My Heart’s All A-Flutter! The Anointed, The Wisdom Of Crowds, And Another Stupid Study

Years ago, I read an interview with a researcher who said something like, “If you want to study the migratory patterns of squirrels and you name your proposed study The migratory patterns of squirrels, you won’t get funding. But if you name your proposed study How global warming is impacting the migratory patterns of squirrels, you will get funding.”

By this point, it’s safe to say something similar applies to the world of nutrition studies. If you want to get funding, you need to propose a study named something like Low-Carb Diet Is Linked To [Some Bad Thing]. The Anointed and their pals in the Save The Grains Campaign have apparently decided that the best use of scientific (ahem) “research” is to scare people away from low-carb and ketogenic diets. So we keep seeing one stupid study after another claiming to find a link (sort of) between some ailment and a low-carb (sort of, but not really) diet.

The latest came out last week and generated headlines like Low-carb diets linked to atrial fibrillation (, Low-carb diets linked to heart rhythm issues, study says (New York Post) and Low-Carb Diets Linked to Higher Odds for A-Fib (US News). In case you didn’t quite grasp that a low-carb diet will kill your heart, some articles featured a graphic like this:

Boy, that’s scary. Best reach for the bread as quickly as possible.  Here are some quotes from the news-medical article:

Low-carb diets are all the rage, but can cutting carbohydrates spell trouble for your heart? People getting a low proportion of their daily calories from carbohydrates such as grains, fruits and starchy vegetables are significantly more likely to develop atrial fibrillation (AFib), the most common heart rhythm disorder, according to a study being presented at the American College of Cardiology’s 68th Annual Scientific Session.

The study, which analyzed the health records of nearly 14,000 people spanning more than two decades, is the first and largest to assess the relationship between carbohydrate intake and AFib. With AFib, a type of arrhythmia, the heart doesn’t always beat or keep pace the way it should, which can lead to palpitations, dizziness and fatigue. People with AFib are five times more likely to have a stroke than people without the condition. It can also lead to heart failure.

And a quote from USA Today:

Keto, Paleo, Atkins — there’s no shortage of low-carb diets to try, but new research suggests that over time, living low-carb can raise your risk of a heart condition called atrial fibrillation, or a-fib.

And a quote from The New York Post:

Carb-crunching weight loss trends like keto, paleo and the old-school Atkin’s diet are linked to a higher chance of developing atrial fibrillation, according to new research to presented March 16-18 at the American College of Cardiology‘s 68th annual Scientific Session.

Well, there you have it: a low-carb or ketogenic diet can cause atrial fibrillation. Obviously, the researchers noticed this among people following ketogenic diets, the Atkins diet and paleo diets. Thank goodness they reported their finding in time to save our hearts.

But wait … let’s put on our Science For Smart People hats and ask some questions about this study:

Q: Is this a clinical study or an observational study?

To answer that, let’s quote from the news-medical article again:

Researchers drew data from Atherosclerosis Risk in Communities (ARIC), a study overseen by the National Institutes of Health that ran from 1985-2016.

Study participants were asked to report their daily intake of 66 different food items in a questionnaire. The researchers used this information along with the Harvard Nutrient Database to estimate each participant’s daily carbohydrate intake and the proportion of daily calories that came from carbohydrates.

It’s an observational study based on food questionnaires — which are so unreliable, some people report a total calorie intake that would cause unpleasant side-effects … such as starving to death. As a reminder, here’s what a food questionnaire looks like:

Over the last 12 months, how often did you eat the following foods? (Ignore any recent changes.)

Whole milk (4%), NOT in coffee, NOT on cereal: Never | 1-6 per year | 7-11 per year | 1 per month | 2-3 per month | 1-2 per week | 3-4 per week | 5-6 per week | 1 per day | 2-3 per day | 4-5 per day | 6+ per day. Portion size: less than ½ cup | ½ to 1 cup | more than 1 cup.

