Strengthen your immune system against seasonal illnesses

With the holiday season comes festive gatherings and travel, making it an ideal time to prioritize your health and boost your immunity. While influenza (flu) viruses are detected year-round in the United States, flu season peaks during the fall and winter months. Along with getting the flu shot, a strong immune system can lessen the severity of symptoms, shorten the duration of the illness and help you recover faster.

Robert Carpenter, MD, MPH, FACS, clinical professor at Texas A&M University College of Medicine in the Department of Neuroscience and Experimental Therapeutics (NEXT), explains the value of strengthening your immune system with a healthy lifestyle.

“The single best thing people can do is lead a healthier lifestyle, but what does that mean?” Carpenter said. Here, he breaks it down.

‘An apple a day keeps the doctor away’

To boost your immune system, focus on a balanced diet rich in fruits, vegetables and foods high in zinc, vitamin C and vitamin D. Avoid excess starch and fats, and maintain a healthy body weight since excess weight can impair your immune response. Choose fresh or minimally processed foods to preserve their nutrients and avoid unhealthy preparation methods like deep frying or heavy dressings. Peppers, garlic and oregano can positively impact immune cells, especially when eaten fresh.

“The fresher and more natural the state of food is, the more beneficial it is for boosting your immune system from a dietary standpoint,” Carpenter said.

Our bodies require a consistent supply of various raw materials, including macronutrients such as proteins, fats and carbohydrates as well as micronutrients like vitamins and minerals. To meet all these needs, eat a well-rounded diet that includes plenty of fruits, vegetables, whole grains, lean protein and healthy fats like nuts and olive oil.

Five key micronutrients—vitamin B6, vitamin C, vitamin E, magnesium and zinc—are essential for maintaining immune function and are commonly sold in high-dose supplements labeled as immune boosters. However, there is no evidence that these supplements provide more benefits than simply following a healthy diet, Carpenter said. Instead of relying on supplements, it’s better to incorporate a variety of nutrient-rich foods to support your immune system.

“Trying to take a handful of vitamins is never going to be as wholesome and effective for you as eating a well-balanced, healthy diet to get the nutrients that we need,” he said.

Vitamins and supplements

Although supplements are not as beneficial as a wholesome diet, taking a daily multivitamin and mineral supplement could offer health benefits if you suspect your diet may be lacking in micronutrients. However, before taking any supplement, you should have a conversation with your health care provider.

Vitamin D and vitamin C supplements can boost your immune system, especially if your diet lacks these nutrients due to food preferences, allergies or dietary restrictions like plant-based diets. However, moderation is key, as taking excessive amounts of supplements can cause health issues. It’s important to choose reputable supplements that fill nutritional gaps without overloading your body, especially if you’re unable to get enough from food sources.

“Dietary restrictions due to faith or allergies or social responsibility choice, like plant-based diets, can lead to low intake of vitamins like D and K, often found in meats, but these can be substituted with supplements,” Carpenter said.

Vitamin B-12 plays a key role in producing red blood cells and supporting a healthy bone marrow system, essential for overall blood and tissue health. A deficiency in B-12 can lead to anemia, fatigue and neurological issues like numbness or tingling. Although B-12 shots are sometimes used for energy, they aren’t proven to boost the immune system unless there’s a deficiency. People with dietary restrictions—especially those who avoid meat—or gastrointestinal diseases may be at risk for B-12 deficiency and should consider supplements to avoid related health problems.

“The vitamin B-12 shots used for energy haven’t been promoted as effective for immune system health unless someone is deficient. Certain dietary restrictions and diseases of the gastrointestinal tract that predispose people to vitamin B-12 deficiency, may cause health problems without proper supplementation,” Carpenter said.

Sleep, stress and sunlight

Maintaining a proper sleep schedule is crucial for boosting your immune system. While sleep needs vary, teenagers and those under significant physical or emotional stress often require around 10 hours of sleep each night. Adequate rest helps reduce stress hormones like cortisol and allows the body to recharge and repair at a cellular level, aiding in recovery and immune function. Prioritizing sleep is especially important during periods of increased physical or mental strain.

Chronic stress and anxiety trigger the release of cortisol, a hormone that weakens the immune system by reducing the effectiveness of white blood cells in fighting infections and recognizing damaged cells. Prolonged stress can have serious negative effects on both mental and physical health. Building real, in-person relationships and maintaining psychological connections with others is crucial for reducing stress and supporting overall well-being.

Spending time outside in the sun is beneficial for both physical and mental health. As the weather cools down from the scorching summer heat, it’s a great opportunity to get fresh air and sunlight. Sun exposure helps the body naturally produce vitamin D, which, along with zinc and other essential nutrients, supports overall health and strengthens the immune system to fight infections.

Vaccines and hand hygiene

Getting a flu shot is the best way to protect against a serious case of the flu. The Centers for Disease Control and Prevention (CDC) recommends everyone 6 months and older get the flu vaccine every season, but the decision to get vaccinated depends on personal beliefs and health history. The flu vaccine can be taken individually or in combination with the COVID-19 and respiratory syncytial virus (RSV) vaccines. Protecting your health through vaccines, along with emotional and physical self-care, can help prevent illness and reduce long-term effects.

“It’s your decision to receive vaccines for respiratory illnesses. It’s possible to receive a COVID vaccine, a flu vaccine or an RSV individually or all at once. It’s recommended but not required and it’s strictly dependent on your beliefs,” Carpenter said.

Although some germs are airborne, most illnesses are contracted by touching contaminated surfaces and then transferring germs to your eyes, nose or mouth. To reduce the risk, try to avoid touching your face and wash your hands often.

A healthy immune system can help prevent or reduce the severity of illnesses like influenza, COVID-19 and RSV. While making healthier choices lowers the risk, even the most health-conscious individuals can still get sick. If you do catch an infectious illness, staying home is the best way to protect others—because no one wants to give (or receive) the gift of sickness this holiday season.