Commenter Kiwi Geoff kindly wrote a program that calculates LDL using the Friedewald equation and the equation from this paper, which may be more accurate for people with a total cholesterol over 250 and triglycerides under 100. For people whose triglycerides are over 100, the Friedewald equation should be relatively accurate. You can plug your total cholesterol, HDL and triglycerides into the program (in mg/dL), and it gives you both LDL values side-by side. Here it is:
LDL Cholesterol Calculator
Thanks, Geoff.
Monday, June 29, 2009
Sunday, June 28, 2009
Another Fatty Liver Reversal
Just to show it wasn't a fluke, reader "Steve" replicates the experiment:
The liver is a remarkable organ. Besides being your "metabolic grand central station", it's the only organ in the human body that can regenerate almost completely. It can be 75% obliterated, and it will grow back over time. Fatty liver and NASH are largely reversible.
I had a similar problem as what Sam described, and it just happened to coincide with my discovery of and commitment to a new eating plan (based on low/good carb, high in good fat and omega 3, and good protein--basically a mix of paleo, primal, low carb, whatever they call it). I consider myself lucky to have had great fortune in my timing of finding out about my fatty liver.And a later comment:
My ALT and AST [markers of liver damage] had been at 124 and 43 respectively, and then still at 80 and 30 in a follow up a few months later. I weighed in at about 205 (I'm 6'1.5" on a slimmish frame), which was my heaviest. I had been on a basic American (bad) diet. The whole thing shocked me, especially after a CT with contrast showed the fatty deposits on my liver (and prior to that, when the muddy ultrasound revealed a fatty liver and a possible pancreatic mass, later ruled out by the CT). Like Sam, though I was surely overweight, I was not fat or heavy. (Most people have noticed I look leaner, but are shocked when I disclose how much weight I have lost since they say "I cannot believe you had that much to lose.")
At about the same time I found out about my liver issue, I had been getting into reading about diet and health (something I had done once when I read the Zone stuff from Sears many years ago). I practically dove through Taubes, Eades, Cordain, and a bunch of blogs (including yours), and I made a commitment to fix my problem.
I started a pretty severe regimen at first, which included only protein and good fats with a minimal amount of non-starchy fruits and vegetables. Almost immediately, I started losing weight and body fat (as measured by an electrical impedance scale). I have always supplemented with fish oil, but I added krill oil and I also started eating grass-fed beef and pastured eggs and pastured pork as much as possible. I have added some coconut oil and pastured butter to my diet as well. I have dropped almost 40 pounds, I am down to about 10-11% body fat (from 24%), and my ALT/AST on my last test was 24/14 [normal]. I am getting another test soon, and I expect similar results.
I can add to the story that I first found out about the fatty liver on a routine new patient blood screening when I moved to a new town. I can also add that it took a bit of initiative on my part to get to the right diagnosis. The first doctor suspected hepatitis, but when blood work ruled that out, he ordered the imagining tests. Once I was referred to a GI specialist, it was a quick diagnosis. Still, I had to undertake myself to figure out the best diet. The GI recommended eliminating white bread, rice, pasta, starches, etc. but also recommended lowering fat intake. Having done some of my reading on diet and health, I knew to follow the former advice and to modify the latter to be "get plenty of fat, but make sure its the right kind."Steve took the initiative and fixed his damaged liver. He modified his GI doctor's advice based on what he had read about nutrition, with excellent results. I suspect his doctor will be all ears next time Steve comes into his office.
The liver is a remarkable organ. Besides being your "metabolic grand central station", it's the only organ in the human body that can regenerate almost completely. It can be 75% obliterated, and it will grow back over time. Fatty liver and NASH are largely reversible.
Friday, June 26, 2009
When Friedewald Attacks
I don't get very excited about nitpicking blood lipids. That's not to say they're not useful. There's definitely an association between blood lipids and certain health outcomes such as cardiovascular disease. The thing that tires me is when people uncritically interpret those associations as evidence that lipids are actually causing the problem.
Low-density lipoprotein, or LDL, is the cholesterol fraction that typically gets the most attention. High LDL associates with heart attack risk in Americans and some other groups. Statins reduce LDL and reduce heart attack risk in a subset of the population, and this has been used to support the idea that elevated LDL causes heart attacks. This is despite the fact that lowering LDL via diet doesn't seem to reduce heart attack risk (typically by reducing total fat and/or saturated fat). Statins may in fact work because they're anti-inflammatory, rather than because they reduce LDL. But both explanations are speculative at this point.
The fact remains that if you want to know if Mr. Jones is going to have a heart attack in the next five years, measuring his LDL will give you more information than not measuring his LDL. This association doesn't seem to apply to all cultures or to Americans eating atypical diets. Then you can get into the fractions that associate more tightly with heart attack risk, such as low HDL, high triglycerides, small dense LDL, etc. Triglycerides vary with HDL (that is, when trigs go up, HDL generally goes down) and the ratio also happens to be a predictor of insulin sensitivity. Total cholesterol is virtually useless for predicting heart attack risk in the general population. This is something I'll discuss in more detail at another time.
