As the old year comes to an end I thought it would be appropriate to answer some questions that have been posted as comments. I’m so dilatory in getting to the comments that by the time I answer them there are many more posts so the comments (and my answers) don’t get seen by many readers. If everyone thinks this is a profitable thing to do, I’ll periodically go through these as Q and A’s. Let me know.
Comment: Hello I tried to find something on Thyroid in your blog but could not. My husband has lost 30 lbs LC and a coworker told him that after 6 years LC both he and his wife’s thyroid’s are shot and this guy said both he and his wife’s doctor believe it was from low carbing for the last 6 yrs. I do not believe this so I asked my DH (Darling Husband?) if their weight went up and down over the last 6 yrs because I know alot of people lose and gain over and over and that maybe this could be their problem and not because of LC . He said they did the best they could but that they did go up and down in weight. Just wondering about this.
MRE: Wonder no more. There is absolutely no evidence that low-carb diets (nor any other diet that I know of) can destroy a person’s thyroid. I’ve learned over the years from bitter experience that you can never trust what someone says his or her physician said. All patient/doctor conversations have two parts: what the doctor says and what the patient hears or understands. In many cases the two are worlds apart. Granted, sometimes doctors aren’t the world’s greatest communicators, but some of the things patients take away from the conversation are almost unbelievable. Once I took care of a patient who was extremely upset with his regular physician (who was a good friend of mine), and had come to me for a second opinion. He had a cough, some sinus congestion, and all the rest of the signs and symptoms of a typical viral upper respiratory infection. I told him what I thought he had and how he should treat it. He then confided in me that his other doctor (my friend) had told him he had something that was incurable. After this patient left my office, I called my friend. He remembered the patient well, and told me that he had told this patient that he had a virus and that there were really no medicines to treat a virus; one just needed to rest, drink a lot of fluids, etc., in short, all the same things I had told the same patient a day or two later. What the patient heard was that he had an incurable disease.
Comment: As an apnea sufferer I read with interest your latest posting. About a year ago I read that bariatric stomach surgery affected apnea. They were not claiming cure, but that lower levels of CPAP usage were possible(?). The only improvement on CPAP usage is to not need it (CPAP) at all! You state pretty positively apnea can be cured by low-carb diet. Where can I find out more about this and what’s involved to affect this cure? When I looked into the claims of the bariatric surgeons I expected to find improvements were from weight loss, which seemed to be the case. This is against conventional wisdom (re:Mayo Clinic)which stated once you had it, you had it, weight loss or not. Your statments of a cure are extremely heartening! (I am knowledgeable about low carb in general; would like more info related to apnea specifically.)
MRE: Unfortunately, there is very little information out there about low-carbohydrate diets as a treatment modality for sleep apnea. I was basing what I wrote on my own clinical experience taking care of a number of patients with sleep apnea all of whom responded nicely to a low-carb diet.
Comment: I have had reflux for many years and my most recent endoscope shows ‘no problems’, whatever that means…except now there is a hiatus hernia. My wife seems to be the one that hears these things …like Barrett’s most often starts in a hiatus hernia sufferer. Plus there was a recent comment that connected diarrhea (which I always have big time) with reflux medication use. Please comment.
MRE: A hiatus hernia happens when the upper part of the stomach pushes up past the muscular ring that separates the esophagus from the stomach. When this happens the acid produced by the acid-producing cells of the stomach burns the unprotected cells that line the esophagus. In my experience most diagnoses of hiatus hernia are really another way of putting a name to GERD. The diarrhea you are experiencing can come from a couple of sources. First, many reflux and/or antacid medications can themselves cause diarrhea. Second, a couple or recent studies have shown that patients who take reflux medicines and/or antacids can develop infections of Clostridium difficile, a type of bacteria that often cause diarrhea. In my opinion the best way to treat GERD is with a low-carb diet. Not the easiestâ€”the easiest is to take a pill and eat whatever you want.
