The fact that fewer people here smoke often has been credited for Utah's lower rate of heart disease a rate that is lower still among members of The Church of Jesus Christ of Latter-day Saints.
Now researchers from Intermountain Healthcare say that LDS Church members' fasting skipping meals for a day each month may be another reason.
But they warn that one study is not sufficient to prescribe fasting as a way to reduce heart disease.
The findings were reported Tuesday at the Scientific Sessions of the American Heart Association in Orlando.
The research was conducted at LDS Hospital using the Intermountain Heart Collaborative Study registry, made up of patients who had heart angiography between 1994 and 2002. The researchers focused on patients who are LDS to see if other church-dictated practices besides not smoking had an impact, said Benjamin Horne, director of cardiovascular and genetic epidemiology, now at the new Intermountain Medical Center. He's also an adjunct professor at the University of Utah.
Researchers looked at data from more than 4,600 people, average age 64, who had come through the cardiac cath lab, to see the degree of risk for someone who was LDS compared to others. They focused on those with obvious coronary artery disease (CAD), defined as 70 percent narrowing or blockage in at least one artery, and those who had little or no CAD (less than 10 percent narrowing). They found that while 66 percent of others had CAD, only 61 percent of LDS members did.
Then they did a study of behavioral factors, including fasting, which they figured was, next to smoking, the most likely reason for the difference in risk.
They asked whether people routinely abstain from food or drink for extended periods of time, although they did not specify a time or a particular religion's way of fasting.
According to Horne, 27 percent of the participants said they fast regularly.
When they adjusted for smoking or just looked at nonsmokers, they still found a lower rate of CAD among LDS people. Next, they came up with a survey about other behaviors associated with the religion that might provide some health benefit.
They had 515 patients, also average age 64, who had coronary angiography between 2004 and 2006 fill out a survey that included religious preference and behaviors encouraged by the LDS Church, such as not smoking; fasting; not drinking tea, coffee or alcohol; resting one day a week; going to church; and donating time, goods and money to charity.
Horne said fasting was clearly the strongest predictor of lower heart disease risk. Horne said those who fast had 39 percent lower odds of being diagnosed with heart disease. When they compared only those diagnosed with CAD to those without it, the impact of fasting was even more noticeable, lowering the risk by 45 percent.
The finding would apply to anyone who regularly fasted, regardless of religion, Horne said, but the information they had came from a largely LDS population.
It's not proof that fasting causes healthier arteries. It shows there's a need for more research on the topic, he said.
The association could be a matter of timing. Fasting for a day breaks up the body's constant exposure to food and glucose. One reason people develop metabolic syndrome, which can turn into diabetes (often linked to heart disease), is that the cells that produce insulin become desensitized. Fasting may allow them to reset so they remain sensitive.
Researchers found those who fasted have healthier arteries whether or not they have diabetes. But Horne cautions it's not enough to tell diabetics to skip meals, which can cause potentially serious complications.
It was not a randomized or controlled trial, he points out, and only included people who had sufficient symptoms to undergo heart angiography. And there could be other factors associated with fasting that researchers haven't identified that lower the risk of CAD.
Horne said fasting may indicate a cluster of healthy behaviors. Or fasting itself may make the difference. One recent study found roundworms forced to fast lived longer than those that ate a normal diet.
Or those who routinely fast may be better at eating the appropriate amount of food and have a more healthy diet.
"There's quite a bit more that needs to be done," Horne said. "This is an initial finding that has brought more questions than it answered."The study was partly funded by the National Heart, Lung and Blood Institute.