Easy Ways to Boost Your Immune System Health

Today I’m going to talk about what forest bathing, grounding, heart rate variability, sunlight and pampering have in common when it comes to helping your body keep you better protected from viruses and other pathogens. I’ll also be covering some info on nutrients such as melatonin that can help boost your immunity and provide antiviral support, too.

But wait, you may ask, “Dr. Anna, don’t you always say the best way to optimize your immune system is simply to eat Keto-Green?”

Well, yes, I do because eating protective Keto-Green foods greatly supports us by optimizing our gut health (70% of our immune system can be found in the gut after all) (1) as well as ensuring a healthier alkaline pH state which is anti-inflammatory and supportive of a healthier immune system.

But there are many other things you can do to improve your alkaline state and assist your body in its ability to fight off foreign invaders of all kinds.

With so many potential environmental exposures surrounding us these days, whether that be everyday toxins or new viruses such as the coronavirus we want our bodies to be strong and not have weakened immune systems (in particular if we have underlying health concerns).

The great news is that most of the natural recommendations that I will be reviewing today can be done without incurring any cost and in the comfort of your home or nearby neighborhood. 

They can also be easily done in the spirit of “social distancing,” while still promoting connection with the people and the things you love.

Beyond diet: Achieving the protective benefits of alkalinity

If I could recommend one thing to each of you that would aid in strengthening your immune system (and making you feel more content and less anxious, too!) it would be to consistently remain alkaline by not only eating the right diet but by focusing on activities and habits that improve your stress resilience, sleep and connections.

Fortunately these three key areas can be easily addressed by a number of activities, each of which we’ll talk a bit more about below. All have research as well as my own clinical findings supporting their effectiveness (plus you’ll love doing them):

  • Forest bathing (deliberately connecting with nature)
  • Grounding or earthing (literally plugging in to earth’s energies)
  • Sunlight (resetting your body’s own circadian rhythm; ensuring adequate vitamin D as well as natural melatonin production for its sleep and antiviral effects)
  • Increasing your heart rate variability (for better stress resilience)
  • Pampering (benefiting from mind-body medicine and oxytocin!)

Forest bathing

Yes this is a real thing and was first introduced in Japan in 1982. The idea was to get the Japanese people to leverage Japan’s widely available dense forests beyond the cardio benefits derived from simply using the forest as a walking/running trail. Scientists felt there could be significant mind-body health benefits if people approached the practice more mindfully.

Forest bathing (Shinrin-yoku) isn’t bathing in water, but instead is the idea of  “immersing yourself completely” in a forest environment for the purpose of connecting with the sight, smell, sound and tactile stimulation of the forest.

A few examples would be to pause, engage and “bathe” in nature by intentionally,

  • Using your sight to connect with the visual vibrancy of the forest: compare unique leaf colors or the patterns found in a single leaf’s veins; watch how the sunlight coming through the trees casts dancing shadows on the forest floor.
  • Enjoying aromatherapy via your sense of smell: inhale the varied forest fragrances (wood scents, blossoms, damp pine needles); contrast the smells of shady areas (moss, wet tree trunks, and damp soil) versus those continually basking in the sunlight.
  • Silencing your cell phone (and attempting to quiet your inner thoughts) while focusing on the sounds (or quiet) around you: listen to the wind blow through the trees; hear birds singing or taking flight; or hear the ripple of a stream as it changes course..
  • Using your sense of touch: have you ever hugged a tree? Feel the contrast between the moss and bark; go barefoot to feel the cold forest floor; feel the prickly outline of a pinecone.

Studies have shown that forest bathing has therapeutic effects such as decreasing stress and cortisol levels, lowering blood pressure; and reducing anger, anxiety, and depression. (2,3) 

Forest bathing has also been shown to increase immune function. One study found that forest bathing could aid in the recovery of the human immune system by increasing a component of the immune system that fights cancer and kills virus-infected cells in our body. (4)  “Natural killer” (NK) cells increase after forest bathing (note that high cortisol levels have been correlated with a low level of NK activity as well). (5-7)  

In my women’s restorative health programs participants routinely will tell me that connecting with nature, especially when they mindfully focus on experiencing it with their senses, improves their mood and stress response. We routinely see how connecting with nature in this manner can help support a woman in achieving an alkaline pH which again, the research tells us is a less inflammatory metabolic state and more supportive of immune system health. 

