This post is part of a series about immune balance. It dissects the Th1 response, diseases associated with its elevation, and complementary approaches – including lifestyle, food, and supplements – that may help keep the immune system in good health.<\/p>\n
You\u2019ve probably heard quite a bit about the Th1 and Th2 response if you\u2019ve reached this article.<\/p>\n
Let\u2019s get some basics down first.<\/p>\n
To start with, the human immune system is incredibly complex. We have many types of immune cells that are orchestrated by various factors – from our encounter with microbes, to our health status, genetics, mood, and more.<\/p>\n
The Th1\/Th2 theory is one attempt at understanding immune regulation, and Th1 and Th2 cells are its key players. This theory dates back to studies on mouse immune cells in the 80s. However, it is still considered controversial and it\u2019s not without limitations and discrepancies<\/strong>. More large-scale human studies are needed to determine its validity [R<\/a>].<\/p>\n According to the Th1\/Th2 theory [R<\/a>]:<\/p>\n The Th1\/Th2 theory states that overactivation of either the Th1 or the Th2 pattern can cause disease. Similarly, either pathway is thought to down-regulate the other [R<\/a>].<\/p>\n One of the reasons why an increase in one may <\/em>translate to a decrease of the other is because they differentiate from a progenitor or original cell and there\u2019s a limited number of these cells.<\/p>\n Based on this, some studies claim that most substances that decrease Th1 will increase Th2<\/a> and vice versa (decrease Th1 will increase Th2), but this isn\u2019t always the case.<\/p>\n Some nutrients – including long-chain omega-3 fatty acids (EPA and DHA) seem to improve various inflammatory and autoimmune conditions without any specific Th1\/Th2 effect [R<\/a>].<\/p>\n Often, it\u2019s uncertain whether a certain nutrient or intervention stimulates the Th1\/Th2 immune system or not.<\/p>\n Additionally, many diseases that were previously classified as Th1- or Th2-dominant failed to meet defined criteria. Plus, Th1 dominance can be polarized to Th2 patterns, and vice versa [R<\/a>].<\/p>\n The main issue with the whole Th1\/Th2 theory, as some scientists have recently pointed out, is that the activity of cytokines and other immune messengers rarely fall into strict Th1 or Th2 patterns. Some cells, like non-helper regulatory T cells (Tregs<\/a>), may influence both Th1 and Th2 responses [R<\/a>, R<\/a>, R<\/a>].<\/p>\n Limited studies have suggested that men are more prone to Th17<\/a> and Th2 dominance<\/a>, while women are thought to be more prone to Th1 dominance<\/a>. However, there\u2019s no hard evidence to back this up (R<\/a>, R<\/a>).<\/p>\n Additionally, studies indicate that pregnancy is a Th2 state. Scientists think that lower Th1 activity is part of the adaptive physiological response that women go through in pregnancy (R<\/a>).<\/p>\n This is said to prevent the mother\u2019s antibodies from mounting an attack against the fetus. It\u2019s also thought to explain why women are more prone to infections during pregnancy. Many women with rheumatoid arthritis – typically seen as a Th1 disease – experience relapses after pregnancy (R<\/a>).<\/p>\n On the other hand, male sex hormones or androgens may increase PPAR alpha<\/a>, which causes inhibition of Th1 dominance<\/a> in animals. At the same time, men tend to have lower PPAR gamma<\/a>, which is hypothesized to lead to Th17 dominance (R<\/a>).<\/p>\n To some extent, researchers believe that Th1 and Th17 \u201ccompete\u201d with each other, but this is also uncertain. Some studies indicate that IL-2<\/a> produced by Th1 cells activates STAT5, which competes with STAT3<\/a> (thought to be produced in Th17 dominance) (R<\/a>).<\/p>\n More human research on gender-related mechanisms is needed<\/strong>.<\/p>\n If your goal is to lower your Th1 response because you have serious immune problems – including autoimmunity, and constant fatigue or pain – it\u2019s important to talk to your doctor, especially your symptoms are significantly impacting your daily life.<\/p>\n\n
<\/a>Inconsistency Issues<\/strong><\/span><\/h3>\n
<\/a>Gender Differences<\/strong><\/span><\/h3>\n
<\/a>Lifestyle, Foods, Supplements that May Balance the Immune System (Lower Th1)<\/strong><\/span><\/h2>\n
<\/a>When to See a Doctor<\/span><\/h3>\n