Comment: A very timely entry, because my husband is scheduled for a sleep study in a few weeks to assess for suspected sleep apnea. He has an extremely narrow airway – when he had surgery last year, the anesthesiologist had to use the smallest adult-size endotracheal tube. He is at a normal weight for his height (5’10” and 170 pounds) and his physician believes there is an anatomical cause of his suspected apnea. In your experience, would a low-carb diet be effective for him? Just curious; we will of course be adhering to any treatment method his physician suggests.
MRE: It wouldn’t hurt to give the low-carb diet a try while waiting for the sleep study. It’s been my experience that such a diet makes an enormous difference pretty quickly.
Comment: What is the stand on products already on store shelves come January first? Do these products need to be pulled? Or is there a grace period for these and other products? Plus do restaurants need to put trans-fat on the menu?
MRE: No, any products on the shelves come January first won’t be pulled. In fact, products can continued to be labeled the old way until the manufacturer runs out of the old labels. Then, theoretically, the manufacturer will print new labels reflecting the new law.
And, no, the new trans fat labeling law does not apply to restaurants. Caveat emptor.
Comment: Re my writing the following: “If anyone is interested I’ll be happy to post on p values and confidence intervals and what they all mean in simplified terms. Just let me know.”
Yes! please do!
MRE: After giving this a little more contemplation it might be a little more difficult than I originally thought to make it really understandable to the mathematically disinclined. But, I’ll try within the next few weeks to make a run at it.
Comment: I did not see a contact link on your sight so I would like to ask a question here in the comments. I have been debating a guy on another message board on the causes of diabetes. I contend that it is an over-consumption of carbohydrates that is causing the large increase in diagnoses and he is arguing that it is fat consumption and the increase in obesity caused by fat consumption that is causing the increase. I have done a search of the web and can find no human studies that support the theory that fat consumption causes obesity or diabetes. Are there any such studies out there? I found many health sites that make the statement that fat consumption is the cause but they do not site any studies to back up there contentions. As far as non-human studies there is a new one out that I was wondering if you could comment on. Here is the link: http://news.yahoo.com/s/nm/20051228/hl_nm/diabetes_dc
MRE: Without commenting on this link, which is a news report (and we’ve seen how inaccurate those can be) of a couple of animal studies that have very little relationship to what happens in humans, I can say that at this time most scientists believe that the root cause of insulin resistance and type II diabetes is a defect in the insulin receptor caused by an intracellular accumulation of fat. The question is, what causes the intracellular accumulation of fat? We know that one thing for sure does: fructose. Carbohydrates in the diet cause the liver to produce more VLDL, which in turn leads to increased levels of triglycerides and increased intracellular fat. I would put my money on the theory that overconsumption of carbohydrates, especially fructose, is the culprit.
Comment: Is the South Beach Diet a good diet to stay on for life? I just started it and I’m doing quite well but by Phase 3 of the diet, it allows more carbs. What do you think?
MRE: Uh, it’s a better diet to stay on than the Ornish diet. If I had thought the South Beach Diet was a good diet to stay on for life I would have written the South Beach Diet instead of Protein Power. Protein Power was an outgrowth of the many years that MD and I took care of thousands of patients (including ourselves) on low-carb diets. Over the years we fiddled with this and that and tried all kinds of variations, and what ended up in Protein Power and then the Protein Power LifePlan was the version that we found worked the best and was the easiest to stick to for the greatest number of patients.
I have a couple of problems with the South Beach Diet. One is that the author goes around the country saying that his diet is categorically NOT a low-carb diet while anyone with half a brain can see that it is. By denying that his is a low-carb diet and doing so in pejorative terms he denigrates the low-carb diet, which is being shown in more and more studies to be the most efficacious diet to treat not only obesity but high blood pressure, diabetes, lipid disorders, and a host of other problems. Off the top of my head a couple of other gripes I have are that the author of the South Beach Diet promotes the use of fructose because it is a low-glycemic” sugar and badmouths saturated fat. The problem with this is that whereas the medical literature is full of articles showing in great detail the metabolic derailment brought about by fructose consumption it fails to show any correlation between saturated fat consumption (particularly on a low-carbohydrate diet) and heart disease or anything else for that matter.
