SALT LAKE CITY — Long-term, routine fasting improves survival rates for cardiac catheterization patients, according to a new study by Intermountain Healthcare.
The study conducted at the Intermountain Healthcare Heart Institute involved 2,001 participants who answered lifestyle questions and were followed for nearly five years to see how long they survived and whether they experienced serious heart events or death, said Dr. Benjamin Horne.
Horne served as principal investigator of the study and is the director of cardiovascular and genetic epidemiology at the institute.
“We found that people who said they routinely fasted had a much lower death rate. Their survival was higher, and they also, in conjunction with that, had a lower incidence of heart failure. So we are finding there may be some greater survival among people who fast routinely,” Horne explained.
He said the institute had been studying the effects of fasting for several years, but wanted to perform a long-term study with a larger group. The results were presented Saturday at the 2019 American Heart Association Scientific Sessions in Philadelphia.
Those in the participant group considered routine fasters had been fasting for at least 42 years, or two-thirds of their lives.
“It’s a long period of time. It’s not a quick fix, rapid weight loss diet that they were following. Most of them, of course, were fasting for religious purposes,” Horne said, pointing to a practice among members of The Church of Jesus Christ of Latter-day Saints, who fast on the first Sunday of every month, usually for two meals.
That group experienced higher survival rates than non-fasters, Horne said, as they lived about a year longer on average.
A study from the 1970s and 1980s found a higher survival rate among observant members of the church compared to the rest of the populations of California and the U.S., Horne said.
Additionally, Utah, according to the American Heart Association, has one of lowest cardiac mortality rates in the country, a consistent finding for decades, he said.
“One of the exciting things about this study is it potentially links this factor — this behavior of fasting, that has a known connection to biology and better health — it links it to this survival effect that others have found. But they’ve just linked it to people who had the Latter-day Saints’ religious preference. Now this links it to a specific factor, a specific behavior, in fasting,” he said.
The researchers in the new study corrected for lifestyle factors like smoking. Most members of the church do not smoke.
Doctors believe those who had fasted routinely had a higher survival rate because their bodies have experienced long years of conditioning. During a one-day fast, their bodies activate the benefits of fasting earlier than an average person, Horne said. For an average person, benefits usually start about 12 hours into fasting period.
“We think that this routine fasting for years and decades is conditioning the body to activate the benefits of fasting at eight or 10 hours, and then an overnight fast you’re getting some of the benefits on a daily basis for your lifespan. And that would have a profound impact,” Horne explained.
One group of participants was made up of “new fasters,” those who had been fasting for less than five years. On average, the group had fasted for nine months. Horne said they did not experience a higher survival rate, and instead had potentially worse survival rates than those who didn’t fast at all.
Based on the research, Horne cautions people who want to begin fasting to consider doing so in a “rational, wise manner,” as rapid weight loss diets that include fasting can be taken to extremes.
“We want people to realize there are other things they can do like exercise and eating a good diet, and reducing cholesterol and blood pressure, that are important also for health,” he explained.
Some people shouldn’t fast, including young children, older adults who are frail, people who have organ transplants or chronic diseases, and women who are pregnant or breastfeeding. Those with chronic diseases should talk to their doctors before they begin fasting, Horne said.
But he said the biggest takeaway from the study is for people who are fasting right now — keep doing it. If they’re doing a fasting regimen, it should be long-term to receive the benefits for their heart health, according to Horne.
“I think the central message is that we found that fasting appears to protect humans from heart failure, and that leads to better survival,” he said.
Intermountain is continuing its research on fasting. Horne believes laboratory studies will be needed to figure out the mechanisms that fasting triggers, as well as interventional studies among people to see which groups can benefit the most from fasting, and potential safety issues.
The Beehive State is a “fabulous place” for these studies because there’s a large population who fast routinely for religious purposes, Horne said.
“This is a study that probably could not be done in any other place in the world right now, or very few other places, and it would be something that would require a lot more resources in those other locations to be able to find people who fast on a routine basis and have done so for decades,” he said.
Horne also thanked Intermountain Research and Medical Foundation for funding the study.