Total antioxidant capacity is the term used to describe the ability of antioxidants in different foods to clean harmful free radicals in the blood and cells. Often referred to by the acronym TAC, it takes into account the amount of water-based and fat-based antioxidants present in food. Understanding this figure helps individuals decide which foods offer the greatest antioxidant benefit.
While certain foods, such as berries and artichokes, are deemed to be very high in certain types of antioxidants, researchers have concluded that this fact alone is not reliable for understanding the health benefits offered in these foods. This is because other factors must be considered, such as where foods were grown, how well they are absorbed into the body and how the body will eventually use them. Scientists are, therefore, working to measure and classify each fruit and vegetable according to their total antioxidant capacity in an effort to give consumers a better idea of which foods offer the best defense against free radicals.
Fruits and vegetables cultivated in one geographic location often tend to have a different capacity from fruits and vegetables grown in another. Environmental components largely contribute to TAC, and scientists maintain that such must also be factored into the process of defining the figure for foods before that information is released to the public. Some experts believe that this information should be offered regionally instead of globally to provide a more accurate depiction of a food’s antioxidant benefit to consumers living in a certain area.
Experts sometimes differ on the ways in which total antioxidant capacity is measured. One method in particular has gotten a good deal of attention and is considered to be one of the most reliable measurement scales. Known as the oxygen radical absorbance capacity scale (ORAC), researchers consider this method to be the most accurate.
Complicating the process even further, however, is the fact that each person’s body absorbs antioxidants differently. In each individual food, chemical reactions to other components in the food will also affect its TAC. With so many factors to consider, the figure for most foods and how they will benefit each person may frequently vary from one person to the next and from one part of the world to the next.