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Reducing an Elevated Th1 Immune System + Supplements

Written by Joe Cohen, BS | Last updated:

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Note that each number in parentheses [1, 2, 3, etc.] is a clickable link to peer-reviewed scientific studies. A plus sign next to the number “[1+, 2+, etc...]” means that the information is found within the full scientific study rather than the abstract.

Th1 (cytokine) is a very important marker to monitor, especially if you haven’t been leading the best lifestyle or you have chronic health issues.

This post is part of a series that dissects what kinds of inflammation people get, the diseases and risks associated with such inflammation and how we could dial it down.

Hack Your Th1 System

How it Works

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 differentiate from a progenitor or original cell and there’s a limited number of these cells.

Sometimes, however, both systems are decreased or increased by some factor. T regulatory cells decrease both Th1 and Th2 [1, 2].

When I write confirmed, it means my subjective experience supports the referenced studies, though both aren’t very reliable in this subject. It’s not always easy to tell if something stimulates the Th1/Th2 immune system or not.

Men vs Women

Males are more prone to Th17 and Th2 dominance, while females are more prone to Th1 dominance [3, 4].

This is because Androgens increase PPAR alpha, which causes inhibition of Th1 dominance. At the same time, men have lower PPAR gamma, which leads to Th17 dominance [3].

To some extent, Th1 and Th17 ‘compete’ with each other. IL-2 produced by Th1 cells activates STAT5, which competes with STAT3 (which produces Th17 dominance) [3].

How to Decrease Th1 Dominance

Lectin Avoidance & Th1 Reducers

The most important mechanism for decreasing Th1 dominance for me was the lectin avoidance diet.

I can vouch for these supplements and methods below. I actually have found all of them have helped me and this makes sense because I’m Th1 dominant. My experiments agree with most of the studies.

I prefer Th1 increasing supplements at night rather than in the day. This is because Th1 cells produce cytokines such as TNF-alpha [5] and IL-1beta [6], which are important for inducing fatigue. Many herbs that increase Th1, however, also decrease IL-1beta and TNF-alpha so it isn’t so simple.

Be wary that some people who are Th1 dominant have an underlying and active infection and by inhibiting the Th1 system it will make their situation worse.

It’s easy to think that implementing some measure below to decrease your Th1 system will necessarily fix your problems. But if you have an underlying infection, the opposite may occur. In my opinion, most of the time people don’t have an active infection. Rather, an infection at some prior time period changed gene expression in some unfavorable way.

If you have an active infection, you should stick with Th1 reducers that also have antimicrobial activity. In any case, it’s useful to know if you have an active infection.

Going forward, I’m going to put some energy into how people can figure out what infection they have and the best ways to kill or deactivate that particular infection. I feel this is a missing link.

If we can easily identify a pathogen that’s causing trouble within us, it’s less difficult to figure out how to kill or deactivate it, given a number of supplements and drugs at our disposal in this day and age.

If all else fails, you can try helminth therapy, which will increase your Th2 system and thus decrease your Th1 system [7].

Keep in mind that sometimes the dose matters and different doses will have different effects on Th1/Th2 balance.

Lectins can exacerbate Th2-related inflammation, so if you are having issues stick with low lectin foods. I don’t really need the supplements if I stick with low lectin foods, but I still take them sometimes because although I don’t get acute bouts of inflammation, I feel my Th1 system is probably still elevated since it’s in my genes and it has room to be decreased.

What to Avoid

Also, sometimes I stray from what I should be eating and I don’t have the healthiest lifestyle (I don’t exercise enough, eat too many calories, break my circadian rhythm, don’t always stick to my diet, etc…).

You can take a peek at this post to see what you want to stay away from. Not all the things are bad for Th1 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.

