Daily ingestion of green tea catechins from adulthood suppressed brain dysfunction in aged mice.

Oxidative damage is believed to be an important cause of senescence. We have previously found that green tea catechins (GT-catechin), potent antioxidants, decrease oxidative damage to DNA and suppress brain dysfunction in aged senescence-accelerated mice (SAMP10) when ingested from the age of 1 month to the age of 12 months. To clarify the effect of GT-catechin on suppression of brain senescence, we investigated the effect of starting period to ingest GT-catechin. Six- or 9-month-old SAMP10 mice were allowed free access to water containing 0.02% GT-catechin. SAMP10 mice exhibit senescence characteristics such as shortened life span, atrophied forebrain and lowered learning and memory abilities. Learning ability was significantly higher in mice that ingested GT-catechin from the age of 6 months to 12 months when compared with same-aged control mice drank water without GT-catechin. Starting GT-catechin intake from the age of 9 months tended to improve learning ability. The ages of 6 and 9 months are thought to be adult and middle ages, respectively in SAMP10 mice. This result suggested that GT-catechin was helpful in suppressing brain dysfunction with aging even when ingestion started at the adult age.