The immune system protects your body from outside invaders. These include germs such as bacteria, viruses, and fungi, and toxins (chemicals made by microbes). The immune system is made up of different organs, cells, and proteins that work together.1
During the flu season or times of illness, people often seek special foods or vitamin supplements that are believed to boost immunity. Yet the design of our immune system is complex and influenced by an ideal balance of many factors, not just diet, and especially not by any one specific food or nutrient. However, a balanced diet consisting of a range of vitamins and minerals, combined with healthy lifestyle factors like adequate sleep and exercise and low stress, most effectively primes the body to fight infection and diseases.
There are 2 main parts of the immune system:2
- The innate immune system. You are born with this.
- The adaptive immune system. You develop this when your body is exposed to microbes or chemicals released by microbes.
These 2 immune systems work together.
Conditions that trigger an immune response:
- Antigens are substances that the body labels as foreign and harmful, which triggers immune cell activity. Allergens are one type of antigen and include grass pollen, dust, food components, or pet hair.
- Inflammation is an important, normal step in the body’s innate immune response. When pathogens attack healthy cells and tissue, a type of immune cell called mast cells counterattack and release proteins called histamines, which cause inflammation. Inflammation may generate pain, swelling, and a release of fluids to help flush out the pathogens.
- Autoimmune disorders like lupus, rheumatoid arthritis, or type 1 diabetes are partly hereditary and cause hypersensitivity in which immune cells attack and destroy healthy cells.
- Immunodeficiency disorders can depress or completely disable the immune system and may be genetic or acquired.
Research shows that a large amount of your immune system, which plays a major role in both the development and prevention of disease, is housed in the gut. Like so many systems in the human body, the immune system and digestive tract (gut) are interconnected in fascinating and complex ways.
Immune cells in the gut interact with the microbiome, the diverse array of bacteria and fungi that live in the gastrointestinal tract and are directly influenced by an individual’s diet and lifestyle.
The foods we eat affect the diversity and composition of bacteria in the gut, which in turn affect immune cells. Those gut bugs are healthiest and support strong immunity when their hosts (that’s us) consume plant foods that are high in fibre.
Dietary diversity and microbial diversity go together. The typical Western diet, which is high in animal proteins, sugar, processed foods and saturated fat, results in less-diverse gut bacteria and promotes inflammation and chronic disorders, he says. A fibre-rich diet, on the other hand, supports the microbiome and reduces inflammatory response.
Carrying extra weight also affects immune function. Fat stores, once thought to be inert tissue, actually secrete hormones and chemicals that stimulate inflammation. Medically known as adipose tissue, fat is now understood to be a “metabolically active endocrine organ.3
8. Steps to Help Support a Healthy Immune System:4
- 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.
- If a balanced diet is not readily accessible, taking a multivitamin containing the RDA for several nutrients may be used.
- Don’t smoke (or stop smoking 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.
1 Childs CE, Calder PC, Miles EA. Diet and Immune Function. Nutrients. 2019 Aug
3 Immune System disorders.
4 Ways to Boost Your Body’s Natural Defenses https://www.healthline.com/nutrition/how-to-boost-immune-health