Intermittent fasting is a pattern of eating that is gaining popularity due to its potential health benefits. Research says that it can help you to lose weight and may help to improve blood sugar, reduce inflammation, prevent chronic disease and preserve memory and learning.
The concept of fasting has its roots in our evolutionary history. Our ancestors went through times of famine and seasonal variability of food availability. Fasting is part of many religions such as Islam, Christianity, Judaism and Buddhism.
Mark Mattson is a leading neuroscientist at the National Institute on Aging in Maryland. He has conducted numerous studies on intermittent fasting on animals and humans. He proposes that fasting may serve as an adaptive response to support survival. During a fasting period, cells are under mild stress. They respond to this stress by a set of physiological responses that makes the body stronger and more resistant to disease.
Fasting can trigger a “regeneration switch”. It triggers the release of stem cells which can be converted into fresh immune cells. At any given time, your cells may not be working at top capacity. Over a period of fasting, cells turn over leading to healthier more efficient cells. One human study suggests that fasting over 72 hours can regenerate the entire immune system. This may help to optimize the immune system in cases of chronic infections, cancer and inflammatory conditions.
Metabolic Shift from Burning Glucose to Fat
When you go through a period of fasting, insulin levels come down and metabolism shifts from using glucose (sugar/carbs) for fuel to breaking down fatty acids (fat) for fuel. This metabolic shift reduces insulin, cholesterol and improves cardiovascular risk markers.
When your body breaks down fat stores for fuel, ketones are produced which is an alternative energy source for cells. These ketones are a more efficient fuel for the brain. This ketogenic state increases the number of mitochondria or “energy factories” in the brain cells which can improve learning and memory and protect the nerve cells from age related decline including neurological diseases such as Alzheimer’s and Parkinson’s.
It is recognized that additional quality human studies are needed. Based on animal and human studies, intermittent fasting has been shown to have the following potential health benefits:
- Improve insulin sensitivity
- Weight loss with a reduced caloric intake
- Reduce inflammation
- Lower levels of C-reactive protein (CRP), and inflammatory marker
- Preserve learning and memory
- Reduce risk of neurodegenerative disorders
- Improve cardiovascular risk factors: cholesterol, blood pressure
- Reduce oxidative stress
- Reduce insulin-like growth factor 1, a hormone linked to cancer and aging
- Improve asthma
- Reduce risk of cancer
- Improve longevity
A Word of Caution
If you are considering trying intermittent fasting, it is advisable to discuss risk factors with your health care practitioner. It is not recommended for individuals with a history of eating disorders, pregnant women, women who are trying to conceive or children. There could be added risk for individuals taking medications that influence blood sugar or electrolytes.