Many individuals turn to intermittent fasting in their quest to shed excess weight, unaware that they may face a 91% higher risk of death from cardiovascular disease, as a new study has found.
Intermittent fasting, also known as time-restricted eating, is a dietary approach that limits food consumption to specific hours of the day. New research presented at the American Heart Association’s Epidemiology and Prevention on March 19 revealed that individuals adhering to an eight-hour time-restricted eating regimen, a commonly practised form of intermittent fasting, experienced a 91% increased risk of cardiovascular disease-related mortality.
A study involving more than 20,000 US adults with an average age of 49 years revealed that individuals restricting their eating to less than eight hours per day, following a time-restricted eating pattern, had a higher likelihood of dying from cardiovascular disease compared to those who consumed their meals over 12-16 hours per day. The study participants were followed for a median length of eight years and a maximum length of 17 years.
The meeting, Lifestyle and Cardiometabolic Scientific Sessions 2024, in which the study was presented, is known for offering the latest science on population-based health and wellness and implications for lifestyle. However, the study is to be published in a peer-reviewed scientific journal.
Indian health experts News18 spoke to agreed with the findings while adding that more research is needed to verify the results. They said that irregular eating patterns have the potential to worsen conditions like coronary artery disease, hypertension, and arrhythmias, consequently elevating the risk of cardiovascular mortality. Hence, individuals must focus on a balanced diet and consistent eating routines to promote heart health.
‘Intermittent fasting doesn’t reduce overall risk of death’
The study found that people who followed a pattern of eating all of their food across less than eight hours per day had a 91% higher risk of death due to cardiovascular disease. “The increased risk of cardiovascular death was also seen in people living with heart disease or cancer,” it said. “Among people with existing cardiovascular disease, an eating duration of no less than 8 but less than 10 hours per day was also associated with a 66% higher risk of death from heart disease or stroke.”
The study pointed out that intermittent fasting did not reduce the overall risk of death from any cause. Also, it said that an eating duration of more than 16 hours per day was associated with a lower risk of cancer mortality among people with cancer.
“We were surprised to find that people who followed an 8-hour, time-restricted eating schedule were more likely to die from cardiovascular disease,” Victor Wenze Zhong, study author, wrote.
Zhong, who is also a chairperson of the Department of Epidemiology and Biostatistics, Shanghai Jiao Tong University School of Medicine in China, added, “Even though this type of diet has been popular due to its potential short-term benefits, our research clearly shows that, compared with a typical eating time range of 12-16 hours per day, a shorter eating duration was not associated with living longer.”
Individuals must make mindful eating choices: Experts
Experts believe that the recent study highlighting the potential link between time-restricted eating and an elevated risk of cardiovascular death raises important considerations for both patients and doctors.
Dr Siddhartha Mani, consultant, cardiology, at Narayana Hospital- RN Tagore Hospital, West Bengal, told News18 that the findings were “concerning”.
“It’s essential to recognise that correlation does not imply causation and further research is needed to elucidate the underlying mechanisms. However, it’s plausible that prolonged fasting periods may disrupt circadian rhythms and metabolic processes, leading to adverse cardiovascular outcomes,” he said.
Mani advised that conditions such as coronary artery disease, hypertension, and arrhythmias could be exacerbated by irregular eating patterns, ultimately increasing the risk of cardiovascular mortality.
According to Dr Rajeev Jayadevan, chairman of the research cell, Indian Medical Association, Kerala, the study adds to the existing body of evidence that intermittent fasting does not produce long-term health benefits. “Although popular as a convenient alternative to traditional calorie restriction with every meal, intermittent fasting doesn’t produce additional metabolic benefits according to a 2017 randomised clinical trial published in JAMA,” he noted.
Jayadevan said that the latest study is “definitely worth noting” pending the publication of the full paper after peer review.
“What will be important to know is the baseline health status of the people who followed the different eating patterns. The question is whether the increased death risk is the result of the underlying health conditions or that of intermittent fasting,” he said, while adding that the abstract indicates that there was a higher proportion of black individuals and smokers in the intermittent fasting group, although the average age is lower. “To what extent these differences influence the long-term outcome is yet to be determined.”
Dr Samir Kubba, director, cardiology, at Dharamshila Narayana Superspeciality Hospital, said it’s essential to approach these findings with “caution” while explaining the ill effects on the body.
He said that time-restricted eating may lead to disruptions in “metabolic processes”, such as glucose regulation and lipid metabolism, which are crucial for maintaining cardiovascular health.
“It is important to understand that balance is the key. Furthermore, prolonged fasting periods could contribute to increased levels of stress hormones and inflammation, both of which are implicated in the development and progression of cardiovascular diseases,” Dr Kubba said.
Overall, experts emphasised that while additional research is needed to fully understand the specific mechanisms driving this correlation, individuals should be attentive to their eating habits and strive to maintain a well-rounded diet that promotes overall cardiovascular health.
