Since 2020, the questions about utilizing nutrition for immune function have not stopped rolling in. We’re glad student-athletes, parents, and coaches have this in mind since evidence suggests heavy bouts of training without sufficient recovery can result in impaired immune function and may increase the risk of illness. And having an infection, such as the common cold or upper respiratory infection, is the second cause (after injury) of training days lost for major competitions or events.
We know that as athletes, you want to stay on top of your game, especially if you compete during cold and flu season. Unfortunately, there’s no quick fix, superfood, or supplement to prevent illness during intense training or the winter season. However, there are some simple strategies that enhance nutrition for immune function so you can get the most out of your training. Read on for changes you can make today!
8 Ways to Support Immunity Through Nutrition
1. Eat Enough Carbohydrates
If you follow us here at SAN, then you know carbohydrates are an athlete’s best friend; especially when it comes to immune health. Adequate carbohydrate intake during prolonged workouts helps maintain blood glucose levels. This helps reduce the release of excess stress hormones and inflammatory markers during and after exercise that may otherwise depress immune responses.
Research shows that carbohydrate timing is important too. Consuming carb shortly before and/or during exercise has shown beneficial effects on immune responses to exercise. One study showed that a high-carb diet (about 8.4 g/kg/day) for 3 days after prolonged cycling reduced the level of stress hormones and inflammatory markers that normally circulated in the blood when compared to a low-carb diet. Moral of the story, athletes who conduct prolonged training (read: all student-athletes) should not avoid carbohydrates.
2. Eat Protein Often
Protein is also crucial when it comes to nutrition for immune function. Research shows that there are not only immune system benefits to consuming protein post-workout but having a diet that is overall high in protein also shows benefits. One study followed eight cyclists and showed that those who consumed a high-protein diet (3 g/kg/day or 1.4 kg/lb/day) were associated with fewer symptoms of upper respiratory tract infections such as the common cold.
One easy way to consume a diet high in protein is to spread protein throughout the day amongst your meals and snacks. This also allows your body to get a consistent supply to help aid in recovery by replenishing depleted nutrients and electrolytes. Most student-athletes should aim for 0.3-0.4 g/kg of their weight in protein – about 0.14 – 0.18 grams per pound – four to five times per day. This would be 22-29 grams for a 160-pound athlete and 35-45 grams 5 times per day for a 250-pound athlete. (Check out the best protein powders for student-athletes!)
3. Prioritize Omega-3s
Omega-3s are a type of fatty acid that are most commonly found in fish, algae, nuts, seeds, and some oils, which are well known to have positive effects on the immune system and inflammation. They are often labeled as anti-inflammatory because they are able to inhibit certain inflammatory molecules from causing reactions in the body. Three types of omega 3s known to exhibit these immune-enhancing benefits are the polyunsaturated fatty acids (PUFAs) ALA, EPA, and DHA, with intake of EPA and DHA being most important.
In order to increase the amount of omega-3s in your diet, consider adding foods such as walnuts, chia seeds, and flaxseeds, which are high in omega-3 ALA to your diet, and choose fatty fish or algal oil for omega-3 EPA and DHA, too.
4. Monitor your Vitamin D
Vitamin D has been shown to play an important role in immune function. Without adequate vitamin D levels, certain immune responses that would otherwise protect against infection can be impaired. Studies have shown that low levels of vitamin D can increase the incidence and severity of certain respiratory diseases. These findings might motivate you to begin consuming vitamin D supplements, however, the effectiveness of vitamin D in supplement form is unclear. It may be more beneficial to obtain vitamin D from foods such as salmon, eggs, and full-fat cheese as well as exposure to sunlight in order to have adequate stores, to begin with.
For those of you who follow a plant-based diet, consider working 1-on-1 with a sports dietitian if you need help with a plan for getting adequate stores of nutrients like vitamin D!
5. Eat More Whole Plant Foods
Whole plant foods including fruits, vegetables, legumes, nuts, and seeds contain fiber and antioxidants, which have positive effects for nutrition on immune function. Fiber is the non-digestible part of fruits and vegetables. Antioxidants are substances that may protect your cells from free radicals, which can damage the body’s cells, limiting recovery and immune health now and increasing the risk of chronic disease.
Although we can’t digest fiber nor obtain nutrients from them, they help add bulk to stool and ferment in the gut to form certain types of fatty acids. These fatty acids help bring balance to the gut which enhances its ability to form a strong barrier and prevent unwanted invaders from making a home and ending up causing infection or illness. The recommended intake of fiber is 25-38g per day for the average person, or 14 grams for every 1000 calories you consume, which may mean student-athletes have much greater needs.
Instead of consuming high doses of antioxidant or fiber supplements that can be costly and unnecessary, we encourage athletes to “eat the rainbow!” Having a variety of color on the plate ensures that you are also getting diverse sources of fiber and plant polyphenols (a group of antioxidants that lower inflammation) to support immune health.
6. Stay Hydrated
Our immune system is highly dependent on the nutrients in our bloodstream, and our bloodstream is made mostly of water! If we don’t have enough water, we cannot properly transport nutrients to our muscles during activity, or to each organ system. Research also shows that dehydration can decrease the amount of saliva we secrete and saliva contains several proteins with antimicrobial properties.
Even if it’s cold, keep drinking fluids! Non-caffeinated teas or oral rehydration solutions can be great to add to your hydration regimen if you need the motivation to drink more fluids. If you’re looking for more tips on staying hydrated, check out our FREE hydration guide.
7. Get Adequate Sleep
Remember sleep plays an important role in immune health as well. Research shows that sleep deprivation and disruption affect your circadian rhythm (your body’s behavioral changes that follow a 24-hour cycle). This induces inflammation and immune response changes that can increase the risk of infection along with other diseases. One study showed that people who experience poor quality sleep have a 4-5 times higher risk of getting the common cold. Sleep deprivation also negatively impacts your appetite, energy intake, ability to make protein, and properly utilize carbohydrates – all factors crucial to immune health.
If you have sleep issues, evaluate your evening routine. Go to bed at the same time each night, limit exposure to electronic devices before bedtime, and limit caffeine to before lunchtime. Even daytime naps have been shown to counter the effects of poor sleep!
8. Manage Stress
When your body experiences stress, it releases a hormone called cortisol. When released in the short term, cortisol can enhance immunity by limiting inflammation. However, with chronic stress, your body has too much cortisol in the blood, which can end up causing inflammation. Chronic stress can also decrease certain white blood cells that normally help to fight off infection leaving you at more risk for developing certain illnesses which can ultimately impact athletic performance and recovery.
Learn to adopt habits in your daily life to help you manage your stress. Just 10-15 minutes of meditation 3-4 times per week has been shown to reduce your cortisol levels and inflammation. Apps like Headspace offer excellent annual discounts for students. Practicing yoga has also been shown to lower cortisol levels and reduce inflammation. YouTube has many free yoga videos for athletes. Other ways you can reduce stress include leisurely reading, taking a long walk, hanging out with friends, and listening to relaxing music.
Nutrition for Immune Function Takeaway:
Making changes to the way you eat or your daily habits isn’t easy, especially for athletes who have an even busier schedule than the average student. Start slow and be realistic. Choose one thing from this list that you can and want to work on. Maybe it’s adding more fruits and vegetables to your diet or working on decreasing stress by meditating. Once you’ve got the handle on your first goal, then work towards your second goal. Over time you’ll be strengthening your immune system and giving yourself the best chance to get the most out of your training sessions!