自由基是我們進行呼吸時所產生出來的一種具有異常破壞能力的有毒物質，甚至會破壞身體內的正常細胞而出現氧化。就像蘋果切開後切面會很快變成茶色以及鐵釘生銹等氧化現象一樣，我們的體內也會有同樣的情況發生。細胞膜會因為受到自由基的攻擊而氧化，逐漸失去正常功，如任由自由基操作至一定程度，身體就會出現各種慢性疾病及致癌細胞。

Free Radicals are by-products of human body's natural defense against different forms of pollution we are exposed to everyday.

Take for example a sliced apple, as oxygen in the air comes into contact with its surface, the apple begins to turn brown, ie. it is oxidized. Similar reaction occurs within our bodies. Free radicals cause oxidation of cell membranes and affect the normal functions of our body cells.

Free radicals are believed to be the causal factors in nearly every known disease, from heart diseases to arthritis, cancers and cataracts and might be one of the main culprits for the aging process.