Winter Foods & Practices That Help Support Immune Health

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Your Good Farm in-house nutritionist. Here to bring you essential information on nutrition, diet and permaculture gardening - in a bite size, easy to understand, science-backed way.

Winter Foods & Practices That Help Support Immune Health

Some of the most powerful tools for supporting immune resilience are remarkably simple: the foods we eat, how we prepare them, how often we move, and how much sunlight reaches our skin.

Winter has historically been a season of reduced sunlight exposure, more time spent indoors, and increased circulation of respiratory infections. Interestingly, many traditional winter foods are naturally rich in nutrients and plant compounds that help support immune function during this time of year.

This week, we will explore winter foods, nutrients, and simple strategies that may help support immune health through the colder months. Next week, in Part 2, we will explore winter practices such as sleep, heat therapy, and lymphatic movement.

Garlic

Garlic’s most studied therapeutic compound is allicin, known for its antibacterial, antiviral, antifungal, and antimicrobial properties.

But garlic does not naturally contain allicin in its intact form.

When a garlic clove is chopped, crushed, or chewed, an enzyme called alliinase converts a compound called alliin into allicin. This means garlic becomes significantly more biologically active after it is damaged.

One of the simplest ways to maximise garlic’s therapeutic potential is to:
• crush or finely chop it at the beginning of your food prep
• allow it to sit for 10 minutes before cooking
• then add it toward the end of cooking where possible

High heat can deactivate the enzyme responsible for allicin formation before it has time to develop.

Research suggests garlic compounds may:
• inhibit bacterial and viral growth
• support immune cell activity
• reduce inflammatory signalling
• help shorten the duration or severity of common colds in some individuals

Raw or lightly cooked garlic tends to retain the greatest therapeutic activity.

If a recipe calls for one clove of garlic, don’t be afraid to use four, particularly during winter when these compounds may be especially supportive.

Where possible, choose Australian-grown garlic, as much imported garlic is chemically treated or fumigated after harvest to extend shelf life and prevent sprouting during transport.

Ginger

Ginger contains bioactive compounds called gingerols and shogaols, which possess anti-inflammatory, antioxidant, warming, and immune supportive properties.

Fresh ginger is particularly useful in winter due to its traditional use in supporting:
• circulation
• mucus clearance
• throat irritation
• nausea
• cold sensitivity

Research suggests certain plant compounds may influence viral attachment and replication processes, particularly within mucosal tissues, although human evidence remains limited. In practice, ginger is likely most beneficial not as a single dose, but through regular, repeated intake throughout the day.

Traditionally, ginger decoctions were sipped slowly over time, which may help maintain gentle warming and soothing effects on the throat and upper respiratory tract while providing ongoing exposure to active compounds. Regularly sipping a strong ginger tea may also provide a more therapeutic and soothing alternative to many throat lozenges, which are often high in sugar and contain minimal active herbal ingredients.

Rather than steeping ginger briefly:
• finely slice or crush fresh ginger
• simmer gently for 15–20 minutes
• add lemon and raw honey once slightly cooled

Make a batch and drink from a thermos for continued sipping throughout the day.

Where possible, choose organic ginger and use the whole rhizome, including the peel, which contains additional aromatic oils and plant compounds.

Chicken Soup

Chicken soup has a long history across many traditional food cultures as a restorative food during illness and recovery. Long before the mechanisms were understood, cuisines around the world intuitively combined bones, meat, herbs, vegetables, and aromatic ingredients into deeply nourishing broths during winter and periods of infection.

A properly prepared chicken soup or traditional stock/broth provides:
• fluids and electrolytes
• easily digested protein
• amino acids such as cysteine and glycine
• minerals released during cooking
• gelatin and collagen-derived compounds from bones and connective tissue

What is now commonly referred to as “bone broth” was traditionally a long-simmered stock made using bones, joints, skin, feet, and connective tissue.

Stocks were simmered for many hours using bone-in chicken, joints, skin, feet, and connective tissue. This process creates the rich gelatinous texture characteristic of homemade stock while releasing compounds that may help support hydration, gut lining integrity, and overall recovery during illness.

Stocks are also an excellent way to utilise nutrient-dense ingredients that may otherwise be discarded, including onion and garlic skins, leek tops, herb stems, pumpkin peel, celery leaves, and citrus peel. Many of these contain concentrated minerals, polyphenols, sulphur compounds, and aromatic oils that infuse into the broth over time.

To maximise nutrient density:
• use pasture-raised bone-in chicken and include skin, joints, carcass pieces, or feet
• add onion, garlic, ginger, celery, carrots, leek tops, and fresh herbs
• simmer gently for 12-24 hours
• Add a small splash of vinegar during cooking to help extract minerals and gelatin

Many of our chicken meals contain our homemade chicken stock, made with our regenerative chicken bones. Like our Chicken and Leek, Chicken Curry pie and Chicken and Mushroom Pie to name a few. Explore our pasture raised chicken options here

Probiotics During Winter

A significant portion of the immune system interacts closely with the gut and its resident microbes. During winter, several factors may negatively influence microbiome diversity and resilience, including:
• reduced sunlight exposure
• lower dietary diversity
• increased indoor living
• stress
• poorer sleep
• more processed comfort foods
• greater antibiotic use

This is one reason fermented foods and targeted probiotics may be particularly supportive during colder months.