Breads or dinner rolls, NOT INCLUDING ON SANDWICHES: Never | 1-6 per year | 7-11 per year | 1 per month | 2-3 per month | 1-2 per week | 3-4 per week | 5-6 per week | 1 per day | 2-3 per day | 4-5 per day | 6+ per day. Portion size: less than 1 slice or roll | 1 or 2 slices or rolls | more than 2 slices or rolls.

Ground beef in mixtures such as tacos, burritos, meatballs, casseroles, chili, meatloaf: Never | 1-6 per year | 7-11 per year | 1 per month | 2-3 per month | 1-2 per week | 3-4 per week | 5-6 per week | 1 per day | 2-3 per day | 4-5 per day | 6+ per day. Portion size: less than 3 ounces | 3 to 7 ounces | more than 7 ounces.

People simply don’t count and measure and remember their meals accurately enough to answer a food questionnaire honestly. So they take a wild-ass guess. We can already dismiss this study and go home. But let’s continue anyway …

Q: What was the actual difference?

We’ll quote from the news-medical article again:

Of the nearly 14,000 people who did not have AFib when they enrolled in the study, researchers identified nearly 1,900 participants who were subsequently diagnosed with AFib during an average of 22 years of follow-up.

Participants reporting low carbohydrate intake were the most likely to develop AFib. These participants were 18 percent more likely to develop AFib than those with moderate carbohydrate.

I did a bit of number-crunching in Excel. According to what the researchers are telling us, 13.5 out of every 100 people on a moderate carbohydrate diet developed AFib over the 22 years. In the “low” carbohydrate group, an 18 percent increase would translate to roughly 15.3 people out of every 100. We’ll call it an extra two people out of every 100 over a 22-year span.

But that’s within the study group. Doing a bit of research online, I found that roughly 3.4 out of every 100 adults over age 35 has AFib. If the incidence increased by 18% for people on a “low” carbohydrate diet, the number would be 4.0 out of every 100 adults. So the actual difference is less than one person in a hundred.

There’s a reason I’ve been putting “low” carbohydrate in quotes, however, which leads to our final question:

Q: Compared to what?

This is where it gets fun. Remember what the news articles told us:

Keto, Paleo, Atkins — there’s no shortage of low-carb diets to try … Low-carb diets are all the rage, but can cutting carbohydrates spell trouble for your heart? … Carb-crunching weight loss trends like keto, paleo and the old-school Atkin’s diet are linked to a higher chance of developing atrial fibrillation …

Now let’s look at what the researchers actually compared:

Researchers then divided participants into three groups representing low, moderate and high carbohydrate intake, reflecting diets in which carbohydrates comprised less than 44.8 percent of daily calories, 44.8 to 52.4 percent of calories, and more than 52.4 percent of calories, respectively.

Yup, the “low” carbohydrate diet was anything less than 44.8 percent of daily calories. Boy, doesn’t that sound just like your ketogenic or Atkins diet?

I guess the researchers took their cue from Harvard’s Dr. Frank Sucks … er, Sacks: just raise the bar on what “low” carbohydrate means until you get the association you want to find, then alert the media to the dangers of skipping bread and cereal. Here’s what this crop of researchers had to say:

“The long-term effect of carbohydrate restriction is still controversial, especially with regard to its influence on cardiovascular disease,” cardiologist and lead study author Dr. Xiaodong Zhuang tells reports. “Considering the potential influence on arrhythmia, our study suggests this popular weight control method should be recommended cautiously.”

I’ll be cautious, Dr. Zhuang. I promise I won’t start consuming a diet that’s 44 percent carbohydrate. I’ll stick with 15-20 percent.

The Anointed obviously believe they can scare us away from low-carb diets with crappy studies. That’s because they still believe information flows like this, as I explained in my recent speech on Diet, Health and The Wisdom of Crowds:

From The Anointed on high, down to us little people below. But that’s not how it works anymore. Information flows like this now:

To underscore the point, here are some comments people left on the news-medical article online:

My wife and I went on the keto diet about 2 years ago and she lost 50 lbs and her heart atrial fibrillation went way completely…I read all kinds of negative so-called studies on the keto diet but we have experienced nothing but great health improvements!

