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Intermittent fasting, a way of eating that focuses on when rather than what to eat, dates back centuries and has particularly enjoyed quite the star status over the last decade. Many people favor the protocol for unlocking a new level of discipline in their lives – especially when it comes to shedding pounds.

Of course, the scientific community has also hopped on the fasting bandwagon as countless research has associated it with numerous health benefits. However, much to the bewilderment of fasting advocates, a new yet-to-be-published study appears to contradict this. Preliminary research, presented at a meeting of the American Heart Association, claims that this time-restricted means of eating may have adverse effects on our cardiovascular health.

Certainly, this recent development has thrown a spanner in the works for both seasoned fasters and newbies. Have we all been duped, and is less time spent eating doing more harm than good in the long run?

8-hour intermittent fasting may be tied to a 91% higher risk of cardiovascular death

The American Heart Association (AHA) has only published an abstract of a large study, so far, that links intermittent fasting to a 91% higher chance of heart-related death. It is believed that the risk comes with eating during an 8-hour or shorter window (thereby fasting for 16 hours or more) during a 24-hour day. Essentially, it analyzed the deaths related to cardiovascular diseases in more than 20,000 U.S. adults – who were followed for an average of eight years.

Additionally, patients with preexisting heart disease or cancer had an increased chance of dying from these respective diseases if they participated in this type of intermittent fasting. Nevertheless, it’s hard to determine whether the eating window or food consumed is more relevant to a person’s risk of death. That is, until we have all the facts. With that being said, experts have cautioned fasters to be mindful of the length of their fasting window in the interim.

Why is this new study on intermittent fasting baffling?

Intermittent fasting is the most searched diet trend of 2019 (according to Google), garnering attention for its difference in structure from other diets. Many prefer this approach to getting your weight (and health) in check, as it’s easier to follow than, say, portion control and calorie counting. So, sure, it’s not entirely surprising that researchers are dissecting it from every angle to understand its full impact on our health.

This style of eating is simple in its execution: you have a window in which you consume calories and a larger window in which you don’t eat at all. But since most research reveals over-eating to be problematic heart health-wise, it’s hard to fathom that eating during a shorter period imposes a similar dilemma. In truth, countless studies have indicated that intermittent fasting offers health benefits in abundance, with improved blood pressure and insulin sensitivity being among them.

Humanity has been observing fasting for ages

Time-restricted feeding also has spiritual roots in religions such as Islam, practicing it historically. Coincidentally (or not), this new information comes during Ramadan. It’s the ninth month of the Islamic calendar, in which Muslims carry out a strict fast from sunrise until sunset for 29 or 30 days. Even so, research has shown that it produces enhanced health outcomes.

In total contrast to the AHA’s latest data, a study has identified Ramadan fasting as an element in improving cardiovascular risk factors. Moreover, it’s considered safe for most people with stable heart disease (when under the guidance of a medical practitioner).

How accurate are the findings?

The quality of this study is the first drawback. This is because it was an observational one and not a randomized controlled clinical one. On the other hand, there are numerous clinical studies regarding the positive impacts of fasting. Observational studies tend to be less accurate, while clinical ones are the highest standard for assessing the efficacy of healthcare.

The dietary information provided by the study’s participants is based solely on self-reported data (i.e., their memory recall). This is tricky because most people are not completely honest (whether intentional or not) about their real eating habits. Furthermore, there is no mention of whether the respondents consumed any specific type of diet during their fasts. Of course, this makes all the difference in heart disease risk. Did they possibly eat red meat or processed food in excess, which we know is bad for heart health? Is it something entirely different?

Christopher Gardner, the director of nutrition studies at the Stanford Prevention Research Center, expressed skepticism due to a lack of the full picture. How researchers controlled the variabilities in lifestyle and demographics among participants (to deduce cardiovascular risks) is unclear.

Gardner told The Washington Post, “Did they all have the same level of disposable income and the same level of stress? Or is it that people who ate less than eight hours a day worked three jobs, had very high stress, and didn’t have time to eat?”

Should we believe everything that we read?

The American Heart Association has acknowledged that it receives funding from individuals and companies. Consequently, there is some controversy about this non-profit organization taking payment from meat companies. AHA offers “heart healthy” certification marks on their meat products in return.

This raises alarm bells, given the extensive evidence supporting a link between red meat consumption and heart disease. So it’s challenging to accept their fresh research on avoiding intermittent fasting if their incentive revolves around fostering heart health.

It also turns out that there may be further cause for concern if that’s not bad enough. According to AHA, the study has not yet been published in a peer-reviewed journal. Allegedly, it’s based on the opinions of its authors. Naturally, this proves questionable to scientists and fasters alike. How can we believe the statements made in this abstract? Largely because there are many studies available promoting the opposite effect of fasting. On top of this, these other analyses have already undergone peer review and have been published.

The bottom line

Ultimately, that’s not to say that AHA’s evidence is not credible. Many people have found benefits in fasting, an ancient practice. However, there is a need for further research on its effects. In the meantime, we just need to exercise care in what we read and strive to gather the full scope of something before panicking.


Chamsi-Pasha, M.; Chamsi-Pasha, H. (2016, April-June). The cardiac patient in Ramadan. The National Library of Medicine.
Foreman, P. (2022, August 30). American Heart Association Facing Lawsuit Over ‘Heart-Check’ Labels On Red Meat. Plant Based News.,“heart%20healthy”%20product%20certifications.
Shi, W.; Huang, X.; et al. (2023, July 21). Red meat consumption, cardiovascular diseases, and diabetes: a systematic review and meta-analysis. The National Library of Medicine.
Sutton, E.F.; Beyl, R.; et al. (2018, May 10). Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even Without Weight Loss in Men with Prediabetes. National Library of Medicine.
Caela Bennett

Caela Bennett

Caela Bennett is a wellness content writer and holistic health coach. She hopes to enlighten people through powerful storytelling and offer clarity when navigating the noise within the realm of health. In addition, she guides others in awakening their self-discovery journey and embodying the best version of themselves. Her work is rooted in the philosophy of alchemy: turning metal into gold, i.e., transforming one thing into something better. While she is a maximalist in expressing herself through words, she is a minimalist in lifestyle pursuits.


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