Lifestyle, Foods, Supplements & Hormones to Inhibit Th1



  • Fish [24]
  • Egg white/ovalbumin [25]
  • Soy [26]
  • Avocado [27]
  • Rice [28]
  • Watermelon [29]
  • Apple polyphenols [30]
  • Papain/Papaya [31]
  • Bromelain/Pineapple [32]
  • Extra virgin olive oil/Omega 6 PUFAs [24] – without increasing Th2 (IFNy). I recommend Black Cumin Seed Oil for spicy dishes.
  • Hemp oil and evening primrose oil [33]
  • Blueberry [34] (IL-12, IFNy)
  • Sesame oil (IFNy) without increasing Th2
  • Cinnamon/NaB [35, 36], (IL-12, IFNy)
  • Carob/ D-pinitol [37] (IFNy, IL-12)
  • Cardamom [38]
  • Fennel [39]
  • Mustard [40] – I do well with mustard.
  • Alcohol
  • Areca nut [22]
  • Pistachio nuts [41]
  • Cantaloupe [42] – decreases damaging effects of IFN.




  • Apigenin [113, 114] (IFNy, IL-12)
  • Luteolin [114, 115, 116] (IFNy)
  • Myricetin (in veggies) [117+118] (IL-12)
  • Citrus Bioflavonoids?: Naringin [119] (in grapefruit), Naringenin [120] – inhibits negative effects of IFNy.
  • Rutin [121] (IFNy)
  • Chrysin [122]
  • Baicalin [123, 124] (IFNy, IL-12)
  • Chlorogenic acid [125] (in coffee, plants)… Contradictory – increased IL-12 [126]
  • Rosmarinic acid [127] (in oregano and sage) (IFNy, IL-2)
  • Oleanolic acid [128] and triterpenes [129] (found in olive products, garlic, medicinal plants)

Hormones (if Th1 dominant):

  • Vitamin D3 [130]
  • Melatonin [131] (IFNy)
  • Glucocorticoids (Dexamethasone) [132] i.e. cortisol or steroidal anti-inflammatories. Can get this by licorice root or adrenal glandular
  • Pregnenolone (60) Also decreases Th2.
  • Progesterone [133]. Increases IL-10. Increases immune tolerance so that fetus isn’t rejected. Pregnancy improves the symptoms of rheumatoid arthritis, a disease driven primarily by Th1 immune responses, whereas systemic lupus erythematosus, a disease linked to excess Th2 cytokine production, tends to flare during pregnancy [133]. I get this by taking pregnenolone, which converts to progesterone. You could also get the linked cream for a more targeted approach.
  • Testosterone [134, 135]. Decreases IL-12 and increases IL-10, which decreases TNF and IL-b. Testosterone can be raised with DHEA or creams.
  • Estrogen [136]. Plant-based foods have phytoestrogens, especially soy.
  • Estradiol [137] (high)… (IFN, IL-12)
  • Ingesting insulin [138]
  • ACTH [139]
  • MSH [139]
  • TRH [139]
  • Somatostatin [139]




Further Reading

Want More Targeted Ways to Combat Inflammation?

If you’re interested in natural and more targeted ways of lowering your inflammation, we at SelfHacked recommend checking out this inflammation wellness report by our sister company, SelfDecode. It gives genetic-based diet, lifestyle and supplement tips that can help reduce inflammation levels. The recommendations are personalized based on your genes.

About the Author

Joe Cohen, BS

Joe Cohen won the genetic lottery of bad genes. As a kid, he suffered from inflammation, brain fog, fatigue, digestive problems, anxiety, depression, and other issues that were poorly understood in both conventional and alternative medicine.Frustrated by the lack of good information and tools, Joe decided to embark on a journey of self-experimentation and self-learning to improve his health--something that has since become known as “biohacking”. With thousands of experiments and pubmed articles under his belt, Joe founded SelfHacked, the resource that was missing when he needed it. SelfHacked now gets millions of monthly readers.Joe is a thriving entrepreneur, author and speaker. He is the CEO of SelfHacked, SelfDecode and LabTestAnalyzer.His mission is to help people gain access to the most up-to-date, unbiased, and science-based ways to optimize their health.
Joe has been studying health sciences for 17 years and has read over 30,000 PubMed articles. He's given consultations to over 1000 people who have sought his health advice. After completing the pre-med requirements at university, he founded SelfHacked because he wanted to make a big impact in improving global health. He's written hundreds of science posts, multiple books on improving health, and speaks at various health conferences. He's keen on building a brain-trust of top scientists who will improve the level of accuracy of health content on the web. He's also founded SelfDecode and LabTestAnalyzer, popular genetic and lab software tools to improve health.

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