Comment: Hi Doc…I really enjoy your blog. I was doing some shopping this morning…and came across a product with the trans fat label. It was a lo carb coffee creamer. However, thanks to you and Mary Dan, I have learned to read labels….and this supposedly non trans fat product has listed partially hydrogenated oils. Hmmmmm….very curious….
MRE: Good eye. You’ve got to be careful because manufacturers will abide by the letter of the law but not the spirit. As the law is written anything containing less than one gram of trans fat per serving can be labeled as zero trans fat. What do the manufacturers do? They make sure the serving size is such that it contains less than one gram of trans fat and, Voila!, zero trans fat. If the ingredients section lists partially hydrogenated oils, then you’re looking at a trans fat.
Comment: I’ve read through all the archives on here but really didn’t see much addressing the actual carbs in “low-carb” except the passing mention of your typical low-carb fruits. It’d be great to get more insight on the good carbs from time to time and also address the issue of getting enough fiber for a healthy digestive system. Just a couple suggestions.
MRE: Okay, here are my insights. There are no good carbs and bad carbs. Carbs are carbs. They all run up your insulin levels and play havoc with your metabolic system. They are all sugar. Once you accept that, then the question becomes what is my trade off for eating all these metabolically disruptive carbohydrates. If they are packaged as pure sugar, then there is no good trade off. If they are packaged as, say, blackberries then the small amount of carbohydrate is offset by all the antioxidants and other healthful phytochemicals in the blackberries. Same with blueberries, asparagus, tomatoes, and all the rest. It’s a trade off. How much good stuff can I get to make eating the metabolically disruptive carbs worth it.
As far as how much fiber is required for a healthy digestive system, the more I study the situation and think about it, the less fiber I think we need. In fact, if pressed, I would say we don’t “need” any at all. I plan a major post on this very issue early next year.
I think that is all of the comments that are outstanding; if I’ve overlooked someone, it was unintentional. And, I don’t have time to go back and look because we’ve got guests coming for a New Year’s Eve party, and MD is hounding me to put an end to this and help her get everything ready.
I hope everyone has a safe and enjoyable New Year’s Eve.
Comments and answers
Re:”If everyone thinks this is a profitable thing to do, IÃ¢â‚¬â„¢ll periodically go through these as Q and AÃ¢â‚¬â„¢s. Let me know.”
They are definitely a rich resource. I get some of the Harvard Health Newsletters from Audible.com and find that the Q & A sections one of my favorites since it is current and relative to health concerns addressed by new studies. Your inclusion and disection of studies in your Blog are rich as well and are an enjoyable read.
” I would put my money on the theory that overconsumption of carbohydrates, especially fructose, is the culprit.”
This would place a large part of the blame on the over consumption of soft drinks, especially by younger people. I heard that HFC (high fructose syrup) is the worse culprit.
I wonder how far away we are from lawsuits.
“As far as how much fiber is required for a healthy digestive system, the more I study the situation and think about it, the less fiber I think we need. In fact, if pressed, I would say we don’t Ã¢â‚¬Å“needÃ¢â‚¬ any at all.”
For something that passes through the digestive tract undigested, fiber has an aura of healthfullness attached to it. I have searched quite a lot and have not been able to find any worthwhile research that shows that fiber is needed. If fiber was really needed, then humans would graze on their lawns. Grass is almost pure fiber.
