Th1 vs Th2

This article is for educational and informational purposes only. Nothing in this article should be taken as personal or general medical advice. This article does not purport to cure or treat any disease or condition. Some things here may only be theoretical or experimental, and possibly harmful to certain individuals. Only get medical advice from your doctor.

Helper T-cells have various subtypes, two of which are Th1 and Th2, and  both of which can cross-inhibit each other.

Th1 cytokines include interferon-γ, tumor necrosis factor-α, IL-2, IL-12. Th1 drives 'cellular immunity', which fights viruses and other intracellular pathogens (including tuberculosis and HIV), kills cancer cells, and is associated with delayed type hypersensitivity reactions. Experimental depletion of intracellular glutathione favors Th2 dominance over Th1; mercury will deplete glutathione (1). INF-γ inhibits Th2.

Th2 cytokines include IL-4, IL-5, IL-13, and IL-10 (anti-inflammatory). Th2 cells also stimulate B-cell antibody production, mediate immediate-type allergies and eosinophil accumulation (2). Pregnancy favors Th2 dominance and diminished Th1 activity (1). IL-10 inhibits Th1.

Certain conditions may tend to be associated with different cytokine profiles. For instance, peridontitis tends to have higher concentrations of IL-1ß, TNF-α, IL-2, IFN-gamma, while healthy gum tissue tends to have more IL-4 and 10 (3).

However, this popular "Th1/Th2 balance paradigm" is only a hypothesis, and one with many discrepancies. It should NOT be relied upon as a sole means of treatment. 

Pegging someone as having a certain Th dominance based on which disease they have may be somewhat overly simplistic: Th2 cells also produce INF-γ, and Th1 cells also produce IL-4, just not as much as the other cell type. In HIV, people with both Th1 and Th2 responses but more Th1 do best (1).

Lists of numerous foods, medication, and supplements that supposedly are to be used for Th1 or Th2 are all over the internet...

Th1 stimulating substances including internet listed:

Astragalus

Beta-Glucan

Chlorella

Lemon Balm

Ginseng

Grape Seed extract

Echinacea

Maitake mushroom

Lactobacillus acidophilus can induce IL-12 (23)

Th2  stimulating substances including internet listed:

Caffeine

Curcumin

Lycopene

Genistin

Green Tea extract

Pine bark extract

Pycnogenol

Resveratrol

Quercetin

White willow bark

Lactob.reuteri (26)
Bifidobacterium bifidum (26)

Potentially Th1 suppressing substances include:

Cortisol (4)

Angelica sinensis (inhibits TNF-α) (5)

Statins, such as simvastatin, atorvastatin, lovastatin, and cerivastatin (6, 7, 11, 12)

Apremilast, a phosphodiesterase 4 (PDE4) inhibitor (8)

Tryptophan (9, 10)

Fasciola hepatica (helminth) (13, 16)

Retinoic acid (Vit A) (14)

Rolipram, a type IV phosphodiesterase inhibitor (15)

Eriocalyxin B (EriB), from Isodon eriocalyx (18)

Berberine, from Berberis vulgaris (19)

Bifidobacterium bifidum (blocks INF-ß and IL-12) (22, 25)

Bifidobacterium fragilis (23)

Bifidobacterium infantis (21)

Potentially Th2 suppressing substances include:

Ganoderic Acid (17)

Without actually knowing what really is happening inside the body in terms of exact cytokine balance, attempting to 'outsmart' the body by pushing any of the above substances with the intent of shifting Th balance is not advised, especially if not under the supervision of a knowledgeable medical practitioner.

It is better to use compounds that 'balance' the body instead. These include some probiotics (21), Low Dose Naltrexone (LDN), mycoleptodonoides atichisonii (20).

With probiotics, the strains really do matter, as using the wrong strains can worsen things. 

Many conditions  thought of as "Th1 dominant" such as psoriasis and rheumatoid arthritis may respond to treatment with LDN.

Low Dose Naltrexone tends to decrease IFN-α and other pro-inflammatory cytokines, increase natural endorphin production, and upregulate the Opioid growth factor and receptor (OGF-ORFr) axis. Upregulation of OGF-ORFr may decrease tumor growth.

LDN can help bring Th1 and Th2 into balance, and is relatively low risk. Individual response to LDN may vary.

LDN is prescription only, and has to be compounded. It is available at many compounding pharmacies including CareFirst Specialty Pharmacy in New Jersey (I like this pharmacy due to price and quality).