First, there is no quick fix and we don’t really want to “boost” our immune system, we just want it working as it should be.
The most important thing to consider doesn’t really have to do with nutrition but it is critical!
Sleep
Sleep might be the number one thing you should focus on when trying to support your immune system. Those with fewer than 6 hours of sleep each night are much more likely to catch the common cold. In general, adults should try to get at least 7 hours and teens at least 8 hours of quality sleep each night. Athletes and those who train really hard may need more.
To make sure your sleep is high quality, avoid taking electronics to bed with you and don’t watch TV in bed. Ideally, get that TV out of your bedroom all together! Keep your room dark and cool and stay on a regular sleep schedule.
Stress
Stress can suppress your immune system so practice activities that help you manage stress like laughter, play, meditation, journaling, yoga, mindfulness exercises, or working with a licensed therapist. Keep in mind that managing stress includes not killing yourself at the gym and taking rest days when needed. Prolonged exercise like running a marathon can suppress your immune system in the short term but regular moderate activity will support the function of your immune system. Workout regularly just don’t kill yourself in the gym day after day. As a bonus, regular exercise can help with your sleep quality!
Now the nutrition stuff.
Hydration
Dehydration can increase your susceptibility to bacteria and viruses. Adequate hydration helps support gut health which is an important part of your immune system. The gut acts as a physical barrier to invaders. Fluid needs are quite different person to person but paying attention to the color of your urine is a decent way to determine hydration. If your urine is a lemonde color or lighter, then you are probably well hydrated. Try assessing the color of your urine stream and not the color of the toilet water. Clear urine is not the goal! Water can become toxic if you drink too much without adequate electrolytes so just shoot for the lemonade color. Keep in mind some supplements might make your urine a bright yellow. Aiming for 60-80 fluid ounces of water daily is a good starting point.
Don’t undereat!
Underating in general and specifically under eating carbohydrates can affect the immune system so make sure you are eating enough to support your activity. The more activity you do, the more carbohydrates you should have. If you’re sedentary and don’t do much activity, aim for a tennis ball sized serving of high fiber carbohydrate rich food along with a portion of protein rich food and vegetables at each meal. Some examples of high fiber carbohydrate foods are oatments, brown or wild rice, quinoa, potatoes (white or sweet), buckwheat, barley, whole wheat, beans and lentils.
For the very active, you might need to have ½ of your plate be a carbohydrate rich food at each meal. If you’re not really sure if you’re eating the right amount, reach out for nutrition counseling so I can help you determine your specific needs.
Vitamin D
Maintaining adequate vitamin D status is key to a healthy immune system. I did a video on vitamin D supplements previously but getting your vitamin D levels tested (blood test 25 hydroxyvitamin D) is very important. Over the winter months our vitamin D status tends to drop since we’re not getting as much UVB exposure from the sun. This happens to those living firther away from the equator like most of the US. It is very challenging, if not impossible, to get enough vitamin D from food so we need to get some sunlight exposure over the summer months. About 10 minutes per day of arms, legs, and face exposure most days over the summer will help ensure adequate vitamin D synthesis that can sustain you throughout the year. You don’t want your skin to burn so if you are very sensitive to the sun, you may need less time. If your vitamin D levels still too low after regular sun exposure during the summer, taking a supplement might be warranted. You can ask your doctor to test your vitamin D during your next check up or order an at home test like Thorne Research’s. If you can’t get a vitamin D test for whatever reason, it’s probably safe to take 2,000 IUs per day in supplement form but it is best to determine your levels before supplementing.
Gut Health
We mentioned this when talking about hydration. Eating adequate fiber day to day is the single best thing you can do to promote good gut health. 25-30g of fiber from whole foods is the goal. You don’t need expensive supplements that probably don’t do much anyway. Just eat a variety of vegetables, fruits, and other high fiber whole foods.
Eating fermented foods might also help support the gut. Eat foods like yogurt, sauerkraut, kimchi, kefir, and natto that have not been pasteurized so the beneficial bacteria is still alive when we’re eating these foods.
Skip the probiotic supplement as we just don’t know enough about which specific bacteria strains are most beneficial. Try to get probiotics food regularly.
Zinc
Zinc is a mineral that plays a role in regulating our immune system. It’s been proven that taking zinc lozenges can reduce the duration and severity of the common cold. Taking zinc lozenges daily may even help reduce the rate of getting colds.
Taking minerals in supplement form always comes at a risk because there are a lot of mineral to mineral interactions. It’s possible that taking one will inhibit absorption of other necessary minerals and possibly lead to deficiency in those other minerals.
Make sure your dietary intake of zinc is adequate first, before supplementing. Shellfish, especially oysters, is probably the best dietary source of zinc with liver coming in at a close second. Oysters and liver are thoses powerhouse foods full of a lot of nutrients we tend to lack so if you like oysters or liver, include them regularly in your diet. We can’t absorb a lot of zinc from food in one sitting so aiming for 1-2 oysters 3 times per week might be best.
Unfortunately, most of us (me included) don’t like oysters or liver so make sure you include some of the following foods daily: seeds (specifically sesame, pumpkin, or watermelon seeds) ideally soaked and sprouted, beef or other red meat, dark chocolate or pure cocoa powder, peanuts, and fish.
Because of the nutrient to nutrient interactions of zinc, it’s important to talk with a dietitian that is savvy in supplements before starting to take zinc supplements. However, if you do choose to do so, lozenges are preferred and it is best to avoid products that are in the form of zinc oxide. A daily logenze with 15-20mg zinc is a decent general recommendation but, remember, this should really be individualized.
Vitamin C
The nutrient we tend to think about in relation to preventing colds. Vitamin C is critical to our immune system. Ensuring adequate intake from food is best. Most fresh fruits and vegetables have a decent amount of vitamin C but specifically foods like bell peppers, guavas, currants, kale, broccoli, kiwifruit, chili peppers, jalapeno peppers, and mustard spinach are especially high. Aim for 2 cups or more of vegetables daily and at least 1 cup of fruit.
If we take vitamin C supplements at the first sign of a cold, it might help us get over the cold a day or two earlier.
Elderberry
Elderberry might also be effective in helping to combat the common cold, flu, and potentially other viruses. This can be in the form of lozenges, capsules, or syrup and 300 mg per day seems to be a safe daily dose but you might want to increase the dose to 700-1000mg per day when the threat is high like when you’re traveling or around a lot of people indoors. You just don’t want to maintain that higher dose for more than 2 months at a time. Again, as with any supplement this is a very general guideline and you should be working with something to give you specific recommendations for your individual needs.
Also keep in mind alcohol and smoking will suppress the immune system so try to avoid these.
Want to see what you can do specifically to improve your immune system though nutrition? Contact Alyssa