Protective Mechanisms of Green Tea Polyphenols in Skin

The scientific paper Protective Mechanisms of Green Tea Polyphenols in Skin by OyetakinWhite et al. explores how compounds found in green tea, particularly epigallocatechin-3-gallate (EGCG), help protect the skin from ultraviolet (UV) radiation damage. With skin constantly exposed to harmful environmental factors—especially UV rays that lead to aging, inflammation, and skin cancer—this study highlights the need for alternative, natural photoprotective strategies. The authors review multiple in vitro, animal, and human studies to demonstrate that green tea polyphenols (GTPPs) can reduce oxidative stress, support immune response, and even help repair DNA damage, offering both topical and oral approaches for skin protection and cancer prevention.

Our skin faces many challenges, especially from sunlight. Ultraviolet (UV) radiation from the sun can damage the skin, weaken the immune system, and even cause cancer. According to the study, UV rays are "the main external stress that leads to immunosuppression, oxidative stress, premature aging, and tumor formation."

Although using sunscreen and wearing protective clothing can help, many people don’t follow those guidelines properly. That’s why scientists are looking for other ways to protect the skin. One natural option that is getting a lot of attention is green tea. Green tea is full of powerful plant compounds called polyphenols, which have been shown to fight damage in the body and support the immune system.

The most important of these polyphenols is EGCG (epigallocatechin-3-gallate), which has been studied for its effects on skin protection, both when applied to the skin and when consumed as a drink or supplement.

This scientific paper reviews many experiments and clinical studies in cells, animals, and humans. The researchers examined how green tea polyphenols (GTPPs), especially EGCG, interact with the skin when exposed to harmful UV rays. These studies explored the effects of drinking green tea and applying it directly to the skin.

They examined:

• Changes in skin cells after UV exposure
• How GTPPs affect DNA repair
• Levels of inflammation and oxidative stress
• The risk and progression of skin cancer

The authors gathered a clear picture of how GTPPs can help protect the skin from sun damage by looking at different research findings.

UVB rays from the sun can directly harm DNA and start the process of skin aging and cancer. The study explains that UVB exposure "produces cyclobutane pyrimidine dimers (CPD) and pyrimidine-pyrimidone (6–4) mutagenic photoproducts that lead to tumor initiation and tumor promotion."

GTPPs help prevent this damage. In mice, topical green tea prevented DNA damage caused by UVB and helped maintain the skin's own repair enzymes. One experiment showed that applying EGCG directly to the skin worked better than drinking green tea in reducing damage caused by UV light.

When exposed to UV light, our skin creates reactive oxygen species (ROS). These harmful molecules can damage proteins, fats, and DNA. GTPPs help by neutralizing these ROS before they can cause harm.

According to the study, green tea polyphenols can “improve fibroblast cell shape and absolute cell numbers” after oxidative stress. They also help the skin keep its antioxidant enzymes, like catalase and glutathione peroxidase, which are important for protecting cells.

The sun can suppress the immune system, making it harder for the skin to fight infections or cancers. GTPPs support immune function. In one experiment, mice given green tea in their drinking water had stronger immune responses even after UV exposure.

The study says EGCG may help by encouraging the body to produce more interleukin-12 (IL-12), which supports DNA repair and immune strength. Human studies also showed that green tea reduced UV-caused DNA damage in white blood cells.

Sun exposure causes inflammation, which shows up as redness and swelling. GTPPs have anti-inflammatory properties. They block certain pathways in skin cells that normally lead to inflammation. For example, in rodent studies, EGCG was found to lower the production of histamine and pro-inflammatory cytokines like TNF-α and IL-6.

These effects help reduce sunburn and slow down the signs of photoaging—like wrinkles and dark spots.

The study highlights that EGCG can “inhibit tumor growth, progression, and angiogenesis.” It blocks the creation of new blood vessels that tumors need to grow and interferes with cancer-promoting signals in cells.

In animal studies, applying green tea to the skin reduced the number of tumors caused by UV exposure. Drinking green tea was also linked to a delay in cancer development. One large observational study mentioned in the paper found that people who drank more than 10 cups of green tea a day developed cancer years later than those who drank less.

Topical use of green tea is generally safe, with only mild irritation reported in some cases. Oral consumption is also mostly safe, but high doses—especially when taken on an empty stomach—can lead to health problems. In one study, dogs taking green tea capsules while fasting had serious side effects. However, when taken with food, the risks went down.

So, while green tea polyphenols are natural, they should still be used carefully—especially in supplement form.

Green tea polyphenols, particularly EGCG, offer a natural way to help protect skin from the sun. They support the skin’s defense systems, reduce inflammation, and may help lower the risk of skin cancer. Their ability to reduce damage from UV rays and boost the skin’s natural repair processes makes them useful for both prevention and treatment.

Because GTPPs can be used both topically and orally, they give people more options—especially those who may not use sunscreen consistently. With more research, these compounds could become a regular part of sun protection and skincare routines.

This scientific study shows that green tea polyphenols have real potential to protect skin from sun damage, slow aging, and even reduce the risk of skin cancer. These natural compounds can play an important role in skincare by working as antioxidants, anti-inflammatories, and immune boosters.

As the study says, “GTPPs have important antioxidant, immunomodulatory, and photoprotective functions.” While more research is needed to find the best doses and forms, it’s clear that green tea is more than just a healthy drink—it’s a powerful ally for healthy skin.