 this morning so I could repeat it to myself again. And for those of you who don't know me, I'm a kidney doctor at UCSF, but one of the things that I was working on when I first started was we did a lot of research on osteoporosis and specifically some of the effects of diet on osteoporosis. And so that was one of the things that got me interested in doing this talk today. In the past here at AHS, I've spoken about blood pressure and diabetes, but I thought this would be something that would be a more general interest to people. So first I'm going to talk about like what is bone health? And then I'm going to divide factors that affect bone into non-modifiable factors. So things you really can't do too much about. And then modifiable factors. And the one I'm going to mostly concentrate on is diet. So this is a normal bone, okay? So normal bone on the inside is the bone marrow and that's where the red cells and the white cells are. And then on the outside, especially in the long bones like in the arms and the legs, there's what we call lamellar bone where the, that's really weird isn't it, where the collagen fibers and the mineralized, the mineralized collagen fibers are put into lines inside this extracellular matrix. And that way the bone manages to grow one layer on top of another which makes it particularly strong. And then there's another type of, this is really a weird pointer, there's another type of bone which is called spongy or trabecular bone. And this is the kind that we talk about most often when we talk about osteoporosis because that's the kind of bone that's like in the spine and in the hip. And this is the kind of bone that often the bone that deteriorates the most. And I put this slide up so that you could memorize it all in the next five seconds. Really just to show you that we now understand that it's a very, very complex system, much more complicated than we had originally thought. But the most important thing about this is that one, the bone constantly remodels. So it's not a static organ, it's constantly being broken down and it's constantly being built back up again. And it's being broken down by the cells that are called, sorry about that, cells that are called osteoclasts over here and it gets built up by cells that are called osteoblasts. And so we're going to talk a lot about the balance between what the osteoclasts, the bone breakdown cells are doing and the osteoblasts which is the bone buildup cells. And so on the left over here, this is healthy bone. And the bone, the bone bridges themselves are nice and thick, okay? You can see that there's just a little bit of space in between the various bone sections. But in osteoporosis what, and what this means is that there's that balance between the bone buildup and the bone breakdown. But in osteoporosis what happens is the osteoclasts work a lot more than the osteoblasts. And so the balance tips towards the bone being broken down more. And you can see this really dramatically here. And you see like this little bone bridge over here is broken, okay? What that means is even if you make the bone, even if you make the bones thicker now, the bridge itself has been destroyed. And so you can't make the three-dimensional structure of the bone stronger anymore. And this kind of bone over here is much more likely to collapse. It's part of the reason why as you get older you get shorter as your vertebral bodies collapse. And how dense the bones are is really important because the thinner the bones are the more likely they are to break. And this is shown over here in this light gray area where as bone density declines the fracture rate increases. And this is important because there are lots of complications especially towards hip fractures. We talk about fractures in the hip, in the spine, and in the forearm. But from a medical point of view the worst are the hip fractures. And the worst are the hip fractures before you're more likely to die. You're more likely to end up with permanent disability. It costs a fortune. And what they found is up to 45% of people who have these are malnourished. Meaning that must be some dietary intervention that potentially we could do. So before we get to what we could potentially do, let's talk about what we can't really do. So you can't really change your age. And you can't very easily change your gender, although it is possible these days. So what happens is as you grow as a kid your bone mass goes up. And in the pinkish line over here this is women and in the bluish line over here that's men. One you can see that in general bone density for men is higher than bone density for women. So women are more likely to get osteoporotic fractures. And you also notice that the peak here is like 30 years old. And it's all downhill after that. And it's particularly downhill for menopausal women because you lose the estrogen. And we'll talk about that a little bit more. But estrogen is important for bone health. And as you lose bone mass you get to something called the fracture threshold. And you see how this line is approaching the fracture threshold. When it crosses that or as it approaches that. What that really means is you don't need a lot of trauma for the bone to collapse. I mean if you jump off a 12-story building you're going to break your bones no matter what. But we're talking about non-traumatic fractures. Like all you do is get up and you fracture your spine. And so this idea of how much bone mass do you have is important in terms of bone health. But the other thing that happens as you get older is that you lose muscle mass. And so again this is like your peak is somewhere around 25, 30 years old. It goes downhill after that. And the more muscle you have the more muscle strength you have. The more muscle strength you have the less likely you are to fall. Because the more often you fall the more likely you are to break something. So old people have a double whammy. Your bones aren't very strong and their muscles aren't very strong. And so they're more likely to fall down. And we know that that's a risk factor