Enhancing Immunity through Food & Lifestyle

Throughout my studies, I found the immune system to be the most difficult to fully understand.  It seemed that every time I wanted to know more specifics about the inner workings of our immune system, I would be presented with more information that required more in depth research.  In the end, I determined that this is because the immune system relies on proper functioning of every other body system, making it difficult to discern where to begin when trying to improve immune function.  The following quote from The Encyclopedia of Natural Foods sums up the challenge of optimizing our immune system., “Optimal immune function requires a healthy diet that is rich in whole, natural foods…, is low in fats and refined sugars, and contains adequate, but not excessive, amounts of protein.  On top of this…an individual should drink five or six 8oz glasses of water (preferable pure) per day; take a basic multivitamin – mineral supplement; engage in a regular exercise program of at least thirty minutes of aerobic exercise and five to ten minutes of passive stretching daily; perform daily deep breathing and relaxation exercises; take time each each day to play and enjoy family and friends; and still get at least six to eight hours of sleep daily.” (Murray et.al. p. 737)

I don’t know about you, but just reading that paragraph gives me anxiety! And as I will get into later,  you can be sure that anxiety and stress are also factors that negatively affect our immune function.  My goal, here, is to help sort through some of this anxiety inducing information and provide practical tips and education that can help each individual make choices that will increase their immune system function.  The problem with generally available information and supplementation, is that we are all individuals that require individual approaches to optimal health and therefore varying diet and lifestyle changes to improve immune function.

We can start with the primary cause of a depressed immune system, which is nutrient deficiency.  Unfortunately, it’s not as simple as a Vitamin C or zinc deficiency, but being deficient in almost any single nutrient can cause a depressed immune system since nutrients work synergistically throughout our body systems (Murray et.al. p. 736).  There are a few different reasons for nutrient deficiencies.  Lack of nutrient dense food intake is certainly among the top reasons in western culture, but we also need to contend with the fact that many of our foods are not as nutrient dense as they have been historically, due to the depletion of nutrients in over taxed soil. Supplements are not always as bioavailable as whole foods and without regulation in the supplementation industry, determining the quality of our supplements is extremely challenging. Additionally, we need a properly functioning gastrointestinal system to absorb nutrients for usage and we need to be aware of our consumption of nutrient depleting foods, such as sugar, processed carbohydrates, and highly processed, unstable oils. 

We will come back to the GI system and the best foods for optimal immune health in a bit, but let’s talk about foods that decrease immune function first. Sugar.  I am not one to demonize food and I will be the first to tell clients not to completely deprive themselves of any particular food without a medical reason, but the fact is, that sugar is a major player in the decreasing health of modern society.  Specifically, for immune function, studies show that the consumption of 100 grams of carbohydrates, as sugar, reduces the effectiveness of neutrophils (white blood cells), starting 30 minutes after consumption and lasting for 5 hours.  A 50% reduction of neutrophil effectiveness is noted at the 2 hr mark (Lobo., et al.).  So to put this into practical information, a typical slice of cake or medium sized muffin or pastry is 100 grams.  The majority of pastries are comprised of sugar and white flour, so while they are not completely 100 grams from sugar, they are very close.   And here is a doozy for you, 8 oz of pulp free orange juice is over 200 grams of pure sugar carbohydrates.  So when we jump to the orange juice as soon as a cold or sore throat presents itself, we are actually inhibiting the immune system, rather than boosting it with Vitamin C.  Now, I absolutely love a slug of orange juice when I’m feeling under the weather, but I do not consider a remedy, rather a comfort that should be used in moderation and in conjunction with nutrient dense foods and antioxidant rich beverages. 

Processed carbohydrates should be thought of in similar fashion to high sugar foods.  Their impact on our body systems is very similar to high sugar foods and they add very little in the way of nutrient density.  This category contains everything from boxed crackers to pasta, to sandwich bread and are the staple of many family’s dietary intake.  Again, we will come back to the best way to incorporate these foods into a nutrient dense diet, but let’s look at one last source of food that depletes our immune system.  Vegetable oils became popular when animal fats were deemed bad for us.  The rise of margarine, canola oil, crisco and associated vegetable based fats were absorbed into the health food world without a second question.  While the use of margarine itself has become less popular, the new plant based dietary fad has brought vegetable oils even deeper into the mainstream.  These oils are highly processed which has created a chemical structure that is unstable once ingested, which then becomes a free radical in our system (Margel, D. p. 108). As a doubly whammy for processed carbohydrates, most packaged foods also contain vegetable oils.  I will touch on free radicals & oxidative stress towards the end of this post. 

