What’s in your cup? Various Beverages and their Health Effects – Part 3

By Jocelyn Spizman

With so many beverage options out on the market, it is helpful to understand the health effects of what we choose to drink. In this third section, we will explore the health effects of tea and tea-based beverages. (See here for the first part on water, milk, and coffee and here for the second part on soda, fruit juice, and wine.)

Tea 

In general, each variation of teas has its own unique nutrient profiles and physiological changes associated with them. 

Green, Black, White, Oolong, and Pu-erh Teas

The green, white, black, oolong, and pu-erh classics are derived from the Camellia sinensis plant, native to India and China. Since green tea is the least processed of all of the variations, it tends to have the highest concentration of all of the nutrients studied.[2]

Some of the general health benefits of tea include:[2] 

• High antioxidants called flavonoids help fight against free radicals, oxidative damage which contribute to heart disease, cancer, and clogged arteries.
• Caffeine and theanine in the tea, as mentioned in Part 1 of this series, can help with mental clarity, alertness and stimulate metabolism, and raising energy levels.
  • This can also help reduce body fat mass for  healthy weight management
• The antioxidants help reduce the risk of neurological disorders like Alzheimer’s and Parkinson’s diseases.
• Tea has been shown to reduce the risk of stroke, 
• Tea has been found to regulate cholesterol levels by lowering “bad” (LDL) cholesterol— an important factor in the prevention of heart disease. 

There are some harmful effects of Camelila sinesis based teas, although it is safe in moderation.[1,4]

• Tea in very high doses can compound to have a higher caffeine content. This can result in higher rates of anxiety, restlessness, stomach problems, headaches, or insomnia.
  • The caffeine content can be risky for pregnant women and should be drunk in moderation. 
  • Since research has shown that caffeine can relax the sphincter connecting the esophagus and stomach, those with acid reflux or GERD may feel that the caffeine aggravates their symptoms or gives them heartburn.
• Excessive amounts of tea can result in anemia or iron deficiency due to the tannins that can inhibit iron absorption in the body.
  • In some individuals, the tannin content can lead to nausea or vomiting.

Herbal Teas 

Herbal teas are made from fruits, seeds, roots, or herbs, and can vary widely depending on the plant used. Some examples are ginger, ginseng, hibiscus, rosehip, jasmine, ginkgo biloba, mint, rooibos (red), chamomile, and echinacea. Each type of herbal tea has its own nutritional profile and benefits, but in general have few downsides

One thing to consider when looking for a herbal tea is if it has  any form of laxative effect or added supplement.[1] 

• Some laxatives include senna, aloe, buckthorn.[1] 
• The FDA warns you to take caution with the following supplements: comfrey, ephedra, willow bark, germander, lobelia, and chaparral.[1] 

Yerba Mate

Yerba mate is a caffeinated tea that is native to South America, specifically people native to Paraguay, Argentina and Brazil. 

Some Benefits:[2,5,10]

• Yerba mate is rich in antioxidants (even more than green tea!) and nutrients such as 
  • Xanthine which contains caffeine and theobromine and acts as a stimulant
  • Caffeoyl derivatives, which are great antioxidants
  • Saponins, which have cholesterol-lowering and anti-inflammatory properties
  • Polyphenols, which is a large group of antioxidants linked to reduction in risk of many diseases
  • Vitamin C, vitamin E, selenium, and zinc are all antioxidants in yerba mate that can help strengthen the immune system and promote health.
• Yerba mate has 85 mg of caffeine per cup
  • This can help boost energy levels and improve mental focus and physical performance
• The tea has been shown to help prevent infections against bacteria, parasites, and fungi, although more research is needed before direct effects are known.
  • High doses of yerba mate extract have been found to deactivate E. coli bacteria associated with food poisoning. 
  • Yerba mate has also been studied for its antifungal properties.
• Yerba mate can help you lose fat by boosting your metabolism and reducing your appetite.
  • Studies have found that yerba mate powder helps  people lose body fat mass when compared to a placebo.
• Yerba mate can help lower blood sugar levels and reduce the complications of metabolic diseases.
  • Some studies suggest that yerba mate  improves insulin signaling, reduces cholesterol levels, and lowers risk of heart disease.
• The tea can help reduce the formation of advanced glycation end-products (AGEs), which can worsen many degenerative diseases such as diabetes, chronic kidney disease, and Alzheimer’s disease.

