Nutrition to Boost your Immunity (plus Beef Stew)
Fall is my favorite time of year. The leaves change, the air becomes cool and crisp, you pull out your favorite sweater, root vegetables, pumpkins and apple cider come front and center, and unfortunately, the dreaded cold and flu season begins. As athletes, getting a cold during heavy training, can be quite common. Previously, a study on marathoners done one week post LA marathon showed 13% of runners developed an upper respiratory tract infection (URTI), while only 2% of the controls (runners that didn’t end up running the marathon due to other reasons) did. The main reason that athletes are more susceptible to URTIs, is due to a depression in the immune system following exercise, a decrease in anti-inflammatory proteins and an increase in stress hormones. Nutritionally, there are several ways to help boost your immunity. Here are some common causes of increased risk for URTI and things to help prevent them.
- Low carbohydrate diets-nothing depresses the immune system more than a diet too low in carbohydrates due to increases in stress hormone levels. If you find yourself getting sick, look at your overall carbohydrate levels and make sure yours are adequate. During long workouts, take in 30-60g of carb per hour.
- Low levels of Vitamin D-athletes low in Vit. D have an increased incidence of illness. Vitamin D increases anti-microbial peptides and lymphocyte activation. Best sources: the sun (especially true for winter when we get less sun), oily fish, mushrooms, fortified foods. Aim for at least 600IU/day with some athletes taking up to 2000IU/day.
- Low levels of Vitamin C-Vit. C is an antioxidant that has anti-inflammatory and anti-pathogenic properties. While some antioxidants have been shown to impede exercise induced adaptations, Vit. C has not. Runners that supplemented with Vit. C for 3 weeks prior to an ultra marathon were less likely to develop a URTI post run (33% vs 68%) than those runners that did not. Best sources: peppers, dark green leafy veggies, broccoli and fruit. Aim for at least 75-90mg/day, however athletes in the ultra marathon study took 600mg/day and some athletes take up to 1000mg/day.
Things that have no recommended dietary allowance, but can be beneficial for preventing URTI and other illnesses. These have shown benefit, however further research is still needed:
- Bovine Colostrum- The pre-milk fluid produced in the mammary glands during the first 2-4 days after giving birth and contains numerous antibodies and immune factors. Bovine colostrum increases salivary IgA, which in turn helps prevent URTI. Usually found in powder or capsule form from cows.
- Probiotics-Micro organisms such as bacteria, that increase immunity and reduce the incidence of URTI. Both come in supplement form, however food sources of probiotics include yogurt, kefir and dairy. For probiotics in a supplement form, aim for 50 million to 1 trillion live cells.
- Quercetin- A flavonoid, which is a plant pigment found in many fruits and vegetables has been shown to be effective in reducing the inflammatory response from a URTI, in addition to blocking the virus’s replication. Sources include: onions, capers, citrus fruits, apples, berries, and black and green tea
Once you have an URTI, these can help to shorten the duration of your cold. There is no strong evidence that they will reduce the incidence of getting a cold, just the duration. If you’re training for an endurance event, try taking these in the week prior to your race as if you do get sick, they can help to decrease the duration of your cold:
- Echinacea and Kaloba-These are both herbals with no recommended allowance. Some studies have shown no benefit, while others have shown that they can increase the number of white blood cells, and boost the activity of macrophages. Echinacea tea can do a double duty-hot tea, plus a possible kick to your immune system.
- Zinc- A mineral that is found in lean meats, beans, eggs and nuts. Aim for 75mg of zinc in an ionic form right before your race or at the onset of symptoms and research has shown that it can reduce the duration of your cold by 1 day. That doesn’t sound like a lot, but you’ll be one day closer to feeling better. Zinc has a strange metallic taste (it’s a mineral), so that can be off putting.
- Beta Glucan- Some research has found that beta-glucan strengthens the body’s immune system, in addition to alleviating allergy symptoms. Beta-glucan is found in barley, oats, shiitake mushrooms and bakers yeast and there is no recommended allowance.
*Before you take any supplements, please consult your physician because these supplements can interact or interfere with other medications*
Immunity Boosting Beef and Barley Stew (Serves 6 or 8 as a starter)
*This is perfect to make in the crock pot on a cool fall or winter day, while outside trail running, mountain biking or cross-country skiing. It supplies good amounts of carbs, protein, vitamin C, beta glucan and some vitamin D. Adding a glass of skim milk/fortified milk will provide additional protein and vitamin D *
1 tbsp olive oil
1 lb stew meat, cut into small chunks (Zinc, protein)
2 onions, chopped (Vit. C and Quercetin)
6 cloves of garlic, diced (Vit. C)
4 celery stalks, chopped
4 cups of lower sodium beef broth
2 cup of water
2 lbs sweet potatoes, chopped (Vit. C, carbs)
2 cups of carrots, chopped (Vit. C, carbs)
14.5oz low sodium diced tomatoes with juice (Vit. C)
3/4 cup of barley (Beta Glucan, carbs)
4 cups of kale, stems removed and chopped (Vit. C)
8oz of mushrooms, sliced (Vit. D)
1 tbsp Worcestershire
Spices to taste-pepper, thyme and oregano are good choices
- Crock pot Recipe-Cut stew meat into chunks, and in olive oil, lightly saute until lightly browned. Add the meat, and all ingredients through diced tomatoes into a crock pot and cook on low for 4-5 hours. Add the barley and cook an additional 2 hours. With 1 hour to go, add the kale and mushrooms, Worcestershire and spices. So total cooking time will be 6-7 hours on low. This could be a good weeknight or weekend meal, depending on your work schedule and time leaving/arriving home.
- Stove top recipe-In a large soup or stock pot, saute meat in olive oil until lightly browned. Add the onions, garlic and celery and saute another 5-10 min until softened. Add broth, water, sweet potatoes, carrots and tomatoes and cook 30 minutes over medium heat. Add barley and cook 40 min. Add the kale, mushrooms, Worcestershire and spices and cook another 15-20 min. Total cooking time will be 1:45. This could be done on a Sunday, or if on a bike trainer or treadmill, just jumping off to add ingredients in a workout session.
Vegetarian-Substitute dried/canned beans for the beef (adjust cooking time as needed) and vegetable broth for the beef broth
Gluten Free-Substitute rice or quinoa for the barley and adjust cooking time as needed
Nutrition Info per Serving if using 6 servings/8 servings:
Calories: 446/335 kcal
*additionally, this stew is a good source of potassium, copper, zinc, manganese, Vit. A, Vit. C, Vit. K and the Vit. B’s. and has a breakdown of 53% carbs, 24% protein and 23% fat.*