Nothing can sideline your training like a bad cold or the flu. But your immune system has a complex network in place to keep you healthy—if you fuel it well, consistently and over time.
This is even more important for us runners as our sometimes-heavy training (think: marathon prep) can suppress our immune systems due to hormonal and biochemical changes caused by training, environment, and stress. Sure, some runners seem invincible in enduring the demands of training with little effect on their health. Others are prone to catching any seasonal virus within a mile radius.
Here’s how it works: When a pathogen invades, white blood cells (called macrophages) engulf the virus, prompting B cells and killer T cells to attack it. This response leads to the creation of other cells designed to destroy the same virus if it shows up at a later date. But just a few nutritional missteps can weaken your body’s response. That’s why it’s important to eat foods that provide the nutrients your body needs to shore up your defenses. Here are the foods you should reach for.
1. Almonds
Almonds are packed with an immune-boosting duo (vitamin E and manganese), providing 37 percent of your daily need for both in one ounce. Many runners’ diets tend to be low in these nutrients, and studies show that not getting enough can weaken immune cells’ initial charge on pathogens.
Eat It: Top cereal and yogurt with chopped almonds, or add to salads and rice for extra crunch.
2. Chicken Soup
Whether it’s your soul or your upper respiratory tract that needs healing, there’s a reason chicken soup comes out on top. Research shows that chicken soup carries immunity-boosting benefits thanks to a mild anti-inflammatory effect found in the broth. The protein in chicken also helps bolster your immunities. Add plenty of extra veggies for vitamins, minerals, and antioxidants, all of which are an additional ally in your fight against cold and flu.
Eat it: Load up on soup when you’re sniffly, but avoid high-sodium canned soups—homemade is best.
3. Turmeric and Curcumin
Turmeric is hot right now thanks to its anti-inflammatory benefits. But those benefits actually come from curcumin, the orange-yellow component of turmeric. If you like curry, you’ll have no problem getting in a serving of the powerful spice. You can also supplement. But be wary: “The biggest issue with curcumin and turmeric is its bioavailability,” says Tavis Piattoly, M.S., R.D., a sports dietitian. “The key with curcumin is making sure it is combined with a phytosome to enhance its absorption into the blood stream. I personally like the brands that use Indena’s Meriva which is its patented curcumin, and I personally use Vitacost’s Curcumin Phytosome because it’s effective and affordable.”
Eat it: Treat yourself to Indian food, use turmeric in your own cooking, or consider a supplement.
4. Green Tea
Stay warm while building immune health, thanks to the EGCG, a powerful antioxidant that is abundant in green tea. EGCG naturally protects a variety of cells from being weakened and shields them from potential harm caused by components that serve to attack your health.
Drink it: Substitute your morning coffee for a cup of green tea a few times a week.
5. Onion
Onions provide layer upon layer (pun intended) of health benefits. Many of these benefits stem from the quercetin found in this root vegetable. Quercetin is a powerful antioxidant known for its antiviral and anti-inflammatory properties. In studies with runners and other athletes, research from Appalachian State University in North Carolina shows that daily doses of quercetin can reduce viral infections and inflammation due to heavy exercise.
Eat it: Sautee and add to stir-fry, burgers, omelets, or use raw on sandwiches and in salads. Onions are a great substitute for salt or fat when it comes to adding flavor.
6. Oysters
Studies have shown that low zinc levels are associated with a reduced number of T cells, or white blood cells that help your body fight infection. Oysters are packed with zinc, providing 700 percent of your Daily Value in just three ounces. Increased training cycles also put you at risk for reduced levels of T-cells, which may explain why runners may be more likely to get an upper respiratory infection toward the end of marathon training.
Eat it: Shuck them and eat them raw with some lemon juice, horseradish, or vinegar, or cook them gently and add to stews or chowders.
7. Canned Salmon
A 3-ounce serving supplies more than 100 percent of your daily need for vitamin D. This nutrient keeps a wide variety of immune cells in working order; not getting enough can put you at risk for infection. Salmon also provides protein and omega-3s that boost immune-system strength.
Eat It: Mix with chopped celery, parsley, and a touch of olive-oil mayo; stuff into a whole-wheat pita for a quick recovery meal.
8. Collard Greens
Collards pack 45 percent of your daily folate need into one cooked cup. This B vitamin helps generate immune cells every time your body gears up to fight a pathogen. Com-pounds called glucosinolates calm inflammation caused by killer T cells, helping you feel better when you do get sick.
Eat It: Sauté or steam for a side; stir into soup; or add raw leaves (not stalks) to salads.
9. Kefir
Healthy gut microbes make up a hefty portion of your body’s defenses against unwanted pathogens. Kefir provides a dozen strains of good-for-you bacteria that literally build a barrier in your intestinal tract against unwelcome bugs, and improve immune-cell function. In an 80-day Swedish study of 262 factory employees, those who consumed Lactobacillus reuteri—a specific probiotic that appears to stimulate white blood cells—took 33 percent fewer sick days than those given a placebo.
Eat It: Add kefir to pancake batter, mashed potatoes, soups, or a recovery smoothie.
10. Steel-Cut Oats
Oats contain a fiber called beta-glucan, a type of fiber with antimicrobial and antioxidant capabilities more potent than echinacea, reports a Norwegian study. This bolsters macrophage and killer T cells’ ability to fight off infections. Research suggests that beta-glucan can decrease your risk of upper-respiratory infections after exercise.
Eat It: Steel-cut oats take longer to cook than other varieties, so make a large batch and freeze leftovers then add your favorite toppings.
11. Wheat Germ
Two tablespoons of wheat germ contain 60 calories and pack a variety of nutrients (such as vitamin E, folate, magnesium, and zinc) that are crucial for supporting immune cells. Zinc in particular activates T cells to attack virus- or bacteria-infected cells.
Eat It: Sprinkle on frozen or regular yogurt and oatmeal. Toss into casseroles. It’s also a tasty addition to quick breads and baked fruit desserts.