When you walk into the doctor's office and ask him to measure your cholesterol, the numbers you get back will generally be total cholesterol, LDL, HDL and triglycerides. All of those except LDL are measured directly. LDL is calculated using the Friedewald equation, which is (in mg/dL):
I had a lipid panel done a while back, just for kicks. My LDL, calculated by the Friedewald equation, was 131 mg/dL. Over 130 is considered high. Pass the statins! But wait, my triglycerides were 48 mg/dL, which is quite low. I found a paper through Dr. Eades' post that contains an equation for accurately calculating LDL in people whose triglycerides are below 100 mg/dL*. Here it is (mg/dL):
*This equation was designed for individuals with a total cholesterol over 250 mg/dL.
Low-density lipoprotein, or LDL, is the cholesterol fraction that typically gets the most attention. High LDL associates with heart attack risk in Americans and some other groups. Statins reduce LDL and reduce heart attack risk in a subset of the population, and this has been used to support the idea that elevated LDL causes heart attacks. This is despite the fact that lowering LDL via diet doesn't seem to reduce heart attack risk (typically by reducing total fat and/or saturated fat). Statins may in fact work because they're anti-inflammatory, rather than because they reduce LDL. But both explanations are speculative at this point.
The fact remains that if you want to know if Mr. Jones is going to have a heart attack in the next five years, measuring his LDL will give you more information than not measuring his LDL. This association doesn't seem to apply to all cultures or to Americans eating atypical diets. Then you can get into the fractions that associate more tightly with heart attack risk, such as low HDL, high triglycerides, small dense LDL, etc. Triglycerides vary with HDL (that is, when trigs go up, HDL generally goes down) and the ratio also happens to be a predictor of insulin sensitivity. Total cholesterol is virtually useless for predicting heart attack risk in the general population. This is something I'll discuss in more detail at another time.
When you walk into the doctor's office and ask him to measure your cholesterol, the numbers you get back will generally be total cholesterol, LDL, HDL and triglycerides. All of those except LDL are measured directly. LDL is calculated using the Friedewald equation, which is (in mg/dL):
LDL = TC - HDL - (TG/5)Low-carb advocates have known for quite some time that this equation fails to accurately predict LDL concentration outside certain triglyceride ranges. Dr. Michael Eades put up a post about this recently, and Richard Nikoley has written about it before as well. The reason low-carb advocates know this is that reducing carbohydrate generally reduces triglycerides, often below 100 mg/dL. This is the range at which the Friedewald equation becomes unreliable, resulting in artificially inflated LDL numbers that make you have a heart attack just by reading them.
I had a lipid panel done a while back, just for kicks. My LDL, calculated by the Friedewald equation, was 131 mg/dL. Over 130 is considered high. Pass the statins! But wait, my triglycerides were 48 mg/dL, which is quite low. I found a paper through Dr. Eades' post that contains an equation for accurately calculating LDL in people whose triglycerides are below 100 mg/dL*. Here it is (mg/dL):
LDL = TC/1.19 + TG/1.9 - HDL/1.1 - 38I ran my numbers through this equation. My new, accurate calculated LDL? 98 mg/dL. Even the U.S. National Cholesterol Education Panel wouldn't put me on statins with an LDL like that. I managed to shave 33 mg/dL off my LDL in 2 minutes. Isn't math fun?
*This equation was designed for individuals with a total cholesterol over 250 mg/dL.
Wednesday, June 24, 2009
Letter to the Editor
I just got a letter to the editor published in the journal Obesity. It's a comment on an article published in October titled "Efficiency of Intermittent Exercise on Adiposity and Fatty Liver in Rats Fed With High-fat Diet."
In the study, they placed rats on a diet composed of "commercial rat chow plus peanuts, milk chocolate, and sweet biscuit in a proportion of 3:2:2:1," and then proceeded to simply call it a "high-fat diet" in the title and text body, with no reference to its actual composition outside the methods section. We can't tolerate this kind of fudging if we want real answers from nutrition science. Rats eating the "high-fat diet" developed abdominal obesity, fatty liver and hyperphagia, but this was attenuated by exercise.
As I like to say, the problem isn't usually in the data, it's in the interpretation of the data. The result is interesting and highly relevant. But you can't use terminology that tars and feathers all fat when your diet was in fact high in linoleic acid (omega-6), low in omega-3 and high in sugar and refined grains. Especially when butter and coconut oil don't cause the same pathology. I pointed out in the letter that we need to be more precise about how we define "high-fat diets". I also pointed out that the study is highly relevant to the modern U.S., because it supports the hypothesis that a junk food diet high in linoleic acid and sugar causes metabolic disturbances and fatty liver, and exercise may be protective.
In the study, they placed rats on a diet composed of "commercial rat chow plus peanuts, milk chocolate, and sweet biscuit in a proportion of 3:2:2:1," and then proceeded to simply call it a "high-fat diet" in the title and text body, with no reference to its actual composition outside the methods section. We can't tolerate this kind of fudging if we want real answers from nutrition science. Rats eating the "high-fat diet" developed abdominal obesity, fatty liver and hyperphagia, but this was attenuated by exercise.
As I like to say, the problem isn't usually in the data, it's in the interpretation of the data. The result is interesting and highly relevant. But you can't use terminology that tars and feathers all fat when your diet was in fact high in linoleic acid (omega-6), low in omega-3 and high in sugar and refined grains. Especially when butter and coconut oil don't cause the same pathology. I pointed out in the letter that we need to be more precise about how we define "high-fat diets". I also pointed out that the study is highly relevant to the modern U.S., because it supports the hypothesis that a junk food diet high in linoleic acid and sugar causes metabolic disturbances and fatty liver, and exercise may be protective.
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