Despite being touted as an effective weight loss method by diet trends and health enthusiasts, a recent study presented at an American Heart Association conference has cast doubt on the safety of intermittent fasting by linking it to a higher risk of cardiovascular disease-related deaths, particularly heart ailments.

The study findings, which suggested an increased likelihood of death from cardiovascular issues among individuals engaging in prolonged fasting periods, were met with skepticism by some medical professionals who pointed out the study’s limitations.

According to the Mayo Link health website, intermittent fasting encompasses various meal timing strategies that alternate between periods of voluntary fasting and non-fasting within a designated timeframe. These methods include alternate-day fasting, periodic fasting like the 16:8 diet, and daily time-restricted eating.

While intermittent fasting has gained popularity as a means of shedding pounds, the new research indicated potential drawbacks to this dietary regimen.

The study revealed that individuals practicing extended fasting were more susceptible to cardiovascular-related deaths compared to those consuming food throughout the day. Specifically, individuals observing a 16:8 diet or limiting their eating window to eight hours had a 91% higher risk of dying from cardiovascular disease than those who spread out their meals across 12 or 16 hours.

Conducted using data from over 20,000 U.S. adults enrolled between 2003 and 2018 in the National Health and Nutrition Examination Survey, the study tracked participants for an average of eight years. The research uncovered a concerning correlation between restricted eating periods and heightened cardiovascular mortality risk, particularly among individuals with preexisting heart conditions.

While acknowledging the potential metabolic benefits of intermittent fasting such as enhanced cholesterol and blood sugar control, registered nutritionist Odunayo Babatunde cautioned against the observed association with cardiovascular hazards. She highlighted that prolonged fasting could lead to metabolic changes like increased insulin resistance and elevated stress hormone levels, which might adversely impact heart health in the long run.

Babatunde underscored the necessity of thoughtful reflection on the study’s outcomes, stressing the worrisome link between extended fasting periods and amplified cardiovascular mortality risk. Highlighting the potential downsides of fasting-induced metabolic shifts and dehydration, the expert advised a reconsideration of intermittent fasting as a prolonged dietary strategy, especially for individuals with heart health concerns.

While recognizing the short-term benefits of intermittent fasting, Babatunde emphasized the importance of gathering more extensive safety data before making widespread recommendations regarding its implementation.

She further said, “The results of the study should be given careful thought as they are worrying. The study revealed that those who fast for extended periods are more likely to die from cardiovascular disease than those who ate throughout the day.

“Although observational research of this kind should be interpreted cautiously since they don’t establish causation, the link is nevertheless concerning and requires more research.

“Long fasting times may cause metabolic changes, such as higher insulin resistance, which over time is linked to an increased risk of cardiovascular disease.

“Furthermore, the stress hormone cortisol, which can have negative consequences on heart health if it is constantly high, may also surge during fasting.

“Some people who fast may overindulge or binge during meal windows, which would offset any advantages and increase their risk of heart disease by gaining weight.

“There are concerns regarding whether fasting could occasionally result in dehydration or electrolyte imbalances that could tax the cardiovascular system, as many who fast for long periods don’t take enough water to help them hydrate and balance their electrolytes well.

“This latest research makes me think that intermittent fasting should be reevaluated for safety, particularly as a long-term strategy. Although certain research has indicated possible advantages for metabolic health and weight loss, this study indicates that, for certain individuals, there may be significant risks to cardiovascular health that may exceed those advantages.

“Though I believe it should be done carefully and ideally under medical supervision, generally, healthy people can still think about intermittent fasting for short-term weight loss.

“Before we generally suggest it for health improvement, we need longer-term safety data. Those with cardiovascular disease or risk factors should exercise particular caution.”

When asked if intermittent fasting affects the heart, the food expert said, “I think we should put the brakes on encouraging intermittent fasting for heart health at this point. This signal of higher death risk must now be balanced against the possible advantages that have been demonstrated in some studies, such as improvements in cholesterol and blood sugar control.

“Particularly since heart disease is the leading cause of death globally, any rise in risk is quite alarming from the perspective of public health. At least with extended fasting windows, this study suggests that potential risks may exceed the advantages for heart health.

“Anyone considering intermittent fasting as a weight-loss strategy should preferably select time-restricted feeding with shorter fasting periods (maximum of 12–14 hours) over alternate days or extended fasts, ensuring enough food and drink during eating windows.

“Such a person should avoid binging or overeating. The person should be observed for any unfavourable effects and, if any occur, the fasting should be stopped and medical help should be sought immediately. If you have a cardiovascular illness or several risk factors, you should avoid intermittent fasting.

“We definitely need additional excellent, long-term studies on the safety of various intermittent fasting regimens, particularly causally established randomized controlled trials.

“Future research should contrast intermittent fasting to other eating habits and weight management strategies and closely analyse cardiovascular biomarkers, clinical outcomes, and mortality risk. More varied populations should be studied as well because the impacts could differ according to age, sex, health, etc.