7 Evidence-Based Ways to Avoid Colds & Flu This Winter (That Actually Work)
It's that time of year again. Everyone around you is sniffling, coughing, and reaching for the tissues. You're washing your hands constantly, avoiding crowded places, and crossing your fingers you don't "catch something" before Christmas.
But here's what most people don't realize: your immune system isn't about luck.
After working with clients through multiple winter seasons, I've seen first hand that the people who stay well aren't just "lucky" - they're doing specific things to support their immune system that most people overlook.
Let me share what actually works (backed by evidence, not just wellness trends).
1. Your Gut Health Is Your First Line of Defence
Here's the science: 70-80% of your immune system lives in your gut. If your digestive system is struggling, your immunity is compromised - simple as that.
What this looks like in real life:
Bloating after meals
Irregular bowel movements
Food sensitivities
You’ve taken antibiotics recently
High stress affecting digestion
What to do about it:
Eat fermented foods daily:
Live yogurt (not the sugary kind)
Kefir
Sauerkraut (unpasteurized)
Kimchi
Kombucha
Even just 2-3 tablespoons daily makes a measurable difference. If you’re new to this then build up slowly to avoid digestive discomfort.
Feed your good bacteria:
Oats
Onions and garlic (prebiotic powerhouses)
Bananas (especially slightly green ones)
Asparagus
Jerusalem artichokes
Avoid what damages your gut:
Excessive alcohol (suppresses immunity for up to 24 hours)
Ultra-processed foods
Unnecessary antibiotics
Chronic stress (more on this later)
2. Vitamin D: The Winter Essential You're Probably Deficient In
The reality in the UK: From October to March, we simply cannot get enough vitamin D from sunlight. It's not possible at our latitude.
Why this matters for immunity: Vitamin D isn't just a vitamin - it's actually more like a hormone and it helps to regulate immune cell function. Low levels are directly linked to increased susceptibility to respiratory infections.
What the research shows: Studies show that people with vitamin D levels below 30 ng/mL are significantly more likely to develop upper respiratory tract infections.
What you need:
Supplement dose:
Maintenance: 1,000-2,000 IU daily (October-March minimum)
If you're rarely outdoors or have darker skin: 2,000-4,000 IU daily
Get tested: Ask your GP for a vitamin D test (it's free on NHS if you have symptoms)
Food sources (these are helpful but not sufficient on their own to raise levels):
Oily fish (salmon, mackerel, sardines)
Egg yolks
Mushrooms exposed to UV light
Fortified foods
Pro tip: Take vitamin D with a meal containing fat (it's fat-soluble, so absorption is much better with food).
When to get personalised support: If you've been supplementing vitamin D but still feel exhausted, or you're not sure what dose is right for your health status, testing and personalized assessment can make all the difference. I can help with testing and advice on how much to take and which supplements work best. Drop me a message!
3. Sleep: The Immunity Superpower Everyone Ignores
The hard truth: If you're getting less than 7 hours of sleep regularly, you're more likely to develop a cold when exposed to the virus.
What happens when you don't sleep enough:
Your body produces fewer cytokines (proteins that fight infection)
T-cell function decreases
Inflammatory markers increase
Your body can't properly "remember" past infections
It's not just about hours - it's about quality:
Sleep hygiene basics that actually work:
Same bedtime every night (yes, even weekends)
Bedroom temperature 16-18°C
Pitch black room (blackout curtains or eye mask)
No screens 1 hour before bed
A Magnesium glycinate supplement may help if you struggle to switch off
What's sabotaging your sleep:
Alcohol (disrupts REM sleep even if you fall asleep faster)
Caffeine after 2pm
Large meals close to bedtime
Stress and cortisol (see next point)
4. Manage Your Stress Before It Manages Your Immunity
The connection: Chronic stress produces cortisol, which directly suppresses your immune system. It's not "woo-woo", it's measurable physiology.
Real talk: I can't tell you to "just stress less" when you're juggling work, family, aging parents, and everything else. But you CAN change how your body responds to stress.
Evidence-based stress management:
Daily non-negotiables:
10 minutes of movement - even a walk around the block lowers cortisol
Breathwork - 4-7-8 breathing (inhale 4 counts, hold 7, exhale 8) activates your parasympathetic nervous system
Connection - phone a friend, hug your partner, cuddle your pet (oxytocin is protective)
What makes stress worse:
Skipping meals (blood sugar crashes = cortisol spike)
Too much caffeine (amplifies stress response)
Poor boundaries (saying yes when you mean no)
Doomscrolling before bed
5. Eat Protein at Every Meal
Why protein matters for immunity: Your immune cells are literally made of protein. Antibodies? Protein. Cytokines? Protein. T-cells? You guessed it - protein.
