A recent study presented at an international conference has raised concerns about intermittent fasting, despite its increasing popularity and purported benefits for improved insulin sensitivity in diabetic individuals. The study suggests that intermittent fasting may elevate the risk of cardiovascular mortality by a staggering 91%.
Although experts caution that the study’s findings are not definitive, they emphasize the potential dangers associated with intermittent fasting. They advise against adopting such diets without seeking guidance from a medical professional.
What did the study look at?
Intermittent fasting is a dietary approach that restricts the period of time during which people consume their daily caloric intake, typically spanning eight to twelve hours, with fasting periods spanning the rest of the day.
Research conducted over short periods, ranging from three months to a year, has revealed several benefits associated with intermittent fasting, including weight loss, improved insulin sensitivity, and better diabetes control.
However, recent data aimed to examine the long-term effects of intermittent fasting by tracking the health outcomes of 20,000 adults in a US database for eight to 17 years.
The findings indicate that people who consumed all their daily meals in a period of less than eight hours faced a significantly increased risk of death attributable to cardiovascular disease, with a staggering 91% increase in risk.
Additionally, among people who already had heart disease, intermittent fasting was associated with a 66% elevation in the risk of death attributed to heart disease and stroke.
Why can intermittent fasting be harmful?
Anoop Misra, president, Fortis C-Doc Hospital for Diabetes and Allied Sciences, New Delhi, gave information on intermittent fasting.
First, Misra highlighted that one of the main misconceptions about intermittent fasting is the belief that people can consume whatever they want during the eight-hour eating period. He emphasized that consuming high-calorie foods like pizzas and burgers within this time period does not promote healthier results compared to constant consumption throughout the day. Additionally, Misra noted that diets that impose calorie restrictions at each meal can produce similar weight loss results.
The Harvard review of intermittent fasting revealed that in 12 clinical trials comparing fasting to continuous calorie restriction, there was no significant variation in weight loss results.
Secondly, Misra warned against the possible long-term consequences of intermittent fasting, suggesting that it can have a fluctuating effect on health, particularly when it comes to heart health. He explained that with each meal consumed during intermittent fasting, there is an increase in sugar levels. People with a more consistent insulin release pattern tend to experience better cardiovascular outcomes compared to those with fluctuating insulin levels.
What do experts say about the study?
The information provided can be summarized as follows:
- The data has been presented at a conference but has not yet undergone peer-review.
- There is insufficient clarity regarding the methodology used to reach the conclusions. Dr. VK Bahl, principal director of cardiac sciences at Max Hospitals, and former head of the department of cardiology at AIIMS-New Delhi, expressed concerns about the methodology. He mentioned that the researchers seem to rely on a questionnaire to determine dietary patterns, which may not be reliable due to the limitations of food recall.
- Dr. Misra highlighted the absence of consideration for important factors such as whether participants had diabetes, were on medication for managing it, were taking cardio-protective medicines, or were following a good diet and exercise schedule.
What do existing studies say about intermittent fasting?
Intermittent fasting has garnered attention for its potential benefits, including fat burning, enhanced cellular functions, improved metabolism, insulin sensitivity, blood glucose regulation, and gut health.
Research indicates that intermittent fasting promotes autophagy, a process vital for eliminating damaged cell components, which may aid in conditions such as cancer. Additionally, preliminary animal studies suggest intermittent fasting could have potential benefits for dementia and Alzheimer’s disease.
However, a Cochrane review suggests that while intermittent fasting may result in more weight loss compared to regular eating over three months, it doesn’t surpass energy restriction diets in weight loss outcomes. Furthermore, over longer durations, such as up to 12 months, intermittent fasting doesn’t show superior weight loss results.
Moreover, findings from Harvard reveal that the dropout rates for intermittent fasting are comparable to those of calorie-restrictive diets, indicating that intermittent fasting might not be inherently easier to adhere to than traditional diets.
Nevertheless, there’s a lack of long-term studies assessing the effects of intermittent fasting on conditions like diabetes, hypertension, and cardiovascular diseases. Thus, while intermittent fasting shows promise for certain health benefits, further research is needed to fully understand its long-term implications on various ailments.
