As an antioxidant, the flax oil's lignans can help boost the body's immune system, keeping harmful, disease-causing germs from damaging the cells. These plant hormones are also believed to block the formation of hormone-based tumors. Lignans also boost the productions of a substance attached to estrogen and carries it out of the body. These are substances that defend our body against the ravages brought on by free radicals. The first ever antioxidants to catch the attention of scientists and the vitamin supplement industry is beta-carotene or more commonly known as Vitamin A. Now, you can find antioxidant supplements in the form of Vitamin A capsules in almost any pharmacy or health food store. Due to the lack of sufficient data to support the success of antioxidant vitamins supplement against cardiovascular diseases and other such degenerative illnesses, the American Heart Association does not recommend using antioxidant vitamins supplements. However, they do not want to put a stop to our continued taking of antioxidant vitamins, the ones found in nature and in the foods that we eat. Carotenoids are the largest group of naturally occurring antioxidants, followed closely by indoles and coumarins. Catechins are the natural antioxidants found in the Camellia sinensis plant where we get our green tea, oolong tea, and black tea. In the carotenoid group, beta-carotene is the most common natural antioxidant. Herbal antioxidants are of course found in fresh produce, fruits, and vegetables. A large number of members of the berry family are excellent sources of herbal antioxidants. In fact, most herbal antioxidants you find sold in health food stores today are comprised mainly of berry extracts. Studies have shown that berries are rich in certain herbal antioxidants that help reduce atherosclerosis by acting on the agents that causes the clogging and the hardening of the arteries. Such substances are called super antioxidants. When you slice an apple and leave it on the table, you will notice that the flesh turns brown after some time. This is caused by oxidation - when the oxygen in the air reacts with the substances found in the apple. Oxidation is a natural process that occurs in the human body as well.