Immune Support

Immune System

The immune system depends on a continuous supply of micronutrients to mount effective defenses. Deficiency in even a single key nutrient — vitamin D, zinc, vitamin C, or selenium — measurably impairs immune response and increases infection risk and severity.

Overview

Nutritional Immunology: The Key Micronutrients

Vitamin D is perhaps the most critical immune-regulating nutrient. Vitamin D receptors (VDRs) are expressed on virtually every immune cell — T cells, B cells, macrophages, and dendritic cells. Vitamin D promotes production of antimicrobial peptides (cathelicidins) and modulates the inflammatory response. Deficiency (below 50 nmol/L) is associated with 1.6-fold increased risk of upper respiratory infections. A meta-analysis of 25 randomized trials found vitamin D supplementation reduced acute respiratory infection risk by 12–70%, with larger effects in severely deficient individuals.

Zinc is required for the development and activation of T cells, natural killer cells, and macrophages. Zinc lozenges (not supplements) started within 24 hours of cold symptom onset reduce cold duration by 33% and symptom severity significantly — one of the most replicated findings in cold research. Dietary zinc sources: oysters (highest), beef, pumpkin seeds, chickpeas.

Elderberry (Sambucus nigra) contains anthocyanins that inhibit viral cell entry and stimulate cytokine production. A 2016 randomized trial found elderberry extract reduced cold duration by 2 days and severity by 50% in air travelers. Quercetin (in capers, red onion, apples) inhibits viral replication through protease inhibition.

Recipes & Remedies

Evidence-Based Recipes

Immunity-Boosting Chicken & Turmeric Broth
Zinc, selenium, and anti-inflammatory compounds in one healing bowl
1.5 hrsServes 4

Ingredients

  • 1 whole chicken carcass or 500g chicken legs
  • 2L cold water
  • 3 carrots, roughly chopped
  • 3 celery stalks
  • 1 large onion, halved
  • 1 whole garlic head, halved crosswise
  • 2cm fresh ginger
  • 2cm fresh turmeric (or 1 tsp ground)
  • 1 tsp black peppercorns
  • 2 bay leaves
  • Fresh parsley stems
  • Salt to taste

Preparation

  1. Place chicken in a large pot. Cover with cold water. Bring slowly to a simmer, skimming foam.
  2. Add all vegetables, garlic, ginger, turmeric, peppercorns, and bay leaves.
  3. Simmer uncovered on very low heat for at least 90 minutes. The longer, the better.
  4. Strain through a fine sieve. Season well with salt.
  5. Serve as a warm broth, or use as a base for soups. Refrigerate overnight and skim the fat layer if desired.
Bone broth provides glycine (anti-inflammatory amino acid), proline, and hydroxyproline that support mucosal immunity — the first line of defense against respiratory and gastrointestinal pathogens. The chicken provides zinc and selenium — selenium is required for selenoproteins that regulate oxidative stress during infection. Garlic contains allicin, a compound with demonstrated broad-spectrum antimicrobial activity. Turmeric's curcumin modulates NF-κB, reducing the cytokine storm amplification that worsens infection outcomes.
Zinc-Rich Pumpkin Seed & Chickpea Power Salad
Plant-based zinc and quercetin for immune activation
15 minServes 2

Ingredients

  • 100g chickpeas (cooked/tinned), rinsed
  • 60g pumpkin seeds, lightly toasted
  • 100g mixed leaves
  • 1 large apple, cored and thinly sliced
  • 3 tbsp capers (quercetin)
  • ½ small red onion, finely sliced (quercetin)
  • Dressing: 3 tbsp olive oil, 1 tbsp lemon juice, 1 tsp honey, 1 tsp Dijon, salt, pepper

Preparation

  1. Whisk dressing ingredients together.
  2. Combine mixed leaves, chickpeas, apple slices, red onion, and capers in a large bowl.
  3. Toss with dressing.
  4. Top with toasted pumpkin seeds.
Pumpkin seeds provide 2.2mg zinc per 30g — combined with chickpeas (1.3mg per 100g), this salad provides meaningful zinc toward the 8–11mg daily requirement. Quercetin in capers (234mg/100g — highest dietary source) and red onion inhibits viral protease enzymes that many RNA viruses rely on for replication. Apples provide soluble fiber for microbiome support and quercetin in the skin. Olive oil's oleocanthal has similar COX-inhibiting activity to ibuprofen, reducing inflammatory amplification during infection.
Food Guide

What to Eat & What to Limit

Beneficial Foods

  • Vitamin D foods — oily fish, egg yolks, fortified milk
  • Zinc — oysters, beef, pumpkin seeds, chickpeas
  • Vitamin C — bell peppers, citrus, kiwi, broccoli
  • Elderberry and elderflower
  • Garlic and onion (allicin, quercetin)
  • Ginger (anti-inflammatory, antimicrobial)
  • Fermented foods (gut microbiome = immune training)
  • Selenium — Brazil nuts (1–2/day is sufficient dose)
  • Echinacea tea
  • Colorful vegetables (diverse antioxidants)

Limit or Avoid

  • Excess sugar (impairs neutrophil function for hours after consumption)
  • Alcohol in excess (immunosuppressive at >14 units/week)
  • Highly processed foods (promote inflammatory baseline)
  • Crash diets (severe calorie restriction impairs immune function)
  • Very low-fat diet (fat-soluble vitamins A, D, E, K impaired)

Wine & Immunity: Polyphenols vs. Alcohol

Moderate wine may train immunity; excess alcohol suppresses it severely

Resveratrol and Immune Modulation
Resveratrol activates SIRT1 and inhibits NF-κB — reducing chronic inflammatory activation that exhausts the immune system. Research shows resveratrol enhances natural killer cell activity and improves the immune response to vaccination in older adults. These effects require consistent, moderate intake — the polyphenol benefit disappears with higher alcohol consumption that damages immune cells. Explore Grenache →
Alcohol Above 14 Units/Week: Immunosuppression
Heavy alcohol consumption disrupts every arm of immune function: it reduces circulating lymphocytes, impairs neutrophil phagocytosis, disrupts the gut microbiome (reducing immune training), damages mucosal barriers, and depletes zinc and vitamin C. Studies show heavy drinkers have 3–7 times higher risk of pneumonia than non-drinkers and impaired responses to vaccines.
Red Wine and Polyphenol Synergy with Immune Foods
A glass of Grenache or Tempranillo alongside the immune-boosting chickpea salad creates an interesting polyphenol-quercetin synergy. The wine's resveratrol and the salad's quercetin both inhibit viral replication pathways through complementary mechanisms. Keep the wine to one glass to maintain the immune benefit rather than triggering alcohol-induced immunosuppression.
Important Notice

Signs of Compromised Immunity Requiring Medical Review

Occasional infections are normal. Seek medical evaluation if:

  • You have more than 3–4 significant respiratory infections per year
  • Infections are unusually severe, prolonged, or caused by atypical organisms
  • You have not recovered full energy for more than 4 weeks after an illness
  • You are on immunosuppressive medications — dietary planning needs medical oversight
  • Recurring fungal infections such as oral thrush or nail fungus (possible immune deficiency)