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. 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 defences.
Almonds are packed with an immune-boosting duo (vitamin E and manganese), providing 37 per cent of your daily need for both in 28 grams. 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 yoghurt with chopped almonds, or add to salads and rice.
2. CANNED SALMON
An 85-gram serving supplies more than 100 per cent 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 wholegrain pita for a quick recovery meal.
3. GREEEN LEAFY VEGETABLES
Spinach, kale, broccoli and cabbage are good sources of folate. This B vitamin helps generate immune cells every time your body gears up to fight a pathogen. Compounds 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.
Healthy gut microbes make up a hefty portion of your body’s defences against unwanted pathogens. Yoghurts provide a variety of strains of good-for-you bacteria that literally build a barrier in your intestinal tract against unwelcome bugs, and improve immune-cell function.
EAT IT: Add natural yoghurt to pancake batter, mashed potatoes and muesli. Or make a recovery smoothie (see recipe, below).
5. QUICK COOKING OATS
Oats contain a fibre called beta-glucan, which bolsters macrophage and killer T cells’ ability to fight off infections. In one study, lab mice given betaglucan for 10 days had fewer upper-respiratory infections after running on the treadmill compared to mice that didn’t receive the supplement.
EAT IT: Steel-cut oats take longer to cook than other varieties, so make a large batch and freeze leftovers.
6. WHEAT GERM
Two tablespoons contain 250 kilojoules and pack a variety of nutrients (such as vitamin E, folate, magnesium and zinc) 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 yoghurt and oats. Toss into casseroles. It’s also a tasty addition to quick breads and baked fruit desserts.
Immune-Boosting Berry-Almond Smoothie:
Yoghurt provides plenty of protein and probiotics, while almonds add a slightly crunchy texture.
1 cup frozen berries
1 cup plain natural yoghurt
2 tablespoons almonds
2 tablespoons wheat germ
1 tablespoon honey
1 teaspoon fresh ginger
Combine all ingredients in a blender and process until nearly smooth. Serves two.
Kilojoules per serving: 854 Carbs: 28g Fibre: 4g Protein: 10g Fat: 7g