Can Supplements Boost Your Immune System? What Really Protects It
No supplement "boosts" your immune defenses, but three habits do protect them: staying active, checking your vaccinations and getting enough sleep. We explain how your defenses work from the moment you get a simple cut, and why it isn't a good idea to "boost" them.
What happens when you cut yourself: innate immunity
You get a paper cut. Within a few hours, cells from your blood are already swallowing up the bacteria in the wound. They are alerted by sentinel cells in the skin, such as macrophages.
When these sentinels detect bacteria, they release chemical signals. The blood vessels widen, the cut turns red and neutrophils move out: white blood cells that engulf microbes. This is innate immunity: fast, but generic.
Adaptive immunity and why vaccines work
Next comes adaptive immunity, which works like a team of detectives. B cells produce tailor-made antibodies. Some T cells destroy infected cells.
The first time they encounter a microbe, they take one to two weeks to respond. Afterwards, some of them remain as memory cells, sometimes for decades.
Vaccines take advantage of that memory. They show these cells a "photo of the suspect": a piece of the microbe, its instructions, or a weakened or inactivated version of the microbe, without you having to go through the disease. When the real microbe arrives, they respond sooner and with more antibodies.
What weakens your immune defenses
Two factors disarm these detectives. The first is chronic stress: cortisol that stays elevated over time can hold them back.
The second is smoking. It damages the cilia, the structures that sweep microbes out of the bronchi.
Three habits that protect your immune defenses
One: be active for at least 150 minutes a week, as the WHO recommends. For example, 30 minutes of brisk walking five days a week. Brisk means you can talk, but not sing. Regular, moderate activity is associated with fewer respiratory infections.
Two: check your vaccinations. Ask for your vaccination record at your health center or through your region's health app. If you completed your childhood vaccinations, you still have a tetanus booster due at around age 65. If you are 60 or older, have a chronic illness or are pregnant, the flu vaccine is yearly, because the virus changes.
Three: sleep at least seven hours. In a 2015 experiment, researchers measured how much each volunteer slept and then put cold virus in their noses. Those who slept less than six hours were about four times more likely to catch a cold than those who slept more than seven. A practical tip: set an alarm to go to bed seven and a half hours before you get up.
What about vitamin C and supplements?
According to the Cochrane review, taking vitamin C daily does not prevent colds in the general population. In adults, it only shortens them by 8%.
A supplement usually helps only if you are lacking something. And that is determined by a blood test, not by the product label.
Why you shouldn't "boost" your immune defenses
Your immune defenses shouldn't be stronger, but well calibrated, like a thermostat. If they react to something harmless, such as pollen, an allergy develops.
If they mistake your own cells for enemies, they can destroy them. This is what happens in type 1 diabetes, when they attack the cells in the pancreas that produce insulin.
See a doctor if a cut becomes increasingly red or oozes pus, if a fever lasts more than three days, or if you get one infection after another.
Frequently asked questions
Is there any supplement that boosts the immune system?
No. A supplement usually helps only if you are lacking something, and that should be confirmed by a blood test, not the label.
Does vitamin C prevent colds?
According to the Cochrane review, taking it daily does not prevent them in the general population. In adults, it only shortens their duration by 8%.
How much sleep do you need to protect your immune defenses?
At least seven hours. In a 2015 experiment, those who slept less than six hours were about four times more likely to catch a cold than those who slept more than seven.
Who should get a flu vaccine every year?
People aged 60 or older, those with a chronic illness and pregnant women. It is yearly because the virus changes.
Informative article written with the help of AI tools from the verified script of the video. The video is in Spanish.