Aging is associated with increased risk of various diseases, and much attention is given to the use of natural products (like herbs) and 'functional food', such as teas, for healthy aging.

The body is continuously exposed to potentially damaging agents (known as free radicals). The imbalance between the amount of free radicals and that of antioxidants in the body is known as oxidative stress. It is known that Type 2 DM is a state of increased oxidative stress, which is thought to lead to many long term complications of Type 2 DM, such as heart disease, vision problems and kidney failure. Antioxidant therapy, including increased consumption of antioxidant rich foods and beverages such as green tea, has been suggested as possibly beneficial in lowering the risk of these complications.

The purpose of this study is to examine the effects of regular intake of green tea on indices of oxidative stress and antioxidant defense within cells, plasma and urine so as to investigate if regular intake of green tea can be recommended for health promotion.

Inclusion Criteria:

• Type 2 DM subjects
• Genotyped for polymorphism in the heme-oxygenase gene promoter region to be homozygous for long (> 26) or short (< 24) GT repeats

Exclusion Criteria:

• smokers
• have suffered DM related complication
• already taking antioxidant or herbal supplements