Changes in season, stress, ultraviolet radiation and pollution are some of the external agents that attack our immune system and are accused even more over the years. A key factor in the immune function of our cells is to find the balance between the oxidation process and the availability of antioxidants, which are the nutrients needed to maintain the cell membranes, lipids, proteins and other functions related to the immune system. Or what is the same: the grandmothers have advised the whole life to eat oranges to cool less. Some reason they had. Although vitamin C, a powerful antioxidant, does not prevent the cold, it is true that it strengthens the defenses.
At all stages of life we need to cover adequate amounts of antioxidants to maintain a good immune response, but this need increases as we age, because the immune system has fewer resources to protect itself, according to studies targeting the mature population. This occurs, among other processes, by the accumulation of the absorption of free radicals, substances harmful to our body, which contribute to cellular aging, cardiovascular problems and decreased memory and cognitive ability.
Free radicals, researchers say, can be of two types: endogenous – as stages of stress, physical or mental – and exogenous, derived from pollution, ultraviolet radiation, excessive consumption of alcohol or tobacco and an unbalanced diet. Foods such as green tea, red grapes – and by extension red wine, because of their high content of polyphenols – olive oil, spices, fruits and vegetables contribute to improve nutrition thanks to its antioxidant properties, which become the first line of defense against free radicals.
Nutrients such as vitamin B2, vitamin C, zinc, selenium and carotenoids, among others, have a high antioxidant power and help minimize the negative effects of cellular oxidation and therefore help maintain a proper functioning of immune system.
The US Department of Agriculture (USDA) rates the Oxygen Radical Absorption Capacity (ORAC) of each food, that is, the antioxidant properties that contain the ingredients in our diet. And it recommends a daily intake of between 3,000 and 5,000 “ORAC units” of that score scale. A raw apple with skin would have 3,049 ORAC while a banana only has 795 ORAC and a kiwi 862 ORAC, for example. It depends on each of you whether you want to start to make an account of how many antioxidants it contains in your diet or if you prefer to eat peacefully in a balanced way. In addition, we must take into account that these measurements are made “in vitro” to food and can not experience “in vivo” the assimilation of these antioxidants in humans.
A research developed by the Department of Microbiology of the University of Jaén, concludes that antimicrobial defense depends to a large extent on oxidative stress, induced by microorganisms responsible for infections. That is to say: if we have an insufficient feeding in antioxidant properties we will be breeding ground for the microbes and we can get sick more.
How many tablespoons of olive oil a day, for example, would be needed to have any beneficial effect? A tablespoon of olive oil – whether in salads, stews or bread toast with oil – elevates the natural defenses Of the organism. When the antioxidant properties of olive oil have been investigated against omega-3 fatty acids, polyunsaturated fatty acids have been found to be equivalent at the level of cardiovascular properties, but the abusive consumption of fish oil reduced negatively natural ability to defend against bacterial infections, which is not the case with olive oil.
There is a famous work with Eskimos, where it was seen that they did not suffer from arteriosclerosis, but the death rate from pulmonary tuberculosis was very high, precisely because abusive consumption of a single nutrient is not beneficial to health. Everything in its right measure is healthy, not abuse.
The researchers’ recommendation is to return to the essence of the Mediterranean diet, without obsessing or exceeding the recommended daily amount of antioxidants, because there could come a time when our natural defenses diminish. Several randomized trials, collected at the conclusion of the study, suggest that nutrient supplementation may reduce the possibility of infection from age 50, when the body does not have as much resources to defend itself as a young body. It is for all that, that carrying a diet rich in these nutrients with antioxidant capacity will help us to maintain a correct functioning of our immune system.