Th2 is a very important marker to monitor, especially if you haven’t been leading the best lifestyle or you have chronic health issues.
Top 13 Recommendations
I realize many people just want the bottom line. Here it is:
- Sun/UVB light  – UVB decreases IFNy in Th1 dominance but increases it in Th2 dominance. So it’s balancing. It also decreases IgE responses. UVA in the sun also decreases Th2 dominance .
- Probiotics… Decreases Th2: L Reuteri  (probiotic), L. Plantarum  (probiotic), L. salivarius  (probiotic), L. lactis  (probiotic)….Increases Th1: S Boulardii? , L. Sporogenes, L Acidophilus , L casei , Lactobacillus rhamnosus GG , Lactobacillus paracasei , Lactobacillus salivarius , B Longum , L Brevis , L fermentum .
- NAC/Glutathione sufficiency decreases Th2  and increases Th1 .
- Licorice -18/β-glycyrrhetinic acid+LicoA [15, 16]. Glycyrrhizin increases IFNy and decreases the Th2 response [17, 18].
- Gynostemma . This is a Th1 immune stimulant and reduces allergies. Gynostemma is recommended also because it’s a powerful mitochondrial enhancer.
- Ginger or juice the root [20, 21]. Recommended because it has anecdotal support in addition to the research, but also because you can get it everywhere, it has a long history of use and for its multitude of other benefits. My mother who is Th2 dominant finds this very helpful for her allergies.
- Reishi . Recommended because it’s a medicinal mushroom, which has unique health properties. It works in many ways. It’s a favorite substance of mine but I don’t take it anymore so that I don’t stimulate my immune system.
- Tinospora . This has a clinical trial backing it, with some anecdotal support.
- Quercetin 
- Astragalus  Decreases Th2 and increases Th1.
You should take all of these together, but start one at a time to rule out reactions. These are the most recommended substances that can help Th2 immune dominance, not only because of their ability to lower Th2 but also because these supplements have other beneficial aspects to them.
These recommendations are solely for people who are Th2 dominant. If you are Th1 and Th2 dominant, then read this post.
What is Th1 vs Th2?
T-Helper 1 and T-Helper 2 cells are different types of immune cells (T cells) that originate from a single source (Th0).
People’s immune system often tilts to Th1 or Th2.
The Th1 side is more immune stimulatory, while the Th2 side is more immune deficient. However, both can produce “inflammation” in certain situations.
If you tilt more to one side (most likely), such as Th2 for example, you should take supplements that reduce that side (Th2) and increase the other side (Th1).
Th1 cells produce mainly the cytokines or messengers IL-12 and interferon gamma and Th2 cells produce mainly IL-4. (Both types of cells produce other cytokines.)
Most of the time, a substance that decreases Th1 will increase Th2 and vice versa (decrease Th1 will increase Th2), but this isn’t always the case.
The reason why an increase in one usually translates into a decrease of the other is because they arise from an original cell and there’s a limited number of these cells (at least in the short term).
Sometimes, however, both systems are decreased or increased by some factor.
Lectins can exacerbate Th2-related inflammation, so if you are having issues stick with low lectin foods.
Supplements/Methods to Decrease Th2
Many of the methods to decrease Th2 will simultaneously increase the Th1 system. You might want to additionally look at the methods to increase Th1, as that will help for decreasing Th2.
Accordingly, you can take a peek at this post to see what you want to stay away from. Not all the things are bad for Th2 dominance, but they are more likely to be bad. I’ve experimented with all of the following supplements unless otherwise noted. Any supplements listed here can be found in my toolkit.
- High-intensity exercise 
- Cold exposure (Antarctic winter) 
- Oxytocin (decreases IL-4) Falling in love, having sex, nursing, and positive social encounters all of these lead to increased oxytocin . L Reuteri also increases oxytocin 
- Pregnenolone (32)
- Bright light device  (by decreasing cortisol)
- LLLT 
Inhibiting mTOR is a significant pathway to decrease Th2 Cells.
This is a good picture that shows you the conditions needed for these four T Cells.
- Kiwi 
- Black rice  – make sure you aren’t lectin sensitive
- Rice  – make sure you aren’t lectin sensitive
- Rice Bran Oil 
- Cocoa 
- Black Cumin Seed Oil 
- Coffee  – decreases IgE, prevents allergies from developing
- Cruciferous veggies/broccoli sprouts/Sulforaphane, Contradictory
- Bee products: Royal Jelly , Bee Pollen  Propolis, YS Royal Jelly/Honey….Honey increases Th1 . Also, increases TNF-alpha 
- Black pepper 
- Prebiotics , FOS and GOS (prebiotics) 
- Adequate intake of vitamins B(6), folate, B(12), C, E, and of selenium, zinc, copper, and iron . Also, increases Th1.