If you don’t have a local forest, by the way, a local county park will do…or even find a neighborhood park (hopefully having trees and some quiet). Even mindfully enjoying your garden (without a cellphone or your to-do list in hand) will have a positive effect. It also grounds you, which is our next topic.

Grounding (or earthing) 

If you want to explain why walking barefoot or sitting on the grass or sand can make you feel better, or why (as is true for me) when you travel in different time zones a little barefoot stroll on a patch of lawn or beach seems to help with jetlag and fatigue, grounding may be the reason.

Grounding or earthing is based on the principles that everything in the universe has its own energy level and vibration, including us of course, as well as the earth itself. Our own energy level is also always changing and adjusting based on what is happening both within and around our bodies. 

Grounding is simply the state of connecting your body directly with the earth’s own energy levels; sharing, if you will, earth’s natural electric charge. You can tap into it by just walking barefoot or lying on the ground (meaning it is completely free!), but some people use grounding materials which can include special socks, mats and even special metal rods. Think of it as the ability for you to tap into the earth’s battery and get a little recharge.

Grounding’s effects on our body and mind makes so much sense to me. Think about how humans have evolved, from being more in touch and hands-on with the earth…to living in skyscrapers surrounded by cemented streets, metal cars and sidewalks. Unfortunately many of us do not even have a small patch of earth anywhere in our vicinity. Think about your own situation at home or at work…do you find yourself grounded directly with the earth throughout the day? Probably not. We have all gotten far away from daily connections (getting our battery recharged) with the earth’s energy. 

My daughters and I have always enjoyed hammock camping for these reasons. We camp on hammocks right under the stars, our hammocks tethered to the earth in a relatively primitive state. It is so refreshing, not to mention we enjoy the beauty in the sky as thousands of stars come out to put on a light show just for us. We see the first light of day and the final light of night, so beneficial for our internal circadian clocks.

Connecting with nature

A number of smaller studies (some of which are fairly recent) have shown grounding to help with chronic fatigue (8), chronic pain (9), mood, high blood pressure (10), inflammation (11), and sleep disorders (12)

Grounding can help a person reset their natural biological clock (circadian rhythm) which has been shown to support greater gut health and diversity (greater gut microbiome diversity provides greater resilience for our bodies to deal with environmental stressors), healthy hormone production, sleep quality and more. (13)

What I’ve seen in my clinical practice and in feedback from clients is that grounding can provide a sense of well-being, more energy and reductions in an unhealthy stress response (which can mean better sleep, improvements in mood and a more alkaline state). 

Here is an additional study (14) if you are interested in learning more about the potential benefits of grounding and how scientists think it may work. There is also a fun podcast I did with Robyn Openshaw (the “Green Smoothie Girl”) that reviews her findings relating to our changing energetic frequencies and how they impact us. 

Grounding, just like forest bathing, can be easily done and I can pretty much guarantee it will make you feel better and result in improvements to your body’s stress response, alkalinity level and overall inflammatory levels. You may sleep better, too, as your circadian clock will be supported.

Another great way to strengthen your immune health is simply catching a few rays of sun each day. Unfortunately, with our hectic schedules and indoor lives, many of us don’t seem to do this.


Sunlight hitting our retinas each morning is one way our body’s circadian rhythm stays finely tuned to a healthy 24 hour cycle. This cycle includes turning on and turning off hormone production and many other key biological and metabolic functions (including our appetite control and our ability to get quality sleep). At my house we try and catch the sunrise each day.

Catching some rays for 15-20 minutes every morning (without sunglasses and without being slathered in too much sunscreen) is also a primary way our bodies synthesize vitamin D. Many of us are deficient in this important vitamin. Why? Well, along with the sunscreen use there are many factors that may impact us.

Dark skin individuals typically need as much as four times the exposure period. If you are obese or have certain gastrointestinal difficulties (such as fat malabsorption) you may be more prone to be deficient. If your body’s pH is acidic you are likely to be more deficient (most of the women taking my programs who do blood testing find out that they are deficient).

A lot of the best natural sources of food for vitamin D are unfortunately not the healthiest as they are typically foods that are fortified and thus highly processed and acidic (or they are foods such as dairy that are associated with food sensitivities in many people). 

The bottom line is that many of us are deficient in this all important vitamin and I recommend that all adults should know their vitamin D level (by taking the 25-hydroxy vitamin D blood test).

Vitamin D is vital to our immune health and vitamin D deficiency has been associated with many chronic conditions, including autoimmune disorders such as Hashimoto’s, hypertension, cardiovascular disease, rheumatoid arthritis, type 1 diabetes and several common cancers (including breast cancer). Studies have also shown vitamin D to potentially have antiviral properties. (15) 

Vitamin D also boosts our production of our happy hormone, serotonin (which makes us feel so good).

Seasonal Affective Disorder can occur with people having too little exposure to natural sunlight and low levels of vitamin D, especially during winter and for those living far from the equator. It can result in a lack of energy, mood issues including depression. Vitamin D supplementation and light box therapy has been shown to help. (16) 

Many of my clients find they need to supplement at about 5,000 IUs a day and then retest to measure their levels. I always recommend my formulation Ray of Strength, which combines vitamin D3 with vitamin K (this helps with absorption but more importantly protects against calcium toxicity in the arteries). If someone is exposed to the flu or a virus, or shows early symptoms, I have recommended up to 50,000 IUs for up to four days (but please check with your doctor regarding all changes in vitamins or supplements, especially when dosing this high).

Melatonin, our natural sleep hormone

Our body’s hormone production is controlled by our circadian clock and this includes an important hormone called melatonin. Most of you know melatonin as our natural sleep hormone. If we don’t get enough vitamin D, we don’t get enough sunlight at the right times of the day, or our circadian rhythm is impacted by other bad habits (working late at night using electronics, poor diet, or even when we eat) melatonin production can be affected. (17) This can result in sleep disruption. (18) 

I will often recommend melatonin supplementation (I use my own product, Call it a Nite), along with using my Balance cream to improve sleep and overall mood. 

Melatonin for potential antiviral support

Melatonin is being studied relating to its antiviral properties and you may have heard in the news that it is one of many existing (and widely utilized) nutrients that are being looked at for helping in the prevention and treatment for emerging viruses such as Covid 19. Given the existing research showing its antiviral properties, I and other functional practitioners have been recommending daily supplementation with melatonin as part of bumping up your body’s protection against viral infections.

For my clients, especially during this time of virus outbreak, I recommend 3 mg daily as a preventative measure, and to take 6-20 mg if infected with the virus. The International College of Integrative Medicine’s  March 31, 2020 position statement recommends 6 mg at bedtime for immune regulation.

Melatonin has been shown to be anti-inflammatory (19) along with having antiviral properties. In mouse studies (using high dosage treatments) it has previously been shown to possess therapeutic potential in influenza-induced pneumonia (as an adjuvant treatment along with antiviral drugs). (20) 

In very recent (2020) research focused on COVID-19 the authors concluded that melatonin may offer benefits in treating COVID-19 induced pneumonia, acute respiratory distress syndrome and acute lung injury. (21) That’s quite exciting as Melatonin could someday be routinely used in treating such types of novel viral infections in the future.

Increasing your heart rate variability

The greater your heart rate variability (HRV) the greater your stress resilience. A higher HRV is associated with greater psychological flexibility, resilience, adaptability and reduced vulnerability of your body to disease (less inflammatory markers); it is a biomarker of health and perhaps even of your longevity. There is growing research that a range of disease states are accompanied by a decrease in HRV (including cardiovascular disease, hypertension, diabetes, and psychiatric disorders to name a few). (22) 

HRV has also been shown to be a potentially inexpensive and noninvasive method for predicting potential immune dysfunction due to ongoing stress. (23) 

HRV has also been associated with people’s diets with healthier diets associated with greater HRV. Diets including fish (and omega 3s), a Mediterranean type (low carb) diet and losing weight have all shown increased HRV. Diets high in trans-fats have shown reduced HRV. (24)

So what is HRV and how do you measure it?

You likely have been told by your doctor that your heart rate is a particular measure, maybe 60. But that doesn’t mean your heart is consistently beating at the rate of 60 beats per minute (or one beat per second); our hearts beat a bit irregularly, the interval between one beat and the next will vary. This is called, Heart Rate Variability (HRV) and it is formally measured via an electrocardiogram (ECG or EKG) exam that records the electrical activity of your heart. You’ll often get this exam included as part of annual exams but you can request it when seeing your doctor for other underlying issues. 

To measure HRV ongoing and on your own, this will require you to purchase or have a compatible sensor device along with an app focused on capturing and measuring HRV. I’ll talk more about this in a moment.

Our heart’s variation in beating is controlled (automatically) by our autonomic nervous system which includes the sympathetic nervous system (fight-or-flight response) and the parasympathetic nervous system (our chill-out, tend and befriend, rest and digest response). When we’re relaxed our heart beat is more likely to be variable (think of it as meandering along), we likely have lower blood pressure, we are digesting and producing sex hormones and the like. 

When we’re stressed out (in a fight with our spouse, after a poor night’s sleep, stuck in commute traffic, eating a lot of sugary foods), suffering from chronic stress or in a physically stressed mode (too much exercise or simply the effects of aging) our body’s cortisol levels raise as we go into more of a fight-or-flight response, all non-emergency activities within our body such as digestion, sexual reproduction, oxytocin production (since we are in no mood to connect, love or enjoy!) take a back-seat to fight-or-flight. At that time the variation between heartbeats (our HRV) becomes low (while our heart rate itself, as well as blood pressure, likely goes up).  

The easiest way to measure your HRV (other than at the doctor’s office when you are there) is to utilize one of the many apps and sensor devices available to do so. Note that free apps you may come across still requires that you purchase a sensor device and be cautious as some devices (those you wear on your wrist, for example) typically do not detect HRV but instead just give you heart rate (so in my example, you’ll get the number 60 beats per minute but no info on the heartbeat variability). 

Elite HRV is a good free app which is compatible with a number of devices and Heartmath® also has an app and sensor solution called Inner Balance™.

I like HeartMath and have been recommending their products and principles for many years; both are backed by science and have been shown to lower cortisol, build stress resilience, and have physiological benefits such as lowering blood pressure, reducing fatigue and improving HRV. 

With an app and sensor in hand you can see first-hand how your HRV increases as you incorporate more intentional breathing, mental detoxing (meditation, gratitude, etc.), sleep and oxytocin into your life. 

Remember how I say, “Test don’t guess.” Well HRV is another way to assess where your body is at and to monitor your progress as you make diet or lifestyle changes. Just like you test for alkaline pH and even ketones, you should see evidence of improvements when you make changes to living a Keto-Green diet and lifestyle.

And while on the topic of lifestyle improvements that help increase your HRV and body’s ability to stay healthy, let’s not forget the all important activity of self-care and pampering.


All the wonderful things that make you feel pampered are beneficial to more than just your mood. Self-care and connecting with the things you love support a more alkaline you…and a less inflammatory you.

Hot stone massage

Especially during times of stress (I think virus outbreaks apply here) there are many mind-body activities you should incorporate into your day, everyday:

  • Using essential oils: lavender can help you de-stress and relax; eucalyptus and peppermint are particularly good for upper respiratory concerns (use on your chest in a carrier lotion or use in a diffuser; you can also apply to the balls of your feet or massage it in); Thieves oil is very supportive of our immune function. (25-26) 
  • Sauna: My wonderful friend Magdalena Wszelaki wrote a great blog on how infrared sauna can help strengthen one’s immune system. I also love hydrotherapy, floating in my pool or simply enjoying a hot soak with epsom salt in my bathtub.
  • Meditation, journaling, and deep breathing as already discussed or check out a beautiful discussion about ways to mental detox. 
  • Reflecting on and practicing one’s faith: A true part of my focus on lifestyle medicine along with diet and nutrition is my relationship with God and my spirituality. This is an enormous part of who I am and what my life and mission to help women thrive is all about. We also know from scientific studies that prayer is beneficial to our body, mind and spirit (not that I need research to reinforce this point), and research has also found positive associations between religion and spirituality and increased immune function. (27) Some 56% of 27 studies on this particular topic found positive effects on immune function in response to religious and spiritual intervention. (28) 
  • Connecting with those you love and producing more oxytocin: Even when under virus lockdown my family is generating lots of memories and oxytocin at home and through virtual gatherings with family and friends. Loneliness and isolation are probably the most damaging emotional states in terms of your health. One of the best things you can do is simply to have fun, laugh and play. If you are feeling disconnected or lonely, take my quick oxytocin quiz to see if you need to focus on producing more of this all-important hormone. At the end of the quiz you’ll get some helpful tips to produce more oxytocin, as well.

Final words on strengthening your immune system

Along with vitamin D, melatonin and a regular regimen of other key vitamins and nutrients that can boost your immune system, I always recommend Mighty Maca® Plus for strengthening one’s immune health as it is truly a superfood that reduces inflammation, is an adrenal adaptogen (so helps your stress response) and helps support both detoxification (of all the things your body doesn’t want) and a more alkaline pH (what your body does want). It is nutrient dense and contains many of the nutrients that researchers believe may have antimicrobial and antiviral effects such as quercetin, zinc, omega 3s and green tea.

Maca itself has been shown to have antiviral properties. (29) One 2014 in vitro study found that maca had antiviral activity against both Flu-A but also Flu-B viruses. 

Maca is also an adaptogen found in the high elevations of Peru, an everyday elixir of sorts that the people there eat that helps support them adapt and thrive in both the high altitude and harsh climate environment. 

There is emerging news relating to how researchers are looking at high altitude sickness (high-altitude pulmonary edema or HAPE) to find answers relating to what they see happening with a subset of COVID 19 patients who appear to experiencing high altitude-like symptoms and perhaps the same underlying issues relating to their blood vessels having trouble regulating blood flow. 

Given the Peruvian people have been consuming maca for generations with no high-altitude health effects, it will be interesting to see if maca, as a well-studied adaptogen with antiviral potential (that is also highly alkalinizing) gets looked at as a potential adjunct treatment option for emerging viruses. I’ll keep you posted. 

As always, I hope you will join me on Instagram and on Facebook in my Keto-Green community so that we can share in each other’s health journey.



  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515351/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2793346/
  3. https://www.ncbi.nlm.nih.gov/pubmed/19568835
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5893257/ 
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2793346/  
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5893257/ 
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2793341/
  8. https://www.ncbi.nlm.nih.gov/pubmed/31831261
  9. https://www.ncbi.nlm.nih.gov/pubmed/15650465
  10. https://www.ncbi.nlm.nih.gov/pubmed/30982019
  11. https://www.ncbi.nlm.nih.gov/pubmed/30448083
  12. https://www.ncbi.nlm.nih.gov/pubmed/15650465
  13. https://ucsdnews.ucsd.edu/feature/whats-in-your-gut
  14. https://www.ncbi.nlm.nih.gov/pubmed/28987038 
  15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3308600/
  16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673349/
  17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6406615/
  18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241621/
  19. https://www.hindawi.com/journals/ije/2017/1835195/ 
  20. https://www.sciencedirect.com/science/article/pii/S1756464619302452
  21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102583/ 
  22. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5882295/
  23. https://www.ncbi.nlm.nih.gov/pubmed/31408866 
  24.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5882295/
  25. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943609/
  26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6612361/
  27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4486964
  28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3671693/
  29. https://www.ncbi.nlm.nih.gov/pubmed/25312160
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Dr. Anna Cabeca

Dr. Anna Cabeca

Certified OB/GYN, Anti-Aging and Integrative Medicine expert and founder of The Girlfriend Doctor. During Dr. Anna’s health journey, she turned to research to create products to help thousands of women through menopause, hormones, and sexual health. She is the author of best-selling The Hormone Fix, and Keto-Green 16 and MenuPause.

Learn more about my scientific advisory board.