Our healthy body begins with a healthy immune system. The immune system defends us against threats from both outside and inside our body. With over half of our immune system around the gastrointestinal tract, it’s no surprise that food plays a big role in our overall health. In fact, the food that we eat impacts both our physical health and our mental health. Studies have shown that consistently eating a plant-rich diet that includes leafy greens leads to less inflammation and a better mental state.
The foods we eat will either attack the immune system and cause inflammation or help it by allowing it to fight off viruses and other ailments. In a study that evaluated vaccine response across a population, those that ate five or more servings of fruits and vegetables a day for a few months prior to the vaccine had an 82% greater antibody response to the vaccine compared to a control group. That’s huge!
Often when we begin to feel sick, we try to ‘boost’ our immune system by throwing a bunch of vitamins at it. But we all know that the best defense is a good offense. Instead, we should be proactively restoring balance to our natural defense process and providing the nutrients that it needs for optimal performance on an ongoing basis. So how is this done?
1) Identify Immune-Reactive Foods
A good first step is to identify foods that bother your immune system. While heavily processed foods and sugar may be obvious to most, other ‘healthy’ foods may not. Each of our bodies is unique, and thus the optimal diet for each body is also unique. One person’s body may respond negatively to dairy, another’s may not like tomatoes, and so on. Symptoms may include bloating, stomach or joint pain, mood swings, lack of energy, headaches, or even skin and vision problems. Pay attention to your body, and if you are not feeling your best, consider the foods eaten over the past 12-24 hours. Keep a journal and look for trends over time. Simply removing these foods can make a huge difference in how you feel and the strength of your immune system. Some find it easier to have help during this phase. A coach can help to explain the process and how foods impact us, walking with you to identify the troublesome foods and creating a strategy for eliminating them. If this would help you, let me know! I can be reached at: healthcoach@healthyhappyeating.com.
2) Add Immune-Stabilizing Foods
Immune stabilizing foods are foods that help to proactively build up the immune system. These foods give our body many of the nutrients that it needs. They are all important and a deficiency in any one of them puts our immune system at risk. When we eat plant-based foods, many of the pigments and odors are absorbed directly into our bloodstream and can affect your organs, tissues, and cells on the way to your bloodstream. An example of this is garlic – the garlic breath doesn’t just come from residual garlic in your mouth, but also from the garlic that was absorbed into your bloodstream which was then exhaled from your lungs. Because of this, garlic is actually thought to help clear bacteria in our lungs. Our entire body is affected by what we eat. Here are some foods that you may want to consider in order to optimize your immune system. While animal-based foods can offer some of the nutrients below, this article focuses on the plant-based approach.
Vitamin A – This is in a lot of leafy greens. Orange vegetables also help to improve your Vitamin A levels. Some delicious ones that you may want to try are winter squash, sweet potatoes, and bell peppers.
B Vitamins – These can be found in pine nuts, Jerusalem artichokes, asparagus, nutritional yeast, watermelon, whole grains, acorn squash, sunflower seeds, sesame seeds, garlic, peas, and most beans. If you do not eat meat, make sure that you are getting Vitamin B12. This can come from some fortified plant-based milk products or you may want to consider taking a supplement.
Vitamins C – Blueberries offer more powerful disease-fighting antioxidants than any other fruit or vegetable. Other powerful foods include broccoli, spinach, citrus, pumpkin, tomatoes, garlic, pomegranates, cranberries, bell peppers, and strawberries. Don’t forget that broccoli and other cruciferous vegetables need to be cut and left to sit before you eat them (click here to learn why). Here’s a random fact for you: Aside from humans, guinea pigs are the only other mammal that does not make its own Vitamin C. We, along with guinea pigs, have to get it from our food!
Vitamin E – Green leafy vegetables, blueberries, seeds, nuts (especially walnuts), soy, and pumpkin are great ways get your Vitamin E.