Other Recommended Supplements
- Vitamin A/Retinol  (IL-4, IL-13) – without increasing Th1
- Genistein [51, 52] – I look forward to feedback
- Cromolyn 
- Forskolin  – May increase Th2 . Do your own experiments. Forskolin is the only supplement that potently raises cAMP, which reduces allergies. Forskolin also creates tolerance to antigens (anergy) ,
- Chondroitin sulfate 
- Spirulina  – without increasing Th1
- Oregano oil/Carvacrol 
- Theanine  – decreases a th2 type immune response
- Luteolin 
- Resveratrol 
- Theaflavins  (found in black tea)
- Apple polyphenols 
- Lycopene  (in tomatoes)
- Lutein 
- C60 
- Fenugreek 
- Baicalin/Chinese Skullcap 
- Rutin 
- Fisetin [71, 72]
- Ashwagandha 
- Ginseng (Asian)  – Mostly stimulating, but also regulating. TNF-α, IL-1β, IL-6, and IFN-γ are produced by macrophages treated with ginseng. Spleen cells increased IL-2, IFN-γ, IL-1α, and GMC-SF. However, it decreased TNF-α, IL-1β, IL-6, IFN-γ, IL-12, and IL-18 S aureus challenge.
- Grape Seed Extract [75, 76] – but can decrease Th1 cells in certain conditions like Rheumatoid Arthritis 
- Red Wine Polyphenols 
- Colostrum  – increases Th1
- Bilberry  – increases Th1
- Icariin  – increases Th1
- Lion’s Mane – increases Th1
- Andrographis 
- Germanium  – I look forward to feedback
- Beta Glucans  – found in mushrooms. (depends on dose). Inhibits TNF .
- Thymus glandular  – maybe… I look forward to feedback
- Nicotine  – decreases Th2 and increases Th1
- Schisandra , Deer Antler Velvet , Chrysin , Burdock root , Cordyceps , Ecklonia cava , Butterbur, Bamboo extract 
- Gallic acid  – without increasing Th1,
- Kaempferol  – without increasing Th1,
- Caffeic acid (In coffee, apples, artichoke, berries, and pears, wine) [97, 98] Can be found in Green Coffee Extract.
- Curcumin  – contradictory 
- Choline deficiency , Zinc deficiency 
- Epigenetics: mir-27b , mir-128 , mir-135b , mir-155 , mir-340 ,
Beware of Supplements/Methods That Increase Th2
Although some of these may benefit you, in general, you want to be wary of the Th2 Increasers.
Lifestyle, Hormones, Neurotransmitters:
- Circadian Disruption
- Severe injury 
- Mold, Mycotoxins 
- Diesel exhaust particles 
- Magnesium deficiency 
- Fine-ambient particles 
- BPA 
- Mercury  – although other strains increase IFN-γ and mercury causes you to produce antibodies against your own tissues .
- Glutathione depletion  by heavy exercise, the sun and reducing cysteine amino acids.
- Acupuncture 
- Psychological stress/glucocorticoids , chronic psychological stress ,
- Excess Vitamin D3 
- IGF-1. Doesn’t decrease Th1. Increases TNF and IL-8. Get this by ingesting protein, especially whey or leucine-rich foods.
- Estrogen . Inhibits IL-12, TNF-alpha, and IFN-gamma, and increases IL-10, IL-4, and TGF-beta. Plant-based foods have phytoestrogens, especially soy.
- Progesterone  – I get this by taking pregnenolone, which converts to progesterone. You could also get the linked cream for a more targeted approach.
- TRH 
- Ingesting insulin 
- Serotonin  5-htp is a precursor
- Dopamine [120, 120], L-dopa/mucuna is a precursor
- Histamine 
Nrf2  – the body’s stress response. Exercise, sun, lipoic acid, broccoli sprouts….PGE2 , DPP-4 inhibitors , Nitric oxide scavenging , IL-4, IL-2, STAT-6, GATA-3, mir-21 , mir126 [125, 13].
- Alcohol consumption – I have a friend who says his allergies get worse when he drinks a lot of alcohol
- Soy ,
- MCT oil . Increases TSLP, IL-25, and IL-33.
- FOS/Inulin  (bananas, onions, chicory root, garlic, asparagus, and leeks)
- Garlic [129, 130] (at high doses). Raw garlic is the best.
- Cardamom 
- Cinnamon/Sodium Benzoate 
- Papain/Papaya  – This is used as a model substance to increase Th2 inflammation.
- THC/Marijuana 
- Red Yeast Rice/Lovastatin 
- Hi-Maize /Butyrate  (via inhibiting IL-12 and increasing IL-10)
- Licorice -18β-glycyrrhetinic acid 
- Vitamin E  – maybe
- Grapeseed Extract G , contradictory and increases Th1 
- Olive leaf extract 
- Fulvic + humic acid 
- Honokiol 
- Boswellia 
- LDN  – low dose naltrexone
- Chrysin 
- Emodin 
- Vitamin E 
- Black Cumin Seed Oil – aqueous 
- Inositol 
- Astragalus – increased number of Th2 cells 
- Feverfew/parthenolide 
- Andrographis  Contradictory 
- Ursolic acid 
- St John’s Wort/Hyperforin 
- β-sitosterol  (in plants, saw palmetto)
- Stinging nettle  (IL-4)
- Creatine 
- MDMA/Ecstasy , but increases IL-2 
- Naringin 
- Hesperidin * Mixed effects 
- Theanine+NAC 
- Echinacea [157, 158]
- Chinese Skullcap/Baicalin [69, 159] (IL-4, IL-5, TGFb, IL-10)
- Eucalyptol , Limonene , Thymol 
- Cat‘s claw 
- Ketamine (drug) 
- Valproic acid  (Drug)
- B. fragilis  (common probiotic) – maybe only if low
Irregular Th2 Levels?
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