If you're not eating enough, your body can't mount an effective immune response.
How much do you need?
Aim for: 20-30g per meal
What 20-30g of protein looks like:
100-120g cooked chicken breast
120-150g cooked salmon
3 large eggs
150g Greek yogurt + 30g nuts
150g tofu + quinoa
Why this is often the missing piece:
Many women I work with are having toast for breakfast (5g protein), salad for lunch (10g protein), “proper” dinner (25g protein).
That's only 40g total!
Quick wins:
Add eggs to breakfast
Include protein in every snack
Double your lunch protein portion
Consider a quality protein powder if you struggle to eat enough.
6. Hydration: The Boring Essential That Actually Matters
What dehydration does to immunity:
Thickens mucus (your first defence barrier)
Reduces lymph flow (how immune cells travel)
Impairs detoxification
Decreases nutrient delivery to cells
How much water do you actually need?
Minimum: 2 litres (8 glasses) daily
More if: You exercise, drink coffee, or are in heated environments
Hydrating foods count too:
Cucumber
Watermelon
Oranges
Soup and stews
Herbal teas
7. Move Your Body (But Not Too Much!)
The sweet spot: Moderate exercise boosts immunity. Intense exercise (without proper recovery) suppresses it.
What the research shows:
30-45 minutes of moderate activity daily = 40-50% reduction in sick days
Marathon-level training without adequate nutrition = higher infection rates
Complete inactivity = impaired immune function
The Goldilocks principle:
Good for immunity:
Brisk walking
Cycling
Swimming
Yoga
Strength training with adequate rest
Dancing
Gardening
Can suppress immunity (temporarily):
Marathon training
High-intensity training daily without recovery
Overtraining syndrome
Exercise when you're already run down
Listen to your body:
Feeling a cold coming? Gentle movement only
Already sick? Rest completely
Exhausted? Your body needs recovery, not another workout
The Foods That Actually Boost Immunity (And the Ones That Don't)
EAT MORE:
Vitamin C rich foods:
Red peppers (more vitamin C than oranges!)
Kiwi fruit
Broccoli
Brussels sprouts
Strawberries
Zinc sources:
Oysters (highest source)
Red meat
Pumpkin seeds
Chickpeas
Cashews
Immune-supporting alliums:
Garlic (crushed and left to sit for 10 mins = maximum benefit)
Onions
Leeks
Shallots
Anti-inflammatory foods:
Oily fish (salmon, mackerel, sardines)
Turmeric with black pepper
Ginger
Berries
Leafy greens
EAT LESS:
Sugar
Alcohol
Ultra-processed foods - lack nutrients, increase inflammation
Excessive refined carbs
The Winter Immunity Checklist
Use this daily checklist through cold and flu season (well all year round really!)
Daily non-negotiables:
2L water minimum
20-30g protein at each meal
2+ servings of vegetables with lunch and dinner
7-8 hours sleep
30 minutes movement
Vitamin D supplement
Fermented food (yogurt, kefir, sauerkraut)
Stress management practice (even 5 minutes)
Weekly support:
2-3 portions oily fish or omega-3 supplement
Batch cook immune-supporting meals
Check in with stress levels - adjust as needed
Plan next week's meals (redruces stress + ensures good nutrition)
The Bottom Line
Avoiding every cold and flu this winter isn't realistic. Viruses exist, and we're human.
But what IS achievable:
Catching fewer colds
Recovering faster when you do get sick
Not getting every bug that goes around
Maintaining your energy through winter
The difference between people who are constantly ill and those who stay well isn't luck - it's these daily habits compounding over time.
You don't need to do everything perfectly. Pick 3-4 of these strategies, implement them consistently for the next month, and see how you feel.
When DIY Isn't Enough
If you're doing "all the right things" and still:
Taking weeks to recover from colds
Constantly exhausted
Struggling with recurring infections
Your symptoms are getting worse, not better
You have multiple health issues (gut + hormones + energy)
You're overwhelmed and don't know where to start
You want TESTING to see what's actually going on
There might be something deeper going on:
Underlying gut dysbiosis
Nutrient deficiencies
Chronic stress affecting your HPA axis
Food sensitivities triggering inflammation
Hormone imbalances
This is where personalised nutritional therapy can make all the difference. We can test, identify root causes, and create a plan specifically for YOUR body.
Book a free 20-minute discovery call to discuss whether nutritional therapy could help you
Final Thoughts
Winter doesn't have to mean inevitable illness. Your immune system is incredibly powerful when properly supported.
These aren't quick fixes or trendy hacks - they're evidence-based strategies that work with your body's natural defenses.
Start with one or two changes this week. Build from there. By Christmas, you'll notice the difference.