Antioxidants Part 2, the ORAC values
Foods contain antioxidants, precious substances able to fight free radicals that are considered to be the cause of aging processes and many age-related diseases. We see the foods with a stronger antioxidant power.
As we saw in the previous post, our body continuously produces free radicals, potentially harmful substances without an electron that try to reintegrate by taking it from nearby molecules. This process generates new free radicals and causes damages to the cell structures and DNA by promoting aging processes and creating a breeding ground for many age-related diseases such as arteriosclerosis, cataracts, diabetes but also degenerative illnesses such as Alzheimer's and Parkinson's. What can we do to counteract the action of free radicals? If we cannot act on some mechanisms, in fact we cannot stop breathing, eating or being exposed to the sun, all reasons that produce free radicals, on the contrary we can act on other harmful habits, such as smoking, alcohol, a diet rich in saturated fats and animal proteins, by limiting or avoiding them. But there are not just actions to avoid in order to reduce the production of free radicals, it is also possible to act against free radicals by introducing beneficial substances that counteract them, the antioxidants. To help us to choose the most beneficial foods, in 1993 the National Institute on Aging in Bethesda, USA, carried out a research on the antioxidant power of food and filled out a list in which this antioxidant power was measured (Cao et al, Free Raic Biol Med, 1993). Like any measurement, this also has a unit of measurement, called ORAC, which stands for Oxygen Radicals Absorbance Capacity, and a substance analogous to vitamin E has been taken as a reference for the measurements. Before seeing the ranking, however, it is good to make a premise. The list is an excellent point of reference to get an idea about the antioxidant power of food, but doesn’t describe the time used by these antioxidants to attack free radicals, or doesn’t take into account that often, in food, there are also other mechanisms not dependent on antioxidants, equally beneficial to fight some diseases related to aging. In addition to this, the results change by modifying some steps of the measurement process and the study does not take into account the fact that antioxidants do not only act against free radicals but fight many diseases in different ways. According to expert advice, the intake for an adult should be around 5000 ORAC units per day, although, as we have seen, the list should be seen as advice on which foods to prefer or introduce at least once a day rather than as a precise list. But let's see what foods, according to Bethesda's study, have more antioxidant power. Take an artichoke, this has 9800 ORAC units, also excellent are 100 grams of pomegranate juice (6000 units), 1 glass of grape juice (5200 units), 1 cup of blueberries (3480 units) and blackberries (1460 units) . Three black plums bring 1300 ORAC units, don’t forget strawberries (1 cup provides about 1170 ORAC units), avocado (1000 units) or broccoli (2200 units per portion). Then we can find the peppers (500 units per piece), kiwi fruits (1 kiwi can take 460 ORAC units) and a bunch of black grapes (570 units). Finally come the eggplants (320 units), apples (300 units), peaches (250 units), tomatoes (about 120 units for a tomato) and cucumbers (40 units).