First off this is a questionnaire study (horribly inaccurate) and low carb is anything under 45% of calories from carbohydrates. A ketogenic diet is at most 10% of energy from carbs.

My diabetes went away and so did my high blood pressure. They’re always trying to trick us into going back to the pill farm.

Another day, another shady anti-keto story. Ho-hum. Could it be that big corporations that sell carb-laden food products are panicking over the popularity of the keto diet

Everybody in the study was consuming a high carb diet, less than 44% is still high, keto is 5-10%. The only conclusion from this “study” is that possibly high carb diets cause AFib (1900/14000 = 13.5%), as there are no participants in a low carb diet.

The moment I read the carb % breakdown as well as this being an observational study I new it was the same garbage we have been reading about for years.

This is getting really absurd and annoying. There is nothing wrong with Keto.

Just another ploy to get people to stop doing Keto.

While eating carbs /sugars I would go into atachacardia more than once a month (freaky and terrifying). I’ve been strict keto for 9 months, down 50lbs, no joint pain, and no episodes of fluttering!! Don’t believe this.

They just can’t fool us like they used to, because in the internet age, we can share our experiences with each other like never before … which is why the information also flows like this now:

And when studies like this hit the news, that’s the proper response.

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50 thoughts on “My Heart’s All A-Flutter! The Anointed, The Wisdom Of Crowds, And Another Stupid Study

  1. George Henderson

    I think bad studies should always be taken at face value at some stage in their analysis.
    For example – low carb diets were not popular in this period. Why else would people restrict carbs? Alcohol displaces carbohydrates more than it displaces any other macronutrient. A high intake of alcohol is resoundingly associated with AF
    “The pooled estimate of AF for the highest versus the lowest alcohol intake was 1.51 (95% confidence interval: 1.31 to 1.74). ”
    Did the study adjust for alcohol? I really can’t be bothered finding out. The Seidelmann et al “low carb diet will kill you” study didn’t, even though they had alcohol data for their cohort. In other words, this sort of thing is just propaganda, not science. And “low carb diet score” was not a registered outcome in any of these studies – it is a post-hoc invention for p-hacking purposes.
    Alcohol is not reported with any accuracy in FFQs, and alcoholism by its nature is unlikely to be recorded; it is also, on average, likely to worsen over time.

      1. Walter

        Don’t tell you doctor anything you would regret seeing on the front page of the New York Times.

  2. JR62

    The guy in picture has nice shirt. Just like one of mine.
    When there is no essential carb to human body, that should nullify this kind of “studies”.
    Thank you for opening these.

  3. Tom Welsh

    “Low-carb diets are all the rage, but can cutting carbohydrates spell trouble for your heart?”

    Satirists and propagandists know very well the value of open questions like this. Strictly speaking, the quoted sentence does not assert anything. Questions are far less likely to be actionable (for libel) than statements.

    Yet they make almost as great an impact on the reader’s mind. In a way, perhaps they can be even more disturbing. If I read a claim that “cutting carbohydrates harms your heart”, I’m likely to snort “Pshaw” or something less printable, and ignore the claim.

    But the question quoted above is unsettling. It haunts the reader, and keeps returning to instil vague doubts and fears.

    1. George Henderson

      So true. If they tell you something is bad for you, you’ll feel defiant when you do it, which is probably protective anyway and may be the reason we’re all still kicking here.
      But if they just ask you whether something is harmful, you’re supposed to ask yourself again and again, even though in the case of a low carb diet, you won’t know if it’s harmful until after you drop dead, because you won’t have any chronic disease symptoms to provide an answer while you’re alive.

      1. chris c

        My epitaph

        “See! We told him fifteen years ago that dangerous low carb diet would kill him!”

        There’s a massive confounder in all these studies – most low carbers will have already been eating low fat diets for years if not decades. Some of us will have already tried vegetarian or vegan diets and found they didn’t work either.

