Low Carb Diets and Longevity – Ron Rosedale, MD – Extended Version Dr. Ron Rosedale, MD, gives a “second opinion” about a widely publicized report in the prominent medical journal The Lancet. The Lancet report contends that low carb diets (40% carbs or less) shorten lifespan, and moderate carb diets (roughly 55% carbs) promote longer lifespans. The study is being hailed as proof for why people should “eat carbs in moderation.” But what if the Lancet study didn’t go low enough on carbs to reveal potential benefits of a VERY low carb diet? Dr. Rosedale advocates a very low carb, adequate protein, high fat diet, meaning roughly 15% of calories from carbohydrates, 15% from protein and 70% from fat. – Producer – Shelley Schlender
Shelley – Ron Rosedale what is it about your background that means that you can be somebody who speaks to the idea of low carb diet and longevity.
Ron Rosedale – For the vast majority of my professional career, that’s what I’ve been studying. And I believe at least in the U.S. I was the first person to actually recommend and utilize a high fat low carbohydrate diet to treat a multitude of the chronic diseases of aging and have been studying the biology of aging for my entire adult life. So what my interest has been has been in the dietary connection to the hormones and pathways that are known to influence, if not regulate, the biology of aging teeth. That’s really what one has to look at if one is going to evaluate the health of any particular dietary or interventional regime–how does it affect aging and mortality.
Shelley – Here is a study that came out recently from the Lancet the journal Lancet about just that topic. That longevity study seems to show that people who eat a low carbohydrate diet die sooner than people who eat moderate carbohydrate diet.
“The problem is, they didn’t study a low carbohydrate diet!” — Ron Rosedale
Ron Rosedale – Well first of all ,had they stuck to the title of the study, where it’s different amounts of carbohydrates versus mortality, if they had if they had not used, later in the study, the word “low carbohydrate” it would have been a better study because the problem is that they didn’t study a low carbohydrate diet. So here they are then making conclusions about a low carbohydrate diet, which is you know, picked up everywhere about low carbohydrate diet. And they didn’t study a low carbohydrate diet. Not at all.
Shelley Schlender – In the Lancet study the amount of low carbohydrate that they were looking at was 40 percent or less. You say that that’s not a low carbohydrate diet?
Ron Rosedale – No. They lumped it all into — I think the the lowest quartile was 37 percent. That’s not low carbohydrate at all. In fact that’s probably the worst diet, and that’s what their studies showed. I think the worst diet is one where you mix, kind of, an equal amount of carbohydrate and fat. And the reason it’s the worst is because carbohydrates turn to sugar, then the sugar goes up, and it raises insulin and when you raise insulin, your body can’t burn fat. If you summarize all of nutritional science you can do it in a single sentence. And that is that, one’s health and lifespan is going to be more determined by the proportion of fat versus sugar that a person burns in a lifetime than anything else. The key is to burn fat. And if you eat 40 percent, or 37 percent carbohydrates, you will not be able to burn fat. That’s why people are getting so fat—people get fat not because they eat fat but because they can’t burn it.
Shelley – What stops them from burning the fat?
Ron Rosedale – When you eat a bunch of carbohydrates, and a bunch to me it would be 37 percent. That’s a lot of carbohydrate. Really. This will raise specific nutritional pathways and hormones. People have heard about insulin and I first started talking about the connection with insulin and disease many many decades ago and now it’s becoming more commonplace. Still, we knew even a quarter of a century ago that when you raise insulin it prevents the burning of fat. And so when you eat carbohydrates, the carbs turn into glucose, you raise insulin and you can burn fat. It’s as simple as that. But you also you also raise leptin and you also raise another even more critical pathway called the target of rapamycin that hardly anybody knows about right now. All of these conspired to make a person store fat and not burn it. And that’s always a awful and that’s where you can run into higher mortality and that’s what this study found.
So what this study really showed was that a medium carbohydrate diet, so a diet that consists of high fat and high carbohydrate or you might say medium-fat, medium-carbohydrate, however you want to say it– there was no low involved anywhere that will be unhealthy. And they found also who they should use for them to eat a very high carbohydrate diet. That’s also very bad. So they found two bad groups. One was a medium carbohydrate kind of medium fat diet that’s bad lead to higher mortality and if you eat a very high carbohydrate diet that’s also bad. It’s basically what they found there was no there was no low anywhere, other than the very high carbohydrate diet was what you might call a very low fat diet. And that they found to be very detrimental and lead to higher mortality.
Shelley – What would you consider to be a true low carb diet. If 30 percent or excuse me if 37 percent is not a low carb diet what is what is?
