REGULARLY fasting for 24-hour periods may help individuals reduce their risk of developing type 2 diabetes and lower their overall risk of heart disease, according to a new study from researchers at the Heart Institute at Intermountain Medical Center.
“Fasting causes hunger or stress. In response, the body releases more cholesterol, allowing it to utilize fat as a source of fuel, instead of glucose. This decreases the number of fat cells in the body,” said Dr. Benjamin Horne, who led the study. “This is important because the fewer fat cells a body has, the less likely it will experience insulin resistance or diabetes.”
Dr. Horne is director of cardiovascular and genetic epidemiology for Intermountain Healthcare, a health services and managed care firm in Salt Lake City, Utah. He believes that fasting could hold tremendous promise and may eventually be used to help people reduce their type 2 diabetes risk.
The findings ‒ presented at a meeting of the American College of Cardiology (ACC) 60th Annual Scientific Sessions in New Orleans earlier this week ‒ showed that participants had lower cholesterol levels, less body weight and healthier blood sugar levels. These benefits added up to a reduction in type 2 diabetes and heart disease risk.
The study confirms the scientists’ earlier study, published in a 2008 edition of The American Journal of Cardiology, which indicated fasting has positive effects on heart health. However, the new study adds to those findings, as it is the first to note an improvement in cholesterol levels after fasting. Additionally, the team showed an increase in human growth hormone levels, a protein that protects lean muscle, making fasting easier.
Potential Effects of Fasting on Coronary Artery Disease (CAD)
Patients involved in the recent study were presently undergoing angiography, an X-ray examination of a person’s blood vessels and the chambers of their heart, often used to help determine if a patient has coronary heart disease. Participants were asked if they regularly engaged in fasting. Then, results of each angiography were compared to how individuals answered the fasting question.
A key factor in the study was the fact that approximately 90 percent of the participants were Mormons. Because of this, doctors expected to find a large number of patients who did regularly fast, as their faith encourages them to fast one day each month.
After reviewing the data of more than 200 participants, researchers found that those who did fast regularly had a 58 percent lower risk of coronary disease, as compared to those who stated they did not fast. However, the Mormon faith also insists that followers abstain from alcohol, smoking and caffeine, as well—all known to affect heart health. But, Horne believes that these recent findings affirm the 2008 study.
“The first study we did was not a chance finding,’’ said Dr. Horne, reported The New York Times. “We were able to replicate the findings and show that people who fast routinely have a lower prevalence of coronary disease.’’
In the 2008 study, the potential effects of fasting on coronary artery disease were studied by the group of Utah scientists. After making adjustments for a variety of factors, specifically noting various lifestyle requirements made by the Mormon faith, scientists concluded, “not only proscription of tobacco, but also routine periodic fasting was associated with lower risk of CAD.”
The state of Utah consistently has some of the lowest rates of heart disease in the U.S., and until now many believed it was because the Church of Jesus Christ of Latter Day Saints ‒ the official name of the Mormon Church ‒ teaches its disciples not to smoke.
“The common wisdom has been that nonsmoking has protected Utahans from cardiac disease, but as smoking rates dropped across the country, Utah’s heart disease rate was still the lowest,” he points out. Horne’s preliminary research suggested it could be the fasting that promotes the health benefits, and the new study substantiates that work.
The recent study did not request information specific to individuals’ fasting practices, such as the type or duration. However, scientists indicate that the most common practice among participants as suggested by interview discussions was a monthly ritual of abstaining from everything but water for a full 24 hours.
During their research, the scientists were able to determine that levels of human growth hormone increased dramatically after the fasting period, as much as 20 times in men and 13 times in women. This hormone is known to be released during periods of starvation, to trigger the burning of fat stores and protect lean muscle mass.
“There is a lot more to be done to fill in the research on the biological mechanism,’’ Dr. Horne said, the NYT reported. “But what it does suggest is that fasting is not a marker for other healthy lifestyle behaviors. It appears to be that fasting is causing some major stress, and the body responds to that by some protective mechanisms that potentially have a beneficial long-term effect on risk of chronic disease.”
While the study showed promising results, Horne said that it may be too early to recommend this regimen to patients who are at risk of developing type 2 diabetes or heart disease. The study of the biological effects of fasting is still relatively new and all of its consequences may not be entirely clear.
Blood Fat Levels Measured During Fasts
In a companion study presented at the same meeting, the team looked at blood markers for heart risks among people who had not previously fasted over 12 hours. The blood markers were checked when they fasted and during a normal eating day. The fast was a water-only fast, and participants were allowed to take any necessary medication.
The participants’ HDL “good” cholesterol rose during the fast. Their LDL “bad” cholesterol levels and their total cholesterol levels also increased, which is not considered favorable. During the fast, participants also saw reductions in levels of dangerous blood fats called triglycerides and blood sugar or glucose levels. “Your body goes into self-protection mode to preserve the integrity of cells and tissue until food starts coming in again, so it uses fats instead of glucose for fuel,” Horne says.
The increase in total cholesterol may just be transient. “It appears that the total cholesterol has gone up because the liver is not processing as much cholesterol and instead it is being dumped into the bloodstream to be used as fuel,” he says, adding, “We need to answer a lot of questions to be able to connect all these dots. We know from our tests that these patients had a lower prevalence of diabetes and coronary disease and now we are backing up to see the mechanism.”
Do Juice Fasts Count?
Many so-called “fasts” ‒ such as “juice” fasts ‒ are widely promoted on the Internet. Comparing the water-only fasts to these juice fasts is apples to oranges, Horne says. “These juice fasts and cleanses could have a similar effect to caloric restriction. In animal studies, reducing the amount of daily calories by 40% to 50% has a benefit on your heart, but it is not as strong of a benefit as [water-only] fasting.”
“Fasting is not a quick fix, it’s a long-term lifestyle that you integrate into your normal life and do it for the duration,” says Horne, who says he fasts once a month, adding, fasting is not for everyone. “There are some dangers for people that are at high risk for other conditions, women who are pregnant or lactating, and young children.”
Howard Weintraub, MD, clinical director of the Center for the Prevention of Cardiovascular Disease at NYU Langone Medical Center in New York City, says that the findings of elevated LDL and total cholesterol in the face of reduced heart and diabetes risk warrant further investigation. “We need a lot more information about this,” he says.
The new study “tells us that we eat too much and we don’t need to eat quite so much,” he says. But “before I start advising my patients to fast, I need to see more information as to the other attributes of these study participants.”
One of the dangers of an occasional fast is that it may be followed by a binge that negates all of the potential health benefits. “It’s like having Diet Coke so you can have a cheeseburger,” he says. Or saying, “If I don’t eat on Monday, no one will yell at me when I eat like a pig on Tuesday and Wednesday,” Weintraub points out.
Suzanne Steinbaum, MD, director of women and heart disease at Lenox Hill Hospital in New York City, says you don’t need to fast to see beneficial changes in your heart disease risk factors. “If you don’t eat bad foods, your profiles are better in terms of weight and blood pressure, and your triglycerides go down, and your blood sugar goes down. Anything in the extreme is not the way to go. It’s how you eat on a daily basis that matters. I don’t recommend fasting, but I do recommend getting rid of unhealthy foods in your diet as fast as you can.”
Echoing the sentiment, nutritionist Dr Emma Williams said, “I wouldn’t be in a hurry to commence fasting, as the precise nature by which the body reacts to it remains relatively unknown.”
With inputs from WebMD