8 Foods to Power Your Immune System this Fall
Leslie Beck, RD See Bio
Copyright © Leslie Beck, 2015.
Leslie Beck, Registered Dietitian, is the best-selling author of 12 books on nutrition and health, writes a weekly column in The Globe and Mail, and is a regular contributor to CTV News. Based at the Medisys clinic in Toronto, Leslie offers one-on-one diet coaching, personalized meal plans and evidence-based recommendations on the use of nutritional supplements. www.lesliebeck.comHide
It’s that time of year again. Perhaps you’re already fighting a cold. If you’re lucky you’ll make it through the rest of the season without catching one. More likely, though, you’ll get one or two, especially if you have young kids in school.
You can’t prevent cold and flu viruses from making their fall appearance, but you can bolster your immune system making it better prepared to fend off attacking viruses. And the remedy might be no farther away than your refrigerator.
While good hygiene, proper sleep and getting a flu shot can help cut your risk, a nutrient-rich diet can also make you less likely to come down with a cold or flu. Whole foods contain a package of nutrients – protein, vitamins, minerals and antioxidants – many of which are vital to a strong immune system.
While no single food (or supplement) is guaranteed to keep this season’s viruses away, the following eight foods, packed with immune-enhancing nutrients, can give you an edge against cold and flu bugs. Don’t wait until you’re sick to revamp your diet; add these healthy foods to your fall menu now.
This cultured milk beverage is packed with probiotics, so-called friendly bacteria that stimulate the immune system. In fact, kefir typically contains triple the probiotic content of yogurt.
Once consumed, probiotics strengthen the intestinal lining, which helps keep harmful bugs out, and increase the activity of key immune cells. Certain probiotic strains have also been shown to prevent cold flu symptoms in adults and children.
Pour kefir over cereal, blend it into smoothies or drink it straight up as a snack. Replace yogurt or buttermilk with kefir in dips, dressings and baked goods.
They’re loaded with vitamin C, a nutrient that stimulates the production infection-fighting white blood cells and antibodies. Vitamin C also amps up the release of interferon, a protein than stops viruses from replicating.
One medium red pepper delivers 152 milligrams of vitamin C (one medium orange has 70 mg). Green peppers are decent sources too at 95 mg per medium pepper.
The recommended daily vitamin C intakes are 75 mg (women) and 90 mg (men), however many experts feel 200 mg per day is optimal for disease prevention.
Other good sources of vitamin C include cantaloupe, citrus fruit, kiwi fruit, mango, strawberries, broccoli, Brussels sprouts, cauliflower and tomato juice.
It’s one of the few foods that serves up vitamin D, a nutrient that triggers and arms the body’s T-cells, immune cells that kill invading bacteria and viruses, including the influenza virus. Six ounces of cooked salmon (sockeye) delivers 890 IU (international units) of vitamin D. Not bad, considering one cup of vitamin D fortified milk has 100 IU.
Salmon is also a good source of protein and vitamin B6, also needed for healthy immune function.
Even if you eat salmon regularly, adults should take a 1000 IU vitamin D supplement daily in the fall and winter. (Osteoporosis Canada recommends vitamin D year-round.)
Thanks to their outstanding selenium content, Brazil nuts support the immune system by increasing natural killer cells, white blood cells that destroy viruses. Adults need 55 mcg of selenium each day, about half the amount found in one single Brazil nut (96 mcg). Impressive.
You’ll also find selenium in tuna, halibut, salmon, turkey, chicken, beef, pork, whole wheat bread, sunflower seeds and eggs.
Thanks to its natural sulfur compounds, this flavourful herb increases the production and activity of many immune cells, including white blood cells, natural killer cells and antibodies. Garlic also has antiviral and antimicrobial properties.
Use garlic in soups, pasta sauces, stir-fries, chili, roasted vegetables and salad dressings. Add roasted garlic cloves to pizza, mash them with cauliflower or potatoes and puree them with beans to make a dip.
When it comes to zinc, a mineral critical for the development and action of immune cells, oysters can’t be beat. Six medium oysters – about three ounces worth – supply 33 mg, four day’s worth for women and three day’s worth for men.
Other good sources of zinc include crab, beef, baked beans, black beans, lentils, chickpeas, pumpkin seeds and wheat germ.
Their claim to fame is vitamin E, an antioxidant that enhances the body’s production of immune cells and is thought to reverse some of the decline in immune function that happens with age. One-quarter cup of sunflower seeds supplies 80 percent of a day’s worth of vitamin E (12 mg). (Adults need 15 mg of vitamin E daily; kids need 6 to 11 mg depending on age.)
Toss sunflower seeds in green salads, mix into tuna and chicken salad, sprinkle over hot and cold cereal, stir into yogurt and add to homemade trail mix.
Other vitamin E-rich foods include wheat germ oil, almonds, sunflower oil, safflower oil, grapeseed oil, hazelnuts and cooked spinach.
Research from Brigham and Women’s Hospital and Harvard University found that participants who drank black tea for two to four weeks secreted up to four times more virus-fighting interferon compounds than at baseline. Coffee had no effect.
Tea (black, oolong, green and white) also contains L-theanine, an amino acid that primes the immune system in fighting infection.
Copyright © Leslie Beck, 2015.
Leslie Beck, Registered Dietitian, is the best-selling author of 12 books on nutrition and health, writes a weekly column in The Globe and Mail, and is a regular contributor to CTV News. Based at the Medisys clinic in Toronto, Leslie offers one-on-one diet coaching, personalized meal plans and evidence-based recommendations on the use of nutritional supplements. www.lesliebeck.com