or other food sources of calcium and a reduction in hip or forearm fractures. So this study is often pointed to by people who are trying to make a case against dairy and, oh, there hasn’t been any correlation between a reduction in risk for fracture and also consuming dairy.

But when we look at the vast majority of the research, we do see a link between people that do consume slightly more dairy and therefore calcium consumption and a lower risk of fracture throughout their lifetime. So in regards to dairy, it obviously plays into the calcium stuff. And there really is only that one study that shows no link. I know that some vegans do reference this other study, which I don’t have on me, but it is pretty much saying that it increases the risk of fracture.

Aidan (08:15):

Yeah. I have seen that as well.

Leah (08:16):

It’s been a while since I’ve had a look, but again, that is such an outlier when it comes to the research that looking at the total of the research, dairy intake looks pretty positive for bone health.

Aidan (08:27):

Yeah. I remember seeing that study when I was a new grad dietician. And I sent it to a few people who were a lot more experienced, and they just brushed it off being, “All of the other studies say the opposite. This study shows this one. Which one do you want to go with?” And the other thing, me thinking it through being, how is that even possible necessarily to happen? One of the easiest explanations for how it is possible is there’s a lot of other factors involved in bone health. Some of which 

we are going to talk through, but calcium is just one of these many variables.

Leah (08:55):

Yeah, which is why when you look at the research and you’re looking at one variable and then talking about bone health, it doesn’t always show the whole picture.

Aidan (09:03):

Yeah. So the next one we’re going to talk about probably has an even stronger impact than calcium, and that is vitamin D status. One of the reasons why vitamin D matters so much is because it is involved in the absorption of calcium. If you have a decent calcium intake but a really low vitamin D level on your blood, you don’t get the benefits of calcium as much because you’re not absorbing as it effectively. There is a meta-analysis that I’m pointing to as a starting point that showed that supplementing 700, 800 international units of vitamin D per day improved bone mineral density and reduced the risk of fractures in those above the age of 60. Obviously above the age of 60, that’s when it matters more because it’s more likely for fractures to occur. But in that study, they also showed that 400 international units was insufficient to really do anything.

A bit of a baseline study, but we can obviously do way better than that because firstly, 700 to 800 international units is quite a low dosage as well. If you buy a vitamin D supplement, typically 1,000 international units is the kind of standard dosage. But then also individualization, we can get blood tests to measure our vitamin D status. Very clearly, people make significantly larger improvements in their bone mineral density when they go from a deficient level up to an optimal level or even just a sufficient level. So if we’re seeing these improvements in people just supplementing across the board, we’re seeing improvements on average, the improvements are significantly larger in those who need it more.

And in addition to that, vitamin D helps more than just bone mineral density. Particularly in the elderly population, it helps a lot with balance, and it helps a little bit with muscle strength in the elderly population, too, which could reduce the risk of falls, which, once again, even though it’s not directly improving bone health, can reduce the risk of fractures. And obviously you could either supplement or you could get us through some forms of food, but that is quite hard, more realistically is getting more sun as well, although obviously that would need to be risk with the balance of skin cancer, too.

Leah (10:58):

Totally. The next one I’m going to talk about is vitamin K. So this one is less talked about obviously than calcium and vitamin D, but it’s still pretty high up there on the list of priorities for bone health. So we do know that low vitamin K intake has been linked with reduced bone mineral density and an increased risk of fractures. So the optimal vitamin K intake has been proposed to be around that 90 micrograms per day mark, but it’s estimated that less than half the population reaches this amount. So very few of us are reaching it. And a quarter is out around under the 60 microgram mark, which is fairly significantly under.

Vitamin K supplementation protocols using over 100 micrograms per day have been shown to reduce fracture risk in the research. But what I do find interesting here is a lot of the research doesn’t show a increase in bone mineral density from this supplementation, but it does show obviously that reduction in risk of fracture in terms of just kind of building that bone strength without more bone mineral content. So that’s something I found kind of interesting. But where you can get vitamin K from is a lot of your green leafy vegetables. I think generally people need to work on their intake of those things, so yeah, something to think about again for bone health.