for fractures. In addition as you get older your kidneys don't work so well. And so across the board the worst your kidney function is the lower your bone mass is. And this is a complicated problem. But we're just here going to talk about just osteoporosis in kidney disease. And then finally ethnicity. If you're African American you are less likely to get osteoporosis than if you're some other ethnicity. And we're pretty sure that there's a genetic component to this. Although we're not so sure what it is. So those are some of the non-modifiable factors. So now let's talk about what can you do. Because as a kidney doctor one of the things that happens is that you know there's so little we can do. And so we really focus on the things that we can do. And so when you talk about bone health one of the things that you can do is exercise. Okay. Now I'm not going to talk about this and I'm sorry Daryl Edwards couldn't be here. He comes from the UK and so they wouldn't let him in the country. But he sent me this slide. And what you see here is that and this is from it's a composite of multiple studies in children is that if you gave them weight bearing exercises as they grew as they got older their peak bone mass was higher. And as you remember from a slide a couple of slides ago the higher your bone mass is once it starts to deteriorate okay. The longer you're going to take to hit that fracture threshold. So exercise not just for kids but for everybody but particularly for children we believe it's really important to help increase the total amount of bone that they have. And now finally we'll talk about diet factors and I'm going to talk about a couple different things. So I'm going to talk about weight. I'm going to give my idea of what's important in calcium balance. We'll talk about vitamin D deficiency. And then from a this is where I really started doing research is diet net diet acid intake. So net means how much acid do you take in versus how much base do you take in. And why is that important. Well acids include things like table salt. So we'll talk about salt intake. So acids are things like phosphates and sulfates and so they're in protein. So we'll talk about protein intake. And then finally we'll talk about vitamin K. So the heavier you are the more your bones have to work to keep you upright and to keep you moving around. And the more they have to work the thicker they get. So the more dense they get. So the more you weigh the less likely you are to have a fracture. So in this just in this one instance being heavier is actually good for your bones. Okay and now calcium balance. So calcium balance is how much calcium do you take in versus how much calcium do you lose. And when we talk about how much calcium do you take in we're talking about like literally how much calcium do you take in like how much are you eating every day. In women we're talking about are your estrogen levels not normal or if your menopausal low. Talking about vitamin D deficiency which is becoming more and we're recognizing it's more and more of a problem. And then the older you get the worse everything gets. It's so sad you know. So vitamin D deficiency is really how much sun exposure do you get. And what foods are you eating. So they're talking about 25 vitamin D here. So we know that the closer you are to the equator or the more you are in summer okay the more sunshine you're exposed to the more vitamin D you make. And so this is a worldwide map there's all these different countries over here and you can see that you know they go up and down. Some of them have a lot of some seasonal variation. But there's also a cultural component to this. So for example one of my colleagues Susan knew from Surrey University of Surrey studied women in Riyadh. So these are women who almost never go outside. And when they do go outside they're covered from head to toe. And their vitamin D levels are almost non detectable which is really amazing considering that they live at the equator. And in San Francisco that's another thing that we see you know it's always it's freezing there right now. You know you go out completely covered. So even though it's summertime you know you never never go out for sun exposure. So when in my dialysis patients we'd be when we could actually measure vitamin D levels we saw that they were all in the single digits I mean just ridiculously low. So if you can't get any sunshine what else can you do. Well vitamin D is in foods too. And so you can see it's in meat it's in fish it's in eggs it's in fruits and vegetables. So there's lots of sources of vitamin D in the diet even if you can't actually get vitamin D from going outside. Okay and now let's talk about changes in our diet from what are presumably ancestors ate versus what do we do these days. So raw food contains almost no sodium chloride which is table salt. So we add all the salt to our diet and our diet is really high in salt. And we eat a lot less fruits and vegetables. So what you see here is that there's been a huge increase in the amount of sodium that we take in and a lot less potassium which is coming from the from the fruits and vegetables. And a great deal more chloride which again which is coming from the table sauce and a lot less alkali because fruits and vegetables contain alkali. And so when you're talking about acid and base all foods contain acids because all foods contain chlorides and phosphates and sulfates but only fruits and vegetables contain alkali. So when you talk about the net amount of acid you take in again you're talking about the balance between the acid producing foods and the base producing foods. So let's talk about salt okay. So this has been known for decades. The more salt you eat the more calcium you lose in your urine. And there's a couple of reasons for that. So one is that there's a calcium sodium calcium exchanger in the kidney tube you will. So the more salt you eat the more sodium you absorb the more calcium you lose in the urine. And this is really a dose dependent thing. So if you eat very little salt you lose very