So once we know what to consume and what not to consume for an optimally functioning immune system, we still need to be sure that our GI system is functioning properly in order for those nutrients to be absorbed into the body where they can work their magic. Seventy percent of our immune system is composed of the portion of the lymphatic system that lies within the GI tract and its efficacy relies on both the health of the intestinal microbiota and the integrity of the lining of the GI tract (Lipski, 2012 p. 94).  The health and diversity of our microbiota is determined by our dietary intake, our exposure to bacteria and our exposure to bacteria killing substances such antibiotics and antibacterial soaps and cleaning agents.  The more varied our diet is in whole food substances, the greater the variety of good bacteria within our gut.  Similarly, the more germs we are exposed to as we develop our immune systems, the more good bacteria we develop to fight off bad bacteria. For example, a child who is raised drinking stream water, is less likely to become sick from giardia than a child or adult who has never been exposed to the bacteria.  To be clear,  I’m not suggesting we all start feeding our infants stream water, but our adaptive immune system is designed to fight off bad bacteria, but we need continuous small doses of exposure in order to develop that immunity.  It is well known that antibiotics kill all bacteria, not just the bad bacteria, but unfortunately, it is less clear on how we rebuild our gut bacteria after taking a round of antibiotics.  Ironically, the weaker our immune system becomes from the use of antibiotics, the more likely we are to have them prescribed when we cannot fight off a bacterial infection.   Antibacterial soaps and cleaning products, while offering great protection from dangerous bacteria, also kill all good bacteria, so if they are used excessively, we do not allow the good bacteria a place to thrive.  

So, let’s now address the impact, stress, oxidative stress and lack of sleep and exercise have on our immune system.  After this, we will have a more clear picture of why our immune systems are depleted and will be more empowered to make the changes necessary to boost our immune systems.  

The link between excess stress and the onset of illnesses from colds to autoimmune diagnosis are well documented and still not terribly well understood.  There is some understanding that cortisol, which is released during periods of stress in addition to its natural production associated with sleep & wake cycles, has a tendency to attack white blood cells when it finishes addressing a stressful situation.  While I have no evidence to support the following, it makes complete sense when you consider that many people get sick once they finally relax after a period of stress, for example getting sick when you start your vacation or when, you ‘can finally relax’ after planning a big project or event.  Additional studies have shown that our thoughts and emotions are linked to effectiveness of the immune system, leaving us vulnerable to illness when we are anxious or trapped in negative thought. (Seaward, p. 46).  

Oxidative stress is the imbalance between free radicals and antioxidants within the body.  Free radicals are inevitable and are a byproduct of aging, cellular processes, positive stress such as exercise and exposure to environmental toxins. Temporary increases in oxidative stress can be beneficial such as the production of new cells and tissue after a bout of exercise which also increases antioxidant activity.  While the consumption of antioxidants helps to counteract these free radicals, as our exposure to free radical causing agents increases, it becomes more difficult to consume enough antioxidants to keep oxidative stress at a level where it isn’t causing cellular and DNA damage.  Excess stress, exposure to exhaust, cigarette smoke, chemicals in our cleaning products, chemicals in our lawn care products, chemicals in our hair and body products, fragrances in candles, laundry detergent and air fresheners,  and foods such as fried foods and vegetable oils are just a few examples of where free radical causing agents have made their way into our daily lives.  This oxidative stress attacks our cells and DNA which directly impacts the effectiveness of the immune system. (Seaward, p. 6-12)

Okay, so how on earth can we counteract the barrage of ill effects modern society has produced that deplete our immune system.  My first answer is slowly & methodically.  Attempting to make too many changes at once will have a stressful effect that is in direct opposition to your goals.  And you should have goals.  SMART goals that you can track over time and which help you determine what areas of improvement are most beneficial to you.  Lets now lay out the areas covered here with actionable options. 

Nutrient Intake: 

1. Consider your daily diet and either make mental notes or actually record a week’s worth of consumption to discover…
   1. How much whole foods you consume…this is a food that looks like it would in nature (or close to, ex. Brown rice or other grains that look the way they do beneath the plant count), including meats that are unprocessed.
   2. How much variety are you consuming?  A goal of 30 different whole foods from plants is ideal.
   3. Look at where your food comes from and how far it travels.  The closer a food is grown to your kitchen, the more nutrient dense it will be. 
   4. How often are you eating something that came out of a package? Including bread regardless of type.
   5. How much sugar are you consuming?
   6. How much protein are you consuming?
      1. Focus on high quality proteins, such as sustainable fish, mussels, unprocessed meats (steaks, ground beef, whole chicken).

2. Specifically for immune health, are you consuming enough..
   1. Antioxidants: berries, beans, artichokes, fruit, nuts, spices, herbs, dark leafy greens, brassicas (broccoli, brussels, cabbages, cauliflower, collards, mustard greens, radish, turnips), squash, potatoes, tea, coffee, wine & beer
      1. Milk added to tea and coffee blocks antioxidants
      2. Wine and beer should be consumed in moderation and not looked to as a source of antioxidants if you do not currently drink alcohol.
      3. The deeper the color, the more antioxidants you should expect the food to have
      4. Variety is key as these foods contain various antioxidants that all play different roles in combating free radicals. 
   2. Specifically carotenes: think bright colors in the produce dept.
      1. Dark leafy greens, tomatoes, sweet potatoes, watermelon, avocado, carrots, squashes, broccoli, mango, peppers, apricots, peas, grapefruit, asparagus.
   3. Garlic & onions
      1. *for antibiotic properties, garlic must be consumed raw (1 crushed clove in a teaspoon of honey)

3. Exercise:
   1. Moving your body in a way that feels good to you for 30+ minutes a day.
   2. You do not need to be a runner or a tennis player or whatever else you feel is required.  Find something that you enjoy that has your body moving and preferably sweating.
      1. The lymphatic system relies on movement & contracting muscles to get the lymph moved through.

4. Stress Reduction:
   1. This is very personal to every individual, but finding out what helps you to reduce stress is extremely important.
   2. Some option are: Reading a book, walking in nature (but not for your exercise), meditation, listening to your favorite music while doing nothing else, breathing exercises, a bath, a sauna…the list is endless, just be sure it’s something that you do solely for relaxation, not in combination with other activities.  
   3. Social interaction with people you enjoy is known to help reduce overall stress.

5. Sleep:
   1. For many people, this is the hardest part to figure out, but without sleep, we cannot repair our tissues, fight illness, or recover from oxidative stress.

6. Supplementation:
   1. I do not believe in recommending supplements across the board.  I do believe that having bloodwork done, that evaluates your nutrient profile is a good idea.  While bloodwork is not 100% accurate in measuring your nutrient profile, with the help of a professional, you will get an idea of where you may need supplementation.  
   2. If bloodwork is not in the cards for you, using the Cronometer app can help you determine which nutrients you are not consuming enough of.  It is a TON of work to log all the food you eat, but extremely educational when using an app that gives you the estimated micronutrient profile of your diet, in addition to the macronutrient profile. 
   3. Echinacea is the most scientifically proven herb to help overcome an illness, but because of this, it is also one of the supplements you are most likely to buy that is not as high quality as it should be.  Be sure to buy supplements from reliable sources and products that have been third party tested whenever possible.  

• Tips for increasing nutrient density in daily living.  These tips are for home prepared meals.
  • Consider ways to change the makeup of 100g serving of food…
    • When baking, start by substituting ¼ cup of the flour with a nutrient dense flour such as buckwheat, rye, whole wheat, nut flour.
    • To baked good, add nuts, seeds, pureed avocado, shredded beets, shredded sweet potatoes, pureed spinach or experiment with flavors you like.
    • Use butter, olive oil or coconut oil in place of canola oil or other vegetable oil (1:1)
    • When baking, add less sugar than is called for and see if you even notice!  I usually find, I can cut the sugar in half and it tastes the same….the caveat to this is cookies, the shape and texture of a cookie is directly related to the fat/flour/sugar ratio.
    • When preparing a high processed carb meal, such as pasta, consider how to make a serving more nutrient dense by adding sauce, meat, seafood, veggies, nuts ect…
      • When starting out, just add small amounts until you find what you enjoy and then you can adjust the percentages of processed carbs to whole foods over time. 
  • Aim for as much variety as possible in every dish.
    • I know this can sound like a grocery store nightmare and you envision rotting food in your fridge, but it doesn’t have to be big items.
    • Use coconut oil in one dish, olive oil another.
    • Add hazelnuts to your rice and almonds to your broccoli.
    • Consider salads as broader than greens, cucumber and tomato…
      • For example, try a finely chopped broccoli base; add nut of choice, a pepper of desired heat, some dried fruit, maybe a raw shredded beet and top with some toasted sesame oil, and rice vinegar.

Useful links: 

http://ewg.org  This site is unbelievably useful in determining the toxicity of your day to day products.  They have an app, called EWG Healthy Living, that is very helpful when you are out and about looking to buy everything from sunscreen to cleaning products. Please keep in mind that this can become overwhelming and while the EWG is providing a fantastic service, their ratings on based on many factors, some of which may not apply to you or not worry you.  Consider a source to start learning more about what your daily products contain.

References

Lobo V, Patil A, Phatak A, Chandra N. Free radicals, antioxidants and functional foods: Impact on human health. Pharmacogn Rev. 2010 Jul;4(8):118-26. doi: 10.4103/0973-7847.70902. PMID: 22228951; PMCID: PMC3249911.

Margel, Douglas. 2005. The nutrient-dense eating plan : a lifetime eating guide to exceptional foods for super health. Basic Health Publications. Laguna Beach, CA. 

Murray, M., Pizzorno, J., Pizzorno, L. 2005. The encyclopedia of healing foods. Atra Books. New York, NY

Seaward, Brian. 2021. Essentials of managing stress 5th ed. Jones & Bartlett Learning. Burlington, MA.