Aidan (12:25):

Yeah. And this and a few of the other factors we’re going to mention I find interesting because there are obviously countries outside of Australia that have lower calcium intake than Australia but have better bone mineral density as well. And I think stuff like vitamin K, magnesium that I’m about to talk about, and a few other factors are probably a factor in that, as well as exercise, which we’ll probably touch on as well.

Leah (12:46):

Yeah, yeah. Even going back to what I did for my honors in terms of looking at Asian populations and the fact that their calcium intake overall was actually lower than Western populations, but the fact they were eating so many dark leafy greens, Asian greens, maybe that actually did play a role in things.

Aidan (13:03):

Yeah. It’s definitely something I’m thinking, for sure. You could say genetics. Maybe you could say changes in other stuff, but I think that plays a huge role. Another one, so talking about magnesium, so obviously, increasing intake of magnesium by itself would be the way to go. But looking at a study with people with osteoporosis, it was a two-year study. They supplemented 250 milligrams of magnesium per day. For context, the recommended daily intake is 310 milligrams for women and 420 milligrams for men, so just a little bit shy of that amount. 250 milligrams of magnesium per day for two years significantly improved bone mineral density. Now’s a good point for me to also jump in and point out something that you’ve probably already picked up on, if not earlier in life, through this podcast that you can improve bone mineral density later in life.

I don’t think it’s a topic that a lot of people think about, but you often hear these stats being, bone mineral density peaks by a certain age, call it 30, call it a little bit under or whatever. And you really want to make the most of your youth for building bone mineral density. That is true, but we can also build more later in life. We see in a lot of these studies improvements in bone mineral density. And just for thinking through, that shouldn’t really be that controversial of a statement. But I was looking through being, is this controversial? And I was like, I just Googled, can you reverse osteoporosis? And there’s a lot of statements from governing bodies and stuff like that saying no, that it can’t be reversed. Even in there, sometimes they would say that you could take it from osteoporosis back to osteopenia. It’s like, well, that is reversed.

It’s still improving bone mineral density. I don’t know. I find that really interesting just being, if you have a lot of things that take you away from having optimal nutrition and exercise for bone mineral density, and then you start exercising, and then you start implementing some of these things, there’s so much potential for improvement still. Even if you can’t go all the way from a really bad place to really, really strong bones, there’s still always room for improvement.

Leah (15:04):

Yeah, not like you’re a completely lost cause that’s the kind of, that is the amount of bone mineral density you have, and that’s it for the rest of your life, and then it just decreases from there. So it’s good to know. The next one is zinc. So zinc, it’s definitely a less strong link than the previous things that we talked about. But low zinc intake is associated with lower bone mineral density. And then even on top of that, to build a slightly stronger case, is that one study on zinc supplementation in a group of people with osteoporosis and zinc deficiency found that following supplementation, bone mineral density actually increased so that there is absolutely a link there. And zinc is something that comes into play with bone health. This is something that I definitely am more mindful of in my plant-based people because zinc intake tends to be quite low, but just good to be aware of generally when it comes to bone health.

Aidan (16:04):

The next one is protein, which is a complex one for a few reasons. One of them is that bone is 90% collagen, and collagen is a source of protein. So bone largely is protein. That’s also another point just in terms of, what is bone made up of? Calcium is only a small component of bone when you break it down percentage-wise, but calcium’s also a micronutrient, the small nutrient anyway. But we can use this logic and very clearly see that excessively low protein intake would be detrimental for bone mineral density. And that is something that we do see in the research. But at the other end of the spectrum, there’s a lot of people who claim that high protein intake is bad for bone mineral density. It’s not something I see super commonly. It’s not up there with protein and kidney health and stuff like that. But it is still something that is around. Have you heard of that acid-ash hypothesis?

Leah (16:57):

I hadn’t. I actually Googled it when I saw it in your notes.

Aidan (17:01):

Yeah. So it’s from the alkaline diet. And it’s interesting that a lot of dieticians criticize the alkaline diet by saying we can’t change the pH, blah, blah, blah. But that’s not really what people who have preference of alkaline diet are really claiming. What they’re really claiming is that the body tries to keep stuff in that range, and the mechanisms of keeping things in that range is what causes the issues. So with the acid-ash hypothesis, it’s basically the claim that when we consume acid-producing foods, including those that are really high in protein, so excessive amounts, so protein would be the wording that they would use, the body tries to counteract the additional acidic load by breaking down bone to balance things out. And then that would lead to osteoporosis or just weaker bones in general.

