A Doctor's Three Pillars of Immunity — And the Rules She Lives By

Building resilience against illness takes some deliberate hardening of the body — but the extreme cold-exposure trends currently in vogue aren't right for everyone. According to one doctor, supporting your immune system also comes down to something far less dramatic: enough quality sleep, a genuinely nourishing diet, and regular movement.

In a recent press release, Jurgita Šiupšinskaitė, a physician specializing in endobiogenic medicine, explains that while ice-water swimming has surged in popularity, it's far from a one-size-fits-all route to stronger immunity.

"Cold-water shock really isn't for everyone — it depends a great deal on each person's physical condition and body type. If you want to try ice-water swimming, I'd recommend first talking to specialists who understand cold-water training methods, and looking for reliable information. It's a genuinely effective way to build resilience, but it won't necessarily suit everyone," says Šiupšinskaitė.

Start gently

Her advice: start from wherever your baseline already is.

"If you're already outdoors a lot — say, walking the dog every day regardless of weather — your starting point is higher, and you can begin simply by dressing a bit more lightly. You don't need to stay out as long; just move more briskly," says Šiupšinskaitė.

For anyone who's been mostly indoors — someone who barely left the house during lockdown and put on some weight — she doesn't recommend heading straight outside underdressed. Instead, start with something as simple as airing out your rooms properly: throw the windows wide open and ventilate thoroughly before bed. "After a few days of that, put on a sweater and stand by the open window for a minute or two yourself. Gradually increase your dose of cold from there.

You can also finish your regular shower at home with a splash of cool water. Lower the temperature and extend the time a little more each day," says Šiupšinskaitė.

Three pillars of immunity

Šiupšinskaitė admits that she noticed the biggest difference in her own immunity when she started walking to and from work every day, whatever the weather.

"It was only a few kilometers each way, but the benefit was obvious," she says.

Still, she's quick to point out that immunity rests on three pillars, not one: daily time outdoors, but also enough quality sleep and genuinely good food.

"I don't just tell my patients this — I apply it to my own life, too. I always try to get enough sleep, and if I notice I'm running short on rest, I look for a way to make up for it, even if that means taking an extra day off. If we're not rested ourselves, we can't properly take care of anyone else.

I also try to avoid eating out or relying on processed food — I cook at home instead. That way, I know exactly what I'm eating and whether I'm getting the micronutrients I need. And when necessary, I'll use supplements to support my immune system," Šiupšinskaitė says, describing her own routine.

Supplements: a support, not a substitute

She's careful to note that if your diet is genuinely good, you can get most of your micronutrients from food alone. Supplements, as their packaging usually states, are meant to fill in the gaps — not replace whole foods.

Her recommendation is always the same: see a doctor, get blood work done, and find out exactly which vitamins and trace elements you're actually short on.

"In my own practice, I most often order tests for vitamin D — and for women, folic acid, along with B12, chromium, zinc, and iron. It really depends on the individual. But why not check your vitamin D levels in winter, during the darkest stretch of the year? We're drawing down our body's reserves the whole time. As it happens, around 80% of people need to replenish their vitamin D over winter," says Šiupšinskaitė.