It’s no secret that most of us (Americans) take in more calories than we need to sustain a healthful life. In fact, many of us eat more than is healthy. More than two-thirds of American adults are considered to be overweight; one-third are considered obese. Fasting is becoming a popular way to lose weight and has spawned all sorts of “intermittent fasting” diets, such as eating within an eight-hour window every day or doing one or two 24-hour fasts each week. Many people fast for days at a time to help detoxify their bodies and give their digestive systems a rest. However you choose to fast, you’ll experience some benefits.
Here are just a few:
Fasting changes the function of cells and hormones
When you stop eating, your body starts to undergo several changes. Some of these changes start happening after just 12 hours. First, insulin levels start to drop, which facilitates fat burning. Blood levels of Human Growth Hormone may start to increase, which facilitates fat burning and muscle gain. The body may also induce certain repair processes, such as removing waste material from cells.
Fasting strengthens the immune system
Scientists at the University of Southern California say that fasting “flips a regenerative switch” that essentially restores the immune system. According to Valter Longo, professor of gerontology and biological sciences, “It gives the OK for stem cells to go ahead and begin proliferating and rebuild the entire system. Fasting cycles can generate, literally, a new immune system.” These findings are particularly interesting for those whose immune systems have been damaged by aging or chemotherapy. Tanya Dorff, assistant professor of clinical medicine at the USC Norris Comprehensive Center and Hospital, who co-authored the study says, “The results of this study suggest that fasting may mitigate some of the harmful effects of chemotherapy.”
Fasting may help in the fight against cancer
In addition to the USC study, a study published in the Proceedings of the National Academy of Sciences found that fasting for two days before chemotherapy helped ease its toxic side effects. Researchers at the University of California at Berkeley found that eating every other day decreased cell proliferation rates, which helps slow the development of cancers. Most recently, a study authored by Longo and published in Science Translational Medicine found that five out of eight cancer types in mice responded to fasting alone – without chemotherapy. Longo concludes “the combination of fasting cycles plus chemotherapy was either more or much more effective than chemo alone.”
Fasting is good for the brain
A study from the National Institute on Aging found that fasting one or two days a week may help those living with Alzheimer’s and Parkinson’s. Mark Mattson, Chief of the Laboratory of Neuroscience at the NIA discovered that “Fasting increases BDNF, a protein that’s crucial for learning and protection against age-related cognitive decline. When the brain goes under energy restriction, we see neural activity that’s associated with protection against degeneration from stroke and aging.” You can learn more about Mark Mattson’s research and fasting’s potential benefits for the brain in his TED talk, “Why fasting bolsters brain power.”
As with all health regimens, you should consult your physician before starting any kind of fast. Fasting isn’t recommended for women who are pregnant or nursing or people living with severe anemia. If your doctor thinks you would be able to fast healthfully, you might want to try it. In addition to the benefits listed above, many adherents also mention increased energy, better mental clarity, clearer skin and an easing of the symptoms of allergies and digestive disorders of all kinds.
This article is not intended to replace the advice of your healthcare provider. Speak to your doctor and/or a registered dietitian if you have questions about your nutritional needs.
