Category Archives: vitamins
Antioxidants for Immunity: Where to Find Them
- All berries
- Red grapes
- Alfalfa sprouts
- Zinc: Found in oysters, red meat, poultry, beans, nuts, seafood, whole grains, fortified cereals, and dairy products
- Selenium: Found in Brazil nuts, tuna, beef, poultry and fortified breads, and other grain products.
For optimal health and immune functioning, you should eat the recommended dietary allowance (RDA) of the antioxidant vitamins and minerals. That’s the amount of a vitamin or nutrient that you need to stay healthy and avoid a deficiency.Here are the RDAs for some antioxidants:Zinc: 11 milligrams for men, 8 milligrams for women; if you are a strict vegetarian, you may require as much as 50% more dietary zinc. That’s because your body absorbs less zinc when you have a diet rich in plant-based foods.Selenium: 55 micrograms for men or womenBeta-carotene: There is no RDA for beta-carotene. But the Institute of Medicine says that if you get 3 to 6 milligrams of beta-carotene daily, your body will have the levels that may lower risk of chronic diseases.Vitamin C: 90 milligrams for men, 75 milligrams for women; smokers should get extra vitamin C: 125 milligrams for men and 110 milligrams for women.Vitamin E: 15 milligrams for men and women
How Foods Boost ImmunityCan’t you get antioxidants from taking a vitamin or a supplement? Yes, but you may be missing out on other nutrients that could strengthen the immune system. Foods contain many different nutrients that work together to promote health. For example, researchers delving into the mysteries of fruits and vegetables and the complex antioxidants they contain have discovered benefits of:
If you can’t get enough antioxidants in your diet by eating fresh produce, some experts recommend taking a multivitamin that contains minerals, too. But be cautious about taking individual immune system supplements to boost immunity. With antioxidants, as with most anything, moderation is key. Vitamins A and E, for example, are stored in the body and eliminated slowly. Getting too much can be toxic.
- Quercetin: a plant-based chemical (phytochemical) found in apples, onions, teas, red wines, and other foods; it fights inflammation and may help reduce allergies.
- Luteolin: a flavonoid found in abundance in celery and green peppers; it also fights inflammation, and one study showed it may help protect against inflammatory brain conditions like Alzheimer’s.
- Catechins: a type of flavonoid found in tea; catechins in tea may help reduce risk of heart disease, cancer, and Alzheimer’s disease.
Since we’re not big juice drinkers in our house, OJ usually only makes its way into our fridge when guests come to visit. Even then, it still takes us a few weeks to polish off the carton. I never thought much about keeping the OJ for a few weeks. After all, it still tastes good—and we usually finish it before the expiration date. Then I read this study that showed opened OJ loses all antioxidant benefit after just one week! Seriously? Well, as you can imagine, this led me to wonder if other items in my kitchen lose their health punch over time. (Spoiler alert: they do!)
Keep track of how long you store these 4 items. Here’s why: certain nutrients are unstable when exposed to oxygen (from the air), heat (from cooking) and light.
Orange juice: 1 week
One cup of OJ can offer a full day’s dose of vitamin C. But OJ that has been opened loses all antioxidant benefit after just one week. To get the most vitamin C, buy frozen concentrate and drink within a few days. Frozen concentrate is exposed to less light and air. (Use your OJ before it loses its nutritional punch: make Grilled Orange Chicken Fingers and more delicious recipes with orange juice.)
Green tea: 6 months
A 2009 study in the Journal of Food Science showed that catechins (antioxidants linked with a reduced risk of some cancers) in green tea decreased markedly over time. After six months, catechin levels were 32 percent lower. Make the most of the antioxidants by storing tea in a sealed container in a dark, cool place.
(Add this 1 ingredient to your tea to make it healthier.)
Olive oil: 6 months
Extra-virgin olive oil contains more than 45 heart-healthy antioxidants, but after six months of storage their potency decreases by about 40 percent, according to researchers at the University of Foggia in Italy. Why? Oxygen bubbles in the bottle destroy the antioxidants.
(Find out which brands won our Olive Oil Taste Test and find out how to shop for the healthiest and tastiest olive oil.)
Honey: 6 months
Researchers at the University of Illinois found the antioxidant power of clover and buckwheat honey decreased by 30 to 50 percent after six months. Consider buying buckwheat honey—it generally has more antioxidants to start with.
(Can honey help you lose weight?)
By Brierley Wright, M.S., R.D.
Brierley’s interest in nutrition and food come together in her position as an associate editor at EatingWell. Brierley holds a master’s degree in Nutrition Communication from the Friedman School of Nutrition Science and Policy at Tufts University. A Registered Dietitian, she completed her undergraduate degree at the University of Vermont.