Epigallocatechin gallate (EGCG) is the most abundant catechin (sometimes referred to as tea flavonoids) in green tea extract. A review by Nagle et al (2006) identifies that a large amount of research indicates EGCG (amongst other catechins) is responsible for most of the potential health benefits associated with green tea. EGCG is brain permeable (Nakagawa & Miyazawa, 1997), and it is considered to have neuroprotective and neurorescue effects including modulation of cell survival and cell cycle genes (Levites et al 2002).

Although there have been several human studies looking at the bioavailability of EGCG when administered in varying doses, there have been no studies that have specifically investigated the cognitive effects of this catechin in humans. Therefore, the purpose of this study is to assess the cerebral blood flow (using Near Infrared Spectroscopy), cerebro-electrical activity (EEG) and behavioural effects of EGCG. A randomised, double-blind, placebo-controlled, balanced crossover study will assess the effects of 135 mg and 270 mg pure EGCG in 24 healthy, young adults (18-35). Prior to the first active study day participants will attend a screening/training visit where relevant exclusion criteria will be assessed including any food sensitivities. They will also complete a caffeine consumption questionnaire in order to control for potential caffeine withdrawal effects as a result of restrictions of the study.

Inclusion Criteria:

• healthy
• aged 18-35
• either caffeine consumers (consume more than 150mg caffeine per day) or non-consumers (consume less than 44mg caffeine per day).

Exclusion Criteria:

• smoke or consume any tobacco products
• not proficient in English language
• pregnant (or seeking to become pregnant)
• taking recreational, over the counter/prescription medication (including the contraceptive pill), and/or dietary/herbal supplements
• have food allergies or sensitivities
• have history of/current head trauma, learning difficulties , ADHD, migraines or any gastric problems