        When you find low carb/keto/whatever your symptoms go away, your health and “health markers” improve and obviously you put an end to the damage you have been undergoing previously – but is this enough to reverse the previous harm? I suspect in some cases not, so low carbers WILL die prematurely – but as a result of their PREVIOUS diet.

  4. Don Sproles

    I eat low carb/keto and have for years. (90%) I also have intermittent a-fib, controlled by medication. It seems that eating ‘off plan’, especially foods with added sugar or foods with grains, seems to trigger episodes of fluttering and rapid heart rate. Staying ‘on plan’ keeps this from happening. So take that!, Anointed.

  5. Walter

    And again, total mortality is a more important measure of dietary danger. Or perhaps other conditions by a high carb diet?

    Like statins just give you the choice of dying of something else. Like suicide or being so annoying that someone kills you.

    1. Tom Naughton Post author

      If I feed a study population rat poison, I promise their rate of CVD death will be lower than the general population’s.

  6. Lee Valentine

    In my experience, atrial fibrillation is frequently preceded by a high carbohydrate meal. That’s only clinical experience. It cannot be interpreted to be causative. There are, however, plausible mechanisms for a high carbohydrate intake, either acute or chronic to be causative.

    I advise my acute atrial fibrillation patients to radically cut their carbohydrate intake and to increase their intake of potassium and magnesium.

    Provided there is no kidney disease, the easiest way to increase potassium intake is the unrestricted ( that is, liberal)
    use of a 50/50 mixture of sodium and potassium salt such as Lo Salt or Lite Salt.

    Any over the counter magnesium supplement will work. Magnesium citrate or magnesium glycinate are better adsorbed and less likely to produce diarrhea. Again, given normal kidney function, take as much as you want, just not enough to give yourself diarrhea.

    This information is general in nature, and does not constitute medical advice to any specific person. You will need to consult your physician to determine whether it may apply to you.

  7. Ulfric Douglas

    I just read an observational study that concluded low-carb diets result in nice shirts.

    Can I get funding?

  8. Lori Miller

    I have gotten scary palpitations on very low carb. However, looking back at my blog, these were times of high stress and anxiety, plus having dental work (epinephrine depletes your potassium stores), and I have a history from adolescence of irregular heartbeat.

    Magnesium and potassium helped. But since potassium pills can only have 99mg of the stuff (a homeopathic dose), I had to pop them like candy.

    1. Walter

      The sell potassium chloride in grocery stores and at for example, Amazon, and they at least used to sell mixtures of sodium chloride and potassium chloride.

      Tastes terrible, but you can get a reasonable dose.

    2. Firebird7478

      You can boost your potassium intake by using NuSalt, the salt substitute. A serving size of 1/6 tsp = 530 mg potassium chloride. I’m not suggesting you replace salt, but perhaps add this as a supplement.

  9. Dianne

    Personally, I can just about guarantee that I’ll have rapid, irregular heartbeats if I indulge in sweets. It’s been that way ever since I was in my early twenties (fifty-some years ago), and potassium does help. But what helps most is saying “no” to sugar and starch. Protein never brings on heart flutters. I don’t know if they are dangerous, but they certainly are unpleasant, especially at my age! BTW, that is a very nice shirt — my late husband had one like it, and it was so comfortable he practically lived in it .

    1. Tom Naughton Post author

      I don’t know about irregular heartbeats for me, but I know when I eat crappy carbs, my pulse starts racing.

      1. Firebird7478

        That use to happen to me with popcorn. I’d have some as a snack at night, maybe 8 PM. I’d wake up 1-2 AM with my heart pounding in my chest.

          1. Firebird7478

            That was back in the day when we didn’t use fat. We sprinkled Butter Buds on it instead!

            1. Tom Naughton Post author

              Oh my god, I almost forgot about those things. I sprinkled them on baked potatoes.

