Health benefits of Green Tea

Green tea, derived from the unoxidized leaves of the Camellia sinensis plant, has been celebrated for its health benefits for centuries. As one of the least processed teas, it retains a high concentration of antioxidants and beneficial polyphenols. Modern research has explored various potential health advantages of green tea consumption.

Potential Health Benefits of Green Tea

1. Cancer Prevention: Observational studies have noted lower cancer rates in regions with high green tea consumption. However, human studies have not shown consistent evidence that drinking green tea reduces the overall risk of cancer. A 2020 database review of epidemiological and experimental studies in humans produced inconsistent results and limited evidence of green tea’s benefits for lowering cancer risk. The researchers assessed 142 completed studies, including 1.1 million participants. The topical application of green tea polyphenol extracts may have a role in protecting the skin from UVB radiation. A 2018 review of in vitro, in vivo, and human studies demonstrated the potential benefits of tea polyphenols in the chemoprevention of UVB-induced skin cancer. A 2020 review suggests green tea catechins have some positive impacts on breast, colorectal, esophageal, lung, prostate, and liver cancers. Overall, more research on humans is necessary. healthline.com

2. Weight Loss: Green tea has been associated with weight loss and weight maintenance. A review published in The American Journal of Clinical Nutrition analyzed 11 randomized controlled trials and found that green tea and its catechin content had a small but significant effect on weight loss and weight maintenance. The review suggested that catechins and caffeine in green tea can increase energy expenditure and fat oxidation, which may contribute to weight loss. Another study published in The Journal of Nutrition examined the effects of combining green tea extract with exercise on fat oxidation in overweight women. The results showed that the combination of green tea extract and exercise significantly increased fat oxidation compared to exercise alone. Although the available research shows promising associations between green tea, catechins, and weight loss, it’s important to approach these findings with caution. Individual results may vary, and more research is needed to further understand the mechanisms and determine the optimal dosage and duration of green tea consumption for weight loss purposes. healthline.com

3. Skin Health: The topical application of green tea polyphenol extracts may have a role in protecting the skin from UVB radiation. A 2018 review of in vitro, in vivo, and human studies demonstrated the potential benefits of tea polyphenols in the chemoprevention of UVB-induced skin cancer. healthline.com

4. Heart Health: Regular consumption of green tea has been associated with a reduced risk of heart disease and stroke. One of the key ways green tea benefits heart health is by lowering blood pressure. Studies have shown that the catechins found in green tea can help relax blood vessels, improving blood flow and reducing hypertension. Green tea also possesses anti-inflammatory properties, which can reduce inflammation in the cardiovascular system. Chronic inflammation is a major contributor to heart disease, and by reducing inflammation, green tea can help protect against the development of cardiovascular conditions. Furthermore, green tea has been found to improve endothelial function, which is important for maintaining healthy blood vessels. Endothelial dysfunction is a precursor to vascular disease, and green tea’s ability to enhance endothelial function can help prevent the progression of heart disease. Another significant benefit of green tea for heart health is its potential to decrease cholesterol levels. healthline.com

5. Type 2 Diabetes Management: Green tea, known for its numerous health benefits, may also play a role in diabetes management. Some studies suggest that regular consumption of green tea is associated with a lower risk of type 2 diabetes. healthline.com

Nutritional Profile of Green Tea

An 8-ounce cup of green tea contains:

• Calories: Less than 5

• Protein: Trace amounts

• Fat: Trace amounts

• Carbohydrates: Trace amounts

• Sugar: Trace amounts

• Caffeine: 30–50 mg

• Polyphenols: Significant amounts

Green tea is exceptionally high in polyphenols, particularly catechins, which are a type of antioxidant.

Potential Side Effects

While green tea is generally safe for most people when consumed in moderate amounts, excessive intake can lead to side effects due to its caffeine content. These may include insomnia, nervousness, or stomach irritation. Additionally, high doses of green tea extract supplements have been linked to liver problems in rare cases. It's essential to consult with a healthcare provider before starting any new supplement regimen. healthline.com

Conclusion

Incorporating green tea into your daily routine may offer various health benefits, from supporting weight management to promoting heart health. However, it's crucial to consume it in moderation and be mindful of its caffeine content. As with any dietary change, consider consulting with a healthcare professional to ensure it aligns with your individual health needs.

Medically reviewed by Jared Meacham, PhD., RD, CSCS — Written by Megan Ware, RDN, L.D. — Updated on December 14, 2023

Sources: https://www.medicalnewstoday.com/articles/269538