Ron Rosedale: You’d have to get down to about 15 percent. Up considerably lower than what they were testing at. George Cahill at Harvard showed this — that if you don’t get down that low you’re not going to efficiently burn fat. You’re really not going to burn fat as your primary fuel unless you get down that far. And the reason for that is the reason we stated about the effects on hormones. So you really have to get down there. A major problem with this study is that, first of all I mean there are a lot of things, there’s so many problems with it. Not the least of which is what we talked about there when there was no low carbohydrate diet group to begin with.
Challenges with Food-Recall — from the 1980s
And the reason for that is, what they studied, it was an epidemiologic study. It was a population study. Epidemiologic studies are difficult to begin with because they have so many variables that you have to account for if you can. The problem is you can never account for all the variables because you don’t know all variables nor do you typically get data on all the variables. In this particular study it was a questionnaire. And so number one is an epidemiologic study. Number two they used questionnaires and many studies have shown that when you ask people what they’ve eaten, especially when they have to reflect on it, if you ask the question, “What did you eat last week; what did you eat yesterday?” They’re notoriously wrong. And you can speculate as to why they’re wrong. Many people feel guilty for instance if they ate two milkshakes yesterday and french fries, they’re not going to report that–they might report one milkshake. They didn’t report that they ate too much. There’s kind of a guilt and especially when it pertains to higher fat. You know that the fat has been so vilified that people are just reluctant to admit that. So anyway whatever the reason we know that food questionnaires are fraught with inaccuracies. So that’s another problem with this study. It began in the 1980s and in the 1980s there was there was no such thing as low carb–that it wasn’t even a phrase. So virtually nobody was eating low carb because everybody was told that that you should eat high carbs. And that’s a major major problem then with an epidemiologic study. Also, we mentioned that there’s a lot of confounding variables, and in this study there were at least at least one major one. Actually are two major ones. One you can’t blame them too much for, because in the days when this data was collected, they just didn’t know anything about TOR (the target of rapamycin), but they did know about Ferritin.
Facing up to Ferritin (and Foods High in Iron)
Ferritin–too much iron is very bad for a person. If it accumulates we know that iron rusts, for instance and it actually literally rests inside your body too and it can kind of rust the lining of your arteries and burn the lining of your arteries. It stores in tissues such as the pancreas and we know that high ferritin is very associated with diabetes. Ferritin is a reflection of how much iron a person eats. I knew when I was seeing diabetics every now and then you’d find a diabetic with a very high Ferritin levels and you could literally reverse that person’s diabetes if they did nothing else, just by lowering their ferritin. And so ferritin is also very highly correlated with mortality.
Shelley – What is there diet that tends to lead to higher iron levels, high ferritin levels.
Ron Rosedale – Great question. The major factor, really about the only food that can really shoot up ferritin levels and iron levels, and this can be a an additional factor that causes a greater rate of death i.e. mortality, is red meat. And so people who eat a high red meat diet have to really measure their ferritin, but it’s just rarely done. There’s no money in it for anybody. There’s no drug that really lowers your ferritin, and so it’s not paid attention to. But it’s a really simple variable that can be accounted for, certainly in a study like this — it’s there but only indirectly — the study conclusions did point out that people who got their protein from plant-based sources tended to live significantly longer than people who got their protein from animal sources. A lot of animal based protein comes from red meat which contains high ferritin. And that’s really the point that we’re making–the researchers came to the conclusion that animal-based protein is more hazardous, because in their statistics they did not account for ferritin. That’s even though the association with ferritin and mortality is well known. In other words had they corrected for ferritin levels I think they would have it would have negated the difference in results they had with mortality in a plant based versus animal based diet, because there’s such a high correlation of mortality and ferritin. They came to the conclusion that animal protein was bad as opposed to plant protein, but that was a false conclusion I believe. Ferritin, they didn’t account for that. Had they accounted for that I think it would have eliminated the vast majority of their (negative) results (regarding animal versus plant protein). It would not have been the protein source that led to higher mortality–it would have been the iron. The animal protein consumed was mostly red meat which is lamb, beef even chicken to some extent has red from blood. And that raises ferritin, but they didn’t measure ferritin, and they didn’t compensate for that ferritin when they came to their mortality conclusion. ((NOTE – For someone who has high ferritin levels, Ron Rosedale recommends giving blood to reduce high iron levels)
The Target of Rapamycin (TOR) and the problem of high protein consumption
The other major confounding variable that was not accounted for and this is probably because they didn’t know anything about it. And that’s again a problem with epidemiologic studies that you can’t account for things you don’t even know about. It had to do with a pathway called the mammalian or sometimes now it’s called mechanistic, and you should even forget about the I think. It should be called the target of rapamycin. That’s a newer pathway that is now extensively being studied. It’s a pathway that now has been attributed to the longevity and health benefits of calorie restriction diet, for instance. So it’s an extremely important pathway. It’s a very ancient pathway that regulates almost all life metabolism. The pathway is influenced by all sorts of different nutritional inputs, such as the amount of energy, the amount of ATP which is kind of an energy battery, insulin, leptin but it’s also influenced by nutrients. The most powerful stimulant of Tor is protein. The most powerful stimulants within protein are the branch chain amino acids and particularly something called leucine, which is a particular amino acid that is found much higher in animal protein. Animal protein has long been considered a much higher so-called quality protein — that’s how it’s described in scientific journals. In contrast, plant proteins are deficient in many essential amino acids ((Vegetarians get complete proteins by eating complimenting foods together)). But the relevance here is that plant proteins don’t elevate the target of rapamycin near as much as animal proteins.