little calcium. You eat a lot of salt you lose a lot of calcium. But this study which was done by one of my colleagues Debbie Salmaier showed that okay so here this is just low salt and high salt. There's about a 20% increase in the amount of calcium lost in the urine. But if you gave the same amount of salt but you added an alkali agent which is potassium citrate okay essentially you negated that increase in calcium excretion. And we think that's because there's an effect on bone. So bone is made up of calcium salts and carbonate salts and a bunch of other things. But in order to buffer the acid in the system which the acid is coming from the sodium chloride what you do is you break down your bone to release the carbonate. And the calcium is just out there and your body really cares about how much free calcium is in the system. So if you have extra calcium floating around you're going to dump it in your urine. So the more acid you eat the more bone you break down the more calcium you lose. So two things. One is there's this exchanger in the kidneys and the second is we think you're breaking down your bones. And so that's a physical chemical effect like it's actually if you drip acid on bone like the bone dissolves okay. But there's another effect too and this is because the acid affects the bone cells. And so what you see here is here's an osteoclast eating way at this bone. And the more acid in the system the more the osteoclasts work to break down the bone to release the carbonate to buffer the acid because your body really cares about how much acid is in the system too that is very tightly regulated. So these are the cells that break down bone they increase in an acid environment. But the cells that build up bone the osteoblasts okay in a neutral environment over time you'll see that the matrix here is mineralizing. And over here in the acid environment over the same number of weeks there's essentially no mineralization. So you've broken down the bone and you haven't built up any more bone okay. And then we'll talk about protein. So again I'm talking a lot about balance because a lot of what we're talking about here is this one's too hot and this one's too cold but this is just right. So protein there are some good effects of protein if you don't have enough protein in your diet you can't build enough bone and that's because the protein gives you the amino acids that you need to actually make the bone collagen and help create the bone matrix. And it does a variety of other things. But as I said the protein also contains all of the acid phosphates and sulfates and so that would be help you break down more bone. And so what you want to see is what balance do you need like how much protein is good you know how much protein is enough versus you know how much might be too much. And again you're going to want to say what is the balance here of the good effects of the protein versus the bad effects of the protein. So this data is from the Framingham osteoporosis study and they've been following these people for decades. Now first they followed their parents and then they followed the kids. And what they looked at here was not just the amount of protein but the type of protein. So if all you did was eat animal protein what you can see this over here on the Y axis this is how much bone did you lose. So over here with the animal protein you can see that if they only ate a lot of animal protein they lost more bone mass compared to if the protein came from both animal and vegetable sources. And that's not because vegetable protein is different it's because fruits and vegetables contain other things that are helping the bone out. And so as these people this is Katherine Tucker and the Framingham biostatistics department. So what they say is that although you do need protein it looks like you need to get them from multiple sources because these other fruits and vegetables contain other things. And so if you say to yourself so what's in the fruits and vegetables besides the alkali. Well one is the complex carbohydrates so this was a study which they did in rats and over here in the dark thing this is normal rat chow and rats eat about 10% fat, 30% protein and 60% complex carbohydrates in like rat chow. If you take all the complex carbohydrates out what happens is after a couple weeks the bone density starts to go down and the bone formation rate starts to go down. And if you take out both the carbohydrates and the protein again both start both go down although interestingly you can see there's not a lot of difference between taking away the carbohydrates and the protein versus just the carbohydrates alone not just in the bone density but in the bone formation. So something about the carbohydrates is important but if you just look at vegetarians and you compare them to non-vegetarians and you look at their hip frasks your risk. Multiple studies have demonstrated and this is a meta-analysis done by this guy Enzrod. Shows that in fact you're much more likely to have a hip fracture if you're a vegetarian compared to if you're an omnivore. So again I believe that this is related to how much protein are you taking in. And possibly but I don't believe so the type of protein but I really think that it's just the amount of protein that you're taking in. Okay and then finally vitamin K. So vitamin K does an awful lot of things and it helps your bones. And it does that by increasing the activity of the osteoblasts to build up the bone and by decreasing the activity of the osteoclasts to break down the bone. And so and vitamin K is available in lots of different types of foods. So dark leafy green things, eggs, meat, fish oils. So part of what you can see here is that really you can get these things in your diet from vegetable foods, from fruits, and from animal foods. So that's meat, fish, milk, eggs. Okay so what kind of diet should you eat? Okay and we talked about making sure you're eating enough calories so you weigh enough because if you don't weigh enough you're likely more likely to have a fracture. How much calcium should