Days are short, temperatures are dropping, and the festive season is about to kick start... it also means that the cold & flu season is upon us!
So, what can we do to reduce our risk to get ill during the winter?
First of all, you should consider getting a flu-jab. It is not a comprehensive insurance against all illnesses but it will help your body to fight off some of the nasty viruses out there.
But you can also support your body’s immune system through a few lifestyle and nutrition choices. Here are a few ideas:
1. Take vitamin D throughout the winter
There is more and more evidence that good levels of vitamin D help our immune system throughout the year and that it might protect from upper respiratory tract infection[1].
And guess what – in the winter our vitamin D levels tend to be low. This is because most of our vitamin D intake is actually produced by our body from the sun, while very little comes from our food. If you live in Northern Europe, even on sunny winter day, the body cannot synthesise enough vitamin D.
Your only option is to take a vitamin D3 supplement every day.
2. Enjoy all the vitamin C rich food you can find
Vitamin C plays many functions in our health beyond the protection against scurvy. It has been shown protect from cold, although this is mainly true amongst athletes. For the general population, its truly beneficial effect has been mainly observed in reducing the length of a cold[2].
You should aim at 200mg every day and can take up to 1,000mg when unwell, but be aware that too much can create some abdominal pain and diarrhoea. Such side effects do not occur with food though so, although supplement might be useful when you have a cold, it is much better to get your vitamins and minerals from food (with the exception of vitamin D, as explained above). And thankfully, there is no shortage of vitamin C rich food:
Citrus fruit (1 orange = 70mg)
Kiwi (1 kiwi = 35mg)
Broccoli (4 florets = 50mg)
Red or yellow pepper (1/2 pepper = 85mg)
Cauliflower (80g = 25mg)
Kale (50g = 55mg)
Parsley (1 tbsp = 5mg)
3. A bit Zinc to keep your immune system strengthened up
We don’t need much zinc. The recommendation per day is of 11mg for men and 8mg for women. Yet, it is a crucial in the good functioning our immune defence mechanism.
Good daily intake of zinc appears to reduce the occurrence of cold. And when suffering of the common cold, there is evidence that taking zinc lozenges will reduce the length and the severity of the cold[3].
Here are some good sources:
Meat (e.g. 100g of beef = 4.3mg)
Shellfish (e.g. 100g prawns = 1mg)
Legumes - i.e., chickpeas, beans, lentils (e.g. 70g lentils = 2.24mg)
Nuts, especially cashews, pine nuts, pecans (e.g. 30g cashews = 1.68mg)
Seeds (e.g. 1 tbsp pumpkin seeds = 2mg)
4. Look after your gut microbiota eating pre- and probiotics
It might be a good idea to boost your gut microbiota by feeding it the right stuff[4].
Add some fermented food to your diet such as raw sauerkraut and kefir. These foods are rich in probiotics, beneficial bacteria such as bifidobacterium and lactobacillus. The idea is that some of these ingested bacteria will settle in your gut and will work for your health.
And if, in addition, you eat a lot of food rich dietary fibre such as wholegrain, artichoke, leeks and legumes – what we call prebiotics - you will enable the good bacteria to thrive and proliferate, increasing your chance of good health.
We don’t understand yet all the potential of the gut microbiota but we have some good evidence that large and diverse gut microbiome, rich in bifidobacterium and lactobacillus, is linked to good immune functions[5].
5. Be mindful of your drinking
During the festive season, your alcohol intake can creep up. It will leave you tired, dehydrate and with run down your immune functions[6].
Here are a few tips to make sure you don’t go overboard with your drinking:
Remember that the limit is 14 units of alcohol a week (for men and women) which is the equivalent of 6 pints of beer, 14 shot of spirits (25ml) or 6 glasses of wine (175ml).
Avoid having more than 2 to 3 units per day.
Have several drink-free days and give yourself a limit of 2 or 3 glasses when out.
Drink lots of water and stay hydrate.
Did I announced 5 points? Well actually, there is something else you might want to consider ...
6. Protect your sleep
Time spent sleeping is time well spent: It is during our sleep that a lot of metabolic functions take place, to enable our body to perform optimally in the long run. Lack of sleep has been shown to hinder many aspects of our health, including our immune functions[7].
So, aim at sleeping 6 to 9 hours a day; try to be regular in your sleeping patterns rather than alternating short nights during the week and long ones over the weekend; and respect your circadian rhythm by following your internal clock, staying in sync as much as possible with the natural day light.
Follow these tips and enjoy the month of fun ahead of us!
References:
[1]Martineau et al. Vitamin D supplementation to prevent acute upper respiratory tract infections: a systematic review and meta-analysis of individual participant data. BMJ (2017)
[2]Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database Syst Rev. (2013)
[3]Singh M, Das RR. Zinc for the common cold. Cochrane Database Syst Rev. (2013)
[4]Hao Q et al. Probiotics (livemicro-organisms) to prevent upper respiratory tract infections (URTIs) for example the common coldCochrane Database Syst Rev. (2015)
[5]Yan F, Polk D.B. Probiotics and immune health, Curr Opin Gasteroenterol. (2011)
[6]Sarkar D et al, Alcohol a
[7]Short- and long- term health consequences of sleep disruption https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5449130/