Protecting Your Immune System This Winter: Evidence-Based Nutrition & Lifestyle Tips

As winter approaches, so do the inevitable colds, flu viruses, and lingering respiratory infections. While there’s no magic supplement or “immune booster,” there are several evidence-based nutrition and lifestyle strategies that can help support a healthy immune system and improve resilience during the colder months.

Your immune system is complex and relies on adequate nutrition, good sleep, stress management, movement, and gut health to function optimally. Here are some practical ways to support it naturally this winter.

1. Focus on Nutrient-Dense Foods

Vitamin C-Rich Foods

Vitamin C acts as an antioxidant and supports several immune functions, including the activity of white blood cells. While it won’t necessarily prevent colds altogether, adequate intake may help reduce the severity or duration of illness in some people.

Excellent food sources include:

• Citrus fruits (oranges, naartjies, grapefruit)

• Kiwi fruit

• Strawberries

• Guavas

• Red peppers

• Broccoli

• Tomatoes

Try to include at least one vitamin C-rich food with most meals during winter.

Beta-Carotene & Vitamin A

Beta-carotene is converted into vitamin A in the body, which plays an important role in maintaining the integrity of the skin, respiratory tract, and gut lining, all key barriers against infection.

Good sources include:

• Sweet potato

• Pumpkin

• Butternut

• Carrots

• Spinach

• Kale

• Mango

Cooking these vegetables with a small amount of healthy fat (such as olive oil) improves absorption.

Zinc-Rich Foods

Zinc is involved in immune cell development and communication. Low zinc status may impair immune function and wound healing.

Foods rich in zinc include:

• Oysters and seafood

• Beef and lamb

• Chicken

• Pumpkin seeds

• Cashews

• Lentils and chickpeas

• Eggs

Long-term high-dose zinc supplementation is not recommended unless prescribed, as excessive zinc can interfere with copper absorption.

Vitamin D

Vitamin D plays a major role in immune regulation and deficiency is common, particularly in winter or in people who spend most of the day indoors.

Sources include:

• Sunlight exposure

• Fatty fish (salmon, sardines, mackerel)

• Egg yolks

• Fortified dairy or plant milks

Some individuals may benefit from supplementation, especially if blood levels are low, but it’s best to discuss this with a healthcare professional.

Quercetin Rich Foods

Quercetin is a plant compound with antioxidant and anti-inflammatory properties. Emerging research suggests it may help modulate immune responses and support respiratory health.

Foods naturally rich in quercetin include:

• Red onions

• Apples

• Berries

• Grapes

• Kale

• Capers

• Broccoli

• Green tea

Combining quercetin rich foods with vitamin C-containing foods may help improve absorption and activity.

2. Don’t Forget Gut Health

Around 70% of the immune system is associated with the gut, making digestive health an important part of immune resilience.

A healthy gut microbiome helps regulate inflammation, supports the immune response, and may even influence how we respond to infections.

Ways to Support Gut Health

Eat More Fibre

Aim to include a variety of plant foods daily:

• Vegetables

• Fruit

• Oats

• Legumes

• Nuts and seeds

• Whole grains

These provide prebiotic fibres that help feed beneficial gut bacteria.

Include Fermented Foods

Fermented foods may help support microbial diversity.

Examples include:

• Plain yoghurt with live cultures

• Kefir

• Sauerkraut

• Kimchi

• Kombucha

• Miso

  
  

Consider Probiotics Carefully

Not all probiotics are the same, and their effects are strain-specific. Certain probiotic strains may modestly reduce the frequency or duration of upper respiratory tract infections, particularly during winter months.

3. Herbal Remedies: What Does the Evidence Say?

Herbal medicine can be useful in some situations, but “natural” does not always mean harmless. It’s important to use herbs thoughtfully and avoid prolonged or excessive use.

Echinacea

Echinacea is commonly used at the onset of colds and may modestly reduce symptom severity or duration in some people.

However:

• Evidence is mixed

• It’s generally recommended for short-term use only

• Long-term continuous use is not advised

• People with autoimmune conditions should speak to a healthcare provider before using it regularly

  
  

Pelargonium sidoides (Umckaloabo)

Pelargonium sidoides — a South African herbal remedy — has some evidence supporting its use for acute respiratory infections and bronchitis.

Research suggests it may help:

• Reduce cough severity

• Improve recovery time

• Ease upper respiratory symptoms

It is generally used short term during acute illness rather than as a daily preventative.

Ginger & Turmeric

Both ginger and turmeric contain anti-inflammatory compounds and are commonly used to support general wellness during winter.

• Ginger may help soothe sore throats and nausea

• Turmeric contains curcumin, a compound with anti-inflammatory properties

• Combining turmeric with black pepper improves curcumin absorption

  
  

4. Lifestyle Habits Matter Too

Nutrition is only one piece of the puzzle.

To support immune health this winter:

• Prioritise sleep

• Stay physically active

• Manage stress levels

• Avoid smoking

• Limit excessive alcohol intake

• Stay hydrated

Even mild dehydration can impact energy, concentration, and overall wellbeing.

Warming Winter Immune-Support Hot Toddy

This comforting alcohol-free winter drink combines ingredients traditionally used to support immunity, soothe the throat, and reduce inflammation.

Ginger Turmeric Hot Toddy

Ingredients

• 1 cup hot water

• 1–2 cm fresh ginger, sliced

• ½ tsp turmeric

• Juice of ½ lemon

• 1 tsp honey

• Pinch of black pepper

• Optional: cinnamon stick

Method

1. Add ginger and turmeric to hot water and steep for 5–10 minutes.

2. Stir in lemon juice, honey, and black pepper.

3. Add cinnamon if desired and serve warm.

Potential Benefits

• Ginger may help soothe the throat and support circulation

• Turmeric provides anti-inflammatory compounds

• Lemon contributes vitamin C

• Honey may help ease coughs and throat irritation

• Black pepper enhances curcumin absorption from turmeric