you take in? When you look at, if you look at how much calcium do you lose, the more acid in your diet, the more calcium you lose. So if you're eating a diet which is not a very high acid diet and this is, we've showed this in some of our research studies, you actually decrease the amount of calcium lost by about 40 percent. So if you're eating a low acid diet it may be that you don't need the 1200 milligrams a day, which is the recommended dose. It may be that you can get away with somewhat less calcium and this is actually good news because in the United States it's really uncommon that people meet the RDA for calcium. The average calcium intake for women is something like 800 milligrams as opposed to 1200 milligrams. On the other hand if you're eating a low acid diet that's about 40% less give or take so you know maybe it might balance out. So let me tell you what I think. So in our studies what we did was we said, well let's get rid of some of the things that you don't need in your diet. And so that would be things like junk food. So EDNP stands for energy dense nutrient poor. So that's like candy and Twinkies and donuts and corn chips and stuff. And then grains. And grains are things like rice and bread and pasta. And we specifically took these two things out because these are things that would not have been available to our paleolithic ancestors because these are essentially all processed foods whereas all the other things on this list would have been potentially available. And when you take the calories from those away and this is important because a lot of the calories from our diet come from those two food groups. Okay what you do is you essentially eliminate all the acid in the system. Okay so coming from about this stands for net endogenous acid production is about 50 milli equivalents a day. Whereas if you get rid of those two food categories you get down to about zero. So what we did in our studies was we took those calories and we replaced the calories with fruits and vegetables. So you ended up eating about two-thirds of your calories from fruits and vegetables and about one-third of your calories from everything else. And so if you do that okay my personal belief is you wouldn't need as much calcium. You would be getting a lot of protein because you're making up a lot of those calories with various types of meat and fish and eggs and whatnot. You'd be getting a lot of alkali because you're eating a lot of fruits and vegetables. You'd be getting whatever is in those complex carbohydrates that are apparently are very useful for bone growth presumably to help put together the collagen matrix and the extracellular matrix. You would be getting vitamin D. You'd be getting vitamin K. So if I had to say you know why do I think that this would be a you know a better diet for us is because when you look at some of the factors that are involved in bone health you can see that you know we've covered a lot of them. So and it's a modifiable factor okay. It's something you can do something about. You have some control over this okay. So you know as a doctor I'm going to say that what I think you guys should all do is eat right and exercise. So thank you and questions. Is that okay? Can I just stand up? Great. Hi Linda. Osteo-Kelson. Osteo-Kelson I've recently become vaguely familiar with this protein secreted by bones that can regulate blood sugar. Are you familiar with it? I'm just dying to learn more about it. Okay well forget it then. Bone is a endocrine organ right? I mean what you can say. Part of it is right. Some of it is a hematopoietic organ like the bone marrow is where you make all the cells but bone does make some factors like FGF23 which is important in phosphate excretion and probably important in aging too. So yeah Todd. That was a great talk and I especially like your plot showing the increase in bone density to age 30 and then the decline. So we all got to get a head start right? So my question is you talked about balance between osteoblasts and osteoclasts and mainly focused on the problem with too much activity in the osteoclasts. Is it possible? Is there any downside to having the balance too far in osteoblasts and bone building and not enough breakdown? Is there an imbalance? Yeah but those are all pathophysiologic. Like you don't see that in a healthy person but there are some bone diseases where there's too much bone. Yes absolutely. Could you be shunting calcium to places where it shouldn't go? What happens is you actually there's two. Well there's a couple of different kinds of diseases. One is the bones become really really thick and you actually have trouble moving them. Okay the other is you start to calcify the soft tissues and that's a very serious problem. So yeah thanks. Just a comment about acid-base balance. mitochondrial toxins like mercury can cause lactic acidosis and that can be a major contributor to systemic mineral loss. And that's true although the body has a lot of a lot of buffering and balancing techniques. So even if you have more lactic acidosis there are things that the body does to try to neutralize that acid but you're you know you're correct. If you know it's a constant problem and you're constantly producing too much lactic acid that would tend to go more on the increasing the acid load. Yeah Linda some of your data are providing a major challenge to my confirmation biases in particular the low carb high fat and fracture rates. And if if I saw it correctly that was a four week study. In progress yes. I'm wondering if anyone's looked any longer and specifically at the effect of ketones of nutritional ketosis on long-term bone health. Okay so there are short-term studies that have looked at that but most of the data comes from the Atkins diets where we've shown that you know if you're if you're following an Atkins diet for too long you have an increase in kidney stones from the loss of calcium from bones. But most of the Atkins studies were done over two or three years. But bone health is something that occurs over decades. So you know it's very difficult