Studies suggest that a person’s diet influences their immune system, like all other aspects of health.
For example, nutrition can affect the microbiome, gut barrier function, inflammatory processes, and white blood cell function, all of which impact immune function.
Dietary patterns and individual foods have associations with increased disease risk, greater risk of allergy, and impaired immune response.
Western-type diets tend to contain high levels of saturated fat, ultra-processed foods, added sugar and salt, and overall calories. This diet is often low in foods associated with better health, such as vegetables, fruits, and fatty fish, and has strong links to an increased risk of chronic disease.
Research suggests that Western-type diets induce inflammation and alter immune system function, promoting disease development.
In contrast, diets rich in whole foods, such as vegetables, fruits, nuts, legumes, and seafood, and low in ultra-processed foods can reduce disease risk and promote healthy immune function.
Additionally, a deficiency or insufficiency of nutrients essential to immune function, including vitamin D, zinc, and vitamin C, can also affect immune response.
Although it is clear that dietary choices impact overall health, including immune function, the interaction between diet and immune health is highly complex. Scientists are still learning how the foods a person consumes may help or harm immune function.
How to Support a Healthy Immune System
- Eat a balanced diet with whole fruits, vegetables, lean proteins, whole grains, and plenty of water. A Mediterranean Diet is one option that includes these types of foods. To support immune function, a person should concentrate on following a balanced dietary pattern rich in whole, nutrient-dense foods, especially plant foods, such as vegetables, fruits, legumes, nuts, and seeds. People should avoid or limit ultra-processed foods high in refined grains and added sugar.
- If a balanced diet is not readily accessible, taking a multivitamin containing the RDA for several nutrients may be used.
- Don’t smoke (and stop, if you do).
- Drink alcohol in moderation.
- Perform moderate regular exercise.
- Aim for 7-9 hours of sleep nightly. Try to keep a sleep schedule, waking up and going to bed around the same time each day. Our body clock, or circadian rhythm, regulates feelings of sleepiness and wakefulness, so having a consistent sleep schedule maintains a balanced circadian rhythm so that we can enter deeper, more restful sleep.
- Aim to manage stress. This is easier said than done, but try to find some healthy strategies that work well for you and your lifestyle—whether that be exercise, meditation, a particular hobby, or talking to a trusted friend. Another tip is to practice regular, conscious breathing throughout the day and when feelings of stress arise. It doesn’t have to be long—even a few breaths can help. If you’d like some guidance, try this short mindful breathing exercise.
- Wash hands throughout the day: when coming in from outdoors, before and after preparing and eating food, after using the toilet, after coughing or blowing your nose.