Shelley – Is it good or bad to have high TOR?
Ron Rosedale — Well it’s probably good early in life. This would get us into probably a longer talk than we have time for as far as the biology of aging. But prior to reproductive years it’s good to have higher TOR because you need it you need to grow. You need to grow muscles and you need it just to grow up, so that you can become an adult. But after reproduction — basically after middle age, then an elevated TOR starts causing lots of problems and we know elevated TOR can increase risk of cancer and an increased risk of death from other causes as well, which is why lowering the Target of Rapamycin is more known today. There is even a drug that lowers it. And we know that that is the first drug that actually has been shown to lower TOR also very convincingly reduces the rate of aging in laboratory animals. That’s pretty cool. So in other words TOR really is a powerful pathway, and it high TOR raises its ugly head after middle age. If you raise TOR after middle age, it increases the risk of cancer, and it increases risk of mortality.
Shelley – What I hear you saying is that if someone is eating a lot of protein after middle age, they increase the likelihood that their TOR levels will be high. And if somebody wants longevity they might want to have moderate but not too much protein–ie, less than most Americans eat, in order to give them a better chance at longevity.
Ron Rosedale – That’s exactly correct. But in this study what is particularly relevant is you can eat more plant protein without raising TOR, compared to eating the same number of ounces of animal protein. That’s because plant protein is “lower quality” it’s less usable, and so you can eat more of it because eating more plant protein is like eating less animal protein.
Shelley – The Lancet study does seem to indicate that people who ate plant based proteins were more likely to live longer than people who ate animal based proteins.
“Rather than saying that animal protein leads to higher mortality, they could have just said that eating too many much branch chain amino acids, for instance, will lead to higher mortality, and that’s probably true.” – Ron Rosedale
Ron Rosedale – That’s correct. But the confounding variable that they did not account for was the quality of the protein, in terms of them measuring the “amount” of usable protein in plant versus animal protein. To figure that out, they could have just measured the amount of leucine–it’s actually quite easy to measure in a food-based analysis. And rather than saying that animal protein leads to higher mortality they could have just said that eating too many much branch chain amino acids, for instance, will lead to higher mortality, and that’s probably true. In other words, it’s not the fact that it is an animal or a plant. It is the fact that you have more usable protein in the animal protein.
Shelley – And people in the United States tend to eat an excess amount of protein compared to what their body actually needs?
Ron Rosedale – Exactly. And that will lead to higher mortality. In the same vein, the other reason that, calorie for calorie, a plant based diet can show greater benefits than an animal based diet is because a plant based diet is much higher in cellulose. Cellulose is the stringy part of, let’s say celery. Cellulose is fiber. It’s not digested. So you hear the adage you are what you eat. But that’s not really true. What is much more true is that you are what you don’t excrete, and when you eat a bunch of plants, basically some “calories” are actually fiber, and they go right through you. You basically poop most of it out and so you don’t really eat it; you don’t absorb it. And so it’s a way to eat less without it being counted as eating less.
I don’t care whether a person eats plant or animal protein. It doesn’t make any difference really–what is important is the amount of absorbable protein, and the amount of absorbable carbohydrate. And the same can be said for fat. And so that’s what needs we can in other words what are you really eating what are you eating that’s actually getting absorbed and doing something. And yet if it just goes in and out of you it’s it shouldn’t really be counted. And so if you eliminate that portion what you’re really seeing is that if two groups eat the same so-called calories in one group is eating a bunch of cellulose from plants they’re actually eating them they’re actually eating much less. And so that wasn’t accounted.
The Types of Fat
Ron Rosedale – Also the types of fat weren’t accounted for. And that’s easy to measure. We know the benefit for instance of fish oil and how much omega 3 someone eats, whether from plant or animal sources. How much mono unsaturated versus polyunsaturated fat for instance. Walter Willett ((author of this study)) he’s done a lot of great papers but this I think was not his greatest hour.
