Th1 vs Th2 Type Immune Systems:  Which One Do You Have?

Throughout the COVID-19 pandemic, you couldn’t help but hear a great deal of talk about the human immune system:  what it is, how it functions, how it can help thwart everything from the common cold to the flu to the coronavirus.

It’s long been known that the human immune system is incredibly complex. To begin with, we have many types of immune cells that are influenced by a range of factors such as our encounters with microbes, genetics, our health status, mood, and more. In addition, there’s also Th1/Th2 theory, just one attempt at understanding the intricacies of immune regulation.

Th1 vs Th2 Explained

Th1/Th2 theory dates back to studies conducted in the ’80s; however, the theory is still considered controversial, and more large-scale human studies are needed to determine its validity and examine the theory’s limitations more closely.

According to the Th1/Th2 theory 26:

• T-Helper 1 (Th1) and T-Helper 2 (Th2) cells are key players in Th1/Th2 theory
• Th1 cells drive the so-called type-1 pathway (cellular immunity). It’s believed they are involved in fighting cell viruses and other pathogens, ridding cancerous cells, and triggering delayed-type hypersensitivity (DTH) skin reactions.
• Th2 cells drive the type-2 pathway (humoral immunity). It’s hypothesized that these cells increase antibody production and fight invaders that are outside cells, and that they may be involved in tolerance of organ transplants (xenografts) and of the fetus during pregnancy.
• Th1 cells produce mainly the cytokines or messengers IL-12 and interferon gamma, and Th2 cells produce mainly IL-4.

Th1 cells produce mainly the cytokines or messengers IL-12 and interferon gamma, and Th2 cells produce mainly IL-4; both cell types also produce other cytokines.

Th1/Th2 Theory Inconsistency Issues

According to Th1/Th2 theory, overactivation of either the Th1 or the Th2 pattern can cause disease. According to one interpretation of the theory, people’s immune systems often lean to Th1 or Th2; similarly, either pathway is thought to down-regulate the other. An increase in one could translate to a decrease of the other because they differentiate from a progenitor or original cell (Th0), and there’s a limited number of these cells.

The Th1 side is seen as more immune-stimulatory; the Th2 side is considered to be more immune-deficient. Both, however, can produce inflammation under certain conditions. Based on this, some studies claim that most substances that decrease Th1 will increase Th2 and vice versa, but this isn’t always the case.

Some nutrients, including long-chain omega-3 fatty acids (EPA, DHA), seem to improve various inflammatory and autoimmune conditions without any specific Th1/Th2 effect. Oftentimes it’s not clear whether a specific nutrient or intervention stimulates the Th1/Th2 immune system or has no discernible effect.

In studies, many diseases previously classified as Th1- or Th2-dominant failed to meet defined criterial; additionally, Th1 dominance can be polarized to Th2 patterns, and the opposite can also be true. Recent scientific research has pointed out 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), may influence, and likely suppress, both Th1 and Th2 responses.

Factors That May Disrupt Immune Balance And Raise Th2

Many factors can impact immune system balance, such as fast food, smoking, stress, overeating, excessive alcohol consumption, and more.

Additional lifestyle factors that can disrupt immune system balance include: mold, myocotoxins, magnesium deficiency, severe injury, circadian disruption, BPA, diesel exhaust particles, chronic psychological stress, fine-ambient particles, glutathione depletion, excess vitamin D3, and mercury poisoning.

Factors That May Balance The Immune System And Lower Th2

A healthy lifestyle that includes regular exercise, a well-balanced diet, sufficient nutrients, quality sleep, and a healthy circadian rhythm can help to keep your immune system balanced.

Additional lifestyle factors that can disrupt immune system balance include: high-intensity exercise, bee products such as royal jelly, bee pollen, and propolis, prebiotics FOS and GOS, moderate coffee consumption, kiwi, rice, black rice, rice bran oil, black pepper, black cumin, seed oil, cocoa, cold exposure, oxytocin increase, vitamins B6 and B12, C, and E, selenium, zinc, copper, iron, folate.