The Courier-Journal (Louisville)
Is intermittent fasting linked to heart disease? No
I recently received several emails from readers across the country on a “bombshell” research study. The headline screamed: “Intermittent fasting linked to a higher risk of heart disease death.”
To say I was stunned at this headline is an understatement.
How could intermittent fasting, a highly effective approach to eating that reduces heart disease risk factors, including excess body fat, high blood pressure, and high blood glucose, suddenly be found to promote heart disease? This made no sense.
I have several years of highly successful personal experience with intermittent fasting, plus I have received hundreds of testimonials from folks who have benefited greatly. In addition, I have written a dozen or more columns on intermittent fasting over the past few years.
I’ve also heard from folks who inform me that, based on their personal experience, intermittent fasting doesn’t work. When I follow up with why it did not work for them, invariably it’s because they either did not fast long enough or were not truly fasted.
For fasting to be effective, it must go for a minimum of 16 hours. However, research has shown the best outcomes accrue at 18 hours and beyond. This is a tall order for most folks, and it’s necessary to progress gradually, working toward a prolonged daily fast. But once you “decide” to fast with no exceptions, and go through the two-to-four-week adjustment phase, it becomes second nature.
For me, I started with fasting 16 hours then gradually over about a year progressed to 20 hours of fasting daily.
If I begin to feel hungry which is quite rare, I drink some water, black coffee or unsweetened tea and keep fasting. Then I have dinner at about 6 p.m. and continue eating until about 10 p.m.
Ironically, I eat more now but even so, my results have been incredible, including at age 77 reclaiming the abdominal 6-pack I had in my younger years, plus losing my love handles. Also, ironically, weight management was not why I chose to engage in intermittent fasting. I was attracted to several other healthful outcomes. These include increased human growth hormone production, increased immune function, and increased autophagy (getting rid of old cells and replacing them with new, better-functioning cells).
Does intermittent fasting promote heart disease?
OK, now I’ll get off my soapbox and shift gears. So much has been written about the positive effects of intermittent fasting when done correctly, that any new article is viewed with a “hohum” attitude. In contrast, it’s big news if you proclaim that intermittent fasting not only doesn’t work, but it promotes heart disease.
When I see something like this, my first question is who benefits, and second, who would welcome this news? As to who benefits, consider that weight loss has become a huge focal point in the U.S. with several major drug companies touting the benefits of prescription medications. In addition, consider all the flim-flam diets that have become big business. These folks do not want you to engage in intermittent fasting for two reasons. One, it doesn’t cost anything, and two, it works.
As to who would welcome this news, it’s human nature that all those who tried intermittent fasting and failed would welcome bad news about it. In that way, they don’t have to look in the mirror and admit they lack motivation, discipline, and persistence. Instead, they are relieved that they dodged a bullet by not engaging in a “dangerous” activity.
How was this new intermittent fasting study conducted?
The research was conducted by Chinese researchers from Shanghai Jiao Tong University and based on death records obtained from the US Centers for Disease Control and Prevention. Researchers reported that those who followed an 8-hour eating schedule were 91% more likely to die from heart disease over the follow-up period from 2003 to 2018 when compared with those who ate over 12 to 16 hours.
That sounds impressive until you look behind the curtain.
Let me interject that since 1973, I have conducted research and published well over 100 research papers in peer-reviewed journals. I’ve taught courses on research methods and data analysis and supervised countless graduate and undergraduate research theses. When I examined this research report several obvious negatives jumped out. For example:
This research has not been peer-reviewed, which means it has not been evaluated in any way.
There is a lack of control strategies, the core requirement of bona fide research.
All the data are based on “self-reported” information with no instruction or consistency, so the accuracy is doubtful.
There is no evidence that subjects were “truly” fasted, and if they were, for how long.
There is no information on “why” participants engaged in fasting. It could be that they had limited access to food, which has nothing to do with the choice to fast intermittently.
There is no way to know if participants had conditions that interfered with their appetite, causing them to eat less often and in less quantity. This is problematic because restricting food for such folks would certainly negatively impact their health and, again, have nothing to do with the concept of fasting.
Nothing is known about the healthfulness of the food consumed.
The results of this research are, at best, vaguely correlational and prove nothing. I believe that to grasp onto this sketchy information and leap to the conclusion that intermittent fasting contributes to heart disease death is completely irresponsible.