by Joe Casciani
INTRODUCTION
A subject that I have become interested in recently is intermittent fasting (shortened to “IF” for this article). This has become a trend for the health-conscious population as a way to not only lose weight but also, according to many research studies, reduce disease and slow down the aging process. It basically refers to eating patterns that cycle between periods of fasting and eating – eating within a specific time period and fasting for the rest of the time. It’s typically seen as more of a lifestyle choice than a diet, per se. Is it an ingredient to successful aging and longevity?
If one were to do a search, the articles on this topic all attest to the fact that intermittent fasting is nothing new. Throughout evolution, our ancestors often fasted because food was not always available and the hunting and foraging process often left people cycling between time of food abundance and scarcity. Further, Christian, Jewish and Buddhist traditions, among others, have frequently included fasting as part of their religious practice.
VARIATIONS
IF comes in many variations:
* 5:2 method calls for normal eating 5 days a week, and reduced caloric intake (500 to 600 calories) the other 2 days;
* Eat-stop-eat entails restricting eating for 24 hours, once or twice a week;
* 16/8 is the process of consuming all calories within a 6- to 8-hour period, an fasting the remaining 14 to 16 hours;
* Any similar combinations or permutations marked with periods (hours or days) of reduced caloric intake.
FAVORABLE OUTCOMES
There is no shortage of articles and research findings on the practice of IF. Among the many benefits touted include weight loss, increased energy, cellular repair, and other highly desirable effects. Many of these studies involved small sample sizes or were limited to animal studies. Of course, many questions have yet to be answered with human subjects. The research is promising, nonetheless:
* Improved insulin sensitivity and lowered insulin levels, which in turn, makes stored body fat more accessible (Alternate-day fasting in nonobese subjects);
* Benefits of fat loss and muscle gain due to as much as a 5x increase in human growth hormone (Fasting enhances growth hormone);
* Changes in gene function, related to longevity and the protection from disease (Caloric restriction and intermittent fasting, Effects of intermittent feeding upon life span);
* Boosts metabolism and increases the release of (fat burning) norepinephrine , directly related to weight loss (How intermittent fasting helps with weight loss, Intermittent fasting vs daily caloric restriction);
* Reducing inflammation, precursors to many chronic diseases (Alternate day calorie restriction reduces markers of inflammation);
* Protection against neurodegenerative disorders, coronary artery disease, metabolic disturbances, and diabetes.
Although there is abundant research (as above citations show) documenting how intermittent fasting slows aging, a recent study at Harvard explored the underlying biology of the way our cells process energy over time, a process associated with aging and age-related disease. The subjects were earth worms, and the study looked at molecules contained in the cell’s mitochondria and how well these mitochondria provided cells with sources of energy, over the course of the worms’ (short) life. When the diets were restricted, the result was keeping these mitochondrial networks in a “youthful” state. The authors confirmed that low-energy conditions such as dietary restriction do promote healthy aging, but also show the biological processes occurring with these restrictions in diet.
CONTRAINDICATIONS
There are some risks from IF with people who are underweight, have a history of eating disorders, and have undesired effects on menstrual cycles and fertility in some women. Other contraindications are present for those with diabetes, or have problems regulating sugar levels, or when taking certain medications. It is advisable to consult with your physician before embarking on an IF program.
SUMMARY
It appears that IF can have many benefits for our body and our brain, including living longer. IF tends to help us to take in fewer calories and at the same time, burn more calories. Although there are many favorable outcomes, I think it’s important to remember that IF mostly represents a lifestyle change. The process has been beneficial for me, initially abstaining from food for 24 hours (actually 36 but we don’t eat while sleeping anyway) for about 8 months, and gradually adding in dinner on the day of fasting. Total weight loss has been about 30 pounds. And whether it actually extends our years, I won’t know that for awhile. Fasting for 24 or more hours isn’t easy; most things that keep us healthy aren’t. But, if you have a busy day, and shift your thinking away from being hungry onto other, productive things, the time passes soon enough. And then I think, How many meals have we had over our lifetime anyway, and missing a couple here and there isn’t so bad. In closing, it’s not for everybody, but once risks have been ruled out, I recommend it.
