Regular fasting may improve CVD risk


Orlando, FL - Regular fasting among Mormons may account, at least in part, for their lower risk of cardiovascular disease, a new study suggests [1]. According to researchers in Utah, fasting was the strongest predictor of reduced heart disease among people who identified themselves as members of the Church of Jesus Christ of the Latter-day Saints (LDS), but also among people who routinely fasted for nonreligious reasons.

Dr Benjamin Horne (Intermountain Medical Center, Murray, UT) presented the results of the study during the American Heart Association 2007 Scientific Sessions last week. In an interview with heartwire, Horne explained that studies dating back three decades have indicated that the LDS population lives longer than non-LDS Americans, a finding attributed partly to the fact that the religion forbids smoking. "But smoking isn't the only risk factor for CVD, and because the lower risk is so substantial, we felt there could be other factors," he said.
For the first part of the study, Horne and colleagues looked at more than 4600 participants in the Intermountain Heart Collaborative Study registry and stratified coronary heart disease risk according to religious preference. Compared with 1467 people who identified themselves as being non-LDS, people who identified themselves as LDS Mormons had a significantly reduced incidence of coronary artery disease (CAD; 66% vs 61%, OR=0.81, p=0.009).
In a second analysis, Horne et al surveyed 515 patients scheduled to undergo coronary angiography about religious practices and other behaviors relating to religion that might affect CAD risk. They found that those who said they fasted regularly—regardless of religious beliefs—were significantly less likely to have CAD identified on coronary angiogram. For the purposes of the study, fasting was defined as no food or drink for at least two consecutive meals.
Roughly 8% of people surveyed said they fasted regularly but were not LDS, and these men and women also had reduced CAD, Horne noted.


CAD according to fasting status



According to Horne, 70% of the population of Utah is LDS, making this a "sizable" group in whom to study the effects of fasting: LDS Mormons fast once a month for 24 hours. While the study does not conclusively link fasting to cardioprotection, there are a number of possible hypotheses that might explain the effect.
The most plausible, he said, is that recurring, temporary food deprivation might have an effect on body ----bolism, serving as a reminder to the body to delve into its stores for nutrients, rather than relying on food intake. "Fasting could have some effect on resensitizing the body to glucose and insulin," Horne said, citing an animal study published in Nature earlier this year that suggested that animals subjected to periods of fasting lived longer than animals eating a normal diet and that certain genes upregulated during the fasting period seemed to have some benefit on glycogen, the molecule that stores glucose.
Another possible explanation is that people who fast may also have better awareness and control over their diet generally, enabling them to exercise better restraint in their day-to-day lives. Horne pointed out that other recent studies have also shown that people who practice "caloric restriction"—eating 20% to 30% less than the general population—also seem to have greater longevity.
"Obviously we need to follow up on several different questions raised by these data," Horne said. "The implication is that people could fast periodically and potentially receive some cardiac benefit, even if they're not fasting for religious purposes. There could be some interaction with diet that could have positive coronary artery disease-reducing benefits. . . . There are more questions than answers, but it's a very interesting concept that I think people could adopt in their lifestyle and have some coronary benefit."
Diabetics, however, should not try fasting to improve their CVD risk profile, he added.