Many of the micronutrients/vitamins/antioxidants/etc. that do the body good come from foods that have a lot of fiber (spinach, broccoli, asparagus, etc.), but the fiber does not do anything good.
minor tweak on the thyroid paragraph. Well, yes…a low carb diet can kill thyroid function, but only if that person made a habit of regularly consuming a large amount of non-fermented soy (as exists in so many “low carb” frankenfoods, bars, shakes, etc.). (I probably don’t have to give you the spiel about how the association between soy consumption and thyroid decline has been established since the 1950s) I obvously can’t say that this is the case for this couple, but it has been a problem for me and for a lot of thyroid patients I know–those of us who have to avoid soy because it interferes with the meds or because it makes us a little too symptomatic have to be obsessive label readers. So while low carbing is not to blame, reliance on processed foods might be part of the problem. Another thing to consider is that some people have a higher fluoride intake than others (e.g. heavy tea drinkers, esp green tea)…some people can have a diet a little too heavy in iodine (e.g. those who take “thyroid support” supplements). There are a lot of ways these people can have done their thyroids in by diet, but you can’t blame it on low carbing as such–macronutrient breakdown has little to do with it.
You are right on the money.
Just to say a low carb & controlled carb diet cured my sleep apnea, regardless of weight loss.
Actually there is plenty of evidence showing that T3 drops, Even if protein remains high, when carb levels fall below 100g a day.
It does seem 50g of carbs a day are necessary for proper thyroid function.
Effect of caloric restriction and dietary composition of serum T3 and reverse T3 in man.
Spaulding SW, Chopra IJ, Sherwin RS, Lyall SS.
To evaluate the effect of caloric restriction and dietary composition on circulating T3 and rT3 obese subjects were studied after 7-18 days of total fasting and while on randomized hypocaloric diets (800 kcal) in which carbohydrate content was varied to provide from 0 to 100% calories. As anticipated, total fasting resulted in a 53% reduction in serum T3 in association with reciprocal 58% increase in rT3. Subjects receiving the no-carbohydrate hypocaloric diets for two weeks demonstrated a similar 47% decline in serum T3 but there was no significant change in rT3 with time. In contrast, the same subjects receiving isocaloric diets containing at least 50 g of carbohydrate showed no significant changes in either T3 or rT3 concentration. The decline in serum T3 during the no-carbohydrate diet correlated significantly with blood glucose and ketones but there was no correlation with insulin or glucagon. We conclude that dietary carbohydrate is an important regulatory factor in T3 production in man. In contrast, rT3 concentration is not significantly affected by changes in dietary carbohydrate. Our data suggest that the rise in serum rT3 during starvation may be related to more severe caloric restriction than that caused by the 800 kcal diet.
(scroll down to starvation and fasting)
Composition of the diet rather than reduction in the total calorie intake seems to determine the occurrence of decreased T3 generation in peripheral tissues during food deprivation. The dietary content of carbohydrate appears to be the key ingredient since as little as 50 g glucose reverses toward normal the fast-induced changes in T3 and rT3.52 Replacement of dietary carbohydrate with fat results in changes typical of starvation.39,53 Refeeding of protein may partially improve the rate of T3 generation, but the protein may be acting as a source of glucose through gluconeogenesis.54
Doc – you stated in this column that you would post about needing fiber – have I missed the post? I don’t recall seeing it but am VERY interested in reading it… since my friends are all over me to get more fiber and I tell them that I don’t need it.
I can’t recall without going back through all the posts myself whether or not I posted on the need for fiber. I can tell you in just a few words, however, that you don’t ‘need’ any fiber. As far as I’m aware no studies have conclusively shown that humans require any fiber for optimal function. It’s another one of those vampire myths that just won’t die.
To take your fiber remarks one step further. Do you also believe we do not need vegetables, a major source of fiber, albeit not the only benefit?
This is an ongoing discussion on our low carb forum, and your opinion is valued.
Let me put is this way: I think we could get by just fine on a 100 percent meat diet. Having said that, I do think vegetables contain a number of valuable phytonutrients that are of value. A 100 percent meat diet would become very boring, very quickly in today’s world where we are constantly bombarded with food advertising and easy availability. So, I think vegetables (and some fruits) are a much better choice to increase variety than any kind of processed food.
Thanks for commenting.
On the 100 percent meat diet… Do you see any downsides besides boredom? Would it be important to eat certain types of meat?
