In Blog, Diet, Exercise, Lifestyle, Research

My best advice for conquering this cold and flu season.

Early this summer, COVID made its rounds throughout our household.

My wife’s 92-year-old mother, Grandma Reger, was staying with us at the time. She was the first to fall ill with fever, body aches, and severe fatigue. My wife and daughter fell ill two days later, and then my face pain turned on. I wasn’t surprised as a viral infection can cause a temporary increase in autoimmune-related symptoms called a pseudo-relapse.

Fortunately, no one needed to go to the hospital as we all managed our symptoms at home and we all bounced back relatively quickly.

As we age the effectiveness of our immune cells declines and it takes a smaller dose of the pathogen to infect us. Over the age of 40, our immune cells begin being less effective and are much less effective over the age of 60.  Having more medical problems also increases the risk of immune cell decline.

With the cold and flu season fast approaching, I want to reassure you, there is a lot you can do to keep your immune cells functioning well. I believe my family’s approach to immune system health was a factor in helping us through our bout with the virus earlier this summer.

I reduce my risk of severe bacterial or viral infections by focusing on diet and lifestyle interventions. Here is what we do in my household to support our immune systems during peak season:

  • Take care of your sleep. I have a consistent bedtime and wake-up time. I also shoot for 7 to 9 hours of sleep each night. Inadequate sleep depresses our immune cells and increases the risk of viral infections.1
  • Eliminate or reduce added sugars and high glycemic foods. Elevated blood glucose and metabolic syndrome increase the vulnerability to viral and bacterial infections2
  • Regular consumption of fermented foods improves immune cell function, reducing the risk of serious viral and bacterial infections.3 We eat more sauerkraut, kimchi, kefirs, and non-dairy yoghurts.
  • Maintain a regimen of regular physical activity. Moderate exercise improves metabolic health and immune function and reduces the risk of viral infections.2
  • Optimize vitamin D levels with regular sun exposure (without getting sunburned).  I take a vitamin D3 supplement and I test my vitamin D levels annually to be sure my vitamin D levels are in the top half of the reference range.  A low vitamin D is associated with an increased risk of infection-related hospitalization and death related to influenza and the coronavirus.4,5
  • Ensure plenty of zinc and vitamin C. Zinc is a co-factor for hundreds of enzymes impacting my brain and immune cells. In a meta-analysis of the effectiveness of micronutrient supplements to reduce viral infections,  Vitamin Czinc, and Vitamin D were effective at reducing the frequency and severity of respiratory virus infections.6 Sauerkraut and kimchi are excellent sources of vitamin C. Liver and oysters are excellent sources of zinc.
  • Consider taking N acetylcysteine (NAC) which has antiviral, antioxidant and anti-inflammatory properties. NAC is an adjuvant for reducing the severity of and preventing influenza and other viral infections.7,8

I have curated a supplement bundle that contains Vitamin C, zinc, and NAC—you’ll find the Wahls Protocol® Immune Protection Support Kit here

In addition to the targeted supplements listed above, the Wahls Protocol® Immune Defense can be helpful in supporting immune health.

I encourage everyone to take a food-first approach to get in all your nutrients, but many Wahls Warriors™ will benefit from added targeted supplementation.

I hope you find these tips helpful!



  1. Krueger JM, Toth LA, Floyd R, et al. Sleep, microbes and cytokines. Neuroimmunomodulation. 1994;1(2):100-109.
  2. Lombardo M, Feraco A, Bellia C, et al. Influence of Nutritional Status and Physical Exercise on Immune Response in Metabolic Syndrome. Nutrients. 2022;14(10).
  3. Kok CR, Hutkins R. Yogurt and other fermented foods as sources of health-promoting bacteria. Nutr Rev. 2018;76(Suppl 1):4-15.
  4. Dadras O, SeyedAlinaghi S, Karimi A, et al. COVID-19 mortality and its predictors in the elderly: A systematic review. Health Sci Rep. 2022;5(3):e657.>
  5. Yisak H, Ewunetei A, Kefale B, et al. Effects of Vitamin D on COVID-19 Infection and Prognosis: A Systematic Review. Risk Manag Healthc Policy. 2021;14:31-38.
  6. Abioye AI, Bromage S, Fawzi W. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis. BMJ Glob Health. 2021;6(1).
  7. De Flora S, Balansky R, La Maestra S. Rationale for the use of N-acetylcysteine in both prevention and adjuvant therapy of COVID-19. FASEB J. 2020;34(10):13185-13193.
  8. Wong KK, Lee SWH, Kua KP. N-Acetylcysteine as Adjuvant Therapy for COVID-19 – A Perspective on the Current State of the Evidence. J Inflamm Res. 2021;14:2993-3013.

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