Vitamin D – Mushrooms, along with fortified cereals and milk, are good plant-based sources of Vitamin D. Check this out – if you turn shitake mushrooms upside down and place them in the sun, they significantly increase their Vitamin D levels! If you let them dry completely, the vitamin D is maintained and you can use them over time as you need them. One study found that in doing so, the Vitamin level rose from 100 IU to nearly 46,000 IU! In addition to food, don’t forget the sun! Exposure for 10-30 minutes midday, several times per week will help you maintain healthy Vitamin D levels.
Probiotics – Not only do they stimulate the immune system, but they also help to lower the risk for cancer by decreasing inflammation and reducing the growth of cancer-causing microflora. Plant-based yogurt and kefir are great sources of probiotics. If you choose, this is one of the few nutrients that can be effectively obtained from a supplement. Studies have shown that people who take probiotic supplements appear to have fewer colds and sick days.
“The first study [on probiotics and immunity] demonstrated that white blood cells extracted from subjects on a probiotic regimen for a few weeks [had] a significantly enhanced ability to engulf and destroy potential invaders. This effect lasted for at least three weeks after the probiotics were discontinued.” – Dr. Greger, How Not To Die
Amino Acids – L-lysine (beans, most fruits and vegetables) and L-arginine (Coconut, oats, nuts, whole wheat, peanuts, soybeans and wheat germ) are also key for a healthy immune system.
Zinc – Some examples of plant-based food containing zinc are beans, nuts, whole grains, shitake mushrooms, tofu, oatmeal, and fortified breakfast cereals.
Iron – Found in whole grains, legumes, nuts, seeds, and green, leafy vegetables, iron should be eaten with a source of Vitamin C for best absorption and bioavailability. While enough iron is critical, too much iron is harmful to our bodies (so balance is key). Also, studies from Harvard and the Institute of Health have indicated that heme iron (found in animals) has been associated with higher levels of cancer and early death, while non-heme iron (found in plants) has not. This is believed to be due to our bodies natural thermostat for regulating the amount of iron that it absorbs. When we’ve had enough, the thermostate is five times more effective at stopping the absorption of plant-based iron than it is at meat-based iron.
Copper – Look to wholegrain foods, quinoa, nuts, seeds and beans for your sources of copper.
Mushrooms – These need a special mention when it comes to our immune system. One study found that eating mushrooms boosted the levels of IgA (antibodies that help to prevent viruses from entering our body) by 50%. These levels remained high for about a week, so try making mushrooms a regular part of your diet. While most are familiar with the common button or portobella mushrooms, others that you may want to consider are shitake, maitake, reishi, turkey tails, and chaga. Want to learn more about mushrooms? Here is a short video
Spices – High in phytonutrients, spices help to boost our immune systems. Phytonutrients are what help protect plants from germs, fungi, bugs, and other threats. In similar ways, they provide protection to our body. Some examples are turmeric, which provides us with the phytonutrient curcumin, garlic gives us allicin, and hot peppers deliver capsaicin. There are many other powerful spice options, so add them wherever you can!
Omega-3s – Most people have heard that salmon is high in Omega 3s, but what are the plant-based sources? This is where nuts and seeds come in. Flaxseed, chia seeds, and walnuts are all high in Omega 3s and should be a regular part of any diet.
Water – Don’t forget to drink plenty of fluids! Water, tea, and soup broth hydrate your immune system so it can do its job. The fluids protect the mucous membranes by making sure that they are in good shape and able to kick the germs out.
At first, this may seem like a lot to think about. Fortunately, as you may have noticed, many of the foods overlap across nutrients, making it not quite so overwhelming. Also, some find it helpful to keep a checklist throughout the day. This helps you to keep track of what is left and where to place your focus as the day goes on. You may also find that over a period of a few days, there are one or two nutrients that you are consistently missing, and can then load up on those foods the next time that you shop.
The immune system is a big topic. So much so in fact that there is more to come. Keep an eye out for Part 2 on ways to support your immune system. This will focus more on the power of herbs and other tips for a healthy immune system.
Happy Eating!