Updating majorly as of 1/22/25. One reference was no longer viable and replaced with a new reference and information.

Welcome back - it is time to finish our three-part consideration of the immune system! After seeing different, non-white-blood-cell parts of the immune system (including stomach acid) in Part 1 and the whacky immune system functions of allergies and autoimmune issues in Part 2, we now end with Part 3, nutrients needed by the immune system.
First off, many rush to try to boost the immune system only with certain foods or single nutrients, seasonally or when they feel sick. Admittedly, lacking one nutrient can throw off the immune system(1). [Further, defeating E. coli, influenza, and such isn't the only object of supporting the immune system - ] such things as environmental toxins and stress can suppress the immune system(1).

- N-acetylcysteine (NAC) "is a molecular form of the amino acid L-cysteine" and supports healthy liver AND immune system functioning. NAC converts to "tripeptide glutathione (GSH), the most abundant antioxidant". which in turn is requisite for some antioxidant enzymes. IMPORTANT: neither supplementing with simple regular cysteine nor GSH is efficient for one-upping GSH synthesis(2).
- "[E]ssential electrolytes⎯including sodium, potassium, magnesium, and chloride" are needed for elementary cell functions, including brain transmissions... and in the immune system(2).
​​- "Animal studies have found that deficiencies in zinc, selenium, iron, copper, folic acid, and vitamins A, B6, C, D, and E can alter immune responses."(1)
- Fiber (prebiotics) present in fruits, veggies, and other plant foods help keep up healthy gut microbes - and in turn these microbes "short chain fatty acids, which have been shown to stimulate immune cell activity." Probiotics, in contrast, contain living, probiotic (healthy) bacteria(1).
- Vitamin D is an immune system regulator(1).
- FINALLY, we get to perhaps the most famous immune nutrient: Vitamin C is "the most important water-soluble antioxidant in our circulation... and is concentrated in immune cells." With both Vitamins C AND D, "dietary intake, or serum levels" tend to drop as we age(2).

Personal Product Favorites:

References:
1. "Nutrition and Immunity." Harvard T. H. Chan School of Public Health: The Nutrition Source. The President and Fellows of Harvard College. Web. January 7, 2025. https://www.hsph.harvard.edu/nutritionsource/nutrition-and-immunity/.
2. "Hydrate + Immune Support." Isagenix Health. Isagenix Worldwide, Inc. Web. January 22, 2025. https://isagenixhealth.net/hydrate-immune-support/.

Updated majorly 1/7/2025. One reference was no longer viable. New reference added with new information.

"Immune System Part 1: Workings Beyond White Blood Cells", published two weeks before on this on July 28th, listed different parts and workings of the immune system beyond white blood cells - even stomach acid! Please refer to Part 1, particularly as it speaks about what inflammation is, with the following: [LINK]. We now move on to the second of the three-part Immune System article series, on a couple types of haywire immune system responses, allergies and autoimmune issues. 

All autoimmune diseases involve the body attacking good cells. Rheumatoid athritis, MS, lupus, and celiac are included. Various foods have immune-boosting nutrients or else autoimmune-inflaming properties - take for example some veggies. Green leafy veggies "are rich in antioxidants and immune-boosting nutrients like vitamin C, vitamin A, and magnesium"; cruciferous veggies have the immune-regulating antioxidant compound glutathione. Nightshades are veggies but they have alkaloids that may increase intestinal inflammation. A study showed that blueberries may be helpful to MS patients(1).
​Food allergies are abnormal types of immune responses like hives, breathing constriction, and swelling and are overreactions to proteins of some foods. As much as 8% of US kids have food allergies, compared to approximately 2% of adults. Food intolerances are less serious issues and may cause discomfort, but usually affect the digestive tract more than anything(2).
There are upwards of "160 foods that can cause a reaction in sensitive people, [but] there are eight common foods that account for approximately 90% of all food allergy reactions... [which] include milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soybeans". Intolerance for lactose, the milk sugar, comes from "reduced production of enzyme lactase after infancy."(2) The wrong species of gut flora, lack of good species, and species colonizing inappropriate sections of the gut can induce food intolerances, intolerances to healthy prebiotics or sugars, or food allergies (Davis, 66-69, 284). Those conditions may actually be signs of the need for gut-healthy diet, well-targeted probiotics, and other interventions to revamp the gut microbiome(Davis, 67, 283-84).

[Note: Some allergy-causing foods aren't so good for you anyway, or at least when produced wrong. I do avoid wheat as I get brain fog and lowered immune function. My parents were told I was allergic to milk as a baby, and it turned out the nasty chemicals and hormones in that milk were probably the issue, as I did better after a while. For some examples, please click the "Not the Same" tag on the BNH blog menu to see articles on some foods that aren't so good for the body.]

Personal Product Favorites:
Two servings of veggies with superfood moringa in one scoop
Probiotic with advanced delivery system

References:
1. Younghans, Samantha Faragalli. "The Foods To Eat and Avoid If You Have an Autoimmune Disease:
Defeat Inflammation By Simply Swapping the Worst Foods For Autoimmune Diseases With the Best." Eat This, Not That!. Galvanized Media. January 25, 2020. Web. November 9, 2024. https://www.eatthis.com/autoimmune-disease-diet-foods/.
2. "Questions About Food Allergies? We’ve Got Answers!" Isagenix Health. Isagenix Worldwide, Inc. Web. November 9, 2024. https://www.isagenixhealth.net/questions-about-food-allergies-weve-got-answers/.
3. Davis, William. Super Gut: A Four-Week Plan to Reprogram Your Microbiome, Restore Health, and Lose Weight. 1st ed., New York, Hachette Go, 2022.