You can see where people are coming from with that claim. And if you actually track the mechanisms, you can see that to a certain degree. That actually is a thing, but this is why I do not like getting caught up in mechanisms and I like looking at outcomes because that’s a very easy claim to debunk because if that hypothesis would be true, it should be very easy for us to just look up what happens when people have a high protein intake for multiple years on end. What happens to their bone mineral density? And when we look at those studies, not only is bone mineral density not lower in people with decently high protein intakes, on average, they have higher bone mineral density than those with a low protein intake.

So it’s clearly not something we need to stress about. The current consensus is that if you’re looking to optimize bone mineral density, there’s no need to go super high with protein. There’s no need to go beyond, say, two grams per kilogram of body weight protein per day or anything like that because we know that’s not helping for with muscle growth, that’s not helping for with bone mineral density or anything like that. Hasn’t been actively studied heaps for bone mineral density specifically, but we know that you don’t need to stress about trying to reduce protein intake because if anything, higher protein intake seems to be linked with stronger bones, not weaker bones.

Leah (18:58):

So finishing off with a few other little bits and pieces that we won’t spend too much time on but are worth mentioning, so the first is collagen supplementation. So there’s a little bit of evidence that it could potentially help, kind of going back to that, well, bone is made up of some collagen.

Aidan (19:16):

Yeah, some collagen, yeah.

Leah (19:17):

Yeah. Yeah, not just some 90%, which is a big chunk. So it makes sense that that might help a little bit, but it’s still kind of way too early into that research to make any strong claims. I wouldn’t be recommending that over things like calcium and vitamin D, etc. at this point. Next one is boron. So this is kind of a trace mineral that we don’t need a lot of, but there was a systematic, a review that showed supplementing with three milligrams of boron per day increased bone mineral density. So the mechanism here is due to its role that it plays with calcium and vitamin D metabolism and how that all goes together. But to note is that the upper limit is 10 milligrams per day, so the authors propose that there was minimal downside to this approach because that’s far well away from the upper limit.

And then finally, an increased potassium intake is linked with an increased bone mineral density. But it is hard to tell if the benefit is actually due to the potassium or things that are also in potassium-rich foods, so things like magnesium, for example, which are more associated with bone health. So it could be coming from that link. But generally, kind of having these foods that are high in, yeah, potassium, magnesium, vitamin K obviously going to be pretty good for bone health, so all of your veggies, grains, nuts, seeds, etc. So yeah, that’s probably just a few other things. Anything else on your list?

Aidan (20:51):

The only other thing I wanted to cover is supplementation, our thoughts what should we supplement. Me looking at it, I’m like I can see a place to a calcium supplementation particularly if somebody was going to have a low calcium intake. I can see a place for vitamin D supplementation if they had a blood test identifying that their vitamin D was suboptimal, and they weren’t going to rectify that by getting more sun or whatever. I think it becomes more interesting when we start looking at vitamin K, magnesium, zinc, even potassium and stuff like that.

Sometimes, well, in this podcast, like I’ve mentioned, for example, magnesium, supplementing 250 milligrams seemed to help and stuff like that. I personally probably wouldn’t supplement those. I probably would just try and increase food intake of that. If you can clearly see that you’re not going to get a sufficient amount of that, maybe, but I still think in most cases, it makes sense to try and get that through food. I’ve just spoken about supplementation because I’m just like, hey, I just wanted to show that this actually matters and works at bone mineral density more so than anything, and it’s easier to quantify in supplement studies than it is in dietary intake studies.

Leah (21:54):

Agree. Yeah. So definitely not recommending that everyone go out and try all of these supplements. That’s definitely not something you have to do. supplement with the ones that you might need to, but otherwise, a food first approach is always a good option as well, if you can.

Aidan (22:08):

Awesome. 100% agree. Well, this has been episode 63 of The Ideal Nutrition Podcast. As always, if you have not already, if you could please leave a rating and review, that would be greatly appreciated.