Occasional fasting may have cardiovascular benefits

The day-long, once-a-month fast many Mormons undertake as a part of their faith may help explain the lower rates of coronary artery disease in this population, according to a study presented at the American Heart Assn.'s scientific sessions in Orlando, Fla., last month.

"People who fast seem to receive a heart-protective benefit," said Benjamin D. Horne, PhD, MPH, the study's senior author and director of cardiovascular and genetic epidemiology at Intermountain Medical Center in Salt Lake City.

Dr. Horne and his team analyzed data on 4,629 people who had coronary angiography from 1994 to 2002 and another 515 undergoing this procedure from 2004 to 2006. In the first group, 61% of those who were members of the Church of Jesus Christ of Latter-day Saints were diagnosed with coronary artery disease in comparison with 66% of those who were not of this faith. The later group of patients also was surveyed about religious practices. Approximately 59% of those who fasted occasionally were diagnosed with a significant blockage compared with 67% of those who did not.

That Mormons generally have lower rates of heart disease is well-established. Usually, the religion's prohibition on smoking is credited with this healthy attribute. The authors now suggest that the explanation may be more complicated and that fasting every so often should be studied as a possible healthy lifestyle change that everyone may consider.

"One exciting thing is that the study could be replicated in the general population," said Dr. Horne, who is also an adjunct assistant professor of biomedical informatics at the University of Utah in Salt Lake City.

Meanwhile, caloric restriction, though on a much more significant scale, has been shown in numerous studies to extend life in rodents, yeast and various insects. The National Institute on Aging funds several projects investigating this possibility in monkeys. Investigators at Washington University in St. Louis are studying members of the nonprofit Calorie Restriction Society, a group that exists to promote this type of research in humans. Several compounds also are under investigation in hopes of reproducing the benefits without the negative aspects and challenges of ingesting so little food.

But physicians said these findings suggest that such extreme lifestyle changes are not necessary to improve overall levels of health. For example, people in this study missed just two meals a month on average.

"This study shows how small things can make a difference," said A. Peter Catinella, MD, MPH, associate professor of family and preventive medicine, also at the University of Utah. "You don't have to be running the marathon. People hear the word fasting, and they think they have to starve themselves. That's not what we're talking about."

Not to be discouraged

Study authors and physicians, however, said this study is not conclusive enough to start encouraging patients in this direction. But the paper does suggest that those who occasionally go without food, particularly for religious reasons, should not be discouraged, especially if they have no or few comorbid conditions that could make the behavior risky. Fasting is not unique to Mormonism -- it is also practiced by those of other faiths.

"For those who follow this religious practice, there's no evidence that it's harmful," Dr. Catinella said. He is the past president of the Utah Academy of Family Physicians but was speaking for himself.

The possibility that fasting itself may not be what leads to better heart health also must be considered. For example, religious participation has been associated with improved health status, although it is not clear why. The discipline needed to skip meals may also be utilized to maintain other beneficial behaviors such as regular exercise. The participants of this study who fasted also had a lower BMI, although this finding was not statistically significant.