However, yerba mate is not a miracle drink. The harmful effects of yerba mate include:[3,5]

• Drinking large amounts of yerba mate has been found to increase one’s risk of upper respiratory and digestive tract cancers.
  • This is thought to be due to the presence of polycyclic aromatic hydrocarbons (PAHs), which is a known carcinogen found in tobacco smoke and grilled meat.
  • Drinking the tea at lower temperatures can help decrease this risk of cancer.
• High levels of caffeine from drinking too much of the tea can lead to headaches, migraines, and high blood pressure.
• Yerba mate can interact with monoamine oxidase inhibitor (MAOI) medications, usually prescribed for depression or Parkinson’s disease, due to its monoamine oxidase inhibitor activity; people taking MAOI drugs should drink yerba mate with caution and consult their healthcare provider.
• Some brands of bottled yerba mate tea may add extra sugar to sweeten the beverage, and can counter the beneficial physiological effects of the tea.

Kombucha

Kombucha is a fermented tea that has been a part of Eastern Europe for thousands of years, and is believed to have originated in China or Japan.[6] It is made by adding bacteria and yeast (known in the drink as the SCOBY) to tea with sugar in which the fermentation process produces carbonation. Kombucha contains caffeine, sugar, alcohol due the fermentation process, vinegar, and B vitamins.[6] The bubbly beverage became popular in the United States around the 1990s and is a great soda alternative for someone craving a sweet and bubbly drink.

The fermentation process of kombucha gives it some unique benefits:

• Kombucha is a great source of helpful probiotics, due to the large amount of bacteria in the drink. This helps develop a diverse microbiome and aid in digestion and combating inflammation.[6]
• Kombucha mixes made with green tea have all the benefits of green tea;[6,7,8] 
  • This includes bioactive compounds such as polyphenols that contain great antioxidants, which counteract inflammation and radicals and can prevent cancer, reduce liver toxicity and even improve depressive symptoms. 
  • Green tea helps stimulate metabolism and can help prevent metabolic conditions such as type 2 diabetes and obesity.

Kombucha does come with some health  concerns and drawbacks:[7]

• Some brands have high amounts of added sugar, which as mentioned early, can contribute to a large list of poor health outcomes.
• Since Kombucha is fermented, it can become harmful and make you sick when over-fermented or contaminated. 
• When drunk in large quantities, kombucha can lead to nausea, vomiting, and stomach upset. 

So bottoms up to whatever you have in your cup! Here’s to choosing beverages with good hydration, flavor, health benefits, all of course with moderation.

References:

1. 11 Harmful Green Tea Side Effects (Read Before Drinking). (n.d.). Retrieved from https://senchateabar.com/blogs/blog/green-tea-side-effects
2. Edgar, J. (2009, March 20). Types of Teas and Their Health Benefits. Retrieved from https://www.webmd.com/diet/features/tea-types-and-their-health-benefits
3. Frothingham, S., & Wilson, D. R. (2019, September 26). Is Yerba Mate Linked to Cancer? Retrieved November 1, 2020, from https://www.healthline.com/health/yerba-mate-cancer
4. Hill, A. (2019, November 26). Side Effects of Tea: 9 Reasons Not to Drink Too Much. Retrieved from https://www.healthline.com/nutrition/side-effects-of-tea#The-bottom-line
5. Katherine Zeratsky, R. (2019, January 15). Is yerba mate your cup of tea? Retrieved November 1, 2020, from https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/yerba-mate/faq-20058343
6. Kombucha: Health benefits, risks, and how to make it at home. (2020, September 28). Retrieved November 1, 2020, from https://www.medicalnewstoday.com/articles/319630#what-is-kombucha
7. KOMBUCHA: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews. (n.d.). Retrieved November 1, 2020, from https://www.webmd.com/vitamins/ai/ingredientmono-538/kombucha
8. Leech, J. (2018, August 29). 8 Evidence-Based Health Benefits of Kombucha Tea. Retrieved from https://www.healthline.com/nutrition/8-benefits-of-kombucha-tea
9. Petre, A., MS, RD. (2019, December 13). Is Fruit Juice as Unhealthy as Sugary Soda? Retrieved November 1, 2020, from https://www.healthline.com/nutrition/fruit-juice-vs-soda