to do bone health studies unless you have a really really big effect like using bisphosphonates. Okay you can do a two or three year study on bisphosphonates because they have a major effect on how much bone you make. But for stuff like diet things you probably need much more longer term data. So the answer is there's not a lot of good long-term data. In humans. In humans yes exactly. How do we harmonize that with everything coming out of the carnivore community and what we think we know about ancestral meat-based diets? So my personal bias is that you're tipping the balance too much one way. And that over a long period of and I'm speaking as a kidney doctor over a long period of time and in kidney failure we know that too much acid is really bad for you. Not only do your bones and muscles deteriorate but you actually hurt your kidneys and so it causes faster decline in kidney function which is already declining with age. So my personal belief is it's a bad idea over the long term. Ian. Hi I'm Sally and I have a background in nutrition. I've been a healthy eating stay active geek since about four years old. And it didn't work out so well for me in my 20s I shrank an inch and a half during my high vegetable eating vegetarian years and later developed osteopenia which has been reversed by removing most vegetables and adding more meat to my diet because and the point of this is we've this being such a short talk I think you've had to back down to wild general points. Two to three slides per topic. Yeah so eat well exercise it might work out for some of you but not for Sally and the idea of eating a low acid diet I think is very confusing for people who don't know the technical points. Citric acid is an example of an acid that's in lemons and other citrus fruits which is alkalizing your liver turns a good percentage of that into bicarbonate. We use citrates and citric acid to alkalize that's why I use potassium citrate for bone health and that helped me increase my rate of returning my bones to normal density um after taking another acid out of my diet which is oxalic acid which is well known for 100 years of research to deplete the body of calcium increase acidosis cause interference with growth in children cause bone loss and kidney disease so certain acids are good because they're alkalizing and there is a king of acids that is terrible for bone and kidney health and that's oxalic acid. Right so things like oxalic acid are organic acids which are not metabolizable to bicarbonate or alkali and those are excreted by the kidneys anything metabolizable to bicarbonate turns into carbon dioxide and is excreted by the lungs so there's different kinds of acids and they're broken down different ways but you made the point one of the points is that you have to have an adequate protein intake okay you don't eat enough protein your bones aren't strong enough try and squeeze two more questions in from that side and then this side okay great hey linda so uh should we have another category for organs on the here distinct from meat as food as food you know from my point of view no because organs are made up of vascular tissue and cells which contain potassium and phosphates and you know what not there the building blocks are not that much different so in my sense is they're just extremely nutrient dense though would that not help well if you're not getting enough calories then yeah absolutely but you know kind of depends on what you're talking about do you need more protein our organ meats good yeah um you know like if I'm not exactly sure you know what that would get that balancing all the other things in the diet wouldn't give you two but I can't say no either you know but I consider themselves and so I put them into like the meat category okay thank you hi uh thank you for a great talk um I have two quick questions so one is uh Jane Kerstutter's group uh in Farmington Health Center in Connecticut had shown that um the part of the effect on urinary calcium of dietary protein is to stimulate directly stimulate calcium absorption from the intestines and I think they also showed that higher protein intake's decreased bone turnover and their argument was that the urinary calcium loss is actually more of an excess supply than it is loss from the bone although I think obviously the metabolism into acids as you were talking about makes sense so I was wondering if you could comment on the possibility that the measurement of urinary calcium loss might be overestimating the acid induced loss from the bone and then very sort of related um on the dietary intake uh increase in sodium seems like the old estimates are based on the assumption that people weren't adding any salt to their food so I was wondering if you could comment on the possibility that the increase in sodium is also overestimated because of that okay so there are a couple of very good studies looking at um and and there's a world health organization database that simply shows that if you're looking you know if we want to talk about epidemiologic data across the world the more salt people eat the more calcium they lose I mean this is a worldwide phenomenon but there's some studies from um for example Catherine O'Day in Australia where she's done a lot of studies giving people different amounts of salt in their diet and it's pretty linear you know it's really goes like this the more salt you eat the more calcium you lose um but there's more than one effect okay so it you know you get calcium from a lot of things in the diet um and how much calcium you absorb is is dependent on a variety of factors so it's awfully you know it's I'm not sure what to say about like is is eating more protein does that help your calcium absorption um I'm I don't know because it would depend on things like do you need more protein um you know if you do do you are you building up your bones if you are you need calcium you need phosphorus you need proteins you need calories I mean so I don't I don't know how to answer your question button yeah well let's thank dr linda for sedo once again