  10. egocyte

    Just to give a comparison, here in “French paradox country”, the official recommandations for carbs are from 40 to 55% of the caloric intake. I guess this crazy wide range is a threat to our health…

      1. egocyte

        Now that you mention it, I think it does when I commute by bike after my bread and butter breakfast. I’m not sure if it’s because of the bike, the bread or the butter…

  11. Cameron Hidalgo

    [According to what the researchers are telling us, one out of every 13.5 people on a moderate carbohydrate diet developed AFib over the 22 years. In the “low” carbohydrate group, an 18 percent increase would translate to one out of 15.3 people]

    I think you got your ratio backwards. An 18% increase would be 1.18 out of 13.5 people, or 1 out of 11.4 people. the two numbers equal 7.4 people out of 100 and 8.7 people of of 100, so a 1.3 person increase instead of 1.8.

    Which doesn’t really change your point, but I saw the mistake, figured I’d point it out.

    1. Tom Naughton Post author

      Ahh, dangit, that’s what happens when I write quickly and don’t check my own math. It should be 13.5 out of a hundred, not one in 13.5. Thanks for the catch.

  12. Bob Niland

    re: «…Another Stupid Study»

    Replace “stupid” with “pernicious”. The implicit dietary advice arising from that loo paper is going to get people maimed and prematurely dead.

    Afib is a growing problem. Surviving hunter-gatherer populations, on their ancestral diets, don’t really have it. You might think that this would be a clue where to start looking in terms of prevention, since “cure” doesn’t seem to be on the horizon. (And anyone experiencing an extended episode needs immediate medical attention — prevention strategies do not provide sufficiently prompt results.)

    The program I contribute to has a protocol for AF, developed by a cardiologist, based on results, but it’s for prevention. The protocol does not include increasing carb consumption — quite the opposite, unsurprisingly, given that visceral and pericardial fat correlate nicely with AF.

    Indeed, if someone wanted to cause more AF, consensus dietary advice would be a great foundation for a
    get-Afib, then stroke, and die early program.
    It would, of course, also keep Standard of Don’t Care sickcare providers fully employed between now and the unhappy outcome.

      1. Walter

        Maybe they are trying to decrease the Social Security payments by killing the population?!

      1. Fred Jones

        so Zoe Harcombe has done a good analysis on the egg study: she unveils a spectacular “Conflict of Interest” where one of the lead authors would appear to have received much funding from pharmaceutical manufacturers of st**in drugs ……..

        as you would expect, this egg study is much like the one discussed above …

  13. Don

    Hi Tom,
    I don’t remember exactly how I discovered Fat Head, but you can’t wander through the current game changing paradigm of saturated fat consumption without eventually watching it. I loved it and I’m going to watch the kids movie with my brats soon. I’m changing my diet and theirs.

    Your blog is really good, full of first rate thinking. In reading your thoughts on the wisdom of crowds, I thought I’d mention something you may not be aware of. Horse race betting is a parimutuel system. All the money goes into a pool, the track takes a percentage, and the odds are based on the amount of money left that is bet on each horse. So the crowd sets the odds based on their assessment of how each horse will do. Do they get it wrong? Frequently and spectacularly! But… the crowd is the champion handicapper of all time! Year in and year out, for decades, over all surfaces, weather conditions, cheap races and high class races, races where every horse has never raced before, all distances, etc., the crowd consistently picks the winner about a third of the time. One of the top three crowd picks will win close to 70% of all races. Horses that go off at final odds of 4/1 will win more frequently than horses that go off at 5/1, and horses at 5/1 win more than horses at 6/1. It is literally the wisdom of the crowd playing out and proving out daily.
    Love your work, you have a new fan.

    1. Tom Naughton Post author

      Yup, I believe something like that was mentioned in the book “The Wisdom of Crowds” as well. Similar with when crowds guess how many jelly beans are in a big jar. Many guesses are way off, but the average usually turns out close to the actual figure.

      1. Don

        I tried to post a comment on an old thread about the Annointed and it notified me my comment was awaiting approval and then it disappeared. Are the old articles closed for commenting? I don’t think I said anything bad, especially for a free speech guy, lol.

        1. Tom Naughton Post author

          No, I haven’t set anything that would close comments. I’ll have to see if WordPress set a limit.

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