One way to think about oxidative stress is to imagine certain reactive chemicals in the body as firing electrons—like tiny chemical bullets—at cells. Nutrients known as antioxidants act somewhat like bullet-proof vests, helping protect cells from this damage. Over time, oxidative stress has been linked with age-related cognitive decline, including forms of dementia.
Polyphenols are a class of plant compounds with strong antioxidant activity, and green tea is a particularly rich source.
Research published in Biogerontology (Feb, 2007) examined whether long-term intake of green tea polyphenols could protect brain cells from oxidative damage and support memory. This was an animal study.
In the experiment, mice were given drinking water containing a 0.02% concentration of green tea polyphenols from one month of age until 15 months of age, a period corresponding to aging in mice. Compared with controls, the mice receiving the green tea polyphenols showed less memory decline and reduced oxidative damage to DNA in brain tissue.
Based on these findings, the researchers concluded that green tea polyphenols may help protect brain cells from oxidative stress and delay age-related memory changes. These effects were observed in animals, and the results were presented as supportive, not definitive, evidence for a potential neuroprotective role of dietary polyphenols.
