By David Liu PHD

Sunday March 4, 2012 (foodconsumer.org) -- In the past, fasting was a commonly used medical treatment.  New research suggests we should go back to the traditional therapy.  Experts say drastically reducing dietary intake can trigger a protective process in the brain against age-related degeneration diseases like dementia.

According to news reports released March 3 in Beijing, China, foreign media  outlets reported that in the near future, family physicians may recommend that you should fast two days per week in order to prevent the brain from age-related shrinkage, and lower the risk of heart disease, diabetes and even cancer.  In the past, fasting was a common therapy.  New research now suggests that we should resume this traditional therapy because fasting seems to trigger a cascade of beneficial physiological changes in hormones and metabolism in the body.

To Prevent Brain Disorders

Years ago, researchers found that chronic caloric restriction can elongate lifespan by 50 percent in animals.  Because few people are willing to suffer starvation for a long time, this approach to extend one's life is hard to be accepted and this method because of this could not benefit humans.

However, a growing body of evidence suggests that intermittent fasting. which is more practical, can render the same types of benefits as chronic caloric restriction.  Specifically, by definition, this type of fasting requires people to control their caloric intake under 500 to 800 calories per day.  Normally men and women are recommended to have 2500 and 2000 calories per day respectively.

Research found that fasting seems to be able to lower the serum levels of a growth factor, which is a hormone related to cancer and diabetes, serum undesirable cholesterol and blood fat triglycerides.  Additionally, disease-related destructive free radical can also be inhibited and inflammation can be mitigated, leading to the protection against brain aging and disorders.

Professor Mark Mattson, neuroscience department head of the U.S. National Institute on Aging, said sudden and substantial reduction of food intake - at least reduced by half - can  trigger protective processes within the brain.  This brings the brain benefits which are comparable to that provided by physical exercise.  This can protect the brain from developing degenerative disorders like Alzheimer's disease and Parkinson's disease.

Mattson is a pioneer in research on fasting.  Years ago, he discovered that rats eating calorie-reduced diet every other day experienced the same outcomes as rats complete fasting. Chronic caloric restriction can provide the same benefits.  If people reduce their caloric intake, even if their fasting is not daily routine and only intermittent , they still can experience benefits.  This has been proved in many experiments.

To reverse diabetes

In a study, one group of obese women ate 1500 calories every day and a control group only ate 500 calories daily on two days in a week and 2000 calories on other 5 days.  Both groups were advised to follow the healthy dietary patterns similar to Mediterranean diet.

Research leader, University of Manchester, UK nutritionists Michelle Harvey said: "We found that two groups of women lost almost the same amount of body weight and similar reduction in cancer risk biomarkers.  The purpose is to determine which approach is more effective. We found women in the fasting group experienced better insulin sensitivity."  The findings were published in 2011 in International Journal of Obesity. 

In 2011, University of Newcastle, UK researchers reported that overweight people eating 800 calories per day for eight weeks successfully reversed diabetes. They also found that reduced caloric intake can not only be more acceptable, but also render the same efficacy in controlling blood sugar levels in the overweight diabetics.

Human Trials Soon to Begin

Professor Mattson is now conducting research to examine the benefits different types of fasting can bring to the brain cells.  A research paper says that caloric restriction can prevent the brain cells from being damaged and also increase the brain's tolerance to the stress. The research is scheduled to be published in March in the renowned scientific journal "Nature - Neuroscience"

Mattson said part of the reason is that this positive impact of reduced caloric intake can stimulate gastric ghrelin, leptin and other appetite hormones. If you are not overweight, these hormones can stimulate new brain cell growth, particularly in the hippocampus.  The hippocampus is involved in the storage of memory. 

If body weight begins to increase, ghrelin levels in the stomach tend to be reduced and the renewal of brain cells will be slowed down.  Mattson said this impact is particularly significant among people in their 40's and 50's even though it remains unknown why people in these two age groups are more sensitive.  People who develop obesity at these ages may have age-related cognitive problems in late life. The good news is, brain cells damage of this type can be reversed by fasting two days a week even though right now Professor Mattson only found this effect in rats. It's been reported that human trials will soon begin.  We have reasons to believe that fasting can render the same effect in humans.

Adherence is very important

Mattson conducted a small study years ago and found every-other-day fasting can result in an astonishing positive impact on patients with asthma.  Mattson said.

A small-scale study showed every other day fasting can produce an amazingly positive impact on people suffering from asthma. Mattson said: "After eight weeks, participants lost 8% of body weight and inflammation was also reduced drastically.  Test results showed that the inflammatory biomarker levels decreased by 90% and with inflammation significantly eased, their breathing became easier."  But Mattson also warned that patients must adhere to such a diet, because the symptoms two weeks after the cessation of fasting will come back.

Not every one is able to adhere to intermittent fasting. ?A study of overweight women shows that more women would accept a dietary regimen to eat 1500 calories per day than fasting 2 days a week.

Professor Mattson believes that fasting can improve our health. He said "Research shows that if we can maintain a healthy diet and lifestyle in adulthood, most people can prevent brain aging."   However, Alzheimer's disease is on the rise, due to the high-calories eating habits.

Get your doctor's advice

Head of the British Medical Research Council, Diet and Health Department, Dr. Susan Jeb said the best thing many people can do is lose weight. "I fully believe this approach (fasting) can play a role." However, it is too early to conclude that fasting can be adopted as a treatment for heart disease or dementia in people who are at high risk. Jeb said we need to conduct long term research of more people to learn about all the impact fasting can have on humans.

After finding the health benefits of fasting, Mattson followed a calories-reduced diet.  He said my daily calories intake is about 1800 calories and that is not extreme.  Within a week, I do not eat any breakfast or lunch, but dinner is very sumptuous and I know i can't recommend this diet to everyone, but it works well for me.  However, Jeb opposed fasting. She said we do not know the long term effect of fasting on the metabolism.  If one can fast one or two days a week, he may believe he can overeat other days.

The British Dietetic Association warned chronic fasting can increase the risk of osteoporosis and infertility. At present, many scientists still do not know whether fasting may have a negative impact. But if what people can gain from fasting is exactly same as what is found in research, many people are willing to fast.  But experts suggest that you should talk to your doctors before you actually start fasting. (Editor's note: so how could doctors know good and bad effects of fasting?).