What you eat has an impact on the strength of your body’s defenses. Some foods and drinks support healthy immune function and help you fight off harmful invaders. There are other foods that weaken your immune function. It’s vital to know which help, and to fast from foods that harm your immune function.


How do they do harm?


Foods can be detrimental to the systems that support your immune response. Or, they can weaken your immune system directly causing chronic inflammation, overblown immune responses to allergens, or actually suppressing the cells that fight invaders.


Here are 7 foods that harm your immune function, and what to choose instead.


7 Foods That Weaken Your Immune System

1. Sugars 

Sugars simply wreak havoc on many body systems, especially when consumed in large amounts. In fact, sugar can:

  • directly cause a latent immune response after large amounts are ingested
  • contribute to an unhealthy weight which can harm immune-supporting systems
  • increase blood sugars which can increase the risk of infection
  • raise the risk of cardiovascular disease which suppresses the overall health and immune response
  • increase inflammation, which directly and negatively impacts the immune system

In studies, it’s been found that inflammation is increased with diets high in added sugars (added to teas, sweets, etc.) and natural sugars from fruit juices (1).

Chronic inflammation is associated with a weakened immune system and illness.

Instead of Sugar Use: Do your best to simply wean off of “sweets” as much as possible. When you do want a treat, make them at home using non-sugar keto sweeteners such as stevia and erythritol.

2. Soybean Oil

Sugars simply wreak havoc on many body systems, especially when consumed in large amounts. In fact, sugar can:

  • directly cause a latent immune response after large amounts are ingested
  • contribute to an unhealthy weight which can harm immune-supporting systems
  • increase blood sugars which can increase the risk of infection
  • raise the risk of cardiovascular disease which suppresses the overall health and immune response
  • increase inflammation, which directly and negatively impacts the immune system

In studies, it’s been found that inflammation is increased with diets high in added sugars (added to teas, sweets, etc.) and natural sugars from fruit juices (1).

Chronic inflammation is associated with a weakened immune system and illness.

Instead of Sugar Use: Do your best to simply wean off of “sweets” as much as possible. When you do want a treat, make them at home using non-sugar keto sweeteners such as stevia and erythritol.

3. Refined Carbohydrates

Sugars simply wreak havoc on many body systems, especially when consumed in large amounts. In fact, sugar can:

  • directly cause a latent immune response after large amounts are ingested
  • contribute to an unhealthy weight which can harm immune-supporting systems
  • increase blood sugars which can increase the risk of infection
  • raise the risk of cardiovascular disease which suppresses the overall health and immune response
  • increase inflammation, which directly and negatively impacts the immune system

In studies, it’s been found that inflammation is increased with diets high in added sugars (added to teas, sweets, etc.) and natural sugars from fruit juices (1).

Chronic inflammation is associated with a weakened immune system and illness.

Instead of Sugar Use: Do your best to simply wean off of “sweets” as much as possible. When you do want a treat, make them at home using non-sugar keto sweeteners such as stevia and erythritol.

4. Artificial Flavorings (In Place of Real Spices)

Sugars simply wreak havoc on many body systems, especially when consumed in large amounts. In fact, sugar can:

  • directly cause a latent immune response after large amounts are ingested
  • contribute to an unhealthy weight which can harm immune-supporting systems
  • increase blood sugars which can increase the risk of infection
  • raise the risk of cardiovascular disease which suppresses the overall health and immune response
  • increase inflammation, which directly and negatively impacts the immune system

In studies, it’s been found that inflammation is increased with diets high in added sugars (added to teas, sweets, etc.) and natural sugars from fruit juices (1).

Chronic inflammation is associated with a weakened immune system and illness.

Instead of Sugar Use: Do your best to simply wean off of “sweets” as much as possible. When you do want a treat, make them at home using non-sugar keto sweeteners such as stevia and erythritol.

5. Alcohol

Sugars simply wreak havoc on many body systems, especially when consumed in large amounts. In fact, sugar can:

  • directly cause a latent immune response after large amounts are ingested
  • contribute to an unhealthy weight which can harm immune-supporting systems
  • increase blood sugars which can increase the risk of infection
  • raise the risk of cardiovascular disease which suppresses the overall health and immune response
  • increase inflammation, which directly and negatively impacts the immune system

In studies, it’s been found that inflammation is increased with diets high in added sugars (added to teas, sweets, etc.) and natural sugars from fruit juices (1).

Chronic inflammation is associated with a weakened immune system and illness.

Instead of Sugar Use: Do your best to simply wean off of “sweets” as much as possible. When you do want a treat, make them at home using non-sugar keto sweeteners such as stevia and erythritol.

6. Antibiotics in Foods

Sugars simply wreak havoc on many body systems, especially when consumed in large amounts. In fact, sugar can:

  • directly cause a latent immune response after large amounts are ingested
  • contribute to an unhealthy weight which can harm immune-supporting systems
  • increase blood sugars which can increase the risk of infection
  • raise the risk of cardiovascular disease which suppresses the overall health and immune response
  • increase inflammation, which directly and negatively impacts the immune system

In studies, it’s been found that inflammation is increased with diets high in added sugars (added to teas, sweets, etc.) and natural sugars from fruit juices (1).

Chronic inflammation is associated with a weakened immune system and illness.

Instead of Sugar Use: Do your best to simply wean off of “sweets” as much as possible. When you do want a treat, make them at home using non-sugar keto sweeteners such as stevia and erythritol.

7. Gluten or Other Individual Intolerances


Although the majority of adults do not likely have a gluten or wheat allergy, many display symptoms of intolerance when they eat modern strains of wheat. While they may tolerate smaller amounts or ancient grains, modern wheat may cause an immune response from their digestive tract or skin.


When it comes to intolerances, gluten stands out since it can weaken and flatten the villi in the intestines responsible for absorbing nutrients (7). When these are flattened, digestion suffers, and therefore the immune system suffers as well.


In addition, any individual intolerances can cause chronic immune responses and inflammation.


Instead of Eating Foods in which you are Intolerant: Avoid any foods that elicit immune responses from your skin, digestive tract, or respiratory system. If you are not sure what foods are the problem, make sure to rotate your foods and avoid eating the same foods or ingredients every day. If you know you are intolerant of gluten, avoid all wheat products and look for wheat and/or gluten listed on the ingredients list. Use non-wheat ingredients in its place, including nut flours, fiber supplements, and more.

How to Fast from These 7 Foods That Harm Your Immune Function

You’ve got the knowledge to make great choices with nutrition. Now, deliberately choose foods that support immune health (see 14 here), and avoid these foods that harm your immune function.