The Science of Illness: Why We Get Sick

1. Pathogen Entry

Our bodies are not closed systems. We interact with our environment constantly, which provides numerous entry points for pathogens:

• Respiratory tract (breathing): We inhale approximately 11,000 liters of air each day, potentially containing airborne pathogens.
• Gastrointestinal tract (eating/drinking): Food and water can carry harmful microorganisms.
• Skin and mucous membranes (touching): Direct contact with contaminated surfaces can transfer pathogens.

2. The Immune Response

Once pathogens breach our initial barriers, our immune system springs into action:

• Innate Immunity: This is our first line of defense, responding quickly but non-specifically.

  • Includes physical barriers (skin, mucous membranes), chemical barriers (stomach acid, enzymes), and cellular responses (neutrophils, macrophages).
  • Triggers inflammation and fever to create an inhospitable environment for pathogens.

• Adaptive Immunity: This is our targeted response, developing specific defenses against particular pathogens.

  • B-cells produce antibodies to tag pathogens for destruction.
  • T-cells directly attack infected cells and help coordinate the overall immune response.

The symptoms we experience during illness (fever, fatigue, inflammation) are often the result of our immune system working to eliminate the threat.

3. Immune System Challenges

Our defense system can be compromised in several ways:

• Insufficient sleep:

  • Reduces production of cytokines crucial for fighting infections
  • Decreases T-cell activation and efficiency
  • Disrupts stress hormone regulation (e.g., cortisol)
  • Lowers natural killer (NK) cell activity
  • Increases chronic low-grade inflammation

• Poor nutrition:

  • Deficiencies in key vitamins and minerals (e.g., Vitamin C, D, zinc, selenium) necessary for immune cell function
  • High intake of processed foods and refined sugars can promote inflammation
  • Glucose spikes can temporarily suppress neutrophil activity and complement function
  • Inadequate protein intake can impair antibody and immune cell production

• Lack of exercise:

  • Reduces circulation of immune cells (NK cells, T-cells, B-cells)
  • Lowers production of anti-inflammatory cytokines and myokines
  • Decreases efficiency of pathogen removal through respiration and perspiration

• Chronic stress:

  • Elevates cortisol levels, suppressing overall immune function
  • Can lead to chronic inflammation, misdirecting immune resources

• Environmental factors:

  • Pollution and extreme temperatures can irritate airways and reduce immune efficiency
  • Disruption of circadian rhythms can affect immune cell trafficking and production

When challenged, our immune system may experience:

• Decreased production and activation of white blood cells, particularly lymphocytes and NK cells
• Impaired communication between immune cells, leading to slower or weaker responses
• Reduced antibody response to vaccines or infections
• Increased susceptibility to infections due to compromised barrier function (e.g., in the respiratory tract)
• Dysregulation of the inflammatory response, potentially leading to chronic health issues

Preventing Illness

Preventing Pathogen Entry

1. Hygiene:

   • Wash hands frequently (20 seconds with soap): Mechanically removes and kills pathogens
   • Avoid touching your face: Prevents transfer of pathogens from hands to entry points
   • Use hand sanitizer (60%+ alcohol) when soap isn't available: Kills most pathogens
   • Practice good respiratory hygiene: Reduces spread of airborne particles

2. Environment:

   • Ensure good ventilation: Dilutes airborne pathogens and improves air quality
   • Clean high-touch surfaces: Removes pathogens before they can be transferred
   • Use disinfectant wipes on shared surfaces: Kills pathogens on contact
   • Maintain appropriate indoor humidity (30-50%): Reduces survival of airborne pathogens

Boosting Immune Function

1. Sleep:

   • Aim for 7-9 hours nightly with a consistent schedule.
   • Create a sleep-conducive environment (dark, quiet, cool).
   • Develop a relaxing pre-sleep routine.
   • Why it works: Enhances T-cell function, promotes cytokine production, regulates stress hormones, and supports natural killer cell activity.

