The Importance of What You Drink for Health
The beverages you choose are just as critical to your health as the food you eat. Ideally, you’re hydrating with ample pure water daily and steering clear of unhealthy drinks like sodas, artificial fruit juices, and energy drinks to keep your health in top shape.
After water, tea stands out as one of the most commonly consumed and beneficial beverages you can incorporate into your diet. The Food and Agriculture Organization’s report indicated that tea consumption globally is growing by 3.3% annually, hitting an impressive 6.5 billion kilograms in 2022. In the U.S., over 159 million Americans enjoy tea daily, as per the Tea Association of the U.S.A.
Tea is broadly categorized into two types: true tea, derived from the leaves of the Camellia sinensis plant, and herbal teas, or herbal infusions, which are made from a variety of herbs, flowers, fruits, or spices from other plant species. Both are cherished not only for their delightful taste and fragrance but also for their numerous health benefits, particularly in supporting immune function.
Tea’s Immune-Enhancing Components
A common attribute of both true and herbal teas is their high content of polyphenols. These compounds are celebrated for promoting health and longevity through their antioxidant, anti-inflammatory, and immunomodulatory effects. Polyphenols include flavonoids, phenolic acids, lignans, and stilbenes.
Research published in the journal Molecule elaborates on how polyphenols bolster immune health:
“Polyphenols affect mucosal immunity and inflammation, thereby influencing the gut immune system and overall health. They impact immune cells like T cells, macrophages, and NK cells, promoting the production of anti-inflammatory cytokines while suppressing proinflammatory ones, enhancing NK cell activity, and proving valuable in preventing diseases linked to inflammation.”
The polyphenol content in tea can vary greatly based on the type of tea, its origin, and how it’s processed and prepared. In Camellia sinensis tea, polyphenols make up about 30% of the dry weight, predominantly as catechins:
- Gallocatechin (GC)
- Epicatechin (EC)
- Epigallocatechin (EGC)
- Epicatechin gallate (ECG)
- Gallocatechin gallate (GCG)
- Epigallocatechin gallate (EGCG)
For herbal teas, polyphenols constitute around 25% of the dry weight. A study in the Journal of Future Foods lists several polyphenols found in herbal tea, including catechin, gallic acid, (−)gallocatechin, sinapinic acid, caffeic acid, (−)epicatechin, gallocatechin, chlorogenic acid, ellagic acid, and corilagin, among others.
Beyond polyphenols, both true and herbal teas are rich in other bioactive compounds that enhance their immune-boosting effects. True teas contain amino acids, with theanine being the most prevalent, known for its neuroprotective, anticancer, antianxiety, cardioprotective, hepatoprotective, nephroprotective, and metabolic-regulatory properties. Herbal teas, on the other hand, are sources of polysaccharides, amino acids, vitamins, and carotenoids.
Three Potent True Teas for Enhancing Immune Defense
The diverse range of teas derived from the Camellia sinensis plant each offers unique flavors, aromas, and health benefits, influenced by their specific processing methods and the maturity of the leaves at the time of harvest. Here are three types of true tea renowned for their immune-enhancing properties:
- White Tea – Often recommended for its immune-supporting qualities, white tea is a luxurious variety made from the youngest buds and leaves of the plant, harvested during early spring. Unlike other teas, white tea undergoes minimal processing, simply being dried after picking, which makes it one of the least altered forms of tea.
Due to this minimal processing, white tea retains a high concentration of bioactive compounds, including catechins, amino acids, and other beneficial constituents. It boasts more antioxidants than green tea and contains less caffeine. Research at Pace University revealed that white tea is superior to green tea in bolstering the immune system against pathogens.
- Black Tea – Known for its robust flavor and extended shelf life, black tea is favored in Western cultures and includes popular varieties like English breakfast and Earl Grey. It’s produced by fully oxidizing the leaves before they’re dried, transforming catechins into theaflavins and thearubigins, which are key to its antioxidant profile.
A study published in the Journal BBA Clinical explored how regular black tea consumption impacts markers related to immune system activity, specifically neopterin, tryptophan, and kynurenine. Participants who consumed black tea daily for six months showed increased levels of kynurenine and a higher KYN/TRP ratio, suggesting an association with enhanced immune activation and inflammation.
- Green Tea – Perhaps the most celebrated and researched for its health benefits, green tea is made by quickly heating the leaves to prevent oxidation, preserving its rich array of bioactive compounds. Among its polyphenols, EGCG is particularly abundant, known for its therapeutic effects through immune modulation.
A review in the journal Food Science and Human Wellness detailed how green tea influences the innate, adaptive, and intestinal immune systems. The authors noted, “In green tea, various compounds act on different immune cells or even the same type of cell, causing diverse effects on the immune system. We believe that green tea exhibits greater immunomodulatory potential due to the synergistic effects on innate immunity and adaptive immunity of its different compounds.”
Moreover, green tea’s impact on the immune system is also mediated through its effects on the gut microbiome, where it’s metabolized into compounds that further regulate immune responses.
Whichever Tea You Choose to Brew, Keep This in Mind
Have you ever given a thought to how your teas are packaged? Research has shown that tea bags could be a significant source of microplastics or nanoplastics, which can harm your health in various ways.
The study, conducted by researchers at McGill University, tested four commercial products packaged in plastic tea bags. The tea leaves were removed to ensure any plastic particles in the tea did not contaminate the analysis of the tea bags. The empty bags were then placed in hot water to simulate the brewing process. Upon evaluating the water using an electron microscope, the researchers found that a single bag released billions of plastic particles.
These findings suggest that the level of contamination from tea bags is thousands of times greater than has been reported with other foods and beverages. Tea in paper bags could also be just as dangerous, as filter paper bags are often treated with epichlorohydrin, an industrial solvent and a known carcinogen, to reduce the risk of tearing during use.