Intermittent fasting and heart failure: information incomplete

CHENNAI: Anyone who has struggled to lose weight has been advised at least once to consider intermittent fasting (IF). Whether it’s to lose a few kilograms, balance hormones, lower cholesterol and/or blood pressure, and even to reduce stress and anxiety, intermittent fasting is recommended as the ‘easiest solution’ for all health issues.

However, a recent study has raised serious concerns regarding the cause-and-effect of heart health with intermittent fasting.

Presented at an American Heart Association’s event in Chicago, the study (conducted by researchers from the Shanghai School of Medicine) still in its preliminary stages, analysed data from approximately 20,000 adults in the US. It revealed that an 8-hour restricted eating schedule, a form of intermittent fasting, posed 91% higher risk of fatality from cardiovascular diseases.

They found that participants who followed a time-restricted eating plan, a type of intermittent fasting, had a greater chance of dying from heart-related issues compared to those who spread their meals out over 12-16 hours.

The study has become a hot topic of discussion given the popularity of intermittent fasting in India. However, health experts are sceptical about the findings of the study, and opine that the study has taken limited data into consideration, as intermittent fasting can really be good for heart health.

No long-term data

Dr Aravind Duruvasal, consultant cardiologist, Kauvery Hospital, explained that one cannot say intermittent fasting as the causative factor for death. “It’s a mere associated factor and that association itself is questionable because we do not know about their eating habits and other risk factors. This can only open gates for studies to concentrate on long term benefits of intermittent fasting,” he said.

Intermittent fasting has a lot of short-term benefits from insulin resistance to prevention of type 2 diabetes, hypertension, dyslipidemia and obesity. He added that the study took self-reported dietary information based on the participants’ memory which may not accurately assess eating patterns.

“There can be other factors that may also play a role in the fatalities as the daily duration of eating, and cause of death were not included in the analysis. We need research and larger studies to examine the biological mechanisms too,” he opined.

Elaborating further on the study, Dr Iniyan Xavier, cardiology resident, CMC Vellore, pointed out that it was a single study and therefore, does not offer enough research data. “We need a study with a larger sample size, followed up for a very long time to substantiate what the said study claims. Until then, all this is causes mass hysteria,” he said. “The link between intermittent fasting and cardiovascular illnesses is different from its causation. It does not mean it’s causative of cardiac issues or even related to it.”

The resident-doctor averred that when there is no glucose from food sources, the body uses the stored fat from the tummy and liver for metabolism and energy. “Intermittent fasting is good biochemically, as the body looks for alternate sources of energy when one is fasting,” he said.

Needs more insight

Though many people have seen the benefits of intermittent fasting in terms of weight loss and fitness, this study which has a sample of 20,000 people and a long follow-up period, shows a completely different aspect for cardiac health.

Experts say that the study stating that intermittent fasting has deleterious aspects on cardiovascular health needs a lot more insights.

“Firstly, dietary restriction cannot be a standard protocol for every single person. Only one’s diet cannot be linked to heart health because it may depend on the age of the patient, their current comorbid conditions, family history, genetic history, and whatever medications they are taking. It’s also important to understand if a person is physically active or has a sedentary lifestyle,” said Dr Deeyaneswar D, consultant interventional cardiologist, Prashanth Hospitals.

While everyone cannot benefit from calorie restriction, there have been several instances where intermittent fasting has helped. But it has to be tailor-made based on the patient’s genetic makeup, metabolism and body needs. “The basic ideology behind intermittent fasting is to avoid insulin spikes throughout the day. This helps to get a better metabolic control. There are short-term benefits such as weight loss, loss of fat, good visceral fat control and good overall cardiovascular health that we’ve seen in everyday clinical practice,” added Dr Deeyaneswar.

Consult doctor

Nutritionists pointed out that the study data was not strong enough to be reliable, as it did not consider long-term data.

“Researchers asked about the people’s diet only for two days, which might not be precise. The study has many limitations like that,” says Dr Dharini Krishnan, senior consultant nutritionist. “Those who struggle to lose weight despite exercising, find intermittent fasting useful. We cannot deny that because of a single study. Besides, fasting is not a new thing, especially in India. We have people fasting during Lent, Ramadan and Navaratri as a part of our culture.”

Intermittent fasting can help with reducing bad cholesterol, triglycerides and improves heart health. “When you’re fasting, you should not consume processed foods or junk food. This can certainly impact the body in an adverse manner. That’s why you must consult a doctor especially before you start intermittent fasting, if you have underlying health conditions,” she advised.