You might not realize it, but your body hosts a sophisticated immune system that vigilantly scans 24/7 for viruses and harmful bacteria. In nine out of ten cases, it neutralizes invaders before they can cause harm. Here's your complete guide to understanding and strengthening your immunity.
If the system is overwhelmed or encounters a new pathogen for the first time, you might reach for paracetamol as symptoms like colds or flu set in. A strong immune system is essential, especially during flu season. But how can you support it, and what exactly does it do?
"Your immune system is an ingenious network safeguarding your body from head to toe," explains Ger Rijkers, PhD, medical immunologist and professor of biomedical sciences at University College Roosevelt in Middelburg. "Unlike your liver, you can't pinpoint it—it's distributed everywhere to protect you comprehensively. Key components cluster around vulnerable areas like your respiratory and digestive tracts, which are prime entry points for infections."
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Your immune system comprises a complex array of cells and organs—everyone has one. Why do some people catch every flu bug while others stay healthy? "Absolutely, immunity varies widely," says Rijkers. "Differences arise from multiple factors. Even in the womb, the foundation forms in a sterile environment, leaving the newborn immune system 'naive' to pathogens."
Post-birth, the immune system springs into action amid a world teeming with microbes. "When a baby encounters a pathogen, it may get sick temporarily, but the body crafts an army of specialized lymphocytes—cells with unique receptors that target that specific threat," Rijkers notes. "This defeats the infection."
The brilliance lies in memory cells: a subset of these lymphocytes that persist. "On re-exposure, they activate instantly, preventing illness—you're immune," he adds. More memory cells mean broader, faster protection against familiar threats.
In an ideal scenario, we'd have memory cells for every pathogen. "Lifelong exposures vary, so immunity profiles differ," Rijkers explains. "If I've built defenses against 20 flu strains versus someone's 10, I'm less flu-prone—but they might resist chickenpox better. Each person's immunity is uniquely tailored."
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To maintain robust immunity, your body must keep generating memory cells. Factors like gender and age play roles: women often have stronger responses due to sex hormones, while aging slightly weakens it. "Over time, accumulated memory cells can crowd out new production, and overall bodily functions decline," says Rijkers.
You can actively support it: prioritize a healthy diet and regular exercise. "Nutrient-rich foods supply vitamins C and D, plus zinc and selenium—all proven to enhance immune function," he advises. No need for vitamin C supplements if you eat cabbage, citrus, kiwis, berries, and strawberries. Dutch soils provide ample zinc and selenium via fruits and veggies.
Vitamin D is trickier. "Sun exposure suffices in summer, but winter shortages are common when immunity is tested most," Rijkers warns. Aim for 30 minutes outdoors daily between 11 a.m. and 3 p.m. If not feasible, supplement wisely—check dosages, as excess (up to 1,000 times the daily need) harms.
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Probiotics offer another edge. "Studies confirm they promote balanced immune development in children," Rijkers says. "Adult benefits are promising, fostering beneficial gut bacteria—like driving a reliable new car on a long trip versus a clunker. A healthy gut microbiome improves odds against microbial foes."
If flu strikes, aid recovery by easing up. "An active immune response consumes 10% of your energy—conserve it by resting, even if bed isn't required," Rijkers recommends.
Bonus: Sip chicken soup. Japanese research shows it mildly boosts immunity. As the saying goes, it can't hurt.
Text by Priscilla Borgers
