Can Fasting Reduce the Severity of COVID-19?

Fasting is a centuries-old discipline that many people embrace as a vital part of their religious tradition, while others adhere to a fasting schedule for health reasons. Fasting has been shown to boost health in many ways, but can it help guard against severe infection if you catch the COVID-19 virus?

According to research published in the British Medical Journal this year, it appears that fasting is indeed beneficial for reducing the severity of COVID-19. Read on to learn about how this practice may help you stay healthy.

What is fasting?

Many people think of fasting as merely refraining from food, but it’s a bit more complex than simply not eating. Fasting has been around since at least the fifth century B.C., observed largely by religious groups but also for other reasons. Depending on a person’s motivation for fasting and what they want to accomplish through it, someone who is fasting may choose not to eat certain foods, consume only liquids and not eat solid foods, or refrain from all food and drink.

The length of time that people fast varies as well. Individuals fasting for health reasons typically omit food and drink for several hours each day. This type of fasting, known as intermittent fasting, has become popular in recent years as a weight loss method.

Periodic fasting involves refraining from all food and drink for 24 hours or more and is often observed for religious purposes. This form of fasting has been linked to a multitude of health benefits, including weight loss, lowered risk of heart attacks, heart failure, and type 2 diabetes, and improved blood glucose control. The researchers who conducted this study suspected that periodic fasting might also have benefits for people who have contracted the COVID-19 virus.

Periodic fasting and COVID-19

In the study, scientists compared rates of COVID-19 cases, hospitalization rates, morbidity (other health problems caused by COVID-19), and mortality (death from COVID-19) in people who reported practicing periodic fasting for at least the previous five years compared to those who did not report fasting. Just over a third of the participants reported routine fasting, largely for religious purposes.

People who practiced periodic fasting became infected with the COVID-19 virus at the same rate as those who did not fast. However, those who regularly fasted did not get as sick: only 11% were hospitalized and/or died from COVID-19 infection compared to 28.8% of those who did not fast.

Rates of hospitalization and death from COVID-19 infection were also higher in participants with the following characteristics:

• Hispanic ethnicity
• History of heart attack or stroke
• Kidney failure
• Older age

How can fasting help protect against COVID-19?

The study authors explain that fasting triggers multiple reactions in the body, all of which may play roles in helping support the immune system and prevent infection.

First, fasting promotes an anti-inflammatory state in the body via increased production of a protein called galectin-3. This protein reduces inflammation and attacks invaders, known as pathogens, circulating in the blood. Galectin-3 has been associated with a decreased risk of diabetes, and it may lower the severity of infections such as COVID-19 as well.

As most people who are familiar with the ketogenic diet know, fasting switches the source of fuel used for energy from carbohydrates to fat. This is why both fasting and the keto diet lead to weight loss; they both result in the body burning fat (as ketone bodies) rather than carbs for fuel.

One result of this fat-burning state is an increase in blood levels of the fatty acid, linoleic acid. This is relevant to COVID-19 because linoleic acid binds to SARS-Cov-2, the virus that causes COVID-19 infection. Once the two molecules are bound, it is more difficult for SARS-Cov-2 to enter human cells and cause infection.

The takeaway

Does this mean you should start fasting? The researchers are quick to state that fasting is not a guarantee against COVID-19 infection. But multiple studies have found results similar to this one regarding fasting and COVID-19, and regular fasting has been shown to benefit overall health in many ways.

If you’re interested in trying it, talk to your doctor or another healthcare provider first for more information and ways to safely begin a fasting routine. Also, check out the WellRx Grocery Guidance App for nutrition information to help you follow a healthy eating plan.

Cara Everett, MS, RDN, is a Registered Dietitian Nutritionist who helps clients reach optimal health and manage chronic conditions with smart food choices. Her work has been featured in a variety of online publications such as WellRx, Road Runner Sports, VeryWell, and National Council on Aging. She writes about nutrition, parenting, pediatrics, and healthcare devices. Cara lives with her family and a collection of animals on a farm in southern Ohio. When she’s not writing, she loves to run with her two dogs.

Resources:

https://nutrition.bmj.com/content/early/2022/06/30/bmjnph-2022-000462

https://www.britannica.com/topic/fasting

https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work

https://pubmed.ncbi.nlm.nih.gov/22425331/

https://www.hindawi.com/journals/mi/2017/9247574/

https://pubmed.ncbi.nlm.nih.gov/25303959/

https://www.eatright.org/health/wellness/fad-diets/what-is-the-ketogenic-diet