January 8, 2024 • 2hr 1min

How to Prevent & Treat Colds & Flu

Huberman Lab

In this episode, Dr. Andrew Huberman discusses the biology of the common cold and flu, how the immune system works to combat these infections, and evidence-based ways to prevent and treat colds and flu. He covers the latest scientific research on behavioral, nutritional and supplementation-based approaches to enhance immune function and better fight off these common viral infections.

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Key Takeaways

The common cold is caused by over 160 different types of rhinoviruses, which is why we don't have a cure and can get multiple colds per year
Cold viruses can survive on surfaces for up to 24 hours; flu viruses for about 2 hours
The primary entry points for cold and flu viruses are the eyes, nose and mouth
People tend to unconsciously touch their face, especially eyes, shortly after shaking hands with someone, increasing infection risk
The immune system has 3 main components: physical barriers, innate immune system, and adaptive immune system
Regular moderate exercise (60 minutes or less) can boost innate immunity, but excessive exercise (e.g. marathon training) can suppress it
Sauna use (3 x 15 min sessions at 176-210°F) can stimulate innate immunity
Nasal breathing helps maintain a healthy nasal microbiome that can fight infections
Consuming 2-4 servings of low-sugar fermented foods daily supports gut health and immunity
Zinc (100mg/day with food) may help shorten cold duration
N-acetylcysteine (600-900mg 2-3x/day) may help prevent and treat colds/flu

Introduction

In this episode, Dr. Andrew Huberman discusses the biology of the common cold and flu, how the immune system works to combat these infections, and evidence-based ways to prevent and treat colds and flu. He covers the latest scientific research on behavioral, nutritional and supplementation-based approaches to enhance immune function and better fight off these common viral infections.

Topics Discussed

Common Cold Biology (6:00)

The common cold is caused by over 160 different types of rhinoviruses. This is why we don't have a cure and can get multiple colds per year - our antibodies for one type don't protect against the others. Cold viruses are very small (about 5 microns) and can survive on surfaces for up to 24 hours.

Key points about cold transmission:

Primarily spread through breathing, sneezing, coughing
Can spread by touching contaminated surfaces then touching eyes/face
Cold temperatures don't directly cause colds, despite the common myth
Most contagious when symptoms are worst, but can spread before symptoms appear

Flu Virus and Transmission (17:43)

The flu is caused by influenza viruses, with different types (A, B, C) and strains like H1N1. Flu viruses only survive on surfaces for about 2 hours, so transmission is more often through direct contact or airborne droplets.

"The flu virus, unlike the cold virus, can only exist on surfaces for about 2 hours. After about 2 hours, it tends to die off."

Flu shots target specific strains predicted to be common that season and reduce risk by 40-60% for those strains.

Immune System Components (30:43)

The immune system has 3 main components:

Physical barriers: Skin, mucus membranes, tears, etc.
Innate immune system: Fast, general response (white blood cells, inflammation)
Adaptive immune system: Slower, targeted antibody response

The physical barriers are the first line of defense. If breached, the innate immune system launches a rapid, general attack. The adaptive system then creates specific antibodies over several days.

Enhancing Innate Immunity (1:00:19)

Ways to boost innate immune function:

Get adequate quality sleep each night
Regular moderate exercise (details below)
Proper nutrition and avoiding severe calorie restriction
Managing stress levels
Supporting gut and nasal microbiomes

Nasal Breathing and Microbiome (1:06:19)

Nasal breathing is important for maintaining a healthy nasal microbiome that can fight infections. The nasal passages have a unique microbiome distinct from the mouth.

"Being a nasal breather is known to provide the right milieu, the right environment, to keep that nasal microbiome at its healthiest, and to promote the diversity of microbiota in the nasal passages that can best protect you against colds and flus."

Supporting Gut Microbiome (1:10:58)

To support gut health and immunity:

Consume 2-4 servings of low-sugar fermented foods daily (sauerkraut, kimchi, kefir, etc.)
Consider prebiotic/probiotic supplements
Optional: Swish and swallow water upon waking to introduce oral bacteria to gut

Exercise and Immunity (1:21:39)

Regular moderate exercise boosts innate immunity, but excessive exercise can suppress it:

Aim for 60 minutes or less of moderate-high intensity exercise
This increases circulation of immune cells and chemicals
Marathon-level training significantly reduces immune function
If feeling run down, rest instead of pushing through with exercise

"People who just ran a marathon and people who have been training for a marathon and are approaching that marathon are severely immune compromised."

Sauna Use for Immunity (1:34:52)

Sauna use can stimulate innate immunity:

3 rounds of 15 minutes at 176-210°F
2 minute cool-down between rounds
Increases cortisol and immune cell counts
Don't use if already feeling ill

Supplements: Vitamin C, D, Zinc (1:42:20)

Vitamin C: High doses (6-8g/day) may slightly reduce cold duration, but evidence is weak. Normal dietary intake is likely sufficient.

Vitamin D: Deficiency linked to increased infections. Supplementing 1000-2000 IU/day is generally safe. Higher doses may be needed for some.

Zinc: 100mg/day with food may help shorten colds. Take within 24 hours of symptom onset.

N-acetylcysteine (NAC) (1:55:08)

NAC may help prevent and treat colds/flu:

Precursor to antioxidant glutathione
Acts as a mucolytic (thins mucus)
Preventative dose: 600mg twice daily
Treatment dose: 600-900mg three times daily

"Whether or not you decide to use N-acetylcysteine as a preventative...or if you decide to take N-acetylcysteine in the manner that I did, which was not as a preventative, but once I had a cold...900 milligrams three times per day."

Conclusion

While there is no cure for the common cold or guaranteed way to prevent all infections, we can take evidence-based steps to boost our innate immunity and reduce the likelihood and severity of colds and flu. Key approaches include:

Practicing good hygiene and being mindful of touching your face
Getting adequate sleep and managing stress
Engaging in regular moderate exercise
Supporting gut and nasal microbiomes through diet and nasal breathing
Considering targeted supplement use like zinc and NAC
Using sauna for immune stimulation when healthy

By implementing these science-based strategies, we can better equip our immune systems to fight off viral invaders and stay healthier during cold and flu season.