Fasting is best known as a religious practice. It is a practice in which one abstains from eating for a long time. Although it is originally a spiritual diet practice, some people apply it for specific health benefits.
For example, several pieces of research suggest that intermittent fasting can reduce the risk of health conditions such as cancer.
Overview of intermittent fasting
Intermittent fasting means scheduled fasting, alternated with eating times. For instance, you may follow your regular eating pattern for most of the week, but you only eat for 7 hours while fasting for the remaining 17 hours on Wednesdays and Fridays. Intermittent fasting is also known as a fasting-mimicking diet.
Intermittent fasting may seem very unusual in a society where there’s plenty of food. Still, it is worth noting that the human body is designed to accommodate times of food scarcity. Historically, fasting has often been necessary during famine or other natural disasters that limit food supply.
How does fasting work?
The human body is designed to protect you against starvation. It does this by storing a reserve of the nutrients required for survival when you eat.
When you are not eating as you should, the cells in your body will be subjected to mild stress, and your body will start to release those stores to fuel itself. However, clinicians believe that as long as your body has sufficient time to recover after this stressful period, you won’t experience any adverse effects.
One of the first signs or effects of fasting is weight loss because your body is expending more calories than it is taking in.
One should be careful about fasting more than the body can handle. Total fasting or continuous fasting will turn on what is known as “starvation mode.” During starvation mode, your body starts slowing down to extend your life. Usually, the starvation mode is triggered after three days of continuous fasting. Within a three-day fast, your body will hold on to its fuel stores for as much as possible, and you won’t notice immediate weight loss.
What does the science say about fasting and cancer?
Weight loss is a benefit of intermittent fasting — just one use for a healthy adult with no underlying medical conditions. Recent studies and a couple of preliminary human trials have shown that intermittent fasting decreases the risk for cancer. According to the studies, the anti-cancer effects of intermittent fasting may be due to the following:
· Decreased production of blood glucose
· Balanced nutrition intake
· Triggering of stem cells to rebuild the immune system
· Increased production of tumor-killing cells
A study of time-restricted feeding of 9–12 — hour phases showed that fasting effectively reverses the progression of type 2 diabetes and obesity in animals. It is important to note that obesity is a primary risk factor for cancer and may support cancer treatment through fasting.
Another rodent study showed that cancer incidence was reduced during a bimonthly intermittent fasting pattern. Similar results were observed in a pilot trial involving 19 humans; the results showed a drastic decrease in biomarkers and cancer risk factors.
A 2016 study showed that a combination of chemotherapy and fasting slowed the advancement of skin and breast cancer. In addition, combining both treatment methods increased the production of common lymphoid progenitor cells (CLPC) and tumor-infiltrating lymphocytes. Common lymphoid progenitor cells are precursors to lymphocytes. Lymphocytes are white blood cells that migrate into tumors and kill them.
The study also suggested that short-term starvation increases the sensitivity of cancer cells to chemotherapy but protects normal cells.