“Einstein once said that you want to keep things as simple as possible but not too simple. You don’t want to keep things too simple because it will make it wrong. And what they did in this study, is they kept things too simple.” – Ron Rosedale
Shelley – Would you like it if the researchers would make available the entire database of what they collected over 25 years in these informational interviews, to see what else could be teased out of the study from people looking through different lenses?
Ron Rosedale – My guess is they would have they would have then come to no conclusions. I think it would have shown nothing because of the the other factors. For instance, even if they did have a very low carbohydrate branch in this study, there would probably be too few who ate that way for statistical analysis because, really nobody was eating a very high fat, very low carb, adequate protein diet in the 1980s. And that’s the other major problem in that you know we haven’t even talked about the major problem in this study. Now Einstein once said that you want to keep things as simple as possible but not too simple and you don’t want to keep things too simple because it will make it wrong. And what they did in this study, is they kept things too simple. You can’t just measure the amount of carbohydrate and compare it to everything else. When I first started talking about high fat – low carbohydrate diets in the late 80s and early 90s, nobody was talking about it then. But I knew even back then and there were maybe four or five other people in the world that were talking writing about low carbohydrate and they were all high protein. But at the time people didn’t really pay that much attention because they were just thinking about low carbohydrate. But since we now know, and I’m very happy because I’ve been pushing a high fat instead of a high protein diet for the last quarter century, there’s a huge difference between a low carbohydrate high fat diet and a low carbohydrate high protein diet.
“There’s a huge difference between a low carbohydrate, high fat diet and a low carbohydrate, high protein diet.” – Ron Rosedale
And the vast majority of people who were undertaking a low carbohydrate diet since they started since we started talking about it in the late 80s and beyond, they gravitated to a high protein diet because fat had been so vilified. It’s only been very recently that the the falsity of the detriment of high fat is coming to light. They’re not even talking about low carbohydrate diet anymore. They’re talking about ketogenic diets and that’s also a name I’m not really fond of ((because consuming excess protein can increase ketone production as well)), but they talk about it because in general, ketones are chemicals that are produced when you burn fat. It’s not the it’s not the fact that you’re eating low carb it’s the fact that you’re allowing the burning of fat and that allowing the burning of fat is what we talked about earlier. By regulating hormones that tell you whether you can burn fat, it regulates insulin and leptin and Tor, so you eat to regulate the hormones that tell you whether you can burn fat or not.
And so you can’t just talk about low carbohydrate and compare it to everything else which is what this study did. And that’s really the major problem with it. So not only did they not have a low carbohydrate diet, but they then lumped low carbohydrate with anything else. They didn’t tease out: Was it a low carbohydrate high fat? Was it a low carbohydrate high protein in their mortality statistics? They didn’t tease it out.
Shelley – Are you concerned that this kind of study and the way that it’s been reported, ie publicity asserting that you live longer you eat over half your calories is carbohydrates–this may scare a lot of people into avoiding trying a very low carb diet?
Ron Rosedale – Yes I am very concerned. I think that papers such as this are extremely dangerous because diet is so important to a person’s health. I mean everybody’s heard that you know. Yeah what they eat is important. People don’t understand how important it is. By influencing diet in laboratory animals you affect the rate that they age. That’s huge. You affect the most important pathways in the body that regulate cardiovascular disease and cancer such as the TOR pathway. What you eat is extremely important. And so people authors such as this have to show greater responsibility.
Shelley – If you were to start this kind of study today to get the kind of information you think would be of use to people, what would you do?
Ron Rosedale – Well the problem is it’s very difficult to do human mortality studies because you have to wait at least a generation. You know it would be a study that would take 50 years and most people don’t want to wait that long. Certainly most researchers don’t, because the results of the research wouldn’t come in until after most of them had died. But you can glean at least something from animal studies. The basic pathways that regulate metabolism have been around almost since animals have evolved and the reason for that is those pathways are so important that they they weren’t mutated away. Any type of major mutation to these major pathways would have led to death, so that species wouldn’t be around today. So the major pathways, the major metabolic hormones Tor and insulin and leptin, they’ve been around for a very long time.
“You just have to do it and then you’ll see huge benefits,” Ron Rosedale
Shelley – What do you recommend for health — 15% carbs, 15% protein, 70% fat?
Ron Rosedale – (YES — HOWEVER . . . ) if you are going to go on a low carbohydrate diet you really have to go on a low carbohydrate diet. You can’t do it. Well I don’t know if I can say this on air but you can’t do it half assed You’ve got to do it. You’ve got to go on a low very low carbohydrate diet and substitute good fats into the type of fat make a big difference. And so it has to be done properly. You can’t just do it haphazardly and you can’t do it half assed. You just have to do it and then you’ll see huge benefits. Best thing you can do.