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 (news-medical.net), 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 News-Medical.net 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.
