How maintaining a balanced diet supports seniors’ immune systems, according to Mayo Clinic

A strong immune system helps your body fight infections, recover faster, and reduce inflammation that can lead to chronic illness. According to experts at Mayo Clinic, changes in the immune response make older adults more vulnerable to viruses, slower healing, and longer recovery times.

Nutrition plays a key role in how your immune cells function and communicate. Here, we’ll look at how diet supports immunity in older adults and what Mayo Clinic specialists recommend for keeping your immune system strong through balanced eating and smart daily habits.

How diet affects the aging immune system

Your immune system is made up of billions of cells that travel through your bloodstream and tissues, constantly monitoring for threats. As Jessica N. Lancaster, Ph.D., an assistant professor of immunology and cancer biology at Mayo Clinic, explains, it’s a collection of cells that surveil the body for anything that isn’t you.

Over time, though, the system becomes less efficient. The “adaptive” immune cells, such as T and B cells, decline in number and function, which means the body can’t fight off infections or respond to vaccines as effectively. Meanwhile, the “innate” cells, the body’s first responders, can become overactive, leading to chronic, low-level inflammation. This process can wear down the body and contribute to different diseases.

Eating nutrient-dense, minimally processed foods helps regulate inflammation and support the production of immune cells. Experts recommend focusing on a variety of whole foods—such as fruits, vegetables, lean proteins, whole grains, nuts, and legumes—to give your body the vitamins, minerals, and antioxidants it needs to stay resilient.

These foods also promote a healthy gut microbiome, which influences immune activity throughout the body. A well-fed gut helps regulate inflammation and supports the communication between immune cells, making it easier to respond to infections without overreacting.

Healthy aging habits that strengthen your immune system

Lifestyle factors like sleep, movement, and vaccination are also central for protecting the immune system as you age. Pair balanced eating with other habits to keep immune defenses functioning smoothly.

1. Prioritize sleep. During sleep, your immune system releases proteins that fight infection and repair tissue. People who sleep fewer than six hours a night tend to get sick more often and recover more slowly.
2. Stay active. Moderate cardiovascular activity, like brisk walking or swimming, boosts circulation and activates immune cells. Strength training twice a week also helps maintain muscle, which releases anti-inflammatory compounds.
3. Keep up with vaccines. Vaccinations prepare your adaptive immune system to recognize and attack viruses faster. For older adults, staying current on flu, RSV, COVID-19, and shingles vaccines can reduce the risk of illness.
4. Get enough vitamin D. Many older adults are deficient in this vitamin, which is key for immune regulation. Experts suggest 600 IU daily for adults up to age 70 and 800 IU for those older than 70, unless otherwise directed by a healthcare provider.
5. Limit ultra-processed foods. Highly processed snacks, refined grains, and sugary drinks can increase inflammation and crowd out the nutrients your body needs for immune support.

Aging changes how your body responds to illness, but that doesn’t mean getting sick is inevitable. By eating balanced meals, staying active, and caring for your body’s daily needs, you give your immune system the tools it needs to stay alert, efficient, and ready for whatever comes next.