Fasting may slow prediabetes progression to type 2 diabetes

DIABETES DIGEST – June 20, 2014 – Many religions observe some form of occasional fasting, however, Mormons forgo at least two consecutive meals in a 24-hour period one Sunday each month. With such a regular fasting schedule researchers have been able to study the effects of fasting on this population for some time.

A 2011 study showed that healthy people who observed water-only fasting had lower glucose levels and weight loss. The lower blood sugar findings intrigued Benjamin Horne, PhD, director of cardiovascular and genetic epidemiology at the Intermountain Medical Center Heart Institute.

“Together with our prior studies that showed decades of routine fasting was associated with a lower risk of diabetes and coronary artery disease,” Horne said in a press release, “led us to think that fasting is most impactful for reducing the risk of diabetes and related metabolic problems.” 

He designed a study that would look at the effects of fasting in prediabetics over an extended time. He enrolled an unpublished number of people* who were between the ages of 30 and 69 who also had at least three risk factors for metabolic syndrome, a cluster of conditions that increase the risk of heart disease, stroke and diabetes. These include high blood pressure, high blood sugar levels, excess body fat around the waist and abnormal cholesterol levels (high LDL and low HDL).

Horne and his colleagues began the study in 2011 and presented the findings June 14, 2014 at the American Diabetes Association Scientific Sessions in San Francisco. While the blood sugar levels were unchanged during the first six weeks of the study, participants lost and average of 5.5 pounds. LDL (bad) cholesterol increased initially, but was then lowered significantly later in the study from an average of 100.0 mg/dL to an average of 87.8 mg/dL.

"During actual fasting days, cholesterol went up slightly in this study, as it did in our prior study of healthy people, but we did notice that over a six-week period cholesterol levels decreased by about 12 percent in addition to the weight loss," said Dr. Horne. "Because we expect that the cholesterol was used for energy during the fasting episodes and likely came from fat cells, this leads us to believe fasting may be an effective diabetes intervention."

Horne explains that extracting LDL cholesterol from fat cells for energy could reduce insulin resistance.

"The fat cells themselves are a major contributor to insulin resistance, which can lead to diabetes," he said. "Because fasting may help to eliminate and break down fat cells, insulin resistance may be frustrated by fasting."

Dr. Horne cautions that these effects of fasting took place over time. How long and how often people need to fast to obtain these benefits is still unknown. For that reason he says more in-depth study is needed, but the findings lay the groundwork for that future study.

*The abstract presented at the American Diabetes Association Scientific Sessions and published online did not include the number of participants.