Tuesday, November 6, 2007

Intermittent Fasting - For Health: Research update

Fasting - reduces Heart Disease?

Ok I'm sorry. If things go on like this I'll have to call this blog "Intermittent Fasting Research". I do not want to keep banging on about IF, but I keep coming across interesting research on the subject.

Here is one from the American Heart Association’s Scientific Sessions 2007, reported by Eureka News.

The researchers were looking at Mormons in Utah:
ORLANDO, Nov. 6 – Foregoing food for a day each month stood out among other religious practices in members of the Church of Jesus Christ of Latter-Day Saints (LDS or Mormons), who have lower rates of heart disease than other Americans, researchers reported at the American Heart Association’s Scientific Sessions 2007.

“People who fast seem to receive a heart-protective benefit, and this appeared to also hold true in non-LDS people who fast as part of a health-conscious lifestyle,” said Benjamin D. Horne, Ph.D., M.P.H., study author and director of cardiovascular and genetic epidemiology at Intermountain Medical Center and adjunct assistant professor of biomedical informatics at the University of Utah in Salt Lake City.

In the 1970s, scientists recognized that Latter-Day Saints (LDS) in Utah are less likely to die of heart disease than other Utah residents and Americans overall. The religious prohibition against tobacco use is usually credited for the health benefit, but researchers wondered whether other religious teachings also may be important.

Researchers first examined the records of the Intermountain Heart Collaborative Study registry comprised of patients who had undergone coronary angiography, an X-ray examination of the blood vessels of the heart to look for blockages, between 1994 and 2002. Of those patients, 4,629 men and women, average age 64, could clearly be diagnosed either with coronary artery disease (CAD) – which is at least 70 percent narrowing or blockage detected in at least one artery, or as free of significant CAD – less than 10 percent narrowing or blockage. As expected, CAD was less prevalent in patients who identified their religious preference as LDS than those who stated another or no religious preference. Sixty-one percent of LDS members had CAD versus 66 percent of others.

“When we adjusted for smoking, or looked just at the nonsmokers, we still found a lower rate of CAD in people having an LDS religious preference,” Horne said. “We thought this was very interesting, so we devised a survey about other behaviors associated with LDS that might bring a health benefit.”

“Fasting was the strongest predictor of lower heart disease risk in the people we surveyed. About 8 percent of the people who fasted did not express an LDS religious preference, and they also had less coronary disease,” Horne said.

Patients who did not drink tea were also less likely to be diagnosed with CAD, but once fasting was considered the finding wasn’t significant, Horne noted.

Fasting was associated with lower odds of being diagnosed with CAD by 39 percent. When the researchers compared only those diagnosed with CAD with those who had minimal or no coronary disease (less than 10 percent blockage), the impact of fasting was even more striking, with the odds of a CAD diagnosis being lower by 45 percent.

While this doesn’t prove that fasting is the cause of having healthier arteries, it does suggest that it is an important, and new, hypothesis.

Horne said this association between fasting and healthy arteries could be due to timing.

“When you abstain from food for 24 hours or so, it reduces the constant exposure of the body to foods and glucose,” he said. “One of the major problems in the development of the metabolic syndrome and the pathway to diabetes is that the insulin-producing beta cells become desensitized. Routine fasting may allow them to resensitize — to reset to a baseline level so they work better.”

Like all of the stuff I put up here, I am not prescribing anything for you. Read the reports. Think for yourself. Chew these things over a bit. There are other things at play here too - e.g. religious groups often have lower rates of stress which can be a big risk factor for heart disease.

Even allowing for that, personally I think there is compelling evidence that IF is a useful healthy practice. I've pointed before to other resources and books on this topic, so have a dig through for yourself.

The mechanism identified is also interestingly the same mechanism that is at play in a low carb diet - insulin control. All these things fit together.


alexandra said...

Hi Chris,

Lots of interesting stuff you gathered on this blog. Just wanted to let you know I appreciate the effort!

"Read the reports. Think for yourself." Excellent advice.

Chris said...

Cheers Alexandra. Thanks for the feedback