2. Exercise:

   • Aim for at least 150 minutes of moderate-intensity exercise per week.
   • Incorporate a mix of:
     • Zone 2 cardio: Enhances circulation of immune cells
     • HIIT: Provides intense immune cell circulation boost
     • Resistance training: Stimulates anti-inflammatory cytokines
   • Why it works: Promotes circulation of immune cells, reduces inflammation, and enhances overall immune function.

3. Nutrition: Focus on a balanced diet rich in:

   • Colorful fruits and vegetables: Provide antioxidants and phytonutrients
   • Lean proteins: Support immune cell production
   • High fiber foods (whole grains, vegetables, chia/flax/hemp seeds): Support gut health
   • Healthy fats, especially omega-3s: Reduce inflammation
   • Probiotic and prebiotic foods: Enhance gut microbiome health
   • Limit processed foods, refined sugars, and excessive alcohol
   • Why it works: Provides essential nutrients for immune function, reduces inflammation, supports gut health (a key component of immunity), and stabilizes blood sugar.

4. Hydration:

   • Drink plenty of water throughout the day.
   • Why it works: Supports lymphatic system function, helps eliminate toxins, and maintains mucous membrane health.

5. Stress Management:

   • Address major sources of stress (e.g., ethical conflicts, unfulfilling lifestyle).
   • Incorporate stress-reducing activities:
     • Regular exercise
     • Yoga or meditation
     • Quality time with loved ones
     • Engaging hobbies
   • Why it works: Reduces cortisol levels, improves sleep quality, and enhances overall immune system resilience.

Action Items for Illness Prevention

• Hand Hygiene: Wash hands frequently (20 seconds with soap), especially before touching your face and upon entering your home. I leverage the feature on Apple Watch that detects handwashing and starts a timer, this helps me be accountable and avoid rushing through the hand washing process. I have a beard and play with this a lot, I'm not sure if that helps or hurts!

• Hand Sanitizer: Use 60%+ alcohol sanitizer when soap is unavailable; keep in convenient locations. I make sure to have one in the car, in my office, and a portable one in my laptop bag.

• Surface Hygiene: Use disinfectant wipes on shared surfaces, particularly when traveling or at the gym. I'm particularly anal about this on airplanes or public transportation. I should be better about this at the gym, especially if I'm going to be on a cardio machine for a long steady session.

• Environment: Use HEPA filters, maintain regular cleaning, and ensure proper ventilation in living/working spaces. In practice, I change the air filters in our house (we have central air) regularly, sweep/vacuum once a week, and wipe down the counters every night before going to bed. I don't do anything with a humidifier or additional air purifiers, but I'm planning to look into this. I'm also interested in a CO2 monitor, but haven't figured this out yet. For now, I just run one of the bathroom fans regularly and open the windows when I'm cleaning with harsher chemicals. Lastly, I've seen mixed points of view, and it's clearly highly politicized for whatever reason, but I would consider wearing high quality masks in riskier situations, and would tend to prefer outdoor activities especially during high risk seasons (e.g. maybe going for a run outside instead of on an elliptical at the gym during rush hour). I think one other thing to consider is overall pollution... I don't think you can do much about this, but maybe keep an eye on air quality in the weather app on your phone, and make good decisions about where you settle down in life.

• Sleep: Aim for 7-9 hours nightly in a dark, quiet, cool environment with a consistent schedule. I like the idea of tracking your sleep, but not being obsessive about it. I am using my Apple Watch to do this, I bought one of the braided bands and I switch the band out and put it on my opposite wrist at night. I've thought about using an Oura ring just for this, but I didn't think it was worth the extra $300 + monthly subscription cost. The other thing that works well for me is to have a consistent shut down ritual. On a perfect day, I will have shut down my work / laptop / phone around 6pm and have dinner / quality time with my family. I'll do a little workout usually (cardio and/or core/yoga) and finish with some static stretching... then I'll take a hot shower or bath, read a little, and go to bed. Whatever ritual works for you, I think it's worth playing around and figuring out what works for you -- but it can't hurt to get off your phone and disconnect a little. Lastly, I've read that having a consistent schedule and keeping your sleeping environment dark, quiet, and cool (and ONLY using it for sleeping -- don't work from home in your bedroom for example) helps.