No, I don’t see any downsides. Not even boredom if you like meat. I don’t think there would be any difference in types of meat. As they say, meat is meat.
I recently came across a looooong discussion started by a poster named “theBear” who claimed that he has eaten an all meat diet for 47 years. Another poster named “ubizmo” argued that a carb intake of 30-50g was probably optimal to minimize cortisol. Does that sound right? Quote:
A zero-carb (or nearly so) diet necessarily involves some gluconeogenesis. Yes, some of the glucose needed by parts of the brain, blood cells, and other glucose-dependent tissues can be obtained from the glycerol molecules in triglycerides that we eat, but apparently not enough. So even the keto-adapted individual will have to make some glucose from amino acids. This isn’t a terrible thing, but the signalling hormone used to tell the liver to do gluconeogenesis is cortisol, and I have no real wish to maintain a chronic exposure to this stress hormone either, when I can avoid it by eating a small amount of carbohydrate. Yes, eating some carbs will require some insulin, but then constant ketosis also requires insulin, to avoid ketoacidosis. So my hypothesis is that the optimum carb intake is the minimum needed to arrest gluconeogenesis. How much is that? It’s not easy to get a clear answer to this one, but my best guess is that it’s in the 30-50g range. But the operative word is “guess,” because there are a lot of conflicting data out there.
The whole thread is here:
I’m somewhat familiar with The Bear. He used to be the sound man for the Greatful Dead and has been on an all meat diet since the late 1950s.
It’s not really cortisol that drives gluconeogenesis; it’s glucagon. Glucagon goes up when insulin goes down. Insulin goes down when an individual becomes more insulin senstive. When one is insulin sensitive and doesn’t eat much carb, glucagon drives the conversion of certain amino acids into glucose. The cells of the body that have to have glucose require about 200 grams per day; 70 or so grams of that total can be replaced by ketone bodies, so if one eats only 50 grams of carbs per day, then 80 grams of glucose must be made from protein and fat (the glycerol backbone of triglycerides is also a substrate for glucose production). If one goes on a zero carb diet, themn about 130 grams needs to come from protein and fat.
Hope this helps. I did a longer post about all this sometime in the past, but I can’t even remember the title of it.
I’ve sent you an email in the more recent past, which you so generously responded to. Today, i a pose another question.
I, too, am familiar with “the Bear”. And like him, as well as many of your readers, I absolutely love red meat, especially red meat smothered in pure butter, along with a few herbs and spices to boot, such as garlic, sea salt, oregano and parsely. I do not, however, enjoy eating meat that is under-cooked, something the Bear suggests is necessary if someone plans to maintain a zero-carb diet for the long-haul. In other words, the Bear is adamant that nutrients are lost when meat is cooked for any substantial length of time. Is this true? I gather that the level of nutrients would be reduced, but by how much?
The Bear also suggests that fibrous foods (fruit, veg, nuts and seeds) cause more harm than good. Specifically, he suggests that these types of food damage the GI tract, which can eventually cause mal-absorption of nutrients, due to the mucus forming on the GI tract. This makes sense, and is something which i think i remember you discussing in a previous blog. I do enjoy berries, as well as nuts and seeds, but if what Bear suggests is true, then i would be happy veer away from eating such things.
Lastly, the issue of low-carb diets negatively affecting thyroid functioning is one i find particularly interesting, especially since i know people who complain of symptoms such as cold hands and feet, fatigue, and especially lack of sex drive, after following a very low-carb, high fat, moderate protein diet, for a few months. These people seem to consume an abundance of calories, namely from saturated fat, yet seem to suffer. Perhaps the evidence showing that T3 drops, even if protein remains high, when carb levels fall below 100g or 50g a day, is correct, and therefore, maybe the Bear is an anomaly. But then what about the evidence to the contrary from such people as the Inuit/Eskimo, Masai of Africa, Plains Indians, Rocky Moutain Men, etc, who subsist largely on meat alone.
