We know if we want to avoid catching a cold or other illness, we need to stay away from people who are sick and wash our hands frequently. But there are also small changes we can make to boost our immune system so if we do encounter germs, we can fight them off and stay healthy.

Three small changes that can boost your immunity:

Eat a healthy diet. If we eat well, we will maintain good health for the most part, says Dr. Chauncey Crandall, world-renowned cardiologist and director of preventive medicine at the Palm Beach Cardiovascular Clinic in Florida.

Editor’s Note: 5 Powerful Methods to Enhance Your Health and Increase Longevity

“Eat everything that is fresh. Anything that swims in a river. Everything natural,” Crandall tells Newsmax’s “Newsline.”  Focus on vegetables, fruit, fish and anything natural. Fresh foods are high in vitamins, including vitamin c and other antioxidants that protects the body from harmful free radicals, and have anti-inflammatory properties that help the body fight off germs.

Probiotic-rich foods are also helpful for fighting infection and giving us stronger immunity, says Crandall, editor of the popular newsletter Dr. Crandall's Heart Health Report.

Special: Flu Season Is Dangerous: Make Sure Your Immune System Is Strong to Combat Viruses, Germs, and Bacteria!

Research has shown that probiotic rich foods, including yogurt, sauerkraut, kefir, and kimchi, change the gut microbiome in ways that inhibit the colonization of harmful bacteria that can cause illness, and boost immune system function.

Get more sleep. One of the most powerful things we can for our immune system is getting a good night’s sleep, says Crandall. “We really do need eight hours of sleep,” he advises.

Editor’s Note: 4 Signs Your Heart is Quietly Failing

“When we sleep, our body repairs itself. Our immune function is increased during sleep to protect us during the day,” says Crandall.

For a better night’s sleep, Crandall advises taking a melatonin supplement at night, staying on a predictable schedule, and staying away from things that stress you out before bedtime. In addition, “Go to bed at the same time and get up at the same time every day to get in a proper rhythm. This will improve your health.”

Special: How to Never End Up in a Nursing Home

Take supplements. “Try to change your lifestyle first, but if you need supplementation, I really recommend vitamin C,” says Crandall.  Vitamins C, D, and A are powerful vitamins that reduce infection risk and inflammation and help you through the colds that pop up at this time of year, according to Crandall.   

“Other things we don’t think about that can improve the immune system are turmeric, garlic and even ginger,” says Crandall. They have powerful properties to prevent infections. Studies have shown that curcumin, the active ingredient in turmeric, and garlic and ginger, have antimicrobial properties, supporting immune cells that help fight off viruses and bacteria that can make you sick.

It is important to research vitamins before buying them. Crandall has had patients who became sick after taking supplements from other countries. He suggests talking to your doctor about where to buy supplements, doing your own research, and always buy supplements made in the U.S.