While the jury is out on exactly how antioxidants work to prevent disease, solid science indicates that they can and do play a role. The term "antioxidant" refers to a broad range of substances that reduce damage caused by reactive oxygen species (a type of free radical.) Free radicals scavenge electrons from healthy cells, causing damage at a cellular level. They are thought to contribute to aging, tumor growth, eye problems, and neurological disorders. Antioxidants may help prevent disease by giving free radicals electrons and neutralizing their damaging effects [source: Bagchi and Puri].
Oils, berries, vegetables, herbs, spices and nuts contain some of the best dietary sources of antioxidants. Oil-based salad dressings -- especially those that have been infused with antioxidant-rich herbs, spices, fruits and nuts -- can pack a powerful, antioxidant punch.
- Antioxidants in oil: Olive oil contains up to 5 milligrams of hydroxytyrosol and tyrosol per 10 grams of oil as well as the antioxidant vitamin E [source: OliveOilSource]. Flaxseed oil is another great source of antioxidants; it is the best-known source of the compound lignin. In general, the least processed oils contain the most antioxidants [source: AskDrSears].
- Antioxidants in vinegar: Kurosu (black rice) vinegar contains more polyphenols (non-nutrient plant compounds with antioxidant properties) than other vinegars. It has a deep, smoky flavor and is sold as a health drink in Japan. Other vinegars with antioxidant properties include balsamic, red wine and cider vinegar [source: Johnston].
- Antioxidants in herbs, spices and berries: Adding emulsions of berries and spices to your oil-based dressings will give them an added antioxidant benefit. In general, the deeper the color of the fruit, the more antioxidant compounds it contains. Certain spices have even bigger per-gram antioxidant ratios than fruits and berries. A half-teaspoon of cloves contains more antioxidants than a half cup of blueberries or cranberries. Spices with the biggest antioxidant benefit include cloves, oregano, ginger, cinnamon and turmeric [source: McCormick].
In addition to being a great source of antioxidants, oil-based salad dressings are also heart healthy. Read on for more information.