The Goldilocks Version of the Immune System

Written by

December 19, 2025

As I think about fighting off all varieties of cold, flu and covid over the next few months, I marvel at the complexity of the immune system.  Why can two people become ill from the same infection, one improves in 2 days and the other in 7? It’s complicated and nuanced.  Fighting an infection is a dynamic flow of many moving parts.  

Where is the immune system exactly?  It includes cells all over your body, but with large concentrations on your skin and around your gut.  Just think of how many infections and cancers  your skin is fighting off at any moment – all the bugs in our environment wherever we roam, as well as toxins from the sun (UV light), air pollution, household products, etc.  Similarly, the nose, throat and gut are bombarded daily with other insults.

In the gut, the microbiome – trillions of organisms – are on the inside.  If the microbiome is healthy (see below for simple hints), it maintains a thick mucus layer that keeps everything inside. If there’s only a thin layer, then tiny amounts of toxins can leak, the immune system surrounding the gut gets revved up, causes a lot of inflammation, releases chemicals, and can cause general symptoms like fatigue, headache, joint pain, etc.  We also know now that ongoing inflammation contributes to long-term problems such as heart attacks, strokes, diabetes, arthritis … pretty much everything.

The Goldilocks analogy comes in because we want the immune system to be not too weak, not too strong, but just right – just enough to fight infections and cancers, but not so much that we start fighting ourselves, causing auto-immune diseases like rheumatoid arthritis, lupus, multiple sclerosis, type I diabetes, and others. 

In ageing, ironically, we have both ends of the spectrum.  We’re all well aware that people over 65 benefit from stronger vaccines, because they don’t form antibodies as well and have a higher risk of being hospitalized or dying from the flu or COVID.  At the same time, there’s more inflammation and auto-immune illnesses in this population.  The term ‘inflammaging’ has been used to describe the inflammation with ageing that impacts our healthspan, i.e., longevity associated with favorable health.

Lifestyle factors are much more important than genetics in controlling immune function and general wellbeing.  The microbiome is our partner in good health.  

To optimize it, AIM FOR:

  • Lots of fiber – a variety of fruits, vegetables, whole grains, beans, lentils, tofu, nuts, seeds and herbs and spices. Start low and go slow to avoid upsetting your GI tract.  Allow your microbiome to adapt to digesting more fiber.
  • Ideally 150 minutes per week of moderate movement and 2 days per week of resistance but going from zero to anything is helpful.  Try to take activity ‘snacks’ if you’re sedentary for a while (she says as she’s sitting at her desk).
  • Refreshing sleep – for most people this should be at least 7 hours per night.
  • Personal relationships and interactions, especially including time in nature.
  • Stress relief, in whatever form suits you – focused breathing / meditation, writing, appreciating or performing art or music, …

An exciting finding is that some vaccines also reduce your risk of dementia, particularly the shingles vaccine and the flu vaccine.  This is likely based on the fact that the brain is susceptible to inflammation from viruses, so keeping them at bay is a great idea. 

The wonderful part about using all of these factors to improve your immune health is that they all also impact your overall health by reducing your risk of high blood pressure, heart attacks, strokes, dementia, type II diabetes and certain cancers.  

On that note, all of us at LadyDocs wish you a healthy, joyful, meaningful holiday season!  Consider a gift to yourself of committing to one small change that will improve your microbiome and long-term health.

Here are some resources to help you stay informed with reliable information:

Tags: , , , , , , , ,