Antioxidants help your body combat oxidative stress, a contributing cause of many age-related diseases, such as cancer, heart disease and Alzheimer’s disease, reports the U.S. Department of Agriculture. Green tea and rooibos tisane, an herbal tea, contain high levels of antioxidants that may boost your immune system. Consult your health care provider when deciding on dietary changes that might be appropriate for you.
Made from the fermented leaves of the South African shrub, Aspalathus linearis, Rooibos tea is naturally high in two types of polyphenol antioxidants--aspalathin and nothofagin--the Memorial Sloan-Kettering Cancer Center reports. Many scientists and nutritionists regard these polyphenols as strong agents in combating vascular inflammation, a contributing factor in heart disease.
Green tea is made from the leaves of the Camellia sinensis plant, the same plant used for black and white teas. It contains high levels of catechin epigallocatechin-3-gallate, a different class of antioxidant, not contained in rooibos. Catechins are thought to inhibit cancer cell reproduction and to encourage the cell-death of cancer cells, notes the Memorial Sloan-Kettering Cancer Center.
The U.S. Department of Health uses a rating scale called ORAC, short for oxygen radical absorbance capacity, to aggregate the total amount of antioxidants found in many common foods. Brewed green tea has a score of about 1,250, while brewed rooibos tea rates between 725 and 1,110. Scientists recommend consuming about 5,000 ORAC units per day from a wide range of foods.
Since each antioxidant combats different causes of oxidation in the human body, researchers recommend consuming a wide range of antioxidant sources, including fruits, vegetables, nuts and teas. Selecting choices that are higher in ORAC score may ensure that you consume adequate amounts of antioxidants to reduce your risk of many diseases.