First of all, there appears to be a difference between taking antioxidant supplements and obtaining them through food. Because vitamins, minerals and other phytonutrients work synergistically, it’s best to get them from food where they’re naturally available in the appropriate proportions for optimal absorption and assimilation. This is one of the reasons I recommend taking a multivitamin, rather than supplementing with high levels of single nutrients. In certain cases, taking high levels of some micronutrients can lead to malabsorption of other micronutrients. Many people, for example, pop multiple zinc lozenges during the cold and flu season to prevent illness. But high levels of zinc can interfere with copper absorption. On the other hand, even multivitamins have not been shown to prevent illness or disease or prolong life, which is why you should obtain most of your nutrients from food, not pills.
There’s now a growing field called nutritional immunology where researchers are studying the power of nutrition in healing injuries and preventing illness. Says Anuraj Shankar, researcher at Harvard’s School of Public Health, ” If you don’t have an adequate intake of vitamins and minerals you won’t be able to produce the number of immune cells you need, and the immune cells you do produce may be compromised.” So, eating a nutrient-dense diet is an important defense in warding off both acute illness and chronic diseases.
This is probably the first time in history where its possible to be both obese AND malnourished – to have access to an overabundance of calories containing a low-level of nutrients. Research also suggests that diets high in saturated fat and sugars appear to suppress the immune system. This is perhaps one of the reasons obesity is now a risk factor for cancer.
The key nutrients that appear to boost the immune system are: vitamin D, available through sun exposure and in cold water fish such as salmon, eggs and fortified dairy products; vitamin C, plentiful in fruits and vegetables, including strawberries, kiwi, tomatoes, red bell peppers and, of course, citrus; vitamin A, found in liver, spinach, pumpkin and sweet potatoes; vitamin B-6, found in bananas, potatoes and beans; selenium, whose sources include Brazil nuts, seafood and turkey; and zinc, found in shellfish, pork and beef.
In my next post I’ll look at whether taking antioxidants bolsters or blunts the benefits of exercise. Until then…