Traditional fermented foods naturally contain a wide variety of organisms and metabolites. Regularly consuming fermented foods may help expose the gut to a broader diversity of beneficial microbes and postbiotic compounds. Examples include:
• kefir
• yoghurt
• sauerkraut
• kimchi
• miso
• traditionally fermented vegetables

Some of the probiotic strains most researched for immune and respiratory health include:
• Lactobacillus rhamnosus GG
• Lactobacillus plantarum
• Bifidobacterium lactis BB-12
• Saccharomyces boulardii CNCM I-745

These strains have been studied for their role in:
• supporting immune signalling
• strengthening gut barrier integrity
• supporting mucosal immunity
• modestly reducing the risk, severity, or duration of upper respiratory infections

For children, particularly those with highly selective or restricted diets, regular intake of fermented foods may be unrealistic. In these situations, a targeted probiotic may provide additional support during winter months, especially for children with frequent school or daycare exposure, recurrent antibiotic use, or repeated respiratory infections.

Importantly, many probiotic organisms do not appear to permanently colonise the gut. Much of their benefit is thought to occur while they are actively interacting with the gastrointestinal and immune environment. In this context, probiotic supplements may be best viewed as a short-term, consistent therapeutic support used alongside broader dietary and lifestyle changes, while long-term microbiome health is more sustainably shaped through ongoing intake of fibre-rich whole foods, diverse plant foods, and traditionally fermented foods where tolerated.

Vitamin D

Vitamin D behaves more like a hormone than a vitamin and plays a major role in immune regulation.

During winter, vitamin D levels commonly decline due to:
• shorter daylight hours
• increased time indoors
• heavier clothing coverage
• sunscreen use
• reduced UVB exposure

The body synthesises vitamin D when UVB light from sunlight interacts with the skin. When exposure time is limited, the amount of skin exposed becomes particularly important, as larger surface areas produce significantly more vitamin D than smaller exposed areas such as the face and hands.

Paler, less chronically sun-exposed areas of the body also tend to produce vitamin D more efficiently. Areas that are regularly exposed to sunlight may develop adaptive changes, such as increased pigmentation, which can reduce further vitamin D synthesis.

While food alone is generally insufficient to correct deficiency, some foods help to support overall intake:
• sardines
• salmon
• egg yolks
• cod liver oil
• liver

Cod liver oil is particularly notable historically, having been widely used in traditional European diets long before vitamin D was identified. Its longstanding use reflects observed benefits in supporting health, later understood through modern nutritional science.

Zinc + Vitamin C

Zinc and vitamin C are two of the most studied nutrients in relation to immune function, particularly during winter months when respiratory infections tend to increase.

Both nutrients play complementary roles in supporting the body’s defence systems.

Vitamin C contributes to:
• immune cell function and communication
• antioxidant protection against oxidative stress
• collagen production and maintenance of mucosal barriers that support the respiratory tract

Winter foods naturally rich in vitamin C include:
• citrus fruits such as oranges, mandarins, and lemons
• kiwi fruit
• broccoli
• Brussels sprouts
• cauliflower
• cabbage
• kale

Zinc is involved in:
• development and function of immune cells
• maintenance of skin and mucosal integrity
• antiviral defence pathways
• wound healing and tissue repair
• regulation of inflammatory responses

Low zinc status appears relatively common, particularly in individuals with poor appetite, restrictive diets, gastrointestinal issues, high stress, or low animal food intake (refer to last week’s article on zinc here).

Foods rich in zinc include:
• oysters and shellfish
• red meat
• eggs
• pumpkin seeds
• legumes

Supplementation is widely used during winter, though excessive doses are not necessarily better and may cause adverse effects. Long-term high-dose zinc supplementation may interfere with copper balance.

A food-first approach remains the foundation wherever possible.

Cruciferous Vegetables

Cruciferous vegetables are naturally in season during the cooler months, making them a valuable addition to winter meals. Vegetables such as broccoli, cauliflower, cabbage, kale, Brussels sprouts, bok choy, rocket, radishes, and watercress contain compounds that may help support immune regulation, antioxidant pathways, detoxification processes, and gut health.

They are particularly rich in glucosinolates, which are converted into beneficial compounds such as sulforaphane when chopped or chewed. These vegetables also provide fibre, vitamin C, folate, and a wide range of phytonutrients that help nourish the gut microbiome, an important component of immune health.

Interestingly, exposure to cold weather and light frost may increase the natural sugar and antioxidant content of some cruciferous vegetables, particularly broccoli, kale, and Brussels sprouts, often making them sweeter and more flavourful during winter.

To help maximise beneficial compounds:
• chop vegetables before cooking and allow them to sit for 10–15 minutes
• use gentle cooking methods such as steaming or sautéing
• include some raw forms where tolerated, such as rocket, radish, or watercress

Up Next

Next week, we’ll explore simple winter practices that help support immune health and recovery, including lymphatic movement, heat therapy, and the crucial role sleep plays in immune regulation and resilience.

References

Bayan L, Koulivand PH, Gorji A. Garlic: a review of potential therapeutic effects. Avicenna Journal of Phytomedicine. 2014.

Calder PC. Nutrition, immunity and COVID-19. BMJ Nutrition, Prevention & Health. 2020.

Fahey JW et al. Sulforaphane bioavailability from glucosinolate-rich broccoli. Proceedings of the Nutrition Society. 2012.

Gombart AF, Pierre A, Maggini S. A review of micronutrients and the immune system. Nutrients. 2020.

Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews. 2013.

Marco ML et al. Health benefits of fermented foods: microbiota and beyond. Current Opinion in Biotechnology. 2017.

Martineau AR et al. Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis. BMJ. 2017.

Mao QQ et al. Bioactive compounds and biological functions of ginger. Food Science and Human Wellness. 2019.

Percival SS. Probiotics and immune health. Nutrition in Clinical Practice. 2011.

Rondanelli M et al. Self-care for common colds: the pivotal role of vitamin D, vitamin C, zinc and echinacea. Evidence-Based Complementary and Alternative Medicine. 2018.

Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews. 2013.