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Note to journalists: This column was written by Melissa Wdowik, PhD, RDN, FAND, an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Reagan Nutrition Center.
Antioxidants are like warriors in your body, fighting against free radicals and oxidative stress. While not a new topic, antioxidants are often misunderstood and underappreciated. This time of year, as we are exposed to armies of bacteria and viruses, it is worth exploring the functions, benefits and food sources of these little powerhouses.
Let’s start by understanding what they do. Natural body functions, such as breathing and physical activity, as well as exposure to cigarette smoke or pollution, produce substances called free radicals that attack healthy cells. Stress and infections, from bacteria and viruses, cause additional free radical formation. Antioxidants help protect healthy cells from the damage, or oxidative stress, caused by these free radicals. Oxidative stress and free radicals lead to atherosclerosis, heart disease and cancer, and appear to contribute to the development of diabetes, dementia, arthritis, eye diseases and aging processes.
Benefits of antioxidants include their ability to protect us against chronic disease, infection and cognitive decline, to name just a few. What is important to understand is that we can, and should, get plenty of these warriors from natural food sources, not supplements. Studies have shown antioxidant supplements increase health risks and interact with certain medications. Supplements can also give you too much of a concentrated source of one or more antioxidants while neglecting others. Most importantly, there are many other compounds in foods that improve both the absorption and function of antioxidants, compounds that cannot be replicated in supplements. So, beware supplements and head for the market.
Food sources of antioxidants are abundant. An overarching rule of thumb, if you want to skip the details, is to eat 2 cups of fruits and 2 ½ cups of vegetables daily to reap the benefits. Specific antioxidants in fruits and vegetables include vitamin C, vitamin E and carotenoids, such as beta-carotene, lycopene and lutein. Try the following sources!
- Vitamin C: berries, citrus, kiwi, tomatoes, peppers, potatoes and broccoli
- Vitamin E: olives, avocadoes, spinach, beet greens and pumpkin
- Carotenoids: red (beets, tomatoes), orange (squash, carrots), green (spinach, kale, brussels sprouts) and purple (cauliflower, eggplant) vegetables
Additional food sources of antioxidants include nuts, coffee, tea, wine and dark chocolate (my other favorite food groups). They contain a list of antioxidants too long for this story (resveratrol, polyphenols, catechins and flavonols, for example) but what’s important is the food themselves. Try a variety of each but go easy on the wine and chocolate; they do not contain the significant amounts found in the other foods and drinks mentioned here, and consuming these daily not only adds calories but replaces the more beneficial sources.
No one individual antioxidant can do everything, so be sure to get a variety of foods, of all colors, from all food groups. Enjoy the pleasures of eating while your warriors do all the work.
Melissa Wdowik, PhD, RDN, FAND, is an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Reagan Nutrition Center.