The Real Benefits of Intermittent Fasting

Intermittent fasting is not a new idea.  It has been practiced by many different cultures for over a thousand years in various forms.  Scientists are starting to understand some of the biology related to intermittent fasting and how it affects our body.  It is believed to be safe and effective when used in the right circumstances.  

There’s a multitude of benefits seen with intermittent fasting, ranging from less insulin resistance, reversal of diabetes and prediabetes, improved blood pressure, weight loss, particularly abdominal weight loss, lower cancer risk, improved memory and brain function, decreased risk of Alzheimer’s disease, better recovery from surgery, and improved outcomes from traumatic tissue injury and spinal cord injury.  Granted some of these studies were done in animals, but there are promising results seen in humans as well.  The benefits seen with intermittent fasting seem to be separate from the weight loss effects of fasting.

There’s two mechanisms identified so far that can result in these health benefits.  One is related to insulin and its effects on the body.  After we eat, insulin is secreted from the pancreas to stimulate glucose uptake into the cells.  Insulin also  promotes fat storage.  When insulin is low such as during fasts, the liver breaks down free fatty acids into ketones to be used as energy in place of glucose.  This is similar to the effects of a keto diet.  Not only are ketones used for fuel, ketones also send signals to cells and can alter organ functions as well.  Ketones affect many of the proteins that are involved in aging and health.  There’s one called brain derived neurotropic factor (BDNF) which functions in brain health and mood.  So with lower insulin levels and higher ketones, there are several beneficial effects seen.  In humans, ketone levels rise after a 8-10 hour fast.  

The second mechanism is cellular adaptation to stress from reduced calories.  Cells respond to fasting by making more antioxidant defenses, enhancing DNA repair, and decreasing the products of inflammation.  Studies show that these cells have an increased resistance to damaging insults.  This cellular adaptation is suppressed in individuals who overeat or are sedentary.  

Just a few examples of health benefits seen with intermittent fasting are:

—Improved brain function such as cognition, memory and executive function

—Alternate day fasting showed less tumor growth, less spontaneous tumors, and increased response of cancer cells to chemo and radiation (human studies ongoing)

—Asthma improvement

—Longevity 

—Multiple sclerosis symptoms improve

—Cardiovascular risks such as blood pressure, diabetes, lipids improve

—Waist circumference decreased

—Delay of onset or progression of Alzheimer’s and Parkinson’s disease

Intermittent fasting, however, is not easy and not recommended for everyone esp women who are pregnant or those with eating disorders.  You should also consult your physician if you have diabetes before trying this.  Done appropriately, you can see improvements in your health within just a few weeks.  

In the next blog, more on types of intermittent fasting and how to get started.