You know this moment: a colleague coughs in the room next door, a child comes home from school with a runny nose, and you wonder if you are going to "catch something." What you don't see is that your body has already started to work.
Because when faced with a respiratory virus, your body does not remain passive waiting for symptoms. It has a real internal alarm system, discreet and quick. Understanding how it works is understanding why some winters exhaust you more than others — and especially, what you can do to support it.
What you are going to understand: why your immunity acts in two phases, which part weakens with age, and three concrete actions to support your defenses starting this week.
🛡️ Your defence acts in two waves
Contrary to the image we have of it, your immunity does not react as a single block. It unfolds in two distinct phases.
The first wave, is the so-called "innate" immunity. It is your immediate defence, the one that does not require preparation. As soon as an intruder presents itself, sentinel cells, sensors located within your very cells, and cells called "Natural Killer" spring into action. All within a few hours.
The second wave: the antibodies. More precise, but slower: it takes several days to build up, as your body must first 'learn' to recognise the intruder. It is this wave that vaccination aims at.
In other words: the first wave is the night guard always awake; the second is the specialised investigator who arrives later, file in hand.
⏳ And here is what few people know
With age, it is not the second wave that weakens first. It is the first.
Innate immunity becomes slower, less vigorous. The night guard takes longer to react. This is one of the reasons why the risk of respiratory infection increases with age — long before we talk about antibodies or vaccines.
This distinction changes everything in the way we take care of ourselves. Supporting our defences is not just about 'covering up' when it is cold. It is about maintaining, on a daily basis, this first line that works silently.
But there is one factor that most people underestimate in winter, especially in our latitudes…
☀️ The forgotten factor of the Luxembourgish winter: light
In Luxembourg, between November and February, the sun becomes rare and stays low on the horizon. However, your skin needs sunlight to produce vitamin D. As a result, in winter, a large part of the population in Northern Europe has an insufficient intake.
Why is this important? Because vitamin D contributes to the normal functioning of the immune system. *
It is one of the few statements on immunity officially recognised by European authorities — precisely because it is well documented. In winter, ensuring your intake of vitamin D (through diet, exposure when possible, or appropriate supplementation) is therefore one of the simplest and most established actions.
🌿 Three concrete actions this week
Beyond light, your first line of defence is nourished by very ordinary habits. Here are three levers that you really control:
To remember — 3 actions to support your natural defences:
- Sleep comes first. After a few too-short nights, the activity of your defence cells decreases measurably. Aim for regularity even more than duration.
- Move, without excess. A daily walk of 30 minutes supports the circulation of immune cells. Exhaustion, on the other hand, does the opposite.
- Take care of your light and your plate. Expose yourself as soon as the sun allows, and pay attention to your intake — particularly vitamin D during winter.
No magic formula in there. Just the foundations on which this first wave of defence rests, day after day.
🔬 And research, what about that?
Innate immunity is the subject of numerous scientific studies, particularly around certain natural compounds derived from food. It is precisely this field of research that fascinates us at ImunoBran®.
Our supplements are based on the arabinoxylan from rice bran, a standardised natural compound. ImunoBran® 1000, for example, provides 1,000 mg of arabinoxylan per sachet, obtained from rice bran whose walls are opened thanks to shiitake enzymes. Our range also includes ImunoBran® PLUS Vitamin D3, which combines this compound with vitamin D — which contributes to the normal functioning of the immune system, including in children. *
Our belief, which we often repeat: supporting your natural defences is built over time, not in a few days.
In summary
Your body does not wait for symptoms to defend itself: its first line, innate immunity, works silently from the very first hours. It is the one that weakens with age, and it is supported by sleep, movement, light, and a mindful diet. This winter, taking care of these foundations is undoubtedly the most useful — and the simplest — gesture.
Food supplements do not replace a varied and balanced diet or a healthy lifestyle. Respect the recommended daily dose. Keep out of reach of young children. In case of medical treatment, pregnancy, or breastfeeding, seek advice from your doctor or pharmacist.
* Health claim authorised by the EU (regulation 432/2012).