Perhaps a diet consisting of a few portions of berries and some nuts and seeds with plenty of meat and fat makes the most sense. Then again, perhaps an all meat diet supplemented with some supplements may be even better, since one would attain sufficient micro and macro nutrients without the damage to the lining of the GI tract. What do you think?
P.S. The chapter in Protein Power LifePlan elucidating our hunting and meat eating past is one of my favourite chapters of any book!
I suspect – but don’t know with absolute certainty – that there is some nutrient loss when meat is more cooked verses less cooked. Stefansson discovered that overcooked meat provided less protection against scurvy than did moderately cooked fresh meat, which would indicate that whatever substance that is in meat that is antiscorbutic is lost with cooking. I don’t know that anyone has quantified the loss of nutrients with cooking, however.
I wouldn’t worry too much about a few berries, nuts and seeds because I suspect that our ancestors cut their teeth, so to speak, on these foods along with meat. I suspect that most of the GI damge – such as it is – comes from the much larger doses of fiber that come from grains.
I’ve heard people talk about this decrease in thyroid function with a low-carb diet, but I haven’t seen it in my treatment of a whole lot of patients. A decrease in thyroid function can happen to people on low-carb, very-low calorie diets, but I don’t think it is common on whole-food low-carb diets that contain plenty of calories. At least I haven’t seen it. People often do get a little cold as they’re losing weight, but that’s not really always a function of a lowered thyroid, and usually goes away with time. Protein is important in the conversion of T4 (the inactive form of thyroid hormone) to T3 (the active form), so consuming plenty of protein helps.
Hope this answers your questions.
Many thanks for the reply, and yes, you answered my queries.
I do suspect that many people who attempt low-carb diets, still avoid eating large quantities of fat, and perhaps consume less calories than they themselves think, which explains the symptoms people often complain of in relation to low-carb diets.
It really is too bad that the word fat relates to a macronutrient, as well as the type stored in, and on, our bodies. Perhaps if dietary fat was re-named, there wouldn’t be such an aversion to eating foods rich in fat.
Good idea. Let’s start a movement to rename fat. Send a check and I’ll set up the foundation and get it going.
I have been on protein power and atkins in the past a couple of times. It has been very successful. I worry about these t3 levels, because the last couple of times I have tried the low carb diet, I have felt better, yet didn’t lose any weight. Can I do something to fix the way my body is responding to the low carbing? I can’t do any other diets. I have tried with no success in the past. I need to lose about 30 pounds. Anyone have any ideas for me? I don’t know much about t3 levels.
There are a couple of reasons that the same diet fails the second (or third) time around when it worked so well the first. In my experience people tend not to follow it as closely when they do it again. And, second, their bodies are more prepared for it and so cling on to excess weight a little more strongly. Since weight gain and loss is driven by much more than simply the number of calories in and out, the underlying metabolic status is critical. People who have followed the high everything diet and gotten fat tend to shed a lot of calories in inefficiency. It’s like the old days of cheap gas when most everyone in the US had large cars. It didn’t matter that these cars didn’t get good gas mileage because gas was at give-away prices. Now that gasoline prices have skyrocketed, everyone is making more fuel-efficient cars. It’s kind of the same with the body. If you have a lot of food coming in all the time, your body tends to burn off a lot of it. When you first go on a diet your body still thinks you’re eating like crazy and continues to waste calories, which is why people usually lose quickly right at the start of almost any diet. Then after a few turns of the dietary cycle, the body gets a little smarter and doesn’t fall for the same scam twice. It tightens up on calorie loss making it tougher to lose the second or third time around. Couple that with the fact that most people don’t follow the same diet with the same rigor on multiple attempts and you’ve got a recipe for not losing.
Do I keep at it? If I am relentless in following the low carbing, will my body start to burn the calories as before, except slower? What would you do, or not do?
I think if you keep at it and meticulously keep your carb count low, you will see success ultimately. But it will take a little time for the wheels to start turning.
Keep me posted.