People who practiced the eating pattern were found to have a much higher risk of dying from cardiovascular disease.
Intermittent fasting has caught on as a simple and effective way to manage your weight that research suggests comes with several other health benefits. But a recent analysis has thrown into question whether this popular eating pattern is good for your heart.
This week, the American Heart Association presented a study that found a link between periods of fasting throughout the day and a significantly higher rate of fatal cardiovascular disease. Here’s what you need to know about this eye-opening research.
The latest research on intermittent fasting and heart disease
There are a few intermittent fasting methods that have come into vogue in recent years — they all recommend limiting your calorie intake to certain parts of the day or week. The 5:2 diet, for instance, calls for eating normally for five days of the week and then limiting to between 500 and 600 calories on the other two days of the week, while the 16:8 method is a daily 16-hour fast and an 8-hour window for eating.
This particular study looked at data collected by the Centers for Disease Control’s national survey, which included responses from 20,000 adults on their eating habits. The researchers found that people who restricted their eating to a window of less than eight hours a day had a 91 percent higher risk of dying from cardiovascular disease compared to those who ate across 12 to 16 hours.
“Our study’s findings encourage a more cautious, personalized approach to dietary recommendations, ensuring that they are aligned with an individual’s health status and the latest scientific evidence,” Victor Wenze Zhong, Ph.D., an author of the study and a professor at the Shanghai Jiao Tong University School of Medicine in Shanghai, said in a news release.
The authors didn’t say how fasting could be linked to heart disease, but Benjamin Horne, Ph.D., a professor at Intermountain Health, told NBC that it could be related to the stress it puts on the body. Fasting can put the body in survival mode, leading to an increase in certain stress hormones like cortisol, which may increase the short-term risk of heart problems for older people or those with chronic conditions, Dr. Horne says.
The study has not yet been peer-reviewed or published, and some scientists have warned against condemning the diet too quickly, especially when other studies have linked intermittent fasting to a wide array of benefits, from improved memory to reduced inflammation.
“While informative, this study should be considered exploratory,” Harlan Krumholz, MD, a cardiologist and scientist at Yale, told STAT. “We are still learning about how people can optimize their diets, and this study is more of a call for more research than something that should frighten people who find restricted eating a useful strategy.”
Previous research on intermittent fasting and cardiac health
The concept of restricted eating isn’t new, and in fact may be as old as we are. Some experts believe that intermittent fasting was probably practiced by early humans and that our bodies were designed by evolution to consume food this way.
Studies have found that periodic fasting triggers a metabolic process called ketosis, which occurs when the body runs out of glucose and starts burning fat. (This is where the popular keto diet gets its name.) Because of this, it’s been touted by some as a powerful way to lose weight, but scientists have also started to highlight its other potential assets.
Previous studies have linked it to a reduced risk of diabetes, lower rates of inflammation, longer lifespans, and yes, even, better heart health. Intermittent fasting has been found in some studies to be associated with lower blood pressure and decreased low-density lipoprotein (LDL), or the so-called “bad cholesterol.” However, skipping breakfast, which many people end up doing when they practice intermittent fasting, has been linked to an increased risk of heart disease and death. We still know relatively little about fasting’s impact on our bodies and given these recent findings, Penny Kris-Etherton, Ph.D., a member of the American Heart Association nutrition committee, recommends exercising caution.
“Maybe consider a pause in intermittent fasting until we have more information or until the results of the study can be better explained,” she told NBC.
