How to Boost Your Defense System This Winter
Think about how many germs you encounter in just one day...
You touch doorknobs... shake hands... push shopping carts... and spend time around folks who may be carrying a virus without even knowing it.
If you don't get sick after touching all those germs, you have your immune system to thank...
That's because your body's extraordinary network of defenses works around the clock to protect you from bacteria, viruses, and other invisible enemies.
But as we get older, those defenses start to change. Our bodies might have a harder time fighting infections or bouncing back from being sick.
The good news is, research shows there are some simple things you can do to help your immune system. And it's not too late to start incorporating these strategies into your daily life.
With cold and flu season upon us, here are three basic tips to give your immune system a leg up.
Three Healthy Habits to Fight Off Sickness
1. Get quality sleep.
You already know how lousy you can feel after a poor night's sleep. But losing sleep may do more than just leave you groggy the next morning... It could also make it harder for your body to fight off infections.
Take, for instance, a 2025 study that analyzed the sleep habits of 397,523 U.K. adults aged between 40 and 73 years for about 13 years. During that time, 60,377 participants were hospitalized for infections.
Participants with healthier sleep patterns were less likely to end up in the hospital with an infection. Those patterns included getting seven to eight hours of sleep, having fewer insomnia symptoms, and not feeling extremely tired during the day.
In fact, participants with the healthiest sleep patterns boasted a 41% lower risk of hospitalization for an infection compared with those who had the least healthy patterns.
Sleep plays a critical role in helping your body regulate its immune responses. So do what I do... and make sleep a priority. Aim for seven to eight hours of sleep a night and try to stick to a regular bedtime and wake-up time – weekends included. I also prefer avoiding caffeine in the early afternoon and switching to decaffeinated coffee. Decaf has the same heart-healthy antioxidants as its caffeinated counterpart.
2. Add some movement to your day.
Physical activity is a fantastic way to flush bacteria out of your airways and get your white blood cells into circulation faster...
You can think of these white blood cells like patrolling guards that walk the perimeter to protect you from invaders. Sit on a couch all day, and the guards walk slowly. Get up and walk or jog... and the guards move at double and triple time. They can then check out more areas more frequently throughout the day.
Plus, getting your body moving also boosts your core body temperature, which comes in handy for preventing bacterial and viral growth.
In another 2025 study, researchers looked at health data from 353,834 older U.K. adults and found that walking and other forms of physical activity were associated with a lower risk of both getting an infection that required hospitalization and dying from one.
What's more, the biggest difference was between the folks who did nothing and those who did something. You don't have to start training for a marathon... Instead, set a reminder to get up and walk around the block (or bike) for at least 15 to 20 minutes every day. Even a short walk is better than just sitting all day.
3. Feed your immune system the right foods.
I've long warned readers about the dangers of eating too much sugar and processed junk. But rather than obsessing over every gram of sugar, start by thinking about what you're putting into your diet...
In an interesting study published last year in Nature Medicine, researchers recruited 77 healthy young men to study how different diets affect the immune system. Some participants switched from a traditional diet rich in vegetables, beans, and whole grains to a Western-style diet heavy in processed foods and refined carbohydrates. Others made the opposite switch.
After just two weeks, researchers studied blood samples from both groups... Those who switched to the Western-style diet showed increased inflammation and weaker responses to certain germs in laboratory tests. Meanwhile, switching to the traditional diet reduced inflammatory activity in general.
Plus, some of those changes were still detectable for four weeks after the experiment ended.
This was just a small study, but it shows how quickly improving your diet can boost your immune system.
Now, I'm not saying you should beat yourself up for sneaking in a couple pieces of your kids' or grandkids' Halloween candy this weekend...
Instead, make it your mission to start eating more whole foods. I always strive to fill my plate up at every meal with colorful vegetables, fruits, beans, nuts, whole grains, fatty fish, eggs, and lean meats – the less processed, the better.
After all, the bulk of your body's immune cells hang out in the gut. That means the nutrients found in whole foods − like fiber and antioxidants − are key to keeping those immune cells in tip-top shape.
Of course, these healthy habits are just part of my approach to staying well... I also like diversifying my health "portfolio" by taking the right dietary supplements.
At least 60% of American adults take supplements, but they're often misused. In the latest issue of my Retirement Millionaire newsletter, I shared my personal "supplement stack"... and the research to back up my choices. You can check out the issue here. Not a subscriber? Give it a try for 30 days.
What We're Reading...
- Something different: The smiley face's history.
Here's to our health, wealth, and a great retirement,
Dr. David Eifrig and the Health & Wealth Bulletin Research Team
October 29, 2026