Many people routinely fast, going hungry for a day or a couple of days either for spiritual or health reasons. Some say fasting cleanses toxins from the body. Others enjoy a spiritual awareness that hunger arouses. The irregular diet of our hunter-gatherer ancestors is often cited as an evolutionary basis for deliberately restricting our modern diet.
Tens of millions of people of Muslim faith will soon start a month of fasting from sun up until sun down during Ramadan. The Ramadan fast serves to heighten empathy with those who are hungry or lack water and to test the duty and commitment of practitioners in addition to the spiritual elements so often embraced in the act of denying oneself. But all who embrace the concept of occasional fasting might enjoy learning of some recent scientific findings that support the idea that fasting promotes health.
Late last year, researchers from the University of Ottawa reported that intermittent fasting fights obesity and metabolic disorders better than counting calories. Lead researcher Kyoung-Han Kim reports:
Intermittent fasting without a reduction in calorie intake can be a preventative and therapeutic approach against obesity and metabolic disorders.
The scientists attribute their findings to a change in the immune reactions in fat cells. With obesity and diabetes (a prevalent metabolic disorder) still increasing, this news might be welcome to anyone trying to keep their health under control.
Earlier this year, scientists investigating the value of fasting diets compared to counting calories found a surprise result. The researchers put the 5:2 diet, in which human volunteers eat normally for 5 days and severely restrict calories for two days, up against a standard diet in which volunteers ate 600 calories less per day than the amount calculated to maintain their weight.
The 5:2 diet won the contest, with adherents meeting their 5% weight reduction goal in 59 days compared to 73 days for the calorie counters. The surprise arose as the dieters' metabolic processes were studied after their weight loss: people on the 5:2 diet cleared fats (triglycerides) from their blood after a meal more quickly then the other group. They also found a greater reduction in the systolic blood pressure of the fasters, and other metabolic differences that will need further study.
In the most recent news, scientists at MIT have shown that aging stem cells can be regenerated by fasting. The ability of our bodies to turn stem cells - which are sort of global cell building blocks - into new intestinal liner cells is critical to maintaining our health. Because of the aggressive environment (think about it, the liner cells have to survive in a place where everything else is being treated as food and broken down into bits and pieces), our intestinal liner cells are replaced every 5 days.
As we get older, the ability of the stem cells to turn into new liner cells ebbs. An intestinal infection or a damaging round of chemotherapy becomes difficult to recover from in old age. This makes the finding that stem cells from fasting mice double their regenerative capacity of great interest for the treatment of such conditions in aging patients. But it also hints that fasting can lend valuable powers to our cells at the most basic biological levels.
If you want to try a fast yourself and suspect any health problems, talk to your doctor before trying any extreme changes in your dietary patterns. With the exciting new science around fasting, you may be able to find a study to participate in as well, to help further our understanding of the fascinating biology behind our diet and our health.