Immune-boosting foods: what you need to know about antioxidants for your health

February 20, 2013

By Tarynne Mingione, RD
Registered Dietitian

I felt compelled to write this post primarily because I am exhausted from witnessing those dramatic cold and flu commercials I see everywhere. We all know how to treat a cold or the flu: rest, fluids, and antioxidant rich foods. Yet many of us (I’m guilty, too) reach for Emergen-C thinking that’s all we need and give little (or no) thought to what ‘antioxidant rich’ foods may do to help. So for your health and mine, I’ve highlighted some of those antioxidant-rich foods that should be featured on our plates this season.

First – what are antioxidants?

Antioxidants are nutrients and enzymes that quench free radicals (unstable harmful molecules that are the result of oxidative damage), therefore protecting your cells from damage. Free radicals can do a number on your immune system, thus blunting your ability to respond to a cold. Major antioxidants include Carotenes (beta-carotene), Vitamin C, Vitamin E, Selenium & Zinc.

Where can I get or find antioxidants?

Carotenes (provitamin A carotenoids): Think highly pigmented, bright red, yellow and orange foods. These are fat soluble (derived from vitamin A) so best absorbed with a source of fat (like a dash of olive oil or nuts). Foods high in carotenes include apricots, beets, broccoli, cantaloupe, carrots, mangoes, persimmons, pink grapefruit, leafy greens, pumpkin, winter squash, sweet potatoes, tangerine, tomato, watermelon.

Some carotene-rich recipes include Honey Roasted Vegetables (featuring sweet potatoes and carrots while paired with a source of fat (olive oil and walnuts) to enhance absorption).

Vitamin C (ascorbic acid): We must obtain vitamin C from our diet (humans can’t synthesize it). Also, vitamin C is water soluble, meaning that it’s lost when you pour that liquid down the drain. Good sources include broccoli, citrus fruits (grapefruit, oranges), cruciferous veggies (Brussels, cabbage), melons, mango, pineapple, sweet potato, strawberries, sweet red pepper, tomato (also juice). Try this Tomato Soup recipe and preserve all the water-soluble vitamin C rich liquid by creating soups with these antioxidant rich foods!

Vitamin E: Another fat soluble vitamin. Good sources include vegetable oils (olive, soy, canola, safflower, sunflower, avocados, nuts and seeds, fish and shellfish, leafy greens (spinach), mangoes, nuts, seeds. Combine leafy greens with nuts and seeds to get a Vitamin E packed dish in this Strawberry Spinach Salad with Hazelnuts, Fennel and Balsamic-Sesame Dressing.

Selenium: A trace element in small amounts, however can be toxic at extremely high levels. Also partners with thioredoxin to form thioredoxin reductase which regenerates antioxidants (think vitamin C). Foods sources include Brazil nuts (huge source!), shrimp, crab, salmon, chicken, pork, beef and whole grains. Try this brazil Nut Pesto recipe over whole wheat pasta to ensure adequate selenium delivery to your system.

Zinc: An essential trace element and particularly important for your immune system (by serving as a structural component of proteins which serve as antioxidants). Good sources include oysters (best source!), crab, beef, pork, turkey meat, yogurt, almonds, cashews, chickpeas, beans. Try this beef stew recipe for a warming, satisfying evening on the couch. Feel free to add some chicpeas or beans for added fiber and zinc! Or, combine beans and turkey for a zinc rich chili perfect for winter.


Give your immune system a fair chance by incorporating many of these foods into your diet daily. Bottom line: the more antioxidant rich foods you can grab from the produce aisle, the less you’ll depend on help from the supplement and medicine aisle.