• Exercise: Get 150+ minutes/week of varied exercise (Zone 2 cardio, HIIT, resistance training). I do strength training at least twice a week, lots of cardio and regular movement (walks, hiking, etc.), the occasional yoga class, and MMA/BJJ as a hobby.

• Nutrition: Eat a balanced diet rich in colorful produce, lean proteins, high fiber, healthy fats, and pre/probiotics; limit processed foods and sugar. I usually either have a high fiber protein shake or eggs/sausages for breakfast, salad + lean protein for lunch, lean protein + carbs + lots of veggies for dinner and go for a walk afterwards, and snack on things like salted fancy mixed nuts or veggies. I think it's probably a good idea to supplement with vitamin D, fish oil, and creatine. Ideally you'll get blood work done to check for deficiencies and supplement accordingly. In general, you should be able to get your key needs from eating good high quality food, but I've read about things like less minerals and "good stuff" in the soil your vegetables grow in these days... who the hell knows, but maybe there's something to that. I've also read about various pesticides and plastics and that kind of thing... might be worth buying more organic / local stuff if it's in your budget. I'll follow up in another article if I ever learn more about this or do any testing.

• Hydration: Drink plenty of water throughout the day to support immune function. I try to mostly just drink water and to have lots of it. I also have black coffee and the occasional seltzer (0 calorie carbonated drink). Alcohol is pretty rare, but every once in a while I'll have a nice glass of wine or a good whiskey/scotch. One little trick is to have a big jug of ice cold water setup and chug this first thing. I also sometimes set a reminder on my phone to drink water or put rubber bands on my water bottle to track and keep myself accountable. I have a Hydro Flask that keeps things really cold, but have thought about getting one of those fancy water bottles that sanitizes everything with UV. I make sure to replace the water filter in my refrigerator regularly, and I have thought about buying more bottled water (in glass bottles to avoid microplastics) but don't do this now.

• Stress Management: Address major stressors and incorporate stress-reducing activities (e.g., exercise, meditation, hobbies). For me, the biggest things are to avoid lying, make sure I'm living in a way that is aligned with my values, exercise regularly, eat well, get lots of high quality sleep, have good sex / intimacy, spend time doing things I enjoy with friends / family, etc. I've noticed that I feel better personally when I get plenty of time in the sunshine / daylight and when I spend time in nature (particularly the ocean or the mountains for me). Try to make it a habit to get outside in the sun every day if you can (wear sunscreen as appropriate), and take plenty of trips / vacations / hikes or find ways to spend time in nature if you can. I've also noticed that there is "good stress" that makes me feel excited and like I'm pushing forward in life... and there is "bad stress" that drags on me. Usually the bad stress is caused by my own actions (eating poorly, procrastinating on important work, etc.).

• Balance Social Connection with Risk: In general, I would rather error on the side of getting sick and having lots of time with my loved ones. Kids are absolutely little threat vectors for illness, but they're also so much fun to play with and they're worth every cold you get. You should balance this though obviously, if one of them has a fever or you know they're sick / highly contagious, if there is an outbreak of something like covid, etc... then be more cautious. Hand sanitizer is your friend here. I think it's really important to spend time with people you like, doing things you enjoy -- we are social creatures and we crave social connections. For me, I get this from family, some of my more social hobbies, at work, etc.

Remember: This two-pronged approach minimizes pathogen exposure and maximizes your body's natural defenses. Consistency is key. Start by incorporating a few of these actions into your daily routine and gradually add more over time. Your immune system will benefit from even small, consistent improvements in your lifestyle habits. If you had to focus on just a couple things I would pay the most attention to washing your hands, trying to avoid touching your face, keeping your environment clean (e.g. wiping down counters), and getting high quality sleep