I love this time of year as the seasons change and the holidays really kick off; but there is always one dreaded aspect to the weather getting cooler: flu season begins! The good thing is that there are many ways that we can work with our bodies to prevent the flu and stay healthy all season long. Long story short, the best way to prevent getting sick is to support our immune system function (because even though we don’t FEEL our immune system like a hand or a foot, it’s always working for us, 24/7!), and there are many ways to do this without having to compromise our values as an evolutionary biology-minded, Paleo lifestyle-minded group of people.
So, how do we tackle the task of beating the common cold and flu? We need to approach this from multiple angles.
General Recommendations for Immune Support
Immune system function is determined by a huge variety of factors, which I discuss in great detail in The Paleo Approach. An optimally-functioning immune system will be able to respond to most pathogens (micro-organisms that cause disease, like bacteria, viruses, and parasites) without much of a reaction; this includes the common cold and most strains of the flu.
Eat an Anti-Inflammatory Diet (AKA Paleo!!!). There are specific aspects to following a Paleo template that make it a really good fit for preventing sickness, including its focus on nutrient-density as well as including lifestyle factors. When we eat a nutrient-dense Paleo diet, we are providing our bodies with anti-inflammatory nutrients like omega-3 fatty acids (found in organ meats, fish, and eggs), phytochemicals (found in vegetables and fruit), and the full complement of vitamins and minerals that are critical for optimal immune system function. On the other hand, when we eliminate inflammatory foods such as gluten, we are creating fewer “distractions” for the immune system –that is, our bodies do not need to employ immune system battles against triggering foods and molecules (see Why Grains Are Bad–Part 1, Lectins and the Gut). When we reduce systemic inflammation, we give our bodies the opportunity to focus on fighting the real battle (little invaders that cause sickness!). Luckily, much of the foundation of health can be accomplished with intentional consumption of nutrient-dense foods and avoidance of inflammatory foods (see 3 Ways to Up Your Nutrient Game and The Autoimmune Protocol) But, as we know, the human body is incredibly complex! So regulating immune system function also depends on other lifestyle factors that are equally important.
Exercise a moderate amount with some variability. Exercise is one of those moderate stressors that can be really good for our bodies (see The Benefits of Gentle Movement and Why Exercising Too Much Hurts Your Gut). All in all, it’s important to establish an exercise routine that incorporates a variety of movements that are both aerobic (generally, “cardio”-type exercises) and anaerobic (resistance training like weightlifting) in nature. There are many other reasons to have movement variability, including increased metabolic benefits and reduced risk of injury. Apart from this, studies have demonstrated that regular exercise promotes improved immune system function by reducing inappropriate cytokine activity, improving white blood cell function, and regulating cortisol release (both of which are also related to systematic inflammation – another reason why we need to tackle our health from all of these angles!). Plus, there is added benefit to light exercise when we’re already feeling a little sniffly: the activity may flush microbes out of the lungs and increase body temperature to help fight the infection!
Get enough sleep (quantity AND quality!). In my popular online program, Go to Bed, I discuss all the many ways that sleep impacts our health (also see Sleep and Disease Risk: Scarier than Zombies!) – and the immune system is a major mechanism behind all of them! Just plain old “not getting enough sleep” (see Sleep Requirements and Debt: How do you know how much sleep you need?) causes inflammation (you know, that thing we’re really trying to fight against). Even just three consecutive nights of inadequate sleep can cause increased monocytes, neutrophils and B-cells in the blood, increased pro-inflammatory cytokines (this includes cytokines known to stimulate maturation of native T-cells into Th1, Th2, and Th17 cells; all of these activated immune cells means that our bodies would be ready to mount an attack against infections that don’t exist–that’s bad!), increased C-reactive protein (our general marker of inflammation), increased total cholesterol, and increased low density lipoprotein cholesterol (LDL; the “bad” kind of cholesterol that is linked with worsened heart disease-related outcomes). Our immune system cycles with our circadian rhythm, along with antibody formation (the way our bodies know to respond to super-specific invaders, like chickenpox), which takes place during sleep. So, someone who is not getting enough sleep is also not adequately forming antibodies. As a result, simply getting adequate sleep can protect you from infection. Studies examining differences or changes in sleep quality have found similar differences in immune function; basically, sleep quality and quantity is essential if we’re trying to protect ourselves from the flu season! If the notion of prioritizing sleep is totally overwhelming, Go to Bed is overloaded with tips and tricks (that include everything from tiny tweaks to lifestyle overhauls!).
Excitingly, there is new research coming out every day about what factors impact the immune system – like personality, mood, and even social status! – but the above three factors are some of the best-studied and –understood, so we can rely on these strategies to make marked improvements in immune function for most people without a pre-existing condition or chronic disease.
There are many ways to change our lifestyle to support a healthy immune system, but we can also focus on some specific micronutrients (vitamins and minerals) that can boost immune function to help combat microbes as we encounter them:
- Vitamin A is a vital component of both the innate and adaptive immune response. This vitamin maintains the structural integrity of mucosal cells (think the lining of your respiratory tract and gastrointestinal tract!), so it is essential for keeping our first line of defense physically intact. Plus, it is needed for proper function of a host of immune cells (i.e., natural killer cells, macrophages, neutrophils, lymphocytes, and more!). Supplementing with vitamin A enhances immune system function and improves outcomes when someone is sick. We can either take a high-quality supplement or choose foods rich in vitamin A, such as liver, carrots, and sweet potato.
- Vitamin C might be the most well-known immune support vitamin of them all. The main function that vitamin C holds is to act as an anti-oxidant within certain immune cells; this process actually creates reactive oxygen species to kill pathogens. Since we cannot synthesize our own vitamin C, it is crucial that we get enough of it in our food or through supplementation! The foods richest in vitamin C are citrus fruits, bell peppers, acerola cherries, and wild rose hips.
- Vitamin D is another well-known immune modulator that is worth paying attention to. Normal levels of vitamin D promote genetic expression of several immune cells, including monocytes, macrophages, dendritic cells, and lymphocytes (this means that without vitamin D present, the amount of these cells that are generated is much less! That leads to a sub-optimal immune system, to say the least).
- Vitamin E is a fat-soluble vitamin (meaning that we can store it in our fat and that it is absorbed with dietary fat) that is also responsible for maintaining proper immune function. Specifically, alpha-tocopherol (one of the forms of vitamin E) is known to prevent oxidation or damage to cell membranes and polyunsaturated fatty acids, which protects against systemic inflammation. Foods rich in specifically alpha-tocopherol include almonds, sunflower seeds, hazelnuts, and spinach.
- B Vitamins also play a critical role in maintaining a healthy immune system. Specifically, vitamins B6, B9, and B12 have all been implicated as playing important roles in the synthesis of antibodies and cytokines (the chemical messengers of the immune system), and a deficiency in these vitamins has been associated with increased risk for infection. The foods highest in B vitamins include liver, shellfish, and red meat.
- Zinc, one of the dietary minerals, is also important in maintaining immune system function, because it is needed for both development and function of immune cells. Like vitamin C, zinc is not stored in the body, so regular consumption of foods that contain zinc is essential for an optimal immune system. The foods highest in zinc are oysters and liver.
- Selenium is another mineral to focus on for optimizing the immune system – there are even enzymes in immune cells that specifically need selenium to function, called selenoproteins! Deficiency in selenium has been demonstrated to worsen sickness outcomes (both length of infection and the symptoms of such) and make people more susceptible to illness. Some of the foods highest in selenium include liver, kidney, Brazil nuts, and oysters.
- Iron is another mineral required for a host (i.e., us) to mount an effective immune response against a pathogen. This metal is essential for many cellular processes, including oxygen and electron transport, antioxidant functions, and DNA synthesis – all of which need to be in tip-top shape in order for our immune system to function at its best. Foods rich in iron include organ meats and red meats, but it can also be found in many leafy greens and even spices!
- Finally, we have copper, which is also necessary for the function of certain enzymes within immune cells. Interestingly, copper itself has antimicrobial properties, though its specific involvement in the development and maintenance in our immune system is still be investigated by scientists.
Feeling under the weather? Upping your intake of any (or all!) of the above micronutrients is a natural and effective way to help fight something off (not that there are ever any guarantees), and then continuing to focus on these key nutrients whilst sick is yet another factor.
Homemade Medicine Recipe: Elderberry Syrup!
One of my new hobbies of late has been exploring the literature that supports certain complementary and alternative medical practices. While it’s evident that many practices still need well-designed clinical trials to demonstrate their effectiveness (speaking of, have you seen my epic run-down of all the studies that have examined Paleo in the community, Paleo Diet Clinical Trials and Studies?), there is some substantial evidence that certain medical herbs, taken in the right doses and in the right forms, could be effective at preventing and/or improving a cold. Yet, a lot of the options at the natural grocery store are over-priced, questionably potent, or have ingredients like food dyes, soy, gluten, corn, or another allergen (yes, this even happens with “natural” products!).
There is one natural cold prevention product that I’ve been able to easily replace by making at home, because it’s easy and fun to do with the kids: elderberry syrup! This at-home medicine is an amazing source of antioxidants, including vitamin C, and has been used for hundreds of years as a folk remedy during the winter months. Scientific studies confirm that elderberry has anti-viral and anti-bacterial and anti-inflammatory properties. Plus, elderberry can enhance the immune-modulating effects of probiotic bacterial like Lactobacillus acidophilus, which means that combining this Elderberry Syrup recipe with some raw kraut or probiotic supplement may magnify the benefits (see The Health Benefits of Fermented Foods and The Benefits of Probiotics). And the best thing about elderberry syrup? Elderberry has been validated in scientific studies for cold and flu prevention and treatment! (Note for my Autoimmune Disease peeps, there is some evidence from malaria studies that elderberry may stimulate Th1 cells, so caution is advised!).
1oz dried elderberries, Sambucus nigra
1 cinnamon stick
2 cups water
1 cup honey
- Combine elderberries with water in a large pot and simmer with the slightly lid ajar (so that steam can escape) about 45 minutes or until the water is half reduced
- Strain the elderberries and cinnamon stick from the liquid using a fine metal strainer, ideally into
- Add an equal amount (about 1 cup) of honey
Yield: 2 cups of elderberry syrup
Directions: Take 1-2 tablespoons a day. Store in the refrigerator for up to 12 months. Enjoy!
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