How to Boost Your Immune System to Prevent Colds & Flu

Added: Jan 9, 2024

In this episode of the Huberman Lab podcast, Andrew Huberman delves into the topic of colds and flu, providing insights into what they are, how they impact the body and brain, and how to avoid and treat them.

Key takeaways


Understand that colds are most contagious when symptoms are worst.


Recognize the role of physical barriers as the immune system's first line of defense.


Be aware of the importance of quality sleep for immune support.


The gut microbiome plays a crucial role in immune function.


Moderate exercise can boost the innate immune system.

Understanding Colds

Huberman explains that the common cold is caused by a variety of viruses, known as rhinoviruses, with over 160 different types. This diversity makes it challenging to develop a cure for the common cold. The cold virus is spread through breathing, sneezing, and contact with infected surfaces. It can survive on surfaces for up to 24 hours, making it important to avoid touching the face, especially the eyes, to prevent infection.

He emphasizes that people are most contagious when they feel at their worst, and it's a myth that they are no longer contagious after a few days of symptoms. The immune system plays a crucial role in determining whether an individual will catch a cold after exposure to the virus. Huberman also shares his personal experience of tracking his activities before getting sick to identify patterns that may lead to cold or flu infections.

Understanding Flu

The flu, caused by different types of influenza viruses, is categorized into A, B, and C types. The flu virus can only survive on surfaces for about 2 hours, making human-to-human contact the primary mode of transmission. Huberman discusses the effectiveness of flu shots, which are designed to combat specific strains of the flu virus. He also highlights the importance of understanding one's susceptibility to the flu based on their environment and interactions.

Contagious Period and Immune System

Huberman explains that individuals can shed the flu virus 24 hours before experiencing symptoms, making them contagious even when they are not showing signs of illness. The peak contagious period is during the three days when the individual feels the worst, with fever, coughing, and sneezing. He emphasizes the importance of understanding the immune system's role in preventing infection and the need to bolster its three major lines of defense.

Physical Barriers

The first line of defense in the immune system is the physical barriers, such as ithe skin, mucosal lining of the nose and mouth, and other bodily fluids, which provide protection against viruses and bacteria. Huberman explains that the skin contains antiviral substances and acts as a crucial barrier to prevent the entry of pathogens into the body. The innate immune system is a generalized response system that deploys a basic set of neurochemicals to combat viruses. It is not specific to a particular virus but responds to any virus, bacteria, or fungus that enters the body.

Adaptive Immune System

The adaptive immune system is the aspect of the immune system that recognizes specific viruses and produces antibodies to combat them. It creates antibodies that match the shape of the virus, allowing the body to neutralize the virus and maintain a memory of the battle for future encounters.

Preventing Cold and Flu

Huberman discusses the importance of preventing the entry of viruses into the body, particularly through the eyes, nose, and mouth. He emphasizes the need to be mindful of touching the face after coming into contact with others, as this can transfer viruses to the body. He also highlights the role of the lymphatic system in filtering viruses and cells to combat infections.

Factors Affecting Immune System Function

The podcast delves into various factors that can impact the function of the immune system. These include the importance of getting enough quality sleep, engaging in specific types of exercise to bolster the immune system, maintaining adequate nutrition, and managing stress levels.

Sleep and the Immune System

Huberman emphasizes the importance of quality sleep in supporting the innate immune system. He explains that the ability to sleep at night can reduce the functioning of the immune system. He also discusses the role of cortisol in activating natural killer cells and other aspects of the immune system. Huberman points out that while cortisol is often associated with stress, it is essential for immune system function. He also highlights the negative impact of chronic stress and sleep deprivation on the immune system.

Gut Microbiome and Immune System

The podcast also delves into the relationship between the gut microbiome and the immune system. Huberman explains that the gut microbiome plays a crucial role in supporting the immune system. He recommends consuming low-sugar fermented foods to promote the diversity of microbiota in the gut. Additionally, he suggests a simple protocol of swishing water in the mouth before swallowing it to support the gut microbiome. Huberman also emphasizes the importance of nasal breathing in promoting a healthy nasal microbiome, which can help combat colds and flu viruses.

Exercise and Immune System

Huberman discusses the impact of exercise on the immune system. He explains that moderate to high-intensity exercise for 60 minutes or less can increase the output of the innate immune system. However, he warns against prolonged and intense exercise, such as running a marathon, as it can compromise the function of the immune system. He recommends moderation in the duration and intensity of exercise to support immune system function. He suggests consuming fruit within 45 minutes to an hour after exercise to support the innate immune system.

Supplements to Enhance Immune Function

Huberman discusses the potential benefits of vitamin C, vitamin D, and zinc in preventing and treating colds and flu. He mentions that high doses of vitamin C, ranging from 6,000 to 8,000 milligrams per day, may delay the onset of a cold or shorten its duration. However, he highlights that there is not strong evidence to support the use of high doses of vitamin C for immune system function. Huberman also discusses the importance of vitamin D in supporting immune system function and mentions that supplementing with 1,000 to 2,000 IU of vitamin D per day is likely safe for most people. He explains that people who are vitamin D deficient may have diminished immune system function and are more prone to acute respiratory tract infections. Additionally, Huberman highlights the potential benefits of supplementing with zinc, particularly in doses of 90 to 100 milligrams per day, in reducing the duration of a cold or flu.

An Acetylcysteine as a Mucolytic and Immune System Support

Huberman discusses the potential benefits of an acetylcysteine (NAC) as a mucolytic and immune system support. He shares his personal experience of using NAC to alleviate congestion and pressure in the sinuses during a cold. Huberman also references a study that suggests NAC may prevent symptomatic forms of influenza caused by the H1N1 virus. He explains that NAC is a precursor to glutathione, the master antioxidant, and may help reduce reactive oxygen and nitrogen species that increase under conditions of infection.

The Benefits of Heat Exposure

Huberman also discusses the benefits of deliberate heat exposure, particularly sauna sessions, in increasing the activity of the innate immune system. He explains that sauna sessions can lead to an increase in cortisol concentration, which promotes the activity of the innate immune system.


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