INNATE immunity is the first line of defense and consists of physical barriers, such as the skin and mucous membranes and chemical and cellular defenses.
The innate immune system is a nonspecificTrusted Source because it reacts the same way to all foreign invaders.
If the innate immune system is ineffective against a potential threat, the adaptive immune system takes over.
The adaptive immune system consists of specialized blood cells and proteins that target the specific cause of infection.
The adaptive immune system has a “memoryTrusted Source,” which is why a person’s body becomes immune to specific illnesses after initial exposure.
A person’s immune system needs to function well for them to remain healthy. Certain illnesses, medications, and lifestyle choices, such as smokingTrusted Source and excessive drinkingTrusted Source, can adversely affect immune function.
Research shows that a person’s diet can impact immune health as well.
For example, nutrition can affect the microbiome, gut barrier function, inflammatory processes, and white blood cell function, all of whichTrusted Source 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.
Nutrient deficienciesTrusted Source may be more common in those consuming ultra